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Posts Tagged ‘competition’


Ornaments and Weapons

July 9th, 2014 by nyn1

 

In this post, I will discuss two tactics that animals use in order to gain access to mates as well as an example in each. You can also find both articles on Wikipedia. Find the weapons article at: https://en.wikipedia.org/wiki/Weapons and the ornaments article at https://en.wikipedia.org/wiki/Ornaments.

Weapons are traits that are used by males to fight one another off for access to mates. A mate is won in battle either by a male chasing off a fellow competitor or killing it off, usually leaving the victor as the only option for the female to reproduce with[1]. However, because stronger organisms, whether mentally or physically, are usually favored in combat, this also leads to the evolution of stronger organisms in species that use combat as a way to secure mates[2]. Examples of weapons include the antlers bucks use to fight one another off when competing for females.

Ornaments are traits that are used to attract mates based on physical attractiveness. These traits may help show good genes that potential mates may find desirable[1]. Although these ornaments are usually the main strategy in order to procure a mate, they come with the large cost of making the individuals more susceptible to being tracked by predators as well[2]. The most notable form of ornaments comes in the ornate plumage that the peacock has in order to attract peahens; the brighter and bigger the feathers, the better chance of finding a mate.

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Posted in Spring 2014, Wikipedia contributions | Comments Off on Ornaments and Weapons

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

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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Posted in Science communication, Spring 2014 | Comments Off on Water ripples in Tungara frog interactions