Migratory routes, breeding locations and multiple non-breeding sites of Common Whitethroats Curruca communis revealed by geolocators

Diversity and Population Sizes of Wintering Waterbirds in the Wetlands of the Saïss-Middle Atlas Region (North-Central Morocco): Main Survival Factors and Evaluation of Habitat Loss

Moroccan wetlands host up to half a million wintering birds and provide a stopover for tens of thousands of migrants, while they are inhabited by few nesting species. Most of this avifauna prefers to use the large coastal wetlands or reservoirs, while many species are dispersed across hundreds of small inland wetlands of various types. In this study, we monitored the wintering avifauna of 11 wetlands of the Saïss plain and its adjacent Atlas Mountains (north-center of Morocco), during six wintering seasons (2017-2018 to 2022-2023), with the objective of assessing the importance of this region as a waterbird wintering area. Using the richness of the species, we determine the bird population changes during this pentad and between the different types of wetlands (natural, human-made, and natural wetlands). During this study, we recorded 51 species, belonging to 17 families, among which exist four remarkable birds: the endangered Oxyura leucocephala, the vulnerable Aythya ferina and the near-threatened Aythya nyroca and Limosa limosa. Bird diversity is higher in human-made ecosystems than in peri-urban and natural ecosystems, while the populations' size is similar in urban and non-urban wetlands. With regard to bird conservation, these inland wetlands, mainly the small ones, are threatened by recurrent droughts and various anthropic stressors, which we describe using our observations of the two last decades (2003-2023). The loss of habitat is significant, reaching 348.5 hectares, while the impacts of reduced precipitation and temperature increase are particularly evident in the mountainous natural lakes.

Nanopore MinION Sequencing Generates a White Spot Syndrome Virus Genome from a Pooled Cloacal Swab Sample of Domestic Chickens in South Africa

White spot syndrome virus is a highly contagious pathogen affecting shrimp farming worldwide. The host range of this virus is primarily limited to crustaceans, such as shrimps, crabs, prawns, crayfish, and lobsters; however, several species of non-crustaceans, including aquatic insects, piscivorous birds, and molluscs may serve as the vectors for ecological dissemination. The present study was aimed at studying the faecal virome of domestic chickens (Gallus gallus domesticus) in Makhanda, Eastern Cape, South Africa. The cloacal swab specimens (n = 35) were collected from domestic chickens in December 2022. The cloacal swab specimens were pooled-each pool containing five cloacal swabs-for metagenomic analysis using a sequence-independent single-primer amplification protocol, followed by Nanopore MinION sequencing. While the metagenomic sequencing generated several contigs aligning with reference genomes of animal viruses, one striking observation was the presence of a White spot syndrome virus genome in one pool of cloacal swab specimens. The generated White spot syndrome virus genome was 273,795 bp in size with 88.5% genome coverage and shared 99.94% nucleotide sequence identity with a reference genome reported in China during 2018 (GenBank accession: NC_003225.3). The Neighbour-Joining tree grouped South African White spot syndrome virus genome with other White spot syndrome virus genomes reported from South East Asia. To our knowledge, this is the first report of a White spot syndrome virus genome generated from domestic chickens. The significance of White spot syndrome virus infection in domestic chickens is yet to be determined.

Common Whitethroats Curruca communis show a continuum of residency duration but a high degree of between-years site fidelity at nonbreeding grounds in Nigeria

The nonbreeding period represents a significant part of an Afro-Palearctic migratory bird's annual cycle. Decisions such as whether to remain at a single site and whether to return to it across years have important effects on aspects such as survival, future breeding success, migratory connectivity, and conservation. During this study, we color-ringed 337 common Whitethroats Curruca communis and undertook daily resightings to understand site persistence and the degree of site fidelity throughout three nonbreeding periods (November-April) in Nigeria. The probability of detecting a color-ringed Whitethroat when it was present was 0.33. Site persistence varied widely across individuals (1-165 days) and did not differ significantly with sex or year, though first-year birds remained for significantly shorter periods than adults. We believe that shorter residencies are likely due to the use of multiple stationary nonbreeding sites rather than low winter survival. A minimum of 19% of individuals returned to the study site the following year and shifted, on average, 300 m, suggesting that Whitethroats have a relatively high degree of between-years site fidelity at a very fine scale. An individual's previous residency duration did not seem to determine its residency duration the following year. We suggest that spatial fidelity is high and constant through years, but temporal fidelity is not, and individual residency patterns vary, probably according to yearly and seasonal conditions. Our results highlight the complexity of the annual cycle of a single species and the importance of carrying out in situ, fine-scale research throughout a migrant's annual cycle over several years.