Aggressive chickens get more sex? Don't talk cock!

[caption id="attachment_54" align="alignnone" width="300"] Source: Myself[/caption]

 

Ok I wrote this blog entry for a school assignment, but I decided it wasn't good enough so I went to do an entirely new topic. Rather than just delete this, I decided to post it here. So. Tahdah.

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We eat chicken so often, but how much do we actually know about them? Off the top of my head, I know that roosters crow every morning, hens lay eggs, and breast meat is really delicious. As you can see, my chicken knowledge is quite limited, so I thought it would be interesting to find out more about them.

Some animals have harems where a single dominant male has sexual relations with multiple females, and this harem master will protect his harem from other competing males. The most dominant male is usually the most aggressive/strongest one, as he is able to fight off other competitors. As a result, he is likely to be the most sexually active as well, given his control over the harem. The case is slightly different for the domestic chicken (Gallus domesticus).

[caption id="" align="alignnone" width="275"] The Brown Leghorn, a breed of chicken. (Source: Bullitt from Backyardchickens)[/caption]

Firstly, the proportion of males/females is artificially determined by the farmer/chicken-handler, usually harem-like with a few cocks and more hens. Next, Wood-gush (1957) found that aggressive behavior in the Brown Leghorn cock (a breed of the domestic fowl) was actually uncorrelated with sexual activity! In other words, the most aggressive cock did not want the most sex, despite winning the most fights. Wood-gush proposes that these two drives (aggression and sex) are stimulated by different hormones and thus operate independently

http://www.youtube.com/watch?v=hxWwrRO7oII

A video of a cockfight in the Philippines, where cockfighting is very popular.  

 

This leads to the question - if cocks do not have more sex despite being the dominant male, why do they expend so much energy to win fights to become the dominant male? I suppose the benefit is that they have 'first pick' at the hens of their choice, and it's their instinctive nature to want to ensure the reproductive success of themselves by dominating the social hierarchy, despite not actually having or wanting to have more sex.

 

 

Word Count: 299 words

References: Wood-Gush, D. G. M. (1957). Aggression and sexual activity in the Brown Leghorn cock. The British Journal of Animal Behavior, 5(1): 1-6.