Communal Roosting and Roosting Interactions Between Large- Billed Crow (<i>Corvus macrorhynchos</i>) and House Crow (<i>Corvus splendens</i>) in Relation to Environmental Factors

Community roosting is the aggregation of more than two species of birds in the same tree for nocturnal roosting or nighttime residence. Mixed species community roosting mostly formed during the non-breeding season of birds. We recorded eighteen communal roosting sites of birds in the suburban region of Salem city, and the most dominant communal roosting birds are the large-billed crows (Corvus macrorhynchos) and house crows (Corvus splendens), along with other birds. The communal roosting site varies from a single large tree, like Ficus religiosa to a group of five to six trees in the case of Tamarindus indica, Azadirachta indica and Peltophorum pterocarpum. We recorded eighteen community roosting sites of birds in Salem and 26 species of trees were used for the community roosting. The roosting birds were dominated by large-billed crows and house crows. A positive correlation was found between the canopy cover and the number of birds roosting at the community roosting sites (r = 0.991, P < 0.01). Further, there was a significant variation found between the time spent by large-billed crows and house crows within the communal roosts (t (46) = 4.997, P < 0.01). Other birds that share the communal roosts with crows were common myna, red-vented bulbul and coppersmith barbet. The communal roosting sites are helpful for protection from nocturnal predators, and they also act as sites for information transfer.