after sudden temperature drops, the chimney swift sometimes hunts low over concrete roads (presumably following insect prey drawn to the warmer road), where collisions with vehicles become more likely. severe storms, such as hurricanes, encountered during migration can seriously impact the chimney's swift's survival rates. swifts caught up in 2005's hurricane wilma were swept as far north as atlantic canada and western europe. more than 700 were found dead. the following year, roost counts in the province of quebec, canada showed a decrease of 62 percent, and the overall population in the province was halved.