Prevalence of Trichomonas Gallinae in Northern Goshawks From the Berlin Area of Northeastern Germany

Abstract

In recent years, the northern goshawk (Accipiter gentilis) has colonized suburban and urban areas in Berlin, Germany, and elsewhere in Europe. Because of the high proportion of feral pigeons (Columba livia f. domestica) in their diet, urban goshawks are suspected to have a high infection rate with Trichomonas gallinae. Therefore, from 1998 to 2001, we examined 269 nestlings from 90 nests for infection with T. gallinae by culture of swabs taken from the oropharynx and checked their oropharynx for the presence of caseous lesions indicative of trichomonosis. In 80% of the nest sites (nϭ90), at least one nestling was infected. The nestling infection rate with T. gallinae was 69.7% (nϭ33) in 1998, 73.0% (nϭ89) in 1999, 55.8% (nϭ77) in 2000, and 62.9% (nϭ70) in 2001. In total, 65.1% of the northern goshawk nestlings were culture positive for T. gallinae. Prevalence increased with the age of nestlings ( 2 ϭ12.4, nϭ269, dfϭ5, Pϭ0.03) and tended to increase with brood size ( 2 ϭ9.345, nϭ269, dfϭ4, Pϭ0.053). Caseous lesions were present in 12 nestlings (4.5%), but only 10 of these were culture positive for T. gallinae. Two nestlings (0.7%) had large caseous lesions (diameterϾ1 cm) characteristic of late-stage trichomonosis and died shortly after examination. It is suggested that the combination of a high prevalence of T. gallinae with a low rate of pathologicic changes is the result of an evolutionaryadapted parasite-host relationship.

Health of an ex situ population of raptors (Falconiformes and Strigiformes) in Mexico: diagnosis of internal parasites

“…Nevertheless, affected birds may have good physical condition, and after the appropriate treatment, lesions disappear (Real et al 2000, Jones 2006). Capillariasis, candidiasis, hypovitaminosis A and bacterial abscesses may also cause oral lesions, similar to those of trichomonad infections, especially in the early stages (Deem 1999, Krone et al 2005, Jones 2006). Capillariasis is different from trichomoniasis and is often more extensive, with lesions in mouth, oropharynx, esophagus, crop, small intestine and cecum (Deem 1999).…”

“…However, in this study, lesions compatible with trichomoniasis were found solely in two Redtailed hawks (B. jamaicensis) newly-arrived to the CIVS. It is likely that the birds were infected upon arrival at CIVS, since in this Center birds were not fed with pigeons or other columbiforms, the main primary hosts of T. gallinae, a sarcomastigophoran protozoa (Real et al 2000, Krone et al 2005.…”

“…To study the clinical infection by T. gallinae, the oropharynx of birds were examined macroscopically, for presence of white and caseous lesions, or stomatitis as indicator for trichomonosis (Cooper 1978, Real et al 2000, Krone et al 2005. Unfortunately, confirmatory oropharyngeal swabs could not be performed.…”

The breeding performance of raptors in urban landscapes: a review and meta-analysis

“…For example, some species have been found to have a reduced body mass in urban environments (Liker et al 2008;Dulisz et al 2016;Sprau et al 2016), thus reducing food quality for raptors. Indeed, the disease infection rate of some urban raptors is thought to be higher due to feeding largely on Feral Pigeons and other pigeon and dove species that are hosts to certain diseases, reducing nestling survival (Boal and Mannan 1999;Krone et al 2005). Interestingly, not all species that had higher clutch sizes, brood sizes or number to fledge in urban environments had a higher nest success than rural birds.…”

“…For instance, infectious diseases are thought to be prevalent in some urban-nesting raptors (e.g. Krone et al 2005) but not in others (e.g. Suri et al 2017).…”