Wednesday, October 31, 2007

Monkeys Use Urine to Signal for Attention

Many monkeys exhibit the unusual behavior of washing their hands and feet in their own urine. Researchers have long observed a curious behavior in monkeys, although they have been unsuccessful at proving a hypothesis. Some Capunchin monkeys held in captivity may have provided the answer to this puzzling behaviour.
Previous hypothesis on this behavior were that the animals were cleaning their feet with the urine, or cooling themselves off. This type of use of excretory substances is not entirely new among the animal kingdom. Antelope urinate on their throats and vultures put their own feces on their feet.
The cleaning and cooling hypothesis for monkey's use of urine were tested at the National Institutes of Health Animal Center in Poolesville, Maryland. Researchers recorded urine washing behaviors of the Capunhin monkeys through changes of temperature and humidity. No changes in urine washing behavior were recorded with these changes, however the researchers did notice a correlation between urine washing and attention seeking in the monkeys.
When the male monkeys were separated from female monkeys, their urine washing behaviors increased. In addition, when monkeys fought, the behaviour increased in the loser of the battle. The researchers suggested the losing monkey was looking for sympathy, and signaling this with urine.
Further research of this is suggested since animals using urine to signal is not a new idea. Dogs use urine to mark territories, and perhaps monkeys are using this behavior to signal attention from other monkeys.

Posted by: Emily King (6)

King of the Jungle's Sex life

We all know the lions are the king of the Jungle. These cats usually reside in sub- Saharan Africa, and live in prides which consist of 7 to 8 adults (both male and female) and their cubs.

There is no specific mating season for these wild cats,

Within a pride, lions are promiscuous, but since the pride limits the number of females and males available for mating, lions are termed as being polygynandrous. This means that each male mates with multiple females and each female mate with multiple males.(http://www.bio.davidson.edu/people/vecase/Behavior/Spring2004/shelburne/mating.html).

The female lions usually rub the head of the males when they want to mate, then they begin a courtship display by lifting their hind leg with their paw, or rolling unto their backs and biting their paws. When the male is turned on by this act, he snarls at the female, and she crouches down. The mating duration of the male lions are known to be very quick aka fast, repetitive and unsuccessful. Copulation last about 30-70 seconds, but this is done every 25 minutes for a four day period.

This is the reason why most male lions do not hunt, and spend most of their time sleeping because they spend most of their day mating, which exerts a lot of energy.

Source: http://www.bio.davidson.edu/people/vecase/Behavior/Spring2004/shelburne/mating.html

Posted by KOFI. (6)

Sunday, October 28, 2007

Worm Sex

Worms that haven been contaminated by radioactivity from a nuclear accident are beginning to breed with other worms instead of on their own. Worms are usually asexual, however scientists believe that they are changing their behavior to increase their chances of survival. This is one of the first pieces of evidence that shows how wildlife is affected by radioaticity. This radio acticity came from when a reactor exploded at Chernobyl in Ukraine in 1986. Scientists have done research involving two species of sedimentary worms living near a lake. Both species switched to sexual reproduction from asexual reproduction. We have all learned about natural selection and scientists think that these worms are doing this to keep the best genes for survival alive to protect against radiation damage. It's so crazy to me that animals, even as small and insignificant as worms can alter their behavior so much to increase their survival rate. I think that even little things like this will end up helping all wildlife in the long run, because it is raising the publics' attention on important issues involving the world we live in.


Posted By: Katie Berthiaume

Saturday, October 27, 2007

Dog Breeders Speed Up Evolution

A recent case study of St. Bernards has led scientists to conclude that artificial selection for certain traits by breeders has dramatically sped up the process of evolution for these canines. In nature the evolutionary process would have been much slower with dogs selecting mates on their own and natural selection being the only force driving their evolution. When breeders select dogs with desirable traits and mate them with each other, the process moves along rapidly. In this particular study the emphasis was on skull structure and scientists looked at skulls from 1885 to the present. They found that the skulls in todays St. Bernards are much wider and also posses some characteristics that would probably never have evolved naturally because they don't provide the dogs with any evolutionary advantage.

The artificial selection that has contributed to the evolution of the St. Bernards we see today has been guided by breeding standards that were established in the late 19th century. Since that time the dogs have evolved from much more wolf-life ancestors to the domesticated pets they are today. The scientists who conducted this study estimate that if the changes that have occurred in the last 100 years had occurred via natural selection, it would have taken anywhere from 4000 years to possibly millions of years. It would be interesting to see what St. Bernards would look like today if their evolution had depended upon their survival and behavior alone.

Posted by Christina Breed (5)

The World of Homosexual Nematodes

In a recent study scientists have been able to induce homosexual behavior in Nematodes.
Nematodes are part of the phylum Nematoda and are small string like creatures that feed on bacteria. There are two sexes in Nematodes, hermaphrodite and male. The sex is designated by chromosomes in the DNA which encode the whole cell system of the Nematode to be either hermaphroditic or male.

In terms of sexual attraction males are attracted to hermaphrodites and hermaphrodites are attracted to males. The scientists were able to change the nerve cells so that they could produce nematodes that were attracted to the same sex. The study was done where hermaphroditic nematodes were changed to be attracted to other hermaphrodites, therefore expressing the male sexual orientation. This was done by “turning on” the gene that was responsible for a male sexual orientation in a hermaphrodite’s brain. It was also noted that nematodes may use their sense of smell to find a mate. Apparently males are able to find hermaphrodites based on their smell, which is that of vegetables. While a hermaphrodite is able to find a male based on its “buttery” smell. So maybe the turning on of certain genes could change what smell the nematode is looking for in a mate.

Scientists in this experiment were trying to show that there is a genetic basis to sexual orientation. They also commented on the idea of relating this study to humans. The scientists were recorded as saying “You might think this is a study about sexuality, but it's really our foothold on understanding the brain, So what we learn about how the brain works in a worm will apply to our understanding of humans.” There is a large gap between humans and nematodes in neurons though. A nematode has 383, while a human has a hundred billion.

Hopefully this study is just the beginning of helping us understand the brain.

Posted by Chris Kennedy(5)


Friday, October 26, 2007

Animal Behavior or Human Behavior?

I'm sure everyone has seen the dog who chronically chases its tail. Or how about the anxious person who is always biting their nails. How about the mean cocker spaniel who runs up to you and then bites you when you try to pet it. And what about that extremely sad, angry individual who sometimes appears suicidal. Current research suggests that there are parallels between animal behavior and human behavior when it comes to psychological disorders.

Dr. Nicholas Dodman, an animal behaviorist at Tufts School of Veterinary Medicine, has been anxiously exploring the genetic components of many psychiatric problems in dogs and trying to relate the findings to humans.

Dr. Dodman's first experiment is to look at the genetic differences between Dobermans who constantly suck the hair on their stomach and Dobermans who do not exhibit this behavior. He then plans to compare the genetic differences between bull terriers who consistently chase their tail and bull terriers who have never displayed this behavior. Dr. Dodman is confident that he will be able to locate the genes that are responsible for these psychiatric behaviors.

Some human psychologists are optimistic about Dr. Dodman's research. They claim locating the genetic markers for these disorders in dogs can be directly related over to humans. For example, tail chasing in dogs may be similar to obsessive compulsive disorders in humans. Aggression in dogs may also be related to self-aggression in humans, which may lead to suicide attempts.

Having worked with dogs who display behavior disorders, I am confident that Dr. Dodman's research will unravel many mysteries. I believe many of the quirky behaviors that dogs exhibit are related to psychological disorders in humans. Being able to identify the genetic markers of these disorders should be able to facilitate treatment in both animal and human alike.

Posted by Kathryn DeLisle (5).





Domesticated Foxes- Cute and Cuddly!



When we think about dogs we call to mind the hundreds of unique breeds. However, although physically and behaviorally different, all dogs share the trait of tameness. Before breeds were seperated out from a common ancestor, that ancestor was separated out from its species based on its tolerance of humans.


Russian geneticist Dmitry K. Belyaev wondered how quickly this could occur, and what side effects there would be for selecting for tameness in a population of foxes. The foxes he used to start the experiment were Vulpes vulpes, or silver foxes, from a fur farm. Living in cages these foxes were already more domesticated than their relatives living in the wild.


Each generation the researchers selected the foxes that were most tolerant and friendly towards humans to breed. After nearly 50 years of this selection process and the breeding of over 45,000 foxes, Belyaev's method produced friendly, people-loving vulpines. They can be trained, love attention, and act submissively towards humans. The most interesting thing is the physical changes that accompanied their behavior. The foxes' fur lightened in places giving it a border-collie like "star" on its face,whiter legs and bellies, and mottled fur. Also some foxes have floppy ears and curled tails, another trait commonly associated with canine domestication.








-Alexandra Sprague

here is the article.

It’s Genetic Not Hormonal

Sex differences in cognition and behavior tend to categorize the brain as masculine or feminine and this is often thought to involve hormones. A recent study in mice shows that some sex-linked genes do not need hormones to shape male or female behavior.

Jane Taylor of Yale University looked into the habit-forming behaviors for which gender differences have been noted. They experimented with the Sry, a testes determining gene found on the Y chromosome. Scientists knocked out the Sry in the male mice and added the Sry to the female mice which produce XX mice with male hormones.

Taylor trained the normal male and female mice, and the XX mice with male hormones, to poke their noses through holes to obtain a food pellet. After the mice had developed the habit to poke through the holes for food the researchers injected a chemical into the mice after they obtained a food pellet. The chemical made them sick. Normally the mice will quickly learn to avoid the food but will still eat the food if they have developed an automatic habit; this is often called “condition taste aversion”. In this study, the XX mice regardless of whether they produced male or female hormones continued the behavior of eating the food. The XY mice did not continue eating. Thus, sex difference must have something to do with genes and does not involve the production of sex hormones.

Neurobiologist Lawrence Cahill of the University of California, Irvine, says that the study "relates very well to established sex differences in the acquisition of addictive habits."
She uses the example that women progress from casual drug-taking to a drug habit faster than men do. In this study, Taylor states that women may be good at multitasking because they can form habits that allow them to do chores frequently without thinking which leaves their higher brain functions free to perform other tasks.

This study opens up research in other species in which behavior may be attributed to genes instead of hormones.

Posted By:
Nelina Bridge(5)

Red-Headed Neanderthals

Neanderthal was a species of Homo genus that inhabited Europe and parts of Western Asia. Once the Neanderthals were considered by many to be our ancestors but now many consider it to be an evolutionary dead end. The Neanderthals appear in the fossil record about 400,000 years ago. Our own species of Homo sapiens evolved in Africa and displaced the Neanderthals after entering Europe about 40,000 years ago and drove them to extinction about 28,000 and 24,000 years ago.

A team of researchers extracted DNA remains of two Neanderthals and found an important variation of a gene called MC1R.
In humans a change or mutation in this gene causes red hair. Analysis of this gene has revealed that the Neanderthals had red hair and pale skin color. They found out this gene causes a pale skin and red hair by inserting the Neanderthal gene into a human cell called melanocyte. Melanocytes produce a pigment that give the hair, skin and eyes their color. Researchers saw the same loss of function in the Neanderthal gene that produces the same hair color as in the modern red heads. Having pale skin along with red or blond hair seems to go hand in hand and seems to be evolutionarily advantageous for people who live further away from the equator such as in Europe. So people with fair skin are able to generate more vitamin D which gives them an evolutionary advantage. So any mutation that falls into the MC1R gene is allowed to survive and spread through a population. Research suggests that similar adaptations were evolved independently by Neanderthals and modern Europeans in response to similar environmental circumstances.

This pioneering work on the biology and physical appearance of Neanderthals is important because it addresses key questions such as why we inherited the Earth and not the Neanderthals. This work is mostly done through DNA analysis by various geneticists and biochemists. This research suggests that there is a propensity to reduce melanin in populations that inhabit areas away from the equator where sunlight levels are low. If the Neanderthal and modern variants of this gene are different this is a good example of convergent evolution, a similar evolutionary response to the same situation.

Posted by: Balkrishna Gantyala(5)

Thursday, October 25, 2007

Cry Me A River

One of natures fiercest predators may have a softer side....... Evidence has been provided that during feeding crocodiles shed tears. Obviously they aren’t showing remorse over their recent kill, but why then are they shedding what looks to be like tears? It is difficult to observe a Crocodile in nature when it feeds because they are aggressive, live in water, and tend to submerge their victims before feeding upon them. At the University of Florida researchers observed the feeding behaviors of captive alligators and caimans, close relatives to crocodiles. These to captive species had been conditioned to eat on dry land where they could be viewed. They were fed a dry food diet similar to that of what dogs eat and a majority of they time they both shed tears.

Researchers have come to the conclusion that this is more of a protective response by the animal than an emotional one. The eyes are very close to the mouth were a lot of activity is going on. Crocodiles hiss and huff when they feed this forces air through their sinuses where it then stimulates the production of fluid in the tear glands. The air also forces the fluid into the eye, causing the eye to fill up with moisture and when overflow occurs and drips down the face it looks like tears. Tears are also squeezed out of the ducts when the animals is contracting its jaws muscle while eating. The tears lubricate the eye, and add another layer to prevent contact with the eye. It helps to flush out unwanted particles. The eye also recedes into the head when feeding. So as for a softer side, it looks like the crocodile is shedding “crocodile tears.”

Link

Posted by Jessica Johnson (5)

Machiavellian Monkeys

It seems that humans are not the only primates to use social status, power, and cunning to further themselves and other members of their family in their society. According to research conducted by primate behavior specialist Dario Maestripieri, rhesus macaques also display similar behaviors. With intricate societies, these monkeys have had to develop many ways to climb the ranks in their social world. According to Maestripieri, "After humans, rhesus macaques are one of the most successful primate species on our planet; our Machiavellian intelligence may be one of the reasons for our success," and one can therefore assume, when confronted with evidence of their behaviors, that these monkeys have also utilized this type of intelligence.

Each group of monkeys is composed of about fifty individuals, ruled by one alpha male, who uses force and aggression to secure for himself the best life has to offer: food, shelter, and females included. The most powerful males will often band together to keep lower ranking males in their place, through means of violence and intimidation. And it is no wonder they should have to. Low-ranking males are at the greatest risk of predation (because they are forced to live on the borders of a group’s territory), mating is an option only if the alpha male is not around, and they have the worst pick when it comes to food. Who wouldn’t want to climb the ladder a little when in that position?

Males are not the only ones to use these Machiavellian tactics, however. Females use sex as a means of protection for their young. If they copulate with the alpha male numerous times, it will lead him to believe that he is fathering their children and will thus protect the young they produce. However, at the same time, females continue to mate with the other males in the group – another one of their tactics. If the alpha male dies or by chance is sterile, it will benefit them to have relations with other potential alpha males or ones who can actually produce offspring. Also, because female rhesus macaques share close bonds with other females in their families, mothers will often use their own social standings to bring their daughters up to or higher then their own level.

Civil wars of sorts also occur within rhesus society. Whole families of lower class individuals have been known to rise up against the ruling family. These revolutions can lead to extreme changes in society, causing, for instance, a whole upheaval where lower class males may now find themselves in seats of power. Maestripieri believes that,
"What rhesus macaques and humans may have in common is that many of their psychological and behavioral dispositions have been shaped by intense competition between individuals and groups during the evolutionary history of these species."
And this may be what has made both humans and rhesus macaques so successful when compared to other species of primates. With their smart thinking and cunning, they have been able to develop methods of survival not only for themselves but also for those closest to themselves. And while these methods may not be very kind or anything to boast about, they sure have proven that they are successful in helping individuals survive.

Posted by Elizabeth Adams (5)

Wednesday, October 24, 2007

Love 'em and Leave 'em or Sit There and Breed 'em?

Ever wonder how birds decide to mate? I know I sure do. And for now, so do you.

So, just how do male birds decide how to mate? Do they? Do they just take what comes, or do they have plans of their own? Is it all hormones? Is it the media?

One way to think of it, it turns out, is hormonal. Conventionally, it has been long known that levels of hormones can influence the behavior of birds, especially during the mating season. However, this isn't quite as clear cut as it seems. It might just be that the ability for birds to quickly increase or decrease the amount of testosterone in their system may be more influential, in the 'short' run, than the total amount of testosterone in the system. A study by researchers at the Universities of Indiana, Virginia, and Southern Mississippi hint at this new way of conceiving the impact of hormones on a bird's behavior.

In this view(which, of course, needs much more study), birds whose levels of testosterone quickly fluctuated were more likely to seek multiple matings, while those whose testosterone levels were more stable tended to stick around one mate and invest more energy in their young. This study points to an idea that the individual history of a bird can influence the way it adapts to reproductive success. More specifically, the local environment and present surroundings of a bird can have a larger impact than previously thought. The data also suggest that there may be more than one way to skin a cat:
"Our data also suggest that there is more than one way to be successful at reproduction. Some males may seek mates at the expense of parental behavior, but other males are doing the opposite. They are being more parental at the expense of aggression. And apparently both ways of being in the world work." -IUB biologist Ellen Ketterson


So what it comes down to is the individual bird trying to maximize reproductive success based on some well-worn strategies. The manly Juncos can maximize the amount of offspring they have, and minimize parental care, or they can minimize the amount of offspring and maximize the parenting. Actually, this conception seems to present a n either-or situation - in reality, the system is more complicated. Not every bird can cruise around the woods spittin' game to fly honeys, (That's right, not only did I type that, I meant that pun.) some homely bird may just have to be a homebody. In fact, the whole system is probably dynamic, a continuum, which influences different birds in different ways.

In the near future, the biologists hope to study just to what extent this hormonal variation occurs. The real question, though, is how this modification is achieved in birds - is it purely an environmental factor, or can it be influenced by the bird himself? And how would you test that?

Posted by Brad Garvey (5)

Tuesday, October 23, 2007

Moonlight Causes Mating Frenzy in Corals

In 1982, scientists discovered that at night, just after the full moon corals go into an “orgy of reproduction.” Trillions of eggs and sperm are dissipated into the water to form new life. This mating frenzy can even leave pink floating debris- ironically enough a color usually thought to symbolize love in our culture. This mysterious occurrence is found to take place in the summer but is found that the moon rules this production and depositing of eggs and sperm in order to form young. Whenever people ask Alina M.Szmant, a coral expert at the University of Carolina Wilmington, why do the corals release their eggs and sperm during the specific phase of the moon and her answer always is "It's a mystery."

Today, seven scientists from Australia, Israel, and the United States have found that corals have primitive photoreceptors. These photoreceptors act as eyes for the corals that respond to moonlight when stimulated. The finding of these photoreceptors give a link in order to figure out why these coral reproduce at the exact same time of the year.

This finding opens the door to further research. Scientists’ used to think that corals were brainless creatures that do not respond to any changes in their environment; turns out they are more complex than assumed.

Posted by Kayla Carrero(5).

Sunday, October 21, 2007

Uganda Cranes Declining Due to “Witch Doctors”

In Uganda, East African, there were once fifty-thousand of Gray Crowned Crane in 1980, but just after two decade in 2000, there were only twenty-thousand left and the population of crested crane has been declining since then. The major reason for causing Gray Crowned Crane’s population to decline is due to “Witch Doctors," also known as traditional healers. They believe crane is an important ingredient in some folk medicine, so they capture the cranes from their natural habitat.

Gray Crowned Crane is the national bird of Uganda and it is illegal to capture cranes for medical reasons. Because cranes mate for life, local people believe marriages and relationships will last forever if they consume the feathers and the eggs of the cranes. The Witch Doctors will crush the eggs with herbs and sell it as a “love potion” to local people. Besides the feathers and the eggs, other parts of the cranes are also used in other forms of goods. Claws and the beaks are used in drinks and as a way for promoting monogamy and affection. The cranes also represent good omen that can cast evil spirits away.

The tools they used to capture the cranes are very rough, such as: metallic traps, snares and hooks. The tools are so rough it often kills the cranes or get their wings cut off. "To catch a hundred cranes, you have to kill four or five times as many in the process," Byaruhanda of Nature Uganda said. Young cranes are sold for higher price than adult cranes. Therefore, more young cranes were captured, which made the population become smaller.

Their population had drop 60% during 12 years, if we don’t do something to stop the hunting of Gray Crowned Crane, soon there will not be any more cranes in Uganda. We need to find a way to protect these cranes from being captured by the Witch Doctors and we have to educate those local people that using cranes as illegal medicine and the love potion doesn’t work as they thought it would. So once the local people stop eating cranes and the cranes’ population will increase again.

Sources:

http://news.nationalgeographic.com/news/2007/10/071019-crane-potion_2.html

http://allafrica.com/stories/200710100216.html

~Kaiming (Kyle) Chiang (5)

Giant Snails Once a Delicacy, Now Too Many

The giant African snail once brought to Brazil to be used in the gourmet restaurants is now a nuisance in the country. The mollusk is 8 inches long and can weigh more than 1 pound is now an invasive species in Brazil and can be found in almost every state. Experts say that eradication would almost be impossible because of its vast success.

It was originally brought to Brazil as a substitute for the common garden snail used for escargot but has proven to be notorious. At fairs people would sell kits and instructions on how to raise them since they had so many more benefits in comparison to the garden snail. The thin group of people that ate escargot were not willing to make the substitute since it had a different texture, taste and shady origin. The "snail farmers" were left with many unwanted snails in their backyards. It has been found that it is a potential vector for several pathogens and an intermediate host for worms that can cause parasitic diseases to humans. Some of the worms include one that cause meningitis and in extreme cases can lead to blindness and paralysis. The two cases of meningitis in the state of Espíritu Santo were both cause from the worm that infects the African giant snail.

The snail has already become part of the food chain and there has been an increase in rats and snakes that eat the snails. The snails have also started competing with the native species which are vulnerable to losing habitat to the prodigious invader. A control plan has been started but it includes collecting the snails by hand and destroying the shells which requires serious commitment from the Brazilians. The snails also hide underground making the catching more difficult. Their optimal environment is at night especially when it rains. These snails have become a terrible nuisance and an invasive pest.

http://news.nationalgeographic.com/news/2007/10/071019-brazilian-snails.html

Posted by Carmen Arsuaga (5)

Feather Plucking in Parrots

One of the most unfortunate sights one can ever see in the world is a pet bird with a pluckng habit. My own cockateil, purchased as an older bird from a yard sale when I was in 6th grade, came to me with this problem. Any time she is left in the cage for more than 2 days at a whack, she starts ripping out her tail feathers and playing with them one by one. Unfortunately, once the behavior starts it's like nail biting in humans—depending on the length of time it's been doing it and other factors, it's really difficult to get a bird to stop.

But how does it start? Sometimes it is the result of a nutrition deficiency caused by the all-seed diet many bird owners give to their bird—lacking proper vitamins, the bird's skin gets itchy and dry, so it overgrooms. Soon it plucks the feathers entire from its rough grooming, which becomes a habit. Other times, it is the result of emotional disturbance caused by too many solitary hours in a cage. It's not only a way of getting attention, it's a self-destructive behavior that can provide entertainment to an unstimulated bird. My own bird uses her feathers as a musical instrument, running back and forth in her cage dragging it across the bars. If you take it away, she plucks another and repeats the behavior. Not all find the feather a toy. Some will go further than the feathers and rip off skin. There have been cases of parrots where they've died from self-inflicted injuries.

How likely a parrot will turn to plucking as an outlet to release stress depends on the bird, but some species are much more likely than others. It has been cited in most places the African greys are the most likely to feather pluck. African Greys are among the most intelligent of parrot species, the most notable individual being Alex, who was shown to have the intelligence of a 5 year old with the emotional development of a 2 year old. African Greys are really sensitive to their environment, and are highly neophobic and easily stressed. Smaller, less intelligent psitticines (parrots and parrotlike birds) such as parakeets and lovebirds are much less likely to show plucking behavior In fact, I've been really into bird behavior for years and have never heard or read of a parakeet that plucks.

Unfortunately because of the habit nature of this behavior, the best cure is prevention. Feeding a bird a diet rich in vitamins by providing a nutritious staple (pelleted food being much better than seed) and a constant varied supply of fresh vegetables is one way of eliminating the nutritional type of plucking. Providing the bird with a large variety of toys that are rotated often and hours of one on one time daily with their owners is the best way to prevent this behavior from starting. Once the behavior starts it's very difficult to diagnose the cause and treat it. Plucking is the symptom of a problem in the environment and not of the bird; it's really too bad more people buying birds don't realize this because feather-plucking is among the top causes for birds to be surrendered to shelters or given away for free on Criagslist.

For further reading:

For more information on African Greys:
An African Grey
The people that run this site also run a forum and can provide more practical information than any other place I've seen.

The Alex Studies By Irene Pepperberg Harvard University Press 2002
By the sceintist that works with Alex, it gives a nice overview of African Greys but focuses more on the training techniques used with him compared to traditional science. I highly recommend.

The Gabriel Foundation

The largest bird rescue in America. They are open to the public, take in hundreds of neglected birds year round from all over the US. They have a lot of practical experience with birds and also a lot of professional staff on hand. They write many articles on bird behavior and rehabilitation.


Michelle Vigeant

Labels: , ,

Saturday, October 20, 2007

I've Seen A Housefly, I've Seen a Horsefly...but I Ain't Never Seen an Elephant...Mimic?

Until recently it was known that many animals living complex social lives have the ability to learn and mimic vocalizations. This ability, seen in primates, bats, birds, and some marine mammals can be important for such a social lifestyle. Recently, as of March, this ability has been witnessed as well as researced in two captive African elephants as well.

One case comes from Tsavo, Kenya. An adolescent female African elephant was making low-pitched rumbling sounds. Mlaika, an elephant that belongs to a semi-captive groupd of orphaned elephants, was often heard for hours at dusk and into the night. Just after dusk and into the night is the most optimal time for low-frequency sounds to be transmitted in the African savannah. The stockade where the elephants are kept during the night is located about two miles from the Nairobi-Mombasa highway. Joyce Poole, research director of the Amboseli Elephant Research Project, was quoted saying,
I sometimes couldn't distinguish the sounds of the trucks from Mlaika calling.
The Amboseli Elephant Research Project is found in Sandefjord, Norway.

Another case was witnessed with a 23-year-old African elephant named Calimero that has been living in the Basel Zoo in Switzerland with two other Asian elephants. Over time the African elephant has learned to call to his Asian elephant companions mimicking their chirpy calls instead of the African elephant calls of his own species.

Peter Tyack, who specializes in vocalized mimicking in marine mammals, and Poole made some statistical comparisons between the mimicked calls and the sounds in which it was thought they were trying to mimic. They came to the conclusion that these elephants were indeed trying to copy sounds that they were exposed to. Poole also has the belief that Asian elephants will share the ability to mimic sounds like the African elephant species. There was article uncovered that detailed an adult Asian elephant that knew how to whistle. By holding its trunk a certain way it could provide a whistling sound. This ability was witnessed and studied by a younger Asian elephant and eventually acquired. Now that it is known of this certain ability the next step is to understand why they mimic and how their skills help them in their natural habitats.

In the two cases of the African elephants it seems that these elephants were mimicking sounds out of boredom. We know that elephants are some of the smarter animals we have encountered and their being held in captivity can definitely lead to a case of extreme boredom. All three elephants have learned calls that go far beyond their normal repertoire showing us just how smart they actually are.

Elephants live in tight social groups within their large foraging grounds. As time goes on it has been said that elephants may switch between groups so these calls could be used as individual as well as group recognition (just like the prairie warblers with their opened B-songs). It has been studied and is now known that elephants can hear and recognize other elephants up to a mile and half away. They often use low-pitched frequencies because these sounds travel easily in the night of the savannah. This could be the reason that Mlaika picked up on the truck sounds during the night. According to Poole,
Vocal learning could be used to maintain individual-specific social bonds in the complex and fluid society of elephants, where members of a social groupd come and go, keeping in contact over long distances and maintaining close social bonds over lifetimes.



Sources: http://www.phschool.com/science/science_news/articles/big_mimics.html

http://www.planetark.com/dailynewsstory.cfm/newsid/30067/story.htm

http://news.nationalgeographic.com/news/2005/03/0323_050323_elephantnoise_2.html

posted by: Jesse Graham Thomas (4)

Friday, October 19, 2007

Can Animals Sense Earthquakes?

Have you ever felt that your animal has a sixth sense of some sort? What if that sense was animals being able to predict when earthquakes were going to happen? It has long been recorded that animals would exhibit strange behaviors before earthquakes. In the article entitled, Can Animals Sense Earthquakes? It gives examples of animals exhibiting this behavior and how it is hard to prove this. In the Greek city of Helice in 373 B.C. it was recorded that animals left the city in droves right before a huge earth quake devastated the city. The animals that left were not limited to just dogs and cats, but also rats, snakes and weasels also fled the city. How do you prove that animals can really sense something?

According to seismologists earthquakes are a totally random event and they cant possible see how animals can sense earthquakes. Some people have theorized that maybe they can sense the vibrations in the earth before humans can. I only have one objection to this argument and that is that earthquakes don’t build up over time. It’s not like they are a volcano, the tech tonic plates rub against one another and then an earthquake happens.

Japan is one of the most seismic places on earth. Scientific researchers from Japan hope to be able to find some way in which they can harness this sense, in order to save lives. More specifically in 2003 a medical doctor in Japan published a study about erratic behavior in dogs could be used to forecast earthquakes. But this turned out that forecasts (small earthquakes before the real one) predicted the quake.

Regardless whether or not scientists can figure out how or if animals can sense earthquakes, something is obviously going on. It has been recorded for a long time that animals can sense something. If I had to bet my money on it I think that animals can actually sense earthquakes.

Posted by: Andrew R. Thompson (4)

Owls and the City

Apparently life in the old-growth forests is "so last season" for Barred Owls in Charlotte, the largest city in North Carolina. Scientists are surprised to find that these 1-and-a-half-foot tall owls are thriving successfully in suburban habitats. Usually, these tame birds of prey are found in dense old-growth forests where the trees have large gaping holes within their trunks for favorable nesting sites. However in Charlotte, N.C. these owls recently have been found in areas where there are sparse trees and large well-manicured lawns ; a striking contrast to the textbook habitat which has long been established.

Since 2001, Rob Bierregaard, an ecologist and ornithologist at the University of North Carolina at Charlotte and his graduate students, have conducted this ongoing study and have already made significant findings on these curious owls. "My guess is that as we get more data, we're going to find that the city birds are even doing better than the country birds," Bierregaard said. The fact that these owls have drastically changed their habitat and their way of life is a key to this study because it shows these owls are capable of adapting to different habitat conditions, and are not "stuck" on one single habitat. Since they are able to adapt to different habitats, any change or lack of their current habitat will not mean the owl population will go down with it. The owls in Charlotte nest in the cavities of willow oak trees that are prominent in the new suburban neighborhoods that have recently sprung up there. Sparse trees over wide well-manicured lawns provide the owls with a perfect vantage for hunting.

The birds are doing so well in the suburban area, that they are actually reproducing faster than the adults are dying. The only threat to the birds found in the study so far has been disease and being hit by cars. This indicates that the owls are reproducing successfully, and may also be seen in other similar cities and suburban habitats.
Link

Posted by Christine Tauras (4)

Labels: ,

Moths Mimic Sounds To Survive

I found this article to be somewhat appropriate when related to our previous classroom material. The research for this experiment was conducted by Jesse Barber, a doctoral student in biology at Wake Forest and was co-authored by William E. Connor professor of biology at Wake Forest.

This article discussed the tiger moth's ability to use acoustic mimicry as a defense strategy. The tiger moths main predator is the bat. These bats much like any other use a form of sonar echolocation to locate and consume their prey in the dark of night. In order to combat this sonar employed by the bats, the tiger moth's produce ultrasonic clicks of their own. These clicks are deployed by a paired set of structures called "tymbals" within the moth. In some species of tiger moth's these tymbals are used to make specific sounds that warn the bat of theif bad taste. In the other species of tiger moth's these tymbals are used to make sounds that closely mimic the bats high-frequency sounds.

They found that the moth's that could mimic the bats high-frequency sounds would not be consumed. As a control they used moths of similar size that could not emit ultrasonic frequencies and almost all were captured by the bats. The bats also quickly learned and left the moth's that would warn them of their bad tastes completely alone. The bats that were used for this study were big brown bats and red bats. This study laid a major foundation for species to species acoustic mimicry for survival purposes.

http://www.sciencedaily.com/releases/2007/05/070529211003.htm

Posted by Francis Rogers

Water Spiders Spin Personal “Scuba Tanks”

While some spiders spend their days spinning webs and collecting food on land, the unique water spider found most commonly in eastern Australia and Tasmania thrives in freshwater ponds, creeks and marshes and spends its entire life underwater. This is possible thanks to the creation of a basic “scuba tank” spun form their very own silk. Scientists refer to these tanks as air bells, which act as reservoirs for holding and replenishing oxygen levels to sustain the life of these small brown arachnids. The water spiders are able to trap air bubbles from the water’s surface using the short hairs on their abdomens and legs. Then the spiders carry the bubbles back to their homemade underwater tank for storage. As the spider continues to do this, the tank becomes bell shaped and silvery. The specific silk that the spider uses is important in this process because it allows for oxygen to diffuse in from the water and carbon dioxide to diffuse out, so the spiders do not have to keep replenishing their supply so often.

Even though the creation of an “external lung” is quite impressive, the air bells serve other purposes than just holding oxygen. The water spider can use their air bell as a place where they can hide away from predators. They can also use this safe harbor when they themselves are the predators. In this case, the air bell acts a place where they can take a water mite, or mayfly nymph back and safely consume their prey. When the time comes for breeding and production the water spider also uses the air bell as a safe place to create a nest in which to keep her eggs. From this you could assume that females spend a considerable amount of more time in the air bells. With all of these conveniences of home right underwater, it’s no wonder why the water spiders would ever want to come up for air.

