A study conducted for the first time on five different species of owls inhabiting Western Maharashtra by city-based ornithologist Dr Satish Pandey, a fellow at the Maharashtra Academy of Science, has revealed how these nocturnal birds, who are losing their habitats because of environmental destruction and other superstitions, play a very important role in safeguarding the environment.
Staying alive: A mottled wood owl. The species can be found only in
India, but it is fast losing its nesting sites because of tree-felling
Five species of owls belonging to the Family Tytonidae (barn owl) and the Family Strigidae (Indian eagle owl, brown fish owl, mottled wood owl and spotted owlet) co-inhabiting the Deccan Plateau, the coastal region of Konkan and adjoining places were studied to understand preference habitat, reproductive behavior and food niche partitioning from 2005 till 2008.
The study was presented at the 7th Asian Raptor Research and Conservation Network (ARRCN) Symposium on Migratory Bird held in Korea last week on how the owl's diet can be useful as a means of biological control of agriculture pests.
The studies revealed that spotted owlets and Indian eagle owls had the most compact habitat clusters, indicating a more specific habitat requirement, namely scrubs and grasslands. But since most of the lands are under development, the owls are fast disappearing. As the owls feed on rodents, birds, reptiles and insects and spend longer time in agricultural habitats, they are being subjected to anthropogenic activities and other interferences.
Mottled wood owls, which prefer deciduous forests are found only in India and inhabit mainly forested areas, where the use of pesticides is leading to problems as they eat rodents. Also, as they are tree-hollow nesting species, they are fast losing their nesting sites because of the felling of trees in their inhabited areas.
Barn owls and brown fish owls occupy more diverse habitats, with the latter preferring more water bodies and evergreen forests in their habitat. Due to the rampant destruction of rivers and lakes in Deccan Plateau, the birds have almost disappeared and have gone to upper streams as they require greener patches.
"We selected an area of 1,000 m radius around the nest in order to analyse the landscape features in all of the nest territories and visited each nest at least five times. We collected pellets of digestive foods, which were scrutinised by experts from Zoological Survey of India (ZSI)," said Dr Pande.
The study, besides understanding owl habitats, also included data based on Pianka Niche Overlap Index (PNOI) which suggested that spotted owlets and Indian eagle owls had maximum food overlap in terms of mammalian, avian, reptilian and insect prey, followed by barn owls and mottled wood owls, which are generalist feeders without specific food preference, while brown fish owls had the less overlap as they ate fish.