Professor Dinesh Bhatt of Gurukula Kangri Vishwavidyalaya, an internationally-renowned ornithologist, has been nominated as SPC sub-chairperson for the International Ornithological Congress to be held in 2018 in Vancouver in Canada in which nearly 2,500 scholars from 125 nations would participate.
In recognition of his expertise, he has been assigned the task of reviewing the research papers to be presented under the thematic area “Cognition, learning and Communication” during the forthcoming international meet of the World Bird Scientists. Notably, Bhatt has been engaged in the research of bird communication for the past 22 years and his laboratory is the leading one in the Indian subcontinent.
Professor Bhatt said, “A majority of the birds communicate through acoustic signals, besides visual and other modes of communication. In case of the song birds, the secondary sexual characteristics include sexually dimorphic singing behaviour and plumage colouration during reproductive season. Males sing more and their songs are more complex as compared to the females. It is interesting to mention that in the brain of birds there is a special area called as “song control centre” the size of which increases during the onset of breeding. It provides birds an opportunity to deliver a variety of melodious songs to attract females and form territory.”
In the Indian subcontinent, it is during the spring, summer and monsoon when most of the birds enter into breeding using songs to repel the rival and attract females for pairing.The song recording and spectrographic analysis of signals of some Indian birds such as Magpie Robin, Pied Bush Chat, Indian Chat, Asian Koel, Brahmini Myna and Red-vented bulbul have been conducted in the laboratory of Dr Bhatt. “We have found that in the Indian subcontinent, despite tropical conditions, all song birds breed and sing at a particular season every year with little or great variations in song structure,” said Bhatt.
Bhatt remarked that song learning in juvenile (1-3 month old) birds occurs in two stages: sensory learning, which involves the juvenile listening to the father or other conspecific bird and memorizing the song and sensory-motor learning, which involves the juvenile bird producing its own vocalizations and practicing its song until it accurately matches the memorized song. During the sensory motor learning phase, song production begins with highly variable sub-vocalizations called “sub-song”, akin to babbling in human infants. Finally, after two or three months of song learning and rehearsal, the juvenile produces a crystallised song.
Sharing an interesting incident, Bhatt said, “Birds in the crow family and parrots have been shown to possess large forebrains, and greater cognitive abilities. It has been shown in Japanese Carrion Crow that at a road crossing the birds hop in front of the car during red light and place walnuts on the road. After the lights turn green again the birds fly away and vehicles drive over the nut, cracking them open. When signal turns red again the crow picks up the cracked walnut and feeds upon it. Another interesting example of bird intelligence is of African Grey Parrot which is believed to have intelligence of four- year- old child and can acquire more than 100 words.
Some birds show quite astonishing powers of recall, shares Bhatt. A North American Crow can collect about 30,000 pine seeds over three weeks and buries them. During the winter when there is snow fall the bird succeeds in retrieving it from snow covered area. This bird has keenest memory among all bird species.