Source: http://news.nationalgeographic.com/news/pf/23715169.html

http://www.naturegrid.org.uk/biodiversity/invert/spiderw.html



posted by: Caitlin Sanders

Elephant’s Smell of Fear

It is known that elephants do not forget things that easily, but what is interesting and not known is that they are equipped with some brain power that enables them to be able to distinguish between friends and foes using the sense of smell. Studies show that pachyderms are able to perform this task at ease, they can figure out their threatening groups from those animals that mean no harm.

This particular research was conducted in Kenya, where researches set up experiments to test whether the pachyderms were able to distinguish between the Maasai tribesmen, who slay elephants from the farmers who work there, who are thought to leave these animals in peace. They presented the elephants specifically with identical red garments that these two different groups wore for about four or five days. The elephants were able to distinguish the smell of the different groups. They turned around and ran away once they smelt the Maasai’s clothes, but did not have much of a reaction when they smelt the clothes of the farmers. Also they found out that the elephants were aggressive towards unworn clothes of the Maasai tripe but they were not receptive to odorless white garments from the same clan.

"It tells us a bit about how elephants classify the world," says evolutionary psychologist Richard Byrne of the University of St. Andrews in Scotland. "Instead of treating humans as all one set, they're able to discriminate within one set.” Usually this behavior is observed in humans, but it is quite fascinating to see it in animals.

This sense of smell is used by elephants not only for their enemies, but also among themselves. They usually are able to determine if another elephant is a stranger or an old friend. "It's an innovative way of getting at the problem" of what animals know about their environments, says Karen McComb, an expert in mammal communication and cognition at the University of Sussex in Brighton, England. "The response is very appropriate to knowing what the threat was. It's suggesting they have some sort of reasonably advanced understanding of the sorts of cues that are going to be dangers."

No one has really tested so far as to what sort of biological activity triggers this particular type of action. They are not sure if there is some sort of gene that activates such a behavior, or if it’s a learned behavior. These questions would pave way to more research that can be performed to find out what really is the ultimate cause of such unusual but useful behavior in these elephants.

Source: http://www.sciam.com/article.cfm?articleID=B4F19421-0EA5-62AE-89758AC94F723D17&chanID=sa003

Posted by:
Kirubakaran Sivagurunathan (4)



Silly Dog: Human Influence Alters Dog's Inferential Reasoning

They say that a dog is "man's best friend". Dogs look up to their human companions, often so much that it seems like they will often do silly or illogical things just to please us. I have often witnessed dogs acting like total goofs around people. This behavior can lead people to question a dog's intelligence.

A study in Budapest was conducted with 42 dogs to see how much of influence humans are when dogs make decisions. In one experiment, a toy ball was placed underneath a small plastic flower pot under another larger plastic flower pot. The researchers also used an identical set of pots with nothing underneath them. Both pots were lifted in front of the dog, who was anxious to retrieve the ball. A researcher would do things such as look at the empty pots, or move them then look at the dog. Because the human researcher showed interest in the empty pots, the dogs usually chose that set. In a second experiment, researchers used pots which could be lifted remotely by a string so that any human behavior would not be a factor. After the dogs were shown the empty set of pots, they immediately went to the other set looking for the ball, by process of elimination.

In the first experiment, the dogs were copying the behavior of the human researcher. In the second experiment, the dogs were using inferential reasoning. They were concluding where the location of the ball was by knowing where it wasn't. This study has pointed out two things about dog behavior. One is that dogs do use inferential reasoning, and the other is that dogs don't exhibit this reasoning when exposed to cues from humans. The study shows a similarity between the influence of humans on dogs and the influence of adults on children. The dogs made mistakes in locating the ball due to human signals, just as children often make poor life decisions based on signals they received from adults.

Source: http://dsc.discovery.com/news/2007/10/09/doglogic_ani.html?category=animals&guid=20071009124530

Posted by: Gina Sciartilli (4)

The Hawaiian Nene's Endangerment, Who is Responsible?

The Hawaiian Nene has been listed as Vulnerable on the IUCN's extinction scale for the past 50 years. A Vulnerable status is given to any species at high risk for extinction. The Nene's numbers during the middle of the 1900's were reduced to a laughable 30 on one island in the middle of the Pacific. Thirty - less than half of the Animal Behavior class. This near extinction was belived to be caused by the isolation of the species to just the Hawaiian islands. On top of just a tiny extant population, these geese are all almost genetically idential.

However, researchers from Smithsonian's National Zoological Park and National Museum of Natural History investigated these matters. By sampling the goose's DNA from four different time periods in the past 2500 years (bones from paleontological dig sites 2500 years old, DNA samples from middens around 500 years ago, museum specimens 80 years ago, and geese still alive today). Much to their surprise, the geese only showed significant genetic variation in the oldest samples - ones older than 500 years.

This data coincides with the arrival of humans at the islands roughly one thousand years ago. Perhaps through slight environmental changes, the Nene's natural habitat was altered and no longer was able to support them in a way it had for thousands of years prior. Should the geese be considered unlucky, or quite lucky? On one hand, they were able to overcome extinction (with human intervention) like many other extinct Hawaiian species, on the other they no longer are the thriving populus they once were.

http://www.sciencedaily.com/releases/2002/06/020610074732.htm

Posted by Dave Sokolowski(4)

More Important than the Hump

We have done a lot of discussion about animal calls from smaller animals, such as birds, crickets and many more. It turns out that even the largest of animals in the kingdom have their own open or closed systems of calling for their mates during breeding system. And the Megaptera novaeangliae, more commonly known as the Humpback Whale or Baleen Whale, is one of them.

Normally these particular whales are known for their unique appearance, with it’s enormous lower jaw and large head covered with tubercles. It has very long flippers with these same tubercules (which look like knobs) on them. Baleen whales normally grow to be about 52 feet (16 m) long and weigh around 30-50 tons (females grow to be a little bit bigger.) In front of the dorsal fin lies the famous “hump” of it’s back.

But what is even more intriguing and unique about these whales is that “During breeding season the Humpback males are known for singing the longest and most complex songs in the animal kingdom.” http://www.omplace.com/omsites/discover/HUMP/humpg.html. Upon hearing this, I was a little surprised. I can understand how they would sing very long drawn out songs, since they have a huge, robust body to encompass vast amounts of air and large lungs. It is said that their songs can last up to 10 minutes long. But what I was more taken aback by was the fact that this gigantic mammal had such a complex call. When I think of intricate calls I think of smaller animals, having to make their calls more complex so mates can distinguish considering they are small and can’t physically be too loud. But these humpback whales supposedly take home the prize.

Their calls sound like barks, chirps, or moans to the human ear. You can hear a humpback whale call if you go to the website: http://dsc.discovery.com/convergence/blueplanet/sounds/sounds.html. The sound is a bit startling at first since the whale releases such a high frequency call to begin with. But afterward, it changes its call into a low frequency, bellowing sound. To me, it sounds almost as if some kind of brass instrument is playing low notes under water.


Even though it must be hard for the other aquatic animals to “filter out” the calls of the gigantic males because of the volume of their calls, at least their testes don’t grow numerous times the size of their body during breeding season. The call is (in many marine biologists eyes) “beautiful” and even more importantly, extremely effective in giving the information to their mate.

Posted By: Natalie Nicholson (1)

Wednesday, October 17, 2007

Lets Band Together: Cooperative Breeding in the African Starling

“You can turn to me when the going gets tough.” This sentiment is echoed by humans all the time to our friends, family etc. who are in need, but what about other animals, do they extend an offering of help to their brethren in need? Sure, it’s well known of the communal aspects of various insects and animals who work toward the better of their group over the individual, but what about physically stepping in to take over in dire circumstances?

Recently, researchers observed an interesting behavioral pattern among the African starlings, an endemic bird to southern Africa, in which during intense circumstances a “cooperative breeding” occurred. This means that an individual capable of breeding would delay her breeding in order to help another starling and her young in times of environmental stress. What’s more interesting is that the receiver was not necessarily a relative! Ornithologists were puzzled as to why females capable of breeding would delay. A previous theory into cooperative breeding suggested that an individual would engage in cooperation only if they were incapable of breeding themselves, but this was certainly not the case. Also, of the forty-five species of starlings, only a small handful engaged in this act.

