Spatially different annual cycles but similar haemosporidian infections in distant populations of collared sand martins

Abstract

Background Populations of long-distance migratory birds experience different environments and are consequently exposed to different parasites throughout their annual cycles. Though, specific whereabouts and accompanied host-parasite interactions remain unknown for most migratory passerines. Collared sand martins (Riparia riparia) breeding in the western Palaearctic spend the nonbreeding period in Africa, but it is not yet clear whether specific populations differ in overwintering locations and whether these also result in varying infections with vector-transmitted endoparasites. Results Geolocator tracking revealed that collared sand martins from northern-central and central-eastern Europe migrate to distant nonbreeding sites in West Africa and the Lake Chad basin in central Africa, respectively. While the ranges of these populations were clearly separated throughout the year, they consistently spent up to 60% of the annual cycle in Africa. Ambient light recorded by geolocators further indicated unsheltered roosting during the nonbreeding season in Africa compared to the breeding season in Europe. We found 5–26% prevalence of haemosporidian parasites in three breeding populations and one migratory passage population that was only sampled but not tracked. In total, we identified seven Plasmodium and nine Haemoproteus lineages (incl. two and seven new lineages, respectively), the latter presumably typical for swallows (Hirundinae) hosts. 99.5% of infections had a low intensity, typical for chronic infection stages, whereas three individuals (0.5%) showed high parasitaemia typical for acute infections during spring migration and breeding. Conclusions Our study shows that blood parasite infections are common in several western Palaearctic breeding populations of collared sand martins who spent the nonbreeding season in West Africa and the lake Chad region. Due to long residency at the nonbreeding grounds blood parasite transmissions may mainly occur at host population-specific residences sites in Europe and Africa; the latter being likely facilitated by unsheltered roosting and thus high vulnerability to hematophagous insects. The rare cases of high parasitaemia during spring migration and breeding further indicates either relapses of chronic infection or primary infections which occurred shortly before migration and during breeding.

Exo-erythrocytic development of two Haemoproteus species (Haemosporida, Haemoproteidae), with description of Haemoproteus dumbbellus, a new blood parasite of bunting birds (Emberizidae)

“…According to the MalAvi database, both lineages were frequently found in D. urbicum sampled in Europe, with 371 records for hDELURB1 (out of 1101 birds tested) and 271 records for hDELURB2 (out of 1082 birds tested) (MalAvi database, last access in September 2022 ( Bensch et al, 2009 )), indicating a similar prevalence for both lineages (25%) in this bird species. Apart from D. urbicum , hDELURB2 was also found in two barn swallows Hirundo rustica ( Von Rönn et al, 2015 , Garcia-Longoria et al, 2019 ), and 10 sand martins Riparia riparia ( Ciloglu et al, 2020 ; Hahn et al, 2021 ), including one record under the lineage name hRIPRIP07, which is identical to hDELURB2 over the 478 bp section.…”

The Gap of Chad, a Dearth of Migratory Birds in the Central Sahel

“…One out of four birds remained at a single site for the entire wintering period.– Montagu's Harriers switched between one and six fixed sites during their stay in the Sahel, undertaking a southward movement in the course of the winter; consecutive sites were on average 229 km (range 10–1434 km) apart (Schlaich et al 2016, Schlaich 2019). – Sand Martins Riparia riparia from eastern Europe spent their full winter period in the surroundings of Lake Chad and the nearby Waza Logone floodplains (Szép et al 2017, Hahn et al 2021). – Red-rumped Swallows Cecropis daurica wintered between 7 and 15°N and used there, probably depending on rainfall, one or more sites (Wong et al 2022).…”

“…– Sand Martins Riparia riparia from eastern Europe spent their full winter period in the surroundings of Lake Chad and the nearby Waza Logone floodplains (Szép et al 2017, Hahn et al 2021).…”