Climate change does affect our biodiversity
Jul 02 2014
While examining the impact of this climatic fluctuation on the animal world, we see the case of Tal Chhapar, which is a small sanctuary of the desert ecosystem, where hundreds of black buck and many small carnivores like desert fox, small Indian fox and Asiatic wildcat are found. The forest official in charge of the sanctuary, Surat Singh Poonia, reported that carnivores usually deliver their pups in winter, and cubs that are five to six months old can be seen by June around their natal den. In June, cubs were sighted, but they were not older than one to two months. Poonia observed this phenomenon in three species of carnivores — desert fox, small Indian fox and desert cat. The reason could be the extended winter and, thus, late monsoon.
According to Poonia this is the first time in the last eight years in his Taal Chhapar posting that he has seen such a phenomenon. He also documented the late return of migratory wader birds. There could be other reasons as well. A wildlife researcher, Yogendra Sha, said the late breeding was not seen in Kutch, Gujrat.
Scientists divide seasonal breeders in two groups — short day breeders (winters) and long day breeders (summer and monsoon). Examples of short day breeders include sheep, goat, foxes and deer. Long day breeders are horses and minks. Breeding is regulated by photoperiod, the duration of sunlight during the day. The pineal gland, which is found in the brain, is responsible for this. When there is less light, the retinal nerves decrease their movement or activity, which in turn produces melatonin hormone in the pineal gland. Melatonin works both ways: reproduction in long day breeders is repressed by melatonin and reproduction of short day breeders is stimulated by melatonin.
Reproductive biology of animals is, of course, not based only on photoperiod. Many other factors, including temperature, contribute towards it. Temperature, for instance, governs the basic physiological processes of all the reptiles (ectotherms). Crocodile researcher Suyash Katdare says temperature is responsible for determining the gender of the crocodiles. During the incubation of eggs, even small variations in temperature can change the gender of the embryo.
These examples indicate how climate change can influence our biodiversity. The late breeding case of Taal Chhapar is not sufficient or scientifically proven. But such reports are important beginnings for a study that may help us understand the impact of climate change on the living world.
(The writer is a conservation biologist at Tiger Watch, Ranthambore)