Ectoparasites of American Kestrels in Northwestern New Jersey and Their Relationship to Nestling Growth and Survival

Abstract

Abstract American Kestrel (Falco sparverius) populations have been declining throughout much of North America during recent decades. To determine if the ectoparasite burdens of nestlings may be a contributing factor, we examined broods of kestrels in nest boxes in northwestern New Jersey. Our objectives were to identify and quantify the arthropod ectoparasites of nestlings, and to determine if removing these parasites from nestlings would increase kestrel nesting success. Of 26 broods we examined, we randomly chose 13 and manually removed from the nestlings all visible arthropods during three visits, when nestlings were age 5–7, 10–12, and 15–17 d old; we handled the 11 control broods similarly but did not remove arthropods. Both the experimental and control broods were measured and banded at age 20–22 d, and all visible arthropods were collected from both groups. Of 1767 arthropod specimens collected, 1679 (95.0%) were Carnus hemapterus (Diptera: Carnidae). Our observation of the next most abundant paras...