Birds of a feather moult together: Differences in moulting distribution of four species of storm-petrels

The non-breeding period of pelagic seabirds, and particularly the moulting stage, is an important, but understudied part of their annual cycle as they are hardly accessible outside of the breeding period. Knowledge about the moulting ecology of seabirds is important to understand the challenges they face outside and within the breeding season. Here, we combined stable carbon (δ13C) and oxygen (δ18O) signatures of rectrices grown during the non-breeding period of two pairs of storm-petrel species breeding in the northern (European storm-petrel, Hydrobates pelagicus, ESP; Leach’s storm-petrel, Hydrobates leucorhous, LSP) and southern (black-bellied storm-petrel, Fregetta tropica, BBSP; Wilson’s storm-petrel, Oceanites oceanicus, WSP) hemispheres to determine differences in moulting ranges within and between species. To understand clustering patterns in δ13C and δ18O moulting signatures, we examined various variables: species, sexes, years, morphologies (feather growth rate, body mass, tarsus length, wing length) and δ15N. We found that different factors could explain the differences within and between the four species. We additionally employed a geographical distribution prediction model based on oceanic δ13C and δ18O isoscapes, combined with chlorophyll-a concentrations and observational data to predict potential moulting areas of the sampled feather type. The northern species were predicted to moult in temperate and tropical Atlantic zones. BBSP was predicted to moult on the southern hemisphere north of the Southern Ocean, while WSP was predicted to moult further North, including in the Arctic and northern Pacific. While moulting distribution can only be estimated on large geographical scales using δ13C and δ18O, validating predictive outcomes with food availability proxies and observational data may provide valuable insights into important moulting grounds. Establishing those, in turn, is important for conservation management of elusive pelagic seabirds.

Annotated Checklist of the Marine and Coastal Birds of Lebanon

The study of marine and coastal birds in the Lebanon recorded 75speciesalong the shore line of Lebanon and for a distance of 7 kms offshore.Of those species,35 are seabirdspecies, 38 marine or seawater/freshwater coastal birds, and 2waterbird specieswintering on the archipelagoes of Mina/Tripoli in North Lebanon (Grey Heron and Little Egret)with apparently much affinity to seawater in the winter season. This study highlighted 3 globally threatened species (Leach’s Storm Petrel Hydrobates leucorhoa [Vulnerable], Mediterranean Yelkouan Shearwater Puffinus yelkouan [Vulnerable], and Dalmatian Pelican Pelecanus crispus [Vulnerable]), underlined7 globally Near Threatened avian species, pointed out to 3 species that may be submitted for reconsideration bythe “Lebanon Bird Record Committee” (LBRC) at LCNRS;and updated the data of 9species of high significance from the past studies, of which, 2 species are upgraded from vagrants to winter visitors/passage migrants, one to passage migrant and one to wintervisitor..Regarding the final phenological statusesof species, one is resident breeding, one is summer breeding, 3 are formerly bred, one extirpated (extinct) from Lebanon 31are passage migrant/winter visitors, 25passage migrantsonly, 2winter visitors and 14vagrant species.

Olfactory receptor subgenome and expression in a highly olfactory procellariiform seabird

Procellariiform seabirds are known for their well-developed olfactory capabilities, reflected by their large olfactory bulb to brain ratio and olfactory-mediated behaviors. Many species in this clade use olfactory cues for foraging and navigation, and some species can recognize individual-specific odors. Their genomes and transcriptomes may yield important clues about how the olfactory receptor (OR) subgenome was shaped by natural and sexual selection. In this study, we assembled a high-quality Leach’s storm petrel (Oceanodroma leucorhoa) genome to facilitate characterization of the OR repertoire. We also surveyed expressed OR genes through transcriptome analysis of the olfactory epithelium - to our knowledge, the first avian study to interrogate OR diversity in this way. We detected a large number (∼61) of intact OR genes, and identified OR genes under positive selection. In addition, we estimated that this species has the lowest proportion (∼60%) of pseudogenes compared to other waterbirds studied thus far. We show that the traditional annotation-based genome mining method underestimates OR gene number (214) as compared to copy number analysis using depth-of-coverage analysis, which estimated a total of 492 OR genes. By examining OR expression pattern in this species, we identified highly expressed OR genes, and OR genes that were differentially expressed between age groups, providing valuable insight into the development of olfactory capabilities in this and other avian species. Our genomic evidence is consistent with the Leach’s storm petrel’s well-developed olfactory sense, a key sensory foundation for its pelagic lifestyle and behavioral ecology.