Those Puppy-Dog Eyes

Communication does not always have to be vocal; it can also be visual or chemical. You wouldn’t ordinarily think that dogs and humans communicate through chemical signals. However, have you ever wondered why you get that innate feeling to forgive your dog when he looks up at you with those sad puppy-dog eyes after destroying your new pair of shoes or digging a hole in the yard which you then fall into and twisted your ankle? It turns out that the dog’s gaze elicits the release of a hormone called oxytocin, which causes this forgiving response.

Previous research has found that when a person smells oxytocin, a hormone produced in the pituitary gland, their tendency to trust others increases. Recently, Mino Nagasawa and colleagues from Azabu University in Japan conducted a study in which dog owners were placed together with their dogs in half hour sessions. Urine samples from the owner were taken before and after the sessions to measure oxytocin concentrations. The researchers found that higher frequencies of behavioral exchanges initiated by the dog’s gaze correlated with higher concentrations of oxytocin in the urine.

Another set of similar experiments was conducted, however the owners were not allowed to look at their dog. No correlation was found between the levels of oxytocin in the owner’s urine and the frequencies of behavioral exchanges. This concludes that the interactions between dogs and their owners can increase oxytocin concentrations in the urine of the owner, particularly when the interactions are visual.

So there’s the scientific proof that those cute little puppy-dog eyes really do work.

To read the full article, click here.

Posted By Crystal Young

Chimps communications regulate by left side of the brain

New study has shown that chimpanzees mostly uses their right hands when communicating with other chimpanzees. This indicate that their left side of the brain does most of the work for regulating and expressing their ways of communicating. Understanding their gestures leading to suggestion for another similarity between chimpanzees and human, for most language skills human uses the left side of the brain. This could be another reason why chimpanzees are extremely close to human. Chimpanzees learns as quickly as human, the only thing is that they can't express our language.
Scientists conducted the experiment at Yerkes National Primate Research Center in Atlanta, where they observed and recorded 70 captive chimpanzees for their behaviors and their gestures when communicating. They were focusing especially on chimpanzees gestures and how these gestures are produce under different social situations. William Hopkins from Anges Scott College who was the supervisor in the study said that they found the chimpanzees used the left side of the brain to control their right hands when gesturing.
Another idea that researchers believe is that speech was evolved from gestures. They said that the gestures in apes shares the same features as in human language and others properties.


Tiffany Phan
12/1/09

Red Squirrel Communication, a Misinterpretation

Red squirrels use alarm calls to warn others when predators are near – no surprise there. Lately, however, a discovery has put these little guys back into the news. The reigning hypothesis used to be that Red Squirrels used different calls, matched to different types of predators. Specifically, Red Squirrels had a tonal sound for aerial predators, and another barking sound for ground danger. However, Dr. Shannon Digweed of Grant MacEwan University in Edmonton, has a completely new take on what those sounds mean.

Digweed first became suspicious of the projection that Red squirrels warn others of danger when she realized they were mostly a solitary species. Red squirrels are loners except for the short period when they are mating with another. If mating is not involved, the squirrels tend to be very aggressive towards each other. She spent many months in the field following individually marked squirrels and recorded every vocal response. She even set up some predator experiments involving taxidermies. All this data concluded that the calls were not just for aerial or ground predators, but for ANY types of disturbances in the squirrel’s immediate area. The tonal sound is to indicate the squirrel is aware of the disturbance, and the bark is to indicate the continued detection of a disturbance. These disturbances can include the presence of other squirrels, non-threatening animals like deer, and actual predators.

Digweed concludes that different call types should not be related to language, ie that they have different meanings aimed toward other conspecifics. Rather, the red squirrel uses the calls to let the disturbance, whatever it may be, know that it has been detected and it is continuing to be detected.

Find the interview with Dr. Shannon Digweed here: http://www.cbc.ca/quirks/archives/09-10/qq-2009-10-31.html#3

Edit:

This study is very new with very new material, so information on how the solitary red squirrel uses alarm calls during mating season is unknown. The same is true of other squirrel species. Simply not enough information has been compiled to state conclusive results.

However, I can tell you that typically, red squirrels mate during February, March, June, and July, and the females typically raise 2 litters a year. Males know when females are in heat because of an odor they generate. A pack of males will chase a female for about and hour, and the female will typically mate with the largest male in the group. I would think that if a cestrus odor is being produced by a female that other red squirrels in the area probably abandon their alarm calls if they know the ‘intruder’ is a possible mate.

Posted by Bethany Rappleyea

If all of your friends jumped off of a bridge, would you follow?

A group of researchers have demonstrated that animals can be just as incapable of making good decisions as humans are. We've all heard of, been witness to, or even participated in extreme cases of social facilitation: consumer frenzy, the mob effect, panicked rushes in human crowds. You've got no idea what everyone is running from, but you're sure as hell getting the **** out of there! Well, this is in part due to what is called an "informational cascade." An individual forsakes the information they have acquired as an individual in order to conform to the decision made by the group because of how many other individuals have adopted this decision.

