Distinguishing local and global correlates of population change in migratory species

Exploring the conservation of historic avian corridors under urbanization threats in China: A case study of egrets in the Greater Bay Area

This study explores the conservation of historic flyway corridors for egret in the Greater Bay Area (GBA), with a focus on habitat connectivity and dynamic corridors. To address the gaps in previous research, we used field observations, bio-climatic data and landcover information spanning three decades. Our approach involves MaxENT modeling and the Linkage Mapper method. The results showed that the MaxENT model effectively simulated the egret habitats at different levels, with coastlines and riverbanks emerging as primary habitat zones. Moreover, bio-climatic factors, particularly Bio 19 and Bio 8, played a dominant role, accounting for 90 % of the habitat suitability in 2020. Other factors contributed rather minimally. Through the utilization of resistance surface and corridor extraction methods, noteworthy alterations in the flyway networks emerged post-2000, followed by a gradual return to normal. Connectivity analyses highlighted a critical 30 km threshold for the egret preservation. Corridor widths should be determined based on cost-effective considerations. We conclude that combining MaxENT with the Linkage Mapper method, even with limited egret observations and integrating multi-source data, such as land cover, might simulate potential suitable habitats and flyway dynamics for waterbirds such as egrets. This study provides valuable insights for the egret conservation and the preservation of their habitats in the GBA, contributing to a global waterbird diversity and habitat quality.

Structure and Phylogenetic Relationships of Scolopacidae Mitogenomes (Charadriiformes: Scolopacidae)

The family Scolopacidae presents a valuable subject for evolutionary research; however, molecular studies of Scolopacidae are still relatively understudied, and the phylogenetic relationships of certain species remain unclear. In this study, we sequenced and obtained complete mitochondrial DNA (mtDNA) from Actitis hypoleucos and partial mtDNA from Numenius arquata, Limosa limosa, and Limnodromus semipalmatus. The complete mtDNA contained 13 protein-coding genes (PCGs), two ribosomal RNA genes, 22 tRNA genes, and a control region. Scolopacidae contained three types of start codons and five types of stop codons (including one incomplete stop codon, T--). In 13 protein-coding genes, average uncorrected pairwise distances (Aupd) revealed that ATP8 was the least conserved while COX3 had the lowest evolutionary rate. The ratio of Ka/Ks suggested that all PCGs were under purifying selection. Using two methods (maximum likelihood and Bayesian inference) to analyze the phylogenetic relationships of the family Scolopacidae, it was found that the genera Xenus and Actitis were clustered into another sister group, while the genus Phalaropus is more closely related to the genus Tringa. The genera Limnodromus, Gallinago, and Scolopax form a monophyletic group. This study improves our understanding of the evolutionary patterns and phylogenetic relationships of the family Scolopacidae.

The complete mitochondrial genome of Eastern Curlew Numenius madagascariensis (Charadriiformes, Scolopacidae)

The complete mitochondrial genome of Numenius madagascariensis Linnaeus, 1766 was sequenced in this study. The circular mitogenomes was 17,147 bp in length, containing 13 protein-coding genes, two ribosