@article {Pendleton:December 2007:0141-6707:566, author = "Pendleton, Frank N.", author = "Baldwin, Andrew H.", title = "The effects of spraying deltamethrin for tsetse fly control on insectivorous bird populations in the Okavango Delta, Botswana", journal = "African Journal of Ecology", volume = "45", year = "December 2007", abstract = "

We investigated the effects of spraying deltamethrin for tsetse fly control on bird populations in the Okavango Delta, Botswana. The northern part of the Delta was sprayed five times in 2001, and the southern part was sprayed five times in 2002. While deltamethrin is not particularly toxic to vertebrates, it is highly toxic to many types of insects. Therefore, we hypothesized that birds could be affected indirectly through reductions in their insect food supplies. We monitored resident bird populations using point counts at four sites (two sprayed in 2001 and two sprayed in 2002). We conducted 22 analyses of insectivorous bird numbers and four (18%) of these showed declines, five (23%) showed increases, and thirteen (59%) showed no change. No insectivorous species declined at more than one study site. When insectivorous species were lumped as a guild, there were weak declines at one site but no changes at the other three sites. Our results indicate that spraying deltamethrin did not cause catastrophic population declines in insectivorous birds within a year. However, foraging behaviour, physiology, breeding success and longer-term population effects were not investigated and cannot be ruled out.", pages = "566-576(11)", url = "http://www.ingentaconnect.com/content/bsc/afje/2007/00000045/00000004/art00016" doi = "doi:10.1111/j.1365-2028.2007.00770.x" }