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Posts Tagged ‘communication’


How to Steal a Mate: Frog Edition

June 30th, 2014 by nyn1

 

When it comes to finding mates, that privilege is usually saved for the biggest, strongest, smartest, and whatever other positive adjective you might think of to describe the “perfect mate.” But that leaves you to wonder, what about those who aren’t necessarily the best at what they do, but still find a way to mate? The answer is simple: they’re the cheaters! The saying goes that “cheaters never win,” but in the case of this species of frog, that isn’t always necessarily the case.

A study was done on the European tree frog, Hyla arborea, to figure out why the males in this species choose to either seek out mates “traditionally” or “parasitically.” The traditional way would include actually going out and finding attracting or procuring a mate on their own, while parasitically involves using another competitors skills in order to procure a mate. They wanted to know if this behavior is caused by the size of the frog, or if it is caused by the energy cost that it would take to attract a mate. In order to test these two hypotheses, Brepson and his team set up an experiment in which they randomly caught 100 male frogs from a pond in France and emptied said frogs’ stomachs. The frogs were then split into two groups, one group was fed crickets and flies for seven days consecutively while the other group was starved for the same period of time. Then each frog was put into a container with two speakers, one in the center that played the “chorus” noise (mating calls at the average frequency of the male H. arborea’s croak), and one at the end of the container that played either “attractive” or “unattractive” mating calls for that species. A call was determined to be “attractive” or “unattractive” depending on how low or high the frequency of the call was as well as how often the call was played, with lower and more often was considered more “attractive.” The “satellite” zone was set at any point that was 10 cm or less from the speaker playing the mating calls as a standard for measuring levels of parasitism in this species. Males found in the satellite zone were identified to be acting more “parasitically” than “traditionally”. (more…)

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Posted in Science communication, Spring 2014 | Comments Off on How to Steal a Mate: Frog Edition

Whooper Swan Signaling Behavior

May 30th, 2014 by vld3

 

Originally, the wikipedia page for Whooper Swans focused on their feeding habits and distribution, but focused very little on the behavior of these swans. I added this information about Whooper Swan behavior to the page: http://en.wikipedia.org/wiki/Whooper_Swan#Distribution_and_behaviour.

When Whooper Swans prepare to go on a flight as a flock, they use a variety of signaling movements to communicate with each other. These movements include head bobs, head shakes, and wing flaps and influence whether the flock will take flight and if so, which individual will take the lead. Whooper Swans that signaled with these movements in large groups were found to be able to convince their flock to follow them 61% of the time.  In comparison, swans that did not signal were only able to create a following 35% of the time.  In most cases, the Whooper Swan in the flock that makes the most movements (head bobs) is also the swan that initiates the flight of the flock – this initiator swan can be either male or female, but is more likely to be a parent than a cygnet. Additionally, this signaling method may be a way for paired mates to stay together in flight. Observational evidence indicates that a swan whose mate is paying attention to and participates in its partner’s signals will be more likely to follow through with the flight. Thus, if a Whooper Swan begins initiating flight signals, it will be less likely to actually carry through with the flight if its mate is not paying attention and is therefore less likely to join it.

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Communication and Scrounging in Grackles

May 26th, 2014 by ss55

 

The common grackle, or Quiscalus quiscula, may seem little more than a pest. However, I found that these birds made a surprisingly good study for some of the basic principles of animal behavior.

My first observations were on a cold, cloudy afternoon in Rice University’s west parking lot. A small group of birds was perched on the roofs of several cars. Grackles look a bit like small, lanky crows, with longer legs and tail. They are sexually dimorphic, meaning that there are distinct differences between the sexes. Male grackles are an iridescent blue-green-purple with hints of copper—rather oddly like a patch of gasoline in a parking lot. Females, as we can expect in birds, are much blander, with dull brown bodies and dark-capped heads. Because of this difference, I could tell that there was a mix of sexes in the group—three males and three females.

Male grackle, Quiscalus quiscula. Photo credit to safariari on flickr, used under Creative Commons license (CC BY-NC-SA 2.0).

As the birds hopped and shifted on top of the cars, I noticed that they made several distinct sounds. (more…)

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Vampire Bat

May 14th, 2014 by amm18

 

The following includes an excerpt which was attached to the Wikipedia page “Vampire Bat” (http://en.wikipedia.org/wiki/Vampire_bat). The first and last sentence in this excerpt come directly from previous Wikipedia information and are used solely as a reference to identify what was added.

…This has been noted by many naturalists as an example of reciprocal altruism in nature.

