Low prevalence of blood parasites in a long-distance migratory raptor: the importance of the host habitat

Background The low prevalence of blood parasites in some bird species may be related to the habitats they frequent, the inexistence of the right host-parasite assemblage or the immunological capacity of the host. Here, we assess the parasite load of breeding populations of Eleonora's falcon (Falco eleonorae), a medium-sized long-distance migratory raptor that breeds on small isolated islets throughout the Mediterranean basin and overwinters in inland Madagascar. Methods We examined the prevalence and genetic diversity of the blood parasites belonging to the genera Plasmodium, Haemoproteus and Leucocytozoon in Eleonora's falcon nestlings from five colonies and in adults from two colonies from nesting sites distributed throughout most of the species' breeding range. Results None of the 282 nestlings analysed were infected by blood parasites; on the other hand, the lineages of Plasmodium, Haemoproteus and Leucocytozoon were all found to infect adults. Our results support the idea of no local transmission of vector-borne parasites in marine habitats. Adult Eleonora's falcons thus may be infected by parasites when on migration or in their wintering areas. Conclusion The characteristics of marine environments with a lack of appropriate vectors may thus be the key factor determining the absence of local transmission of blood parasites. By comparing the parasite lineages isolated in this species with those previously found in other birds we were able to infer the most likely areas for the transmission of the various parasite lineages

Low prevalence of blood parasites in a long-distance migratory raptor: the importance of host habitat

Background: The low prevalence of blood parasites in some bird species may be related to the habitats they frequent, the inexistence of the right host-parasite assemblage or the immunological capacity of the host. Here, we assess the parasite load of breeding populations of Eleonora’s falcon (Falco eleonorae), a medium-sized long-distance migratory raptor that breeds on small isolated islets throughout the Mediterranean basin and overwinters in inland Madagascar. Methods: We examined the prevalence and genetic diversity of the blood parasites belonging to the genera Plasmodium, Haemoproteus and Leucocytozoon in Eleonora’s falcon nestlings from five colonies and in adults from two colonies from nesting sites distributed throughout most of the species’ breeding range. Results: None of the 282 nestlings analysed were infected by blood parasites; on the other hand, the lineages of Plasmodium, Haemoproteus and Leucocytozoon were all found to infect adults. Our results support the idea of no local transmission of vector-borne parasites in marine habitats. Adult Eleonora’s falcons thus may be infected by parasites when on migration or in their wintering areas. Conclusion: The characteristics of marine environments with a lack of appropriate vectors may thus be the key factor determining the absence of local transmission of blood parasites. By comparing the parasite lineages isolated in this species with those previously found in other birds we were able to infer the most likely areas for the transmission of the various parasite lineages.This study was partially supported by the Cabildo de Lanzarote, the project CGL2012-30759 from the Spanish Ministry of Economy and Competitiveness and through the Severo Ochoa Programme for Centres of Excellence in R&D&I (SEV-2012-0262). RGL was supported by a FPI grant, JMP and PLL by the Juan de la Cierva program, and LG by a contract from the Excellence Projects from the Junta de Andalucía (RNM-6400). JM was supported by an International Outgoing Fellowship (FP7-PEOPLE-2010). BS was supported by the Algerian Ministère de l’Enseignement Supérieur et de la Recherche Scientifique (DGRSDT/M.E.S.R.S.) and a Distinguished Scientist Fellowship Program from King Saud University, Saudi Arabia. The Hellenic Ornithological Society and A.G. Leventis Foundation financed the fieldwork in Greece

Composition and Distribution on a Host of Avian Lice of White Storks in North-Eastern Algeria

The diversity and spatial distribution of ectoparasites of a large colony of white stork Ciconia ciconia at Dréan, in north-eastern Algeria, were investigated during two consecutive breeding seasons. The results indicated that nestlings were infested by the following four louse species: Colpocephalum zebra (Burmeister, 1838), Neophilopterus incompletus (Denny, 1842), Ardeicola ciconiae (Linnaeus, 1758), and Ciconiphilus quadripustulatus (Burmeister, 1838). Overall, the distribution of chewing lice exhibited a clustered distribution, with C. zebra being the most frequent species, with a prevalence of 39.6% and 41.0% in 2011 and 2012, respectively. Our results also suggested niche partitioning among the four louse species within the host’s body parts. A generalized additive model indicated that size, sex, and year influenced the abundance of ectoparasites; the abundance of chewing lice increased with the size of the host and was greater in females, as well as in the first year of study. Further studies are needed to explore the spatio-temporal variability in white storks’ lice infestations

Diet of breeding Eleonora's falcon Falco eleonorae in Algeria: Insights for the autumn trans‐Mediterranean avian migration

Abstract How environmental changes are affecting bird population dynamics is one of the most challenging conservation issues. Dietary studies of top avian predators could offer scope to monitor anthropogenic drivers of ecosystem changes. We investigated the diet of breeding Eleonora's falcon in an area of Northeastern Algeria in the years 2010–2012. Feathers and insect remains originating from prey plucking behavior were analyzed, providing insights into the seasonally changing diet of this raptor, as well as the trans‐Mediterranean avian migration. A total of 77 species of birds (16 Sylviidae, 11 Turdidae, and 4 Emberizidae), 3 species of insects, and 1 lizard were identified among prey remains, reflecting a diverse diet. Diet composition and prey abundance varied seasonally, faithfully correlating with the passage of migrant birds as recorded from bird ring recoveries. Our findings suggest that dietary studies of predators might be deployed to investigate changes in bird migration. We discuss our results in the context of trans‐Mediterranean migration, with early‐season prey mainly comprising trans‐Saharan migrants (Apus apus and Merops apiaster) and late‐season prey being dominated by Mediterranean winter migrants (Erithacus rubecula, Turdus philomelos, Sylvia atricapilla, and Sturnus vulgaris). Notably, we observed a significant reduction in species richness of passerine remains in 2012, potentially highlighting a decline in the diversity of avian migrants

To Flee or Not to Flee: How Age, Reproductive Phase, and Mate Presence Affect White Stork Flight Decisions

Recognizing, assessing, and responding to threats is critical for survival in the wild. Birds, especially in their role as parents, must decide whether to flee or delay flight when threatened. This study examines how age, reproductive stage, and the presence of a mate influence flight initiation distance (FID) and nest recess duration in white storks. Analyzing the data with a generalized additive mixed model (GAMM), we found significant correlations between FID and age, reproductive stage, and presence of a mate. These results suggest that the trade-off between current and future reproduction shifts during critical breeding periods, such as incubation and nestling care. To increase breeding success, White Storks appear willing to take risks and extend their stay in the nest when offspring are most valuable and vulnerable. In the presence of a mate, individuals leave the nest earlier, suggesting possible sexual conflict over parental care. The duration of nest abandonment is consistent with FID, except for age. These results illustrate how parental age, brood value, vulnerability, and sexual dynamics influence white stork flight decisions in complex ways. Understanding these dynamics enriches our knowledge of bird behavior and adaptations to environmental challenges and highlights the complexity of parental decision making