Factors associated with the geographic distribution of leucocytozoa parasitizing nestling eagle owls (Bubo bubo): a local spatial-scale analysis

Explaining variance of avian malaria infection in the wild: the importance of host density, habitat, individual life-history and oxidative stress

“…This estimate of host density did not explain patterns of Plasmodium infection in the conspecific blue tits, Cyanistes caeruleus [1]. Similar to the present study, however, a positive association was found between large-scale breeding density (i.e., measured as number of nests within a 1500 m radius) and Leucocytozoons prevalence and parasitaemia in nestling eagle owls ( Bubo bubo ) [37]. In temperate regions Plasmodium species show a bimodal peak in infection, one in autumn and one in spring, and the spring peak (measured here) is most often a relapse from the autumn infection gained in the previous year [31,38].…”

Distribution and breeding performance of a high-density Eagle OwlBubo bubopopulation in southeast Spain

“…More experienced birds may lay early to synchronize their reproduction to the breeding cycle of their principal prey, Rabbits, whose abundance peaks in early spring and summer (Aparicio & Bonal 2002, Gonçalves et al 2001. In addition, the chicks of early breeders can benefit from lower parasitism rates which are usually related to temperature (Merino & Potti 1996) and breeding density (Ortego & Espada 2007, Ortego & Cordero 2010. We found no density-dependent effect for either the laying date or for breeding performance, and a similar result has been found for other Eagle Owl populations (Marchesi et al 2002, but not all (Penteriani et al 2002).…”

High Prevalence of Leucocytozoon Parasites in Nestling Northern Goshawks (Accipiter gentilis) in the Northern Great Basin, U.S.A.

“…This intensity range and average was lower than that in other studies of nestling raptors (1-87.5, 0-75: King et al 2010, Ortego andCordero 2010). This may indicate that this population managed infections to lower levels.…”

“…Survivors of infection have immune systems capable of subduing the infection to low levels, which may still produce subtle, additive effects in combination with other stresses and infections (Remple 2004, Valkiūnas 2004, Kilpatrick et al 2006, Bensch et al 2007). Numerous studies have attempted to relate the effects of the infection to breeding success, with conflicting results (Bensch et al 2007, Ortego et al 2008, Lachish et al 2011a. Knowles et al (2009) used a meta-regression approach on selected avian studies and found increased reproductive effort (i.e., manipulated clutch size) resulted in decreased immune function and increasing parasite levels.…”

“…This photo was taken using a PupilCam microscope camera through a 1003microscope lens. above previously reported erythrocyte counts of 2000 (King et al 2010, Ortego andCordero 2010). ImageJ software was then utilized as described by Gering and Atkinson (2004) to count the total number of erythrocytes.…”