ABSTRACT:
There is complete lack of information on roosting behavior of the house swift, Apus affinis native to Chhattisgarh. Therefore, we studied the roosting behavior (exit and entry patterns from/to its roosting site) of the house swift. Attempts were also made to ascertain the modulatory role of environmental factors. We monitored the exit and entry timings of the house swift in the roosting site located on the busiest commercial area of Raipur city, India, for eight consecutive days, every month over a period of two years. The exit and entry timings showed positive relationship with the sunrise and sunset, respectively. The house swift exited tater and entered earlier in winter as compared with summer and monsoon seasons. A significant negative correlation between exit time and morning ambient temperature, and positive correlation between entry time and evening temperature was witnessed. Unlike exit time, the entry time was negatively associated with the humidity. The emry time was also associated with light intensity. In summary, we conclude that various environmental factors, viz., sunrise time, sunset time, temperature, humidity and light intensity are likely to produce statistically significant effect on roosting behavior of the house swift. This study is, however, inadequate to answer the following questions: (1) how the first bird of the colony determines that it is the time to fly out? (2) Is it the same individual that flies out first daily? Nonetheless, the findings of the present study may have important bearings on the safety of civil and military flights.