A group of Ornithologists from Cornell’s Ornithology Lab performed a genetic analysis of the forty-five species in order to show the pattern of evolution and then correlated it with one hundred and forty years of rainfall data from the African starlings habitat. What they came up with was that the cooperative breeding was only expressed in individuals that resided in the arid savannah regions where the rainfall was, at times, unpredictable. The African starlings that resided in the forests with predictable rainfalls generally would have non-cooperative breeding. Basically, what influenced this behavior was the environment, and through the process of evolution a system arose that allowed the starlings the capability of breeding in extreme conditions while getting the support they need to care for their young. Some innate mechanism must override the starlings sense to breed and cause it to go from a breeder to a caregiver when it sensed the need. At times of adequate rainfall, the "cooperative breeding" starlings would generally return to non-cooperative patterns until the next drought came about. Helping out in times of need,I think that’s great :-)



Sources:

http://www.nytimes.com/2007/08/21/science/21obstar.html?_r=1&oref=slogin

http://beheco.oxfordjournals.org/cgi/content/abstract/10/5/465


Posted by Doug Zelisko (4)

Labels:

Saturday, October 13, 2007

Broad-billed Hummingbird

Broad-billed Hummingbirds are one of the smallest and most colorful birds ever found. These different colors make these birds very unique and beautiful among other species of the same kind. Broad-billed hummingbirds have dark green body, a bright red bill and "vibrant blue throat" which is enough to distinguish these hummingbirds from other hummingbirds. These birds mostly reside in Southern Mexico and Southern Arizona. Some of the other interesting physical factors of these hummingbirds include their internal organs and their structures. For example, these birds have the thinnest intestine which is only 2 inches in length.

The Broad-billed hummingbirds have the highest metabolism rate, heart rate, breathing rate compared to other animals and birds and are also thought to live up to 3 to 4 years at least. The longest living hummingbird was found to be 12 years old. They also help pollinate the plants. These birds normally feed on nectar from flowers during day time but as soon as it's night time they are unable to feed. They are unable to feed at night because they have a very poor night vision and they don't like to fly in the dark. As soon as it's night time they just find a spot and just sit down either in their nests or on the tree or even the ground sometimes. Being smart as they are, these birds decrease their body temperature which has a great effect on their metabolism and their need for food. The lowering of body temperature leads to slow metabolism which helps them lower their need for food and helps them survive through the night. This activity is repeated each and every night, it's like their daily routine. Wouldn't it be cool if we could do that every night or every late nights because eating late at night is unhealthy for us anyway.

These birds are not just the cutest species but they are also very helpful in many ways one of which includes pollinating the plants which can only be pollinated by these hummingbirds. These are some of the facts that I found very interesting about the Broad-billed Hummingbirds and I am sure you will also find the facts interesting and the birds real cute once you see the site posted at the bottom of this page.




Sources:

http://identify.whatbird.com/obj/220/overview/Broad-billed_Hummingbird.aspx

http://howtoenjoyhummingbirds.com/baby%20hummingbird%20videos.htm

(The second site shows the life of a hummingbird from it's birth until the time it left the nest, I thought it was really interesting and cute to see these little tiny birds grow up, they're just adorable little birds, you guys should definitely look at the second site!)


Posted by PB&J (Peanut Butter and Jelly)

Friday, October 12, 2007

Bird Flock Movements

Thursday night after the exam, I was sitting on the concrete steps behind Thompson waiting for my ride to come. I looked towards the intramural fields and saw flock of small birds. They were dashing and darting as a cohesive unit. The movements seemed random, but the birds would stay in a tight grouping. This immediately brought questions to my mind.

Zoologist, Wayne K. Potts, conducted an observational study on this manner in 1983. Flocks of Dunlin, a species of bird native to Puget Sound, was filmed using high speed cameras. The maneuvers of the birds were both spontaneous and induced by arrows launched near the flocks. By studying each frame, Potts was able to discern that there was no specific leader of the movements.

The maneuvers could be started by any birds in the group. One bird turning causes its neighbors to turn with it. This chain continues throughout the entire flock until all the birds turn together. He then fired the arrows toward the birds. From these observations he could see that the birds on the exterior, who reacted first, were delayed by their reaction time. However birds reacting to their neighbors could react up to three times faster. This was called "chorus-line hypothesis".

The reason for this behavior is to deter predators. Falcons and other birds of prey are unlikely to fly into a swarm of birds since they could be injured by a collision. This is also the reason behind the movement origins. Exterior birds fly inward toward the rest of the flock, this allows them to be protected while turning away from the risk. If a bird tried to fly away from the flock, they would be very vulnerable.

Well it said that the reaction time of a bird reacting to its neighbor was a 70th of a second and that this was three times faster than a birds normal reaction time. I imagine both these numbers were taken from the frame by frame video analysis that he did. The article didnt say whether the birds kept their positioning or not. I would imagine the birds would pick a spot randomly with the formation of the flock.
Link
Posted by Henry Rafferty (3)

Monkeys Want Justice

In an experiment conducted with caged capuchin monkeys a few years ago, scientists found that the sense of unfair treatment was not only unique to humans. Researchers conducted a series of trials in which pairs of monkeys were given tokens and were then encouraged to swap them in exchange for food.

The scientists observed that the monkeys were glad to exchange their tokens for cucumbers. Next, taking into account that the monkeys preferred grapes to cucumbers, one monkey was given grapes and the other was given a cucumber. After initial trials, it was observed that the monkey receiving the cucumber was less than happy to see her partner receive grapes in exchange for the taken (females were used as it was determined that males cared less about inequality and quality of the food). On some occasions, the monkey receiving the cucumber would refuse to give up the token. Other times, the monkey taking the cucumber would refuse to eat it or would toss it out of the cage entirely!

These results show that the monkeys were definitely paying attention to each other’s benefits. A significant change in a monkey’s behavior occurred when the other monkey undeservingly received food of higher quality. As any human would react to unfair treatment, the monkeys became frustrated and their behavior deviated from the norm. This irrational behavior (occurring despite the presence of a reward) is observed in humans and capuchin monkeys alike.

http://www.sciam.com/article.cfm?articleID=000C3167-BADB-1F68-905980A84189EEDF

Posted by Mayur Patel (3)

THE HYBRID THEORY

No, I’m not referring to Linkin Park’s album for all of you Linkin Park fans out there. What I’m actually referring to breaks current theory and belief. Hybrids come from cross-species mating. Current scientific theory suggests that this interbreeding would affect the offspring in a negative way. The animal hybrids are said to be less fit to survive when compared to the parents; however, a recent study with two species of salamanders and its corresponding offspring suggests otherwise.

A research done at University of California-Davis focused on three types of salamanders; barred tiger salamanders, native California salamanders, and their corresponding interbred offspring. During the research, the young of the original species had a lower survival rate when compared to the hybrid offspring of the two species. As a result this raises some concerns involving the well being of the native salamanders if there were more hybrids. Some conservationists believe that these hybrids are genetically superior to the original as it improves some characteristics, while others believe that these hybrids have impure genes in their pool.

It makes me wonder if there are other species that exhibit this example. As it is, first thing that comes to my mind is if a species is a hybrid, why can’t they take the best features from both species? The article didn’t go to in depth about WHY this doesn’t happen and or how it would affect the salamanders in a negative way.

http://www.sciencedaily.com/upi/index.php?feed=Science&article=UPI-1-20070927-14343000-bc-us-hybrids.xml

Posted by Justin Pok (3)

Is it Time?

Most animal species reproduce during certain periods of time, or seasons during the year. But how many species lay eggs at the exact same time and place? Probably only a rare few. One of these animals is the Olive Ridley sea turtle.

The Olive Ridley sea turtle is native to tropical areas in the Pacific, Indian, and Atlantic Oceans. They are one of the smaller sea turtles, weighing less than 100 pounds. They have a unique behavior not seen among other sea turtles. The females lay their eggs at the same time. There are certain beaches along Costa Rica that are referred to as “arribadas” or “arribazones”. "Arriba" is spanish for arrival. Local human populations around the Olive Ridleys' breeding beaches chose "arriba" or arrival to describe how hundreds to thousands of female turtles return to the exact same beaches at the same time every year. Mating with males usually takes place right near the beaches where the females lay their eggs. The Olive Ridley sea turtles are monogamous and only have to mate once for the female to lay hundreds of eggs multiple times during the breeding season. This is because the female is able to store the male's sperm inside her so she can "save" it for future fertilization. At the same time, thousands of female Olive Ridley sea turtles will travel to these “arribazones” between one and three times a year to lay eggs. It is thought that the female turtles return to the same beach they were born at. Some suggest that they remember the scent of the beach and chemosensors help guide them to it. A typical Olive Ridley female will lay about 110 eggs over a 28 day period. It is not uncommon for the females to lay over a million eggs on one beach. The eggs will hatch about two months after being laid and all the young turtles will find their way to the ocean while dodging possible predators.

