The Cuckoo outwits the Crow

Bird calls end with the Monsoon
By Radhika Nagrath
Haridwar: 17 Sep: Getting its offspring raised by another as the monsoon season drew to a close, the melodious singing of the cuckoo has also ceased. It had effectively demonstrated the purpose of its song, the black male cuckoo used his sweet melody to woo the speckled female, subsequently guiding her to a crow’s nest to lay her eggs. According to Dr Dinesh Chandra Bhatt, a former professor at Gurukul Kangri University, Haridwar, and an international ornithologist, many birds like the cuckoo have stopped making mating calls with the end of the monsoon period.
Dr Dinesh Bhatt says, “Not only the cuckoo bird’s call like ‘Kaphal Pako’, other birds like Chatak, and Papihaa have also stopped their characteristic calls commonly recognised as ‘Pee Kahan’, because their breeding season has concluded.
Dr Bhatt says that such a clever use of song serving both practical and scientific purposes is rarely found amongst bird species. The scientist noted that while the practice and utility of singing among humans likely evolved over the course of many civilisations, nature had bestowed the gift of courtship songs or “love songs” upon the avian world, millions of years before human evolution.
Indian poets have also frequently written about bird songs in their literature; it is said of the cuckoo that she turned black from singing incessantly while pining for her lover during the summer season. The cuckoo’s song is enchanting, yet its behaviour is the exact opposite – deceptive and parasitic. It engages in “brood parasitism”, tricking crows by laying its eggs in their nests and even more remarkably getting the crows to perform the entire task of incubating the eggs and rearing the chicks.
Discussing this unique brood parasitic behaviour where a bird relies on another species to raise its offspring, Dr Bhatt explained that his research team including former students like Dr Vinay Kumar Sethi, Dr Vivek Saxena, and Ashish Kumar surveyed the nesting habits of crows. They found that when a cuckoo is ready to lay eggs, the male and female perch on a branch near a crow’s nest. Irritated by their presence, the crow which is otherwise busy incubating its own eggs leaves the nest to chase the male cuckoo. The male cuckoo flies a short distance and lands again, prompting the crow to chase it once more. Seizing this opportunity, the female cuckoo quickly lays an egg in the crow’s nest, a process taking only four to five seconds and signals the male with a specific call that the task is done and there is no longer a need to keep the crow occupied. The research revealed that the female cuckoo knocks one of the crow’s eggs out of the nest before depositing her own. Although the cuckoo’s egg is relatively smaller, it closely resembles the crow’s egg in colour and appearance.
Notably a single cuckoo may lay three to four eggs in a crow’s nest, discarding one of the crow’s eggs each time. Even more fascinating is that the cuckoo chick hatches before the crow chicks and, by constantly demanding food, grows larger than them. The crow continues to feed the cuckoo chick daily. The scientists say that at one point, eventually, the cuckoo chick leaves to join its biological mother; in this way, the cuckoo successfully achieves its objective by outwitting the crow.
Originally from the village of Bhatgaon in Pauri Garhwal, Dr Dinesh Chandra Bhatt is currently conducting research on human-wildlife conflict and ornithology across various regions of the Haridwar and Pauri Garhwal districts. Data for this study was collected from select villages in the Dugadda block, as well as from the Raja Garden Colony, Gurukul Kangri, and Pathri town in Haridwar. Dr Bhatt is a founding member of the Asian Ornithological Alliance and serves on the scientific committee for a symposium scheduled to be held in Singapore. He has been invited to deliver a lecture at an ornithology conference in Singapore next month.