It was previously thought that food sharing depended equally on relatedness and reciprocation.[i] However, it has recently been discovered that the predictive capacity of reciprocity surpasses that of relatedness.[ii] This finding suggests that vampire bats are capable of preferentially aiding their relatives, but that they may benefit more from forming reciprocal, cooperative relationships with relatives and non-relatives alike.[ii] Furthermore, a recent study demonstrated that donor bats were more likely to approach starving bats and initiate the food sharing. These findings contradict the harassment hypothesis—which claims that individuals share food in order to limit harassment by begging individuals.[ii] All considered, vampire bat research should be interpreted cautiously as much of the evidence is correlational and still requires further testing.[iii] For example, researchers question vampire bats’ ability to identify kin when past association, or interaction, is controlled.[iii] Similarly, scientists question if bats modify investments based on how other bats cooperate.[iii]

Another ability that some vampire bats possess is identifying and monitoring the positions of conspecifics (individuals of the same species) simply by antiphonal calling.[iv] Antiphonal calling is simply a song or verse sung in response.

Vampire bats also engage in social grooming…

[i] Wilkinson, G. S. (1984). “Reciprocal food sharing in the vampire bat”. Nature 308: 181-184. doi: 10.1038/308181a0

[ii] Carter, G. G., & Wilkinson, G. S. (2013). “Food sharing in vampire bats: reciprocal help predicts donations more than relatedness or harassment”. Proc R Soc B 280: 20122573. doi: 10.1098/rspb.2012.2573

[iii] Carter, G., & Wilkinson, G. (2013). “Does food sharing in vampire bats demonstrate reciprocity?”. Communicative and Integrative Biology  6(6): e25783. doi: 10.4161/cib.25783

[iv] Carter, G. G., Fenton, M. B., & Faure, P. A. (2009). “White-winged vampire bats (Diaemus youngi) exchange contact calls”. NRC Research Press 87: 604–608. doi: 10.1139/Z09-051

 

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Group Living

May 10th, 2014 by ss55

 

This post is an edit that I wrote to expand on the “Living In Groups” section on Wikipedia’s “Ethology” page. You can visit the page here.

Benefits and costs of group living

One advantage of group living can be decreased predation. If the number of predator attacks stays the same despite increasing prey group size, each prey may have a reduced risk of predator attacks through the dilution effect1. Additionally, a predator that is confused by a mass of individuals can find it more difficult to single out one target. For this reason, the zebra’s stripes offer not only camouflage in a habitat of tall grasses, but also the advantage of blending into a herd of other zebras2. In groups, prey can also actively reduce their predation risk through more effective defense tactics, or through earlier detection of predators through increased vigilance1.

Another advantage of group living can be an increased ability to forage for food. Group members may exchange information about food sources between one another, facilitating the process of resource location1.  Honeybees are a notable example of this, using the waggle dance to communicate the location of flowers to the rest of their hive3. Predators also receive benefits from hunting in groups, through using better strategies and being able to take down larger prey1. (more…)

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Water ripples in Tungara frog interactions

May 8th, 2014 by ss55

 

When a scientist publishes their research in a journal, the flow of information of doesn’t stop there—science journalism is an important form of communication that makes this research accessible to the average person. Because academic readers and casual readers are very different audiences, differences are necessary in the way that the same information is presented. By comparing a popular science article to its primary source, we can see how a skillful writer can turn research into news.

In a recent study published in Science (Halfwerk et al., 2014), a research team investigated how animals integrate multiple sensory systems when receiving another animal’s signal. The researchers worked with male Tungara frogs, which produce mating calls while sitting in shallow water. Although it was previously known that frogs would respond to a neighboring male’s call (by calling faster, or falling silent in either preparation to fight or flee), Halfwerk and colleagues discovered that the water ripples produced by calling are an important factor—other males were significantly more likely to respond when ripples accompanied a recorded male frog call. If the ripples indicated that the call was outside the male’s territory (about a 15 cm circle), males increase their rate of calling. If the ripples were inside the territory, males more often fell silent as they prepared to fight or yield to the competitor. (more…)

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Asian Elephant Parental Care

April 30th, 2014 by clk5

 

I observed three Asian Elephants (Elephas maximus) at the Houston Zoo on a clear, temperate day. I focused my observations on interactions between the three elephants; a mother and her two children. The elephants were held in a large fenced-in enclosure with a pond, grassy areas, and sandy areas. The mother elephant I observed exhibited many examples of well-known elephant parental care strategies.

When I first arrived, only the mother elephant was in the enclosure. She was drinking from the pond when her two children were released into the enclosure one by one. The mother greeted her children by running her trunk over their faces. According to some studies, elephants use this “mouth check” to determine the health and mood of their companion. Scientists believe that elephants have distinct chemical differences in their breath that another elephant can pick up through their trunks (reviewed in Langbauer 2000). The calves also greeted each other in this fashion.

"Elephants-OregonZoo” by StuSeeger is licensed under the terms of the cc-by-2.0.

The elephants seemed to rely heavily on touch throughout my observation. The initial “mouth check” greeting was then followed by many more instances of contact. (more…)

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