LAUSR

Raptors are common hosts of ectoparasites such as bedbugs, mites, and blood-sucking flies (Bequaert 1955, Hansell 2000, Gonzales-Acuña et al. 2008). Nestlings are particularly susceptible to parasitism in the nest (Smith 1996, de Oliveira et al. 2011). Infestation of nests by bloodsucking parasites can cause nest abandonment, poor body condition, and death, as has been reported for Great Horned Owl (Bubo virginianus) and Red-tailed Hawk (Buteo jamaicensis) nests infested by black flies (Diptera; genera Helodon and Simulium; Smith 1996, Hunter et al. 1997), and Bald Eagle (Haliaeetus leucocephalus) nests infested by Mexican chicken bug (Haematosiphon inodorus; Grubb et al. 1986). Mexican chicken bugs are hematophagous and can cause damage to their hosts (Usinger 1966, Reinhardt and Siva-Jothy 2007). These bugs have been reported in California Condors (Gymnogyps californianus), Turkey Vultures (Cathartes aura), Red-tailed Hawks, Prairie Falcons (Falco mexicanus), Great Horned Owls, Barn Owls (Tyto alba), and Golden Eagles (Aquila chrysaetos; Lee 1954, Wilson and Oliver 1978, Grubb et al. 1986, Kochert et al. 2002). However, more information is needed on ectoparasite prevalence in bird hosts in different ecosystems and environmental conditions to understand their effects on population dynamics. This information is crucial for the conservation of threatened species such as the Golden Eagle. In Mexico, no information on ectoparasites or the effects of parasitism on nestling survival has been reported for Golden Eagles. Here we present information on infestations of Mexican chicken bugs at Golden Eagle nests located north of Chihuahua, México. While monitoring Golden Eagle nests to document diet and productivity, we found two eagle nests where young were parasitized by Mexican chicken bugs. Both nests were built on cliff ledges (height .30 m). Nests N1 and N2 were 24 m and 14 m aboveground, respectively. N1 contained a large number of Mexican chicken bugs, which indirectly caused the death of a nestling approximately 7 wk old. We had placed a camera near the nest to monitor nesting activities. The last image showing the nestling was taken on 9 May 2016 at 2314 H. On 14 May, we visited the nest area and did not observe the nestling in the nest. We found the nestling’s carcass on the ground under the nest (approximately 5 d after death). We deduced that the nestling died soon after the image was taken on 9 May. Because of its age, the nestling was incapable of flight. The carcass showed serious trauma to the skull, fractures to the cervical vertebrae, humerus, ulna and tibia; the cause of death was the fall. On our initial examination of the carcass on 14 May we found Mexican chicken bugs and larvae of dipterans. Later, during the necropsy, we collected 478 nymphs and 63 adult Mexican chicken bugs. These bugs were likely on the body of the nestling eagle at the time of the fall and remained there 5 d until the body was found. On 16 May, we descended to the Golden Eagle nest (N1) to collect prey remains. After 2 min of observing the nest, we detected a large number of bugs, which began to crawl on the observer (IMY). Throughout the 25-min nest inspection, IMY was pestered and bitten by the bugs. We estimated more than 35,000 bugs in the nest (an average of 2 bugs/cm in a nest 166 cm x 106 cm). We collected a sample of bugs from the nest. At nest N2, on 2 June, we estimated 7600 Mexican chicken bugs (1 bug/cm in a nest 127 cm x 60 cm). A 10wk-old nestling successfully fledged from this nest. 1 Email address: [email protected] 2 Present address: School of Natural Resources and the Environment, University of Arizona, Tucson, AZ 85721.