The Indian Peafowl, Pavo cristatus, is rare in Kerala. But, recently, there have been many sightings of peafowl in northern and central Kerala. The geographic range of bird distribution is sensitive to environmental factors. What are the critical factors that led to the increase in peafowl distribution in Kerala?
Sanjo Jose and P O Nameer, from the Kerala Agricultural University were curious: why is the Indian Peafowl, a dry land species, expanding its range into a region which falls under the humid tropics?
They took data on the distribution of Indian Peafowl from eBird, an electronic reference database. They extracted more than 1500 non-duplicate occurrence records for the years 1979-2017 to understand the expansion of the distribution of peafowl in Kerala.
To investigate the environmental factors responsible, the scientists took nine out of nineteen bioclimatic variables for the period 1970–2000 from the WorldClim database. Altitude and land cover were also factored in.
For modeling, the scientists used MaxEnt, a program for modelling species distributions from presence-only species records. From the model analysis, the researchers found that the major factors affecting peafowl distribution are temperature seasonality, precipitation during the driest quarter and precipitation seasonality.
The scientists estimated relative changes in the species distribution by the difference between current and future distribution of the bird, based on the predictions of the climate model. The model suggests that there will be a significant change in the future distribution of the Indian Peafowl in Kerala.
The current distribution of the peafowl is in the central and northern part of Kerala, the eastern slopes of the Wayanad district, the Chinnar range in the Idukki district and the Thenmala range in the Kollam district. The scientists predict that the distribution of the Indian Peafowl would increase in the coming years and may spread across Kannur, Wayanad, Kozhikode, Malappuram, Thrissur, Idukki, Pathanamthitta, Kollam and Trivandrum districts. But Alappuzha, Ernakulam and Kottayam districts may not be suitable to the peafowl.
‘The central and northern parts of Kerala favour the peafowl in every climatic scenario’ says Sanjo Jose, Kerala Agricultural University
The scientists suggest that the Indian Peafowl be taken as a bioindicator of the changing climate in Kerala.
Ecological Indicators, 110: 105930 (2020); DOI: 10.1016/j.ecolind.2019.105930
Sileesh Mullasseri, KUFOS