Informational cascades have been used to explain a variety of phenomena: stock market crashes, stampedes, and even mate choice copying. This particular study, published in the Journal of Behavioral Ecology, has demonstrated how nutmeg mannikins will make foraging decisions against their own better judgement. The birds were given a choice between two types of feeders: one was full of easily accessible, delicious millet seed, while the other had a layer of dried peas on top of the seed, making foraging slower and less efficient. The birds were initially given brief access to both types of feeders so that they would know one was better than the other. However, after watching playback videos of their own buddies preferentially eating from the slower feeder, the vast majority of individuals chose to doubt their personal experience and follow the crowd.

This would be like if you went to the Blue Wall to grab a slice of pizza, and there was one really long line in which every single person was paying with a credit card. Yet, there was another register open and no one was in that line, but you still decided to jump into the long line because that's where everyone else was standing. Lesson learned: your friends are not always smarter than you are.

Persuasive companions can be wrong: the use of misleading social information in nutmeg mannikins

- Posted by Deysha Rivera (final week, hooray!)

Males Have More Personality than Females?!?

So I came across an article that I had to post. It is saying that males have more personality than females. Read on! It states that males have more pronounced personalities in species like humans and even birds. These pronounced traits are what draw females in, like aggression or being daring (which fits nicely with our sexual selection lecture). This study also shows that in most male species, the males show predictable behaviors that relate to parental care even. Females, on the other hand, seem to be less predictable (guilty!). The females, with this unpredictability, have a "choosier" personality upon picking mates (okay, and a lot more...).

The research dates back to 1972 when the Uni. of Exeter looked at gender differences and personality differences (along with sexual selection). They think that the sexual selection drives the personalities. They looked at zebra finches for example: when checking out a new territory, the females would search it out more than the males. The males who were consistent with their exploring were also chosen more as mates (this would mean the males would be consistent with finding food or beating up the predators (or maybe chasing them off).

These scientists really believe that personality is just as important as choosing a male with bright colors or huge...feathers. Could personality really evolve like these other traits? They seem to think so, but what do you think?

-Alyson Paige
(Group 3, last week-finally!)

Hot Honeybees

Honeybees are known for dancing to communicate where a food source is and now it seems they may be able to communicate the quality of nectar or pollen through their body temperature. Nieh and his colleagues found that honeybees who returned to their hive with higher quality pollen, pollen that contains higher levels of protein, had a higher body temperature. The forager is telling the other bees in the hive the net caloric benefit through their temperature so how warm they are tells the other bees the quality of the food. Honeybees are able to use their antennae to sense the temperature of foragers returning to the hive and Nieh tested whether they can actually sense their food through temperature. They found that honeybees are able to identify warmth with their food by training the bees to stick out their tongues for a sugary reward when a warm surface touched their antennae. Next they showed that the bees were able to learn that different temperatures correlated with different food rewards. The honeybees recognized warmer temperature differences much more than they could recognize cold temperature differences. This is likely due to the fact that the center of the flower where they find nectar is 8 degrees Celsius warmer than the outside of the flower. It seems that now not only do honeybees communicate where the food is, but they are able to tell the net caloric benefit through temperature. What do you think they will find out next about communication between honeybees?

-Tara Quist (9)

Feed Me!

Many animals, when they are young, beg to elicit food from their parents. This is commonly seen in birds, but can range throughout various animals. This begging is an interesting trait because it has a conflict of interest between the juvenile and adult: the juvenile gets free food, but at the cost of the adult. Begging eventually stops at a certain age, but the reason why begging stops has been questioned. Three hypothesis were proposed by Madden, et al.: 1) adults stop responding to begging calls, 2) young voluntary switch to foraging from being dependent on the adult, or 3) at a certain time, young cannot produce begging calls. Madden, et al. tested these hypotheses on meerkats, a cooperative breeding animal.

From 2005-2007, free-ranging meerkats were studied in the Kalahari Desert in South Africa by Madden, et al. Playback experiments were used for testing these hypotheses and observations were recorded. They found that adults fed pups more when begging increases, regardless of age. They also discovered that pups stopped producing begging calls that stimulated adult feedings after 100 days. This finding, along with the observation that begging calls changed in structure in age, resulted in a conclusion that hypothesis number three was the most accurate. In many taxa, begging calls change with an increase in age. In meerkats, it was observed that calls become lower in peak frequency due to the growth in body size as age increases.

This finding is important in the study of the evolution of signaling in animal communication systems. With this knowledge, we can now study if the change in begging call characteristics also elicits less feeding by adults in other species.

Madden, J.R., Kunc H.P., English, S., & Clutton-Brock, T.H. (2009) Why do meerkat pups stop begging? Animal Behavior 78:85-89.

Posted by: Christine Rega (Group C, last blogging week)