Animals and anthropology

A recent study into rooster crows reveals a lot about how animal physiology affects human life. Dr. Kevin Birth, an anthropologist from Queens College, City University of New York, studied how the crowing of roosters affects what time people wake up around the world.

Before people had mechanical clocks, cockcrows provided a reliable signal that morning was approaching. In the Middle Ages, monks used cockcrows as a signal for early morning prayer time. Waking up with the cockcrow is so ingrained that the image has made it’s way into cartoons and nursery rhymes–even non-farmers know of the tradition.

Today, many people still use the cockcrow as an alarm. In his paper, Birth writes that the Bororo people of Brazil “keep track of time after midnight through the gradual increase in intensity and frequency of crows between the first cockcrow and dawn; the Ifugao of the Philippines state that cocks crow four times during the night with the third cockcrow at around four o’clock in the morning; and among the Saramaka, a maroon group in Surinam, cockcrow is an auspicious time for sharing secrets in the predawn hours.” 

Unlike in the Middle Ages, scientists today know why roosters crow in the early morning. Like humans, roosters have a circadian cycle that affects their bodies at certain times of day. The faint light of the early morning triggers changes in chicken melatonin secretion, heart rate, and brain and liver function. These physiological changes spur changes in the testosterone levels that make roosters go cock-a-doodle-do.

The relationship between humans and other animals is complicated. Humans have domesticated animals, housed them, cooked them, even learned to heal them. We’ve spent a lot of time training animals to live with us, so it’s easy to forget that living with animals has affected our behavior too.

Read more about the topic in Scientific American.