The Chicken and Tyrannosaurs

We eased into the jungle with a sighting of the red jungle fowl, Gallus gallus. There are two interesting bits of information about these birds. The first is an insight due to Darwin himself, who realized that this is the ancestor of all the chicken which run around in farmyards across the world. This story has been enriched by modern molecular data. These established that there were gene exchanges between domesticated and wild populations, probably due to chicken which fled the coop. It is likely that chicken were domesticated multiple times in different places, and the domestic variety was crossed with other related wild species. The first domestication probably happened about 8000 years ago in India. Although chicken is the default meat in India today, my grandparents never liked it. Their generation thought of chicken as faintly unclean. I wonder how many cycles of food fashion have affected the chicken in its millennia of association with humans. The second fact is that Gallus gallus is the closest living relative of Tyrannosaurs, a fact that was only discovered in 2008 after T. rex tissue samples were first found.

These ancestral chicken wander around the undergrowth in the jungles of Pench National Park, kicking up leaves and pecking at things like thuggish dinosaurs. They are wary of humans and disappear quickly into thickets when they see people. So the photos you see here are about the best I have ever got. The large male (featured photo) has a glossy black tail which shows iridescent greens and blues, rich dark brown and orange back, dark and glossy underparts, and an orange and yellow neck and crown feathers. The individuals we saw had big red combs, small wattles, white ear patches, red eyes and a strong curved beak. I always thought the much smaller females were drab, until the light caught the one whose photo is below. Then I realized that they are a lovely golden-gray in colour.

The remarkable sexual dimorphism is selected by the life style of this bird. The dull colours of the female serve to camouflage her as she tends to eggs and chick, a task that she performs alone. Selection pressures, on the other hand, drive the male to be larger, in order to be able to overcome rivals and maintain its harem. The same pressures make it aggressive enough to be the stars in cockfights around south-east Asia. Interestingly, the comb and wattle are subject to sexual selection. Apparently the females of the wild species prefer larger combs and are indifferent to wattles. You can see the result of this preference in the featured photo.

With the intense heat it is hard to accept that this is still spring. The big male had chased away all other males from its winter’s flock, and was surrounded only by a few females. Moreover, it still had its breeding plumage. From June to the end of the monsoon its warm gold neck feathers will be replaced by dusty black eclipse plumage. Except in springtime, the red jungle fowl lives in mixed flocks in which males and females have separate but strict “pecking order”.

It seems that there has been little study of the social structure of these birds, although it is recorded that there is a variety of different calls. Some of these calls are communicative. Our guide was of the firm opinion that these birds are good negative predictors of the presence of tigers, because they run away before a tiger appears. I did observe this on one occasion when some of these ran from a muddy pool before a tiger family came along. Chicken will be chicken, I suppose.

That left me with the question whether Tyrannosaurus rex was also chicken, at least in the sense that it ran away from confrontation.