Scientists believe that the Olive Ridley females lay eggs at the same time as a defense against predators. But how do they all know what time to lay their eggs? Scientists speculate that these turtles receive some “signal” from the environment that it’s time to lay eggs. Some hypotheses say that changes in tide, phases of the moon, or changes in wind cue the turtles to head to the “arribadas”.

Although the Olive Ridley was taken off the Endangered Species list, people have been reconsidering putting them back on the list due to a large decline in numbers. Humans and fishing nets are mostly to blame for their decline. The turtles’ eggs are considered a delicacy and humans have destroyed many of the “arribadas” trying to collect them.

Though we know the breeding behavior of the Olive Ridleys, it would be helpful to know why they breed that way. What is the actual cue they receive to lay eggs? Is the large grouping of females more than just a defense against predators? If we continue to destroy their breeding grounds, eventually we will destroy their species. We can learn a lot from the environment and how living organisms interact with it. We need to preserve our environments and the species that live in them so we can answer questions, like the ones we still have about the Olive Ridley sea turtles.

http://animaldiversity.ummz.umich.edu/site/accounts/information/Lepidochelys_olivacea.html
http://www.fws.gov/northflorida/SeaTurtles/Turtle%20Factsheets/olive-ridley-sea-turtle.htm
http://animal.discovery.com/fansites/caught/conservation/costa_rica.html

Posted by: Christine McConville (3)

Labels:

A Frozen Hope for the Future

The assisted reproduction technology of artificial insemination may be able to help save a species of White Rhinoceros according to studies conducted at the Leibniz Institute for Zoo and Wildlife research in Berlin. White rhinos are one of the largest land roaming animals, and their weight can exceed 6000 pounds with their length reaching a staggering 14 feet. While only considered ‘near threatened’, there are only possibly four individuals left in the wild, with eight individuals inhabiting zoo’s world wide. This new development could become crucial in rebuilding the population to a more substantial size.

Lulu, the pregnant female, had conceived a baby named Layla through artificial insemination from using fresh sperm from a male rhino that lives with her in Budapest. The sperm donor for the frozen sample, Simba, is a 38 year old rhino from Colchester, UK. The sperm, which was highly vital for his age, was taken at age 35, and was stored for three year with liquid nitrogen at minus 196 degrees Celsius. A new deep-freezing technology, which is very useful in wild life made this possible. The sperm was then thawed and planted deep inside Lulu’s uterus by specialists, using a non-surgical procedure developed by the IZW. Soon after, hormonal analysis showed that Lulu was experiencing signs of pregnancy, which was verified by performing an ultrasound.

Dr. Robert Hermes of IZW says, “The result is enormously important for the conservation of rhinos”. The hope is that sperm could be taken from free ranging rhinos, and with it frozen, could be of use later. Those rhinos still remaining in the wild are at risk of predation particular from poachers. However, the current task is to ensure that Lulu remains healthy throughout her gestation, which lasts between 16-18 months, and results in a baby calf of close to one hundred pounds. Although she is not due for over a year, some suggested baby names have included “Cool” and “Frozen”.

Posted by amolina (3)

Eavesdropping Iguanas

Marine iguanas on the Galapagos islands have to be careful when sun bathing otherwise they may end up as lunch for a hawk. New research shows that the iguanas listen for warning calls from mockingbirds. What is really interesting is that marine iguanas are mute and this is the first time that any mute animal has been observed responding to another species alarm call.

Maren Vitousek, the graduate student who first noticed the behavior, and her colleagues recorded the song and the alarm call of the mockingbird and played it to the iguanas. The researchers found that the alarm call increased the alertness in the iguanas 60% more of the time then the normal song did. At one study site that is close to a hawk nest the difference was even more pronounced. The iguanas have learned to pay attention to alarm call even though they cannot make vocalizations of there own. Very little is known about the iguanas' hearing mainly because they can't use sound to communicate. This research could mean that their hearing is more sophisticated then anyone thought.

Source: http://sciencenow.sciencemag.org/cgi/content/full/2007/1003/2

Posted by Jessica McDonnell(3)

Off! Brought to you by frogs

Insect skin repellents are one of the most popular products use by Americans every summer. A recent scientific experiment conducted on a bottle-green Australian frog of the Litoria Caerulea specie, which is found in forests near the northern parts of New Guinea and Australia, suggested that the secretion released through its skin has the same affect as the active ingredient found in popular insect repellents, also known as DEET.

Scientists were able to obtain a sample of the frog’s secretion by using a gentle zapping current, causing the contraction of the skin glands to release the fluid. The fluid was later applied on a mice’s tail where it remained clear for 50 minutes after being exposed to Culex annulisrostris mosquitoes. Aside from being an insect repellent, previous relevant studies suggested that the secretion release also has the ability to act as a painkiller and hallucinogen.

It is a known fact that toads and frogs use this as a defense mechanism in order to protect themselves from fungus and insect pest, but would humans also be able to benefit from this? Further research will be necessary to determine if it is safe to produce frog secretion as a pharmaceutical product.

http://animal.discovery.com/news/afp/20060227/frog.html

Posted by Vanessa Raphaël (3)

Smart Rats:

Studies show that rats like some humans actually consider problems by weighing the costs and benefits of a situation before taking action. This study was conducted on Wistar rats, a rodent specifically developed for research. This is the first study that actually shows that other animals apart from humans have the ability to actually think over problems and create standards to decide which situation requires more concern and which situation yields better rewards, etc.

The example used in the article is a simple one of a person buying a new car. There are many things a person considers before buying a new car. They need to see if they money they actually pay (the cost of the product) is worth the value of the car. And they believe that all rodents do something very similar except they are under a lot of pressure when they are making the decisions.

"In its natural habitat, rats are facing the problem that little is under their control, so they are facing various levels and forms of uncertainty all the time," said Ruud van den Bos, who led the research. An example of this might be that when they are searching for food in different patches, these patches usually do not yield the same rewards that they want. They have different types of food and so the amount of energy they might spend to obtain these food items will definitely differ greatly. Also they change their behavior in searching for food depending on the type of foraging season or just depending on the weather.

The researcher and his team tried to replicate these different types of situations to get a better idea of how the rats worked. They manipulated barriers in a T-shaped maze that rats explored. Rats entered at the bottom of the "T," which connected two arms.

At the end of each arm was a chamber filled with treats. One side had less amount of reward, maybe just one of two sugar pellets while the other side had a larger amount of about five sugar pellets. But the challenge they were posed with was that if they needed the larger reward, they needed to climb higher barriers to reach them. Now the rats were faced with the question of is it really worth climbing such high barrier for these sugar pellets? And as predicted, the rats first started out with trying to get the lower rewards, but once they realized that there were higher rewards if the barrier was climbed, they tried with all their might to try and get the reward. So in this case the rats decided that the benefit here was worth the cost.

“These findings have been reviewed for publication in the journal Behavioral Brain Research.”

Source: http://animal.discovery.com/news/briefs/20060612/smartrat.html

Posted by:
Swetha Raghavan. (3)

Save a Moose, Build a Road...

At a glance that is what you might decide after reading about recent work by Joel Berger (of the Wildlife Conservation Society) on moose in the Yellowstone and Grand Tetons national park. If you have driven through Yellowstone recently you may have felt like you were on some grand wildlife safari. There are tons of animals along the road including moose, elk, bison, deer, and even big horn sheep. Berger's research shows that this isn't because these animals are densely populated throughout the park, but rather that some of them are attracted to the roads as a mechanism for predator avoidance.

For 9 years Berger monitored the location of 25 birthing moose mothers. He reported that, on average, the pregnant mothers moved 122 meters closer to the roads during each consecutive year. He suggests moose are moving closer to the roads to avoid predation on their young calves, especially by brown bears. It is thought that the bears avoid the roads due to past persecution which lead to immigration of back country bears into vacant territories. These individuals who have had no human contact are likely more wary of roads.

As for the Parks, they are worried that the few roads they have allowed could be affecting the ecosystem so profoundly. There is hope however that as bears become more familiar with roads they too will adapt and that the system will return to a more "normal" state. For instance bears in Alaska are used to roads and consequently pregnant moose don't seem to show the same attraction to them.

