Ectoparasites of American Kestrels (Falco sparverius) Wintering on the Baja California Peninsula, Mexico

. — The American Kestrel ( Falco sparverius ) is a small raptor that may be attracted to agroecosystems during both breeding and wintering seasons. In North America, American Kestrels from northern areas may migrate southward and overwinter in southern territories, co-occurring with resident kestrels in agroecosystems of Baja California, Mexico. We captured 56 adults during autumn and winter (2018/2019 and 2019/2020) in the southern part of the peninsula, and we evaluated the prevalence of ectoparasites on these kestrels. We found ectoparasites on 23.2 % of individuals: 14.2 % had lice, 1.7 % cimicid bugs, and 7.1 % hippoboscids flies. Lice included Degeeriella carruthi , Colpocephalum subzerafae , and Laemobothrion spp. Cimicids bugs found on one male were identified as Hesperocimex sp., a cimicid often recorded on birds that nest in cavities of the giant cardón cactus ( Pachycereus pringlei ). The prevalent louse fly was identified as the potentially pathogenic Icosta americana . All the parasites we recorded were the first records on American Kestrels in Mexico.