Tuesday, October 12, 2010

Desperate Female Spiders Fight by Different Rules

Desperate Female Spiders Fight by Different Rules

Communication through signals, displays, and songs are some ways animals communicate with each other. This communication is important because it helps animals of the same species (and sometimes of different species) live together peacefully. A lack of communication though can cause many problems. Male jumping spiders (Phidippus clarus) perform displays and push each other back and forth like sumo wrestlers. These displays help each male gauge how closely matched they are and fights rarely occur. The displays allow the males to solve things before any injuries come about. Females on the other hand lack these displays. What happens in this case?

Female jumping spiders have different rules for fights. Females have no displays or sizing up of the competition. Instead, they go right at each other, and they go out for blood. As soon as the battle commences, the females will fight till they are unable to fight because of injury or death. The other part to this style of aggression is that the victor was not always the bigger stronger female. When researchers saw that the stronger spider was not the one who would generally win, they created a new hypothesis.

Females live in nests and make sure to protect and take care of their place of residence. Male jumping spiders are nomads. This means that they can change living space at anytime. Females on the other hand value their nests much more. To test this hypothesis, researchers set up a series of fights between nest owners and the homeless. The owner of the nest was not always the winner though. What they found was that the female closer to maturation was the one who would typically win because they use the nest as a place of protection. Before a female can reproduce, she must molt and at this time she is highly vulnerable to predators. She uses her nest as a safe haven and the closer she is to maturation and this process, the harder she will fight to pass on her own DNA.

Communication is important for animals to live their lives. Lack of communication on the other hand has serious consequences with one of them being the ultimate price, death.

By Alberto Suarez

5 comments:

  1. What an interesting way of communication, both for the males and females! However, when they researched this hypothesis and set up fights between nest owners and the homeless was it male-female fights, or female-female fights? Do females always have nests, or can they be nomadic too? Also, these displays the males practice, do they effect mate choice by females?

    Abbie Lamarre-DeJesus

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  3. I had no idea spiders molted. Do females and males ever fight? If so, what do their fights look like?

    Posted by Jen Kodela

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  4. I believe that the fights in this case were female-female only. It would seem females always have nests although I'm sure there are exceptions. Well from what I have learned I'm assuming these specific displays are solely a pre cursor for a fight but who knows they might affect mate choice.
    I wouldn't believe the females and males would ever be able to really fight because males have the displays and signals down to communicate a fight and since females never learn the correct responses needed for this type of interaction with the males. If they ever were to fight I believe the female would just attack and the male would be somewhat surprised. Hope this helps!

    Alberto Suarez

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  5. It is quite interesting to see that during a female-female fight, it is not the stronger one who necessarily wins but the one that has built a home and is closer to passing off its DNA. Does a male ever chose their mates depending on who looks like they are more capable of winning a fight and passing off their offspring?

    On the other hand, how would a female chose a male or judge their dominance/strength if males are just gauging back and forth and resolving situations sort of like a "tie" rather than having a win or lose situation which could have demonstrated their strengths!

    Loba Alam

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