Depending on your mindset you might think this adaptive behavior of moose is great because less cute little calves will be killed. Or maybe you are more concerned about the majestic brown bears that rely on successful predation to be able to have cubs of their own. Regardless, it is interesting that the moose have adapted a natural predator avoidance behavior to incorporate a very unnatural system, roads.

Posted by Kyle McCarthy (3)

Bubbles, Bubbles, Everywhere!

Smelling underwater? That's right! Lobsters can do it with their antennae, and now the star-nosed mole can too! Kenneth Catania led this study and stated,

"If you go through the literature on the historical ideas of olfaction, there's a lot of statements to the effect that 'Obviously, it's impossible for a mammal to smell underwater'." ... Whales, for example, are missing some of the olfactory features that land mammals have. It is assumed that they lost these capabilities when they made the transition to a life aquatic. Semi-aquatic mammals were thought to use their olfactory system only on dry land.

The star-nosed mole blows bubbles out of both of its nostrils underwater, then quickly inhales them. By doing this they are able to follow the scent path of their prey. Ken Catania is the man behind the discovery. He filled a clear glass aquarium and threw a worm in, then put the mole in. The mole followed closely behind blowing and inhaling bubbles the whole way. To further test this, Catania made a path on the bottom of the tank by using the scent of the worms. He then put a star-nosed mole in the tank and it blew and inhaled bubbles quickly following the scent path. He repeated this experiment with several other moles and all followed the path 75-100% of the time. He then put a screen on top of the scent path to create an obstacle between the moles and the scent path. This time, the moles were only able to follow the correct path 50% of the time. This displayed Catania's hypothesis that the star-nosed moles use the bubbles to follow the path of their prey. Catania wonders if other semi-aquatic animals are also capable of smelling underwater.



Posted by: Jennifer McGrath (3)

The Mammal that can Smell Underwater


Thursday, October 11, 2007

What Are These Birds of Paradise Doing?

A few days ago while I was aimlessly channel surfing in an attempt to ease my boredom, I stumbled across a show on the discovery channel call "Planet Earth." I was quickly captivated by the unique plumage I noticed in a few species of the featured animal, the birds of paradise. These birds appeared to be dancing around and puffing up their bright feathers. I wasn't sure if they were doing this to ward off potential predators or males of the same species encroaching on their territory. Upon review of James Dinsmore's article: "Courtship Behavior of the Greater Bird of Paradise," I realized that it was neither.

I learned that this grand display of dancing and showing off their bright feathers is in an effort to attract a female for mating purposes. Females are attracted to male birds which have the brightest feathers in order to ensure that their offspring will be very healthy and well suited for their environment. The display grounds where the male birds of paradise entertain the females are referred to as "leks" and are often kept very tidy by the males, in an effort to impress the females. The species is sexually dimorphic, which means that only the males have brightly colored feathers. This way the females can easily recognize their mating partners and choose the best one. The birds are found mainly in Indonesia, Papa New Guinea, and Australia. The males are most often polygynous, which means that they will not hesitate to mate with more than one partner.

I originally thought that this courtship behavior was aggressive behavior because the bird seemed to be scaring off an enemy. However, upon further analysis it is apparent that these birds are indeed trying to seduce their female counterparts. Male birds of paradise prepare their leks and groom their plumage as soon as the mating season begins, and the next step is to wait for a female to arrive, which can take anywhere from 1 day to 2 months. These birds display an absurd amount of patience as they wait calmly for females to arrive. This courting behavior is also seen in many other species of birds across the world, it is not unique to the birds of paradise. Some species which have highly specialized lek rituals include the sage grouse, black grouse, and prairie chicken. They can also be seen dancing and chanting if it is the appropriate time of the mating season. These courting rituals are advantageous to the females because they are able to pick and choose which male they mate with, rather than settling for the first one that comes along. Choosing a male in good health and fitness will most likely produce offspring that are healthy and strong.

reference: http://elibrary.unm.edu/sora/Auk/v087n02/p0305-p0321.pdf

posted by: Dan O'Halloran (3)

Wednesday, October 10, 2007

Nothing but A Little Buzzing To Send Elephants Running


The African elephant’s natural habitat is decreasing substantially year to year due to agricultural reasons. As a result to the elephants decreasing habitat these animals are raiding farmer’s crops while marauding in search of natural resources. So researchers such as Lucy King and her colleagues of the University of Oxford, are investigating ways to prevent these raids from devastating Africa’s crops and future nourishment of the population.

Researchers have found a stunning effect that the southern Africa bee has on elephants. Lucy King and her team recorded the native bee’s aggressive buzzing and hid speakers in trees and brush around natural resting areas of the elephant. The team discovered that the recordings drove away seventeen elephant families in the resting area only after ten seconds of the native bee’s buzzing. By eighty seconds of the aggressive bee buzzing all but one family of elephants went running from the resting area.

The southern Africa’s native bee is know for its aggressive and chase antagonists ways, explaining why elephants go running when they hear the bee’s buzzing. Most of an elephant’s skin is thick to withstand a sting but curtain areas such as the belly, behind the ears, eyes, and inside the elephant’s trunk are vulnerable to the bee’s sting. If you’ve ever been stung its best to stick with the elephants intuition of, getting up and run!

But these farmers aren’t out of the woods yet. Equipment for recording and translating sound is expensive to place in the natural habitat and without the reinforcement of actual bee’s the elephants could learn to ignore the buzzing. Simply just moving native bee’s hives to resting areas is impractical due to the difficulty, danger, expense, and that some bee’s are actually inactive at night when most raiding have been accruing.

So researchers are still testing this theory along with others to find a solution to these raiding. But what a sight it must have been, to see an elephant running to escape the buzzing bee.

Source:http://sciencenow.sciencemag.org/cgi/content/full/2007

Posted by: Rachel McMahon (3)

Devilish Cancer

Tasmanian devils are native to one region and one region alone; the island of Tasmania. Devils establish physical dominance by posturing and sound. In many cases dominance cannot be established through these methods and results in a fight. T.Devils, when engaged in battle for dominance or mating rights, fight by biting. Wounds almost always occur in and around the face. With each bite there is a high chance that they are spreading cancerous cells to one another. Devil Face Tumor Disease causes infected animals to grow monstrous tumors on their face that usually leads to the death, due to emaciation.

As far as the data shows, DFTD only affects populations of eastern Tasmanian Devils, leaving the western population relatively healthy. Scientists are proposing that western and eastern populations be introduced into a breeding program that will diversify their gene pool and possibly reduce or eliminate the disease completely.

It is projected that without human intervention, Tasmanian Devils could face drastic reductions in populations or even extinction. Will scientists be able to diversify gene pools in these devils enough so that DFTD are rare cases? Or will this deadly disease prove to be the downfall of another australian marsupial? I guess we'll see in due time.

http://news.nationalgeographic.com/news/2006/02/0227_060227_tasmanian.html
http://news.nationalgeographic.com/news/2007/06/070608-devils.html

han beeth kim (2)

Sunday, October 07, 2007

It’s a Bird… It’s a Truck…It’s an Elephant?

Very few animals are capable of learning vocalizations; most commonly we see birds, primates and some marine mammals performing such a behavior. But recently, Joyce Poole, the director of the Amboseli Elephant Research Project in Sandefjord, Norway, working with other researchers, recorded African and Asian elephants learning vocalizations; mimicking the noises from their environment and other elephants. Poole documented a young female African elephant imitating the sound of nearby traffic, and a 23-years old male that had lived with two Asian elephants for 18 years, mimicking chirps and noises made by the Asian species. She recoded elephants exhibiting the behavior in captivity, but notes that elephants, like other animals able to learn vocals, have complex social lives.

Although more work would need to be done to look at the neuronal basis for the elephants learning, we can see that they rely on cultural learning through imitation. As seen with the elephants Poole researched, the animals were mimicking sounds they heard on a daily basis. An older article in the Journal of the Bombay Natural History Society shows an Asian elephant with the same ability as the African elephants. The article states that an Asian elephant could lift her trunk and blow through it to whistle. Not only did she learn the trick, but researchers also noted a younger elephant watched and eventually learned the trick himself.

Reports such as these, on elephant communication have been around for a while, but what shocked the researchers was that the elephants are able to teach and learn new sounds, even non-elephant sounds! It might be interesting to look into whether or not specific vocalizations are being passed on from one generation to the next. Now, researchers must attempt to figure out what this behavior is used for in the wild. Most likely the tool is used in and amonst different groups of elephants as a way of distinguishing family and foe. Future research may help us learn more about elephant’s social lives, and possibly other behaviors we thought were limited to other animals.

Source

Audio Clip of Elephant Being a Truck

Posted By Courtney Huffman (2)