Absence of blood parasites in nestlings of the Eleonora\u27s Falcon (Falco eleonorae)

Volume: 36Start Page: 139End Page: 14

Variation in haematozoan parasitism at local and landscape levels in the red-billed quelea Quelea quelea

The red-billed quelea Quelea quelea, one of the most abundant birds in the world, presents two fundamental conundrums that we investigate here with a novel approach using blood parasite assemblages at two spatial scales, landscape and individual. The quelea of southern Africa Q. q. lathamii are split by a hypothesized migratory divide, where birds follow rain fronts in one of two directions (NW or SE). This divide is not detectable in the host population using microsatellite data, and here we show that it is also not apparent from our large-scale phylogeographical analyses of the haematozoan parasite. At a finer scale, the colourful and variable breeding plumage of male red-billed quelea has not previously shown a correlation with predictors of quality, as it does in many other bird species. The male’s breeding plumage is partially based on carotenoid colouration, the quality of which has been correlated with haematozoan infection in other bird species. However, we found no correlation between intensity of male carotenoid colouration and haematozoan infection. Our results do not contradict the hypothesis that male breeding plumage in this species serves to identify individuals rather than to indicate quality. Finally, we recovered the greatest number of haematozoan lineages from any phylogenetic survey of a single host species to date. Understanding the reasons for the extreme diversity of parasite lineages in this species may assist in explaining the success of the red-billed quelea in anthropogenic landscapes

Research priorities for seabirds: improving conservation and management in the 21st century

Seabirds are facing a growing number of threats in both terrestrial and marine habitats, and many populations have experienced dramatic changes over past decades. Years of seabird research have improved our understanding of seabird populations and provided a broader understanding of marine ecological processes. In an effort to encourage future research and guide seabird conservation science, seabird researchers from 9 nations identified the 20 highest priority research questions and organized these into 6 general categories: (1) population dynamics, (2) spatial ecology, (3) tropho-dynamics, (4) fisheries interactions, (5) response to global change, and (6) management of anthropogenic impacts (focusing on invasive species, contaminants and protected areas). For each category, we provide an assessment of the current approaches, challenges and future directions. While this is not an exhaustive list of all research needed to address the myriad conservation challenges seabirds face, the results of this effort represent an important synthesis of current expert opinion across sub-disciplines within seabird ecology. As this synthesis highlights, research, in conjunction with direct management, education, and community engagement, can play an important role in facilitating the conservation and management of seabird populations and of the ocean ecosystems on which they and we depend

Reduced blood parasite prevalence with age in the Seychelles Warbler: selective mortality or suppression of infection?

Avian malaria can affect survival and reproduction of their hosts. Two patterns commonly observed in birds are that females have a higher prevalence of malaria than do males and that prevalence decreases with age. The mechanisms behind these patterns remain unclear. However, most studies on blood parasite infections are based on cross-sectional analyses of prevalence, ignoring malaria related mortality and individual changes in infection. Here, we analyse both within-individual changes in malaria prevalence and long-term survival consequences of infection in the Seychelles Warbler (Acrocephalus sechellensis). Adults were less likely to be infected than juveniles but, contrary to broad patterns previously reported in birds, females were less likely to be infected than males. We show by screening individual birds in two subsequent years that the decline with age is a result both of individual suppression of infection and selective mortality. Birds that were infected early in life had a lower survival rate compared to uninfected birds, but among those that survived to be screened twice the proportion of infected birds had also decreased. Uninfected birds did not become infected later in life. Males were found to be more infected than females in this species possibly because, unlike most birds, males are the dispersing sex and the cost of dispersal may have to be traded against immunity. Infected males took longer to suppress their infection than did females. We conclude that these infections are indeed costly, and that age-related patterns in blood parasite prevalence are influenced both by suppression and selective mortality.