Individual study: Effect of insecticide treatment on flea numbers and great tit Parus major breeding success in nest boxes near Uppsala, Uppland, Sweden
Dufva R. & Allander K. (1996) Variable effects of the hen flea Ceratophyllus gallinae on the breeding success of the great tit in relation to weather conditions. Ibis, 138, 772-777
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Remove ectoparasites from nests to increase survival or reproductive success
A replicated, controlled study in a mixed deciduous woodland in Uppsala, Sweden, in late spring 1988-91 and 1994 (Dufva & Allander 1996), found that great tit Parus major nest boxes from which hen fleas Ceratophyllus gallinae were removed did not have higher hatching or fledging success compared to control nests (83-96% hatching and 69-100% fledging success for 46-47 experimental nests vs. 83-95% and 85-99% for 82-85 controls). In two out of five years, nests treated with pyrethrin had heavier and larger chicks in better condition, but in the remaining three years there were no differences. In another year, treated nests had shorter nestling periods. The authors argue that the impact of fleas is greater in cooler years with higher precipitation.