Alternative nest-building behavior of the Long-legged Buzzard (Buteo rufinus) and the Short-toed Eagle (Circaetus gallicus) in the Judean Foothills, and the parasitic and non-parasitic arthropod fauna in their nests

One of the most common explanations of the alternative nest-building behavior in raptors’ population is the “Ectoparasite-avoidance’’ hypothesis, which claims that switching to alternative nests each year reduces nests’ parasites that could decrease their breeding success. Our aim was to investigate this hypothesis concerning the Judean Long-legged Buzzard (Buteo rufinus) and Short-toed Eagle (Circaetus gallicus) population, in Israel. Furthermore, we also investigated whether any specific parasites for each of these raptors’ species actually exist.

Thirty-one nests of Long-legged Buzzards (LLB) and 61 nests of Shorttoed Eagles (STE) were located and systematically examined during the period of February-September 2011, in an area of 450 km2 in the Judean Foothills, Israel. Nest material samples were collected from the center of the nest of 26 LLB and 45 STE nests. Four specimens of the Mallophaga Laemobothrion maximum were isolated from three nests of LLB and one male of Degeeriella leucopleura from a nest of STE. In addition, a hard tick larva (Rhipicephalus sp.), an argasid nymph (Argas sp.) and six specimens of dermanyssid mites were  isolated from nests of STE. In 82.1% of the LLB nests, Coleoptera larvae and/or adults were found, most of them belonging to the families Scarabaeidae, Buprestidae, Elateridae and Dermestidae. In 89.8% of the STE nests, Coleoptera larvae and/or adults were found, most of them belonging to the families Buprestidae, Tenebrionidae, Curculionidae, Dermestidae, Elateridae, Coccinellidae and Chrysomelidae. The vast majority of the isolated beetles were damaged and in more or less small pieces. In addition, few specimens of silverfish (Lepismatidae), book lice (Psocidae), ants (Formicidae) and true flies (Muscidae), as well as spiders (Araneae), scorpions (Scorpionida) and pseudoscorpions (Pseudoscorpionida) were isolated from the nests of both species.

Although nest parasites were actually found, in significant small numbers, we cannot support the “ectoparasite-avoidance” hypothesis in our study system. Furthermore, no species specific ectoparasites for either LLB or STE were found.