a1 Ornithologist, Department of Zoology, Punjab Agricultural University, Ludhiana 141 004, India.
a2 Assistant Professor (Wildlife), Department of Forestry & Natural Resources, Punjab Agricultural University, Ludhiana 141 004, India.
a3 Assistant Ornithologist, Department of Zoology, Punjab Agricultural University, Ludhiana 141 004, India.
a4 Professor & Head, Department of Zoology, Punjab Agricultural University, Ludhiana 141 004, India.
Roadside bird mortality is a new environmental dimension in developing countries. With the recent increase in the number of high-speed cars and the simultaneous improvement of roads in India, bird-car strikes and the resultant bird mortality are becoming important. To know how many species frequent roads in Punjab and thus may be prone to be killed by fast vehicles, we censused birds along 420 km of roads of different widths and traffic volumes from a vehicle moving at 50–60 km per hour. We also counted birds along transects c. 1 km away from roads, for comparison.
In all, 35 species of birds were recorded on the road proper or within 3 m of either edge. Common Myna (Acridotheres trisitis) was the most abundant species (34.8% of all birds), followed by House Sparrow (Passer domesticus) (29.5%), Ring Dove (Streptopelia decaocto) (13.1%), and House Crow (Corvus splendens) (9.7%). These four species together accounted for c. 87% of the total of all bird species. The off-road community consisted of 68 species. The species-richness of granivorous, insectivorous, omnivorous, and some other birds, was less on or near roads than in the off-road transects, but within each community, species having different feeding habits were in similar proportions. About 93% of the total birds on or near roads (as against 66% off-road) were either granivorous or omnivorous.
Our results suggested that granivorous birds are attracted, but insectivorous and other birds are repelled, by roads. Omnivores were equally abundant on and off roads. Food (such as spilled grain) seemed to be the main factor attracting birds to roads. Species diversity and equitability of the bird community on roads (1.82 and 0.51, respectively) were less than those off-roads (3.11 and 0.74, respectively). Wider roads had lower species-diversity and equitability, probably because of the greater volume of traffic on them compared with narrower roads. Species richness and bird abundance seemed not to be affected by roadwidth. Bird mortality on roads is discussed, along with the possibility of roads acting as “ecological traps” for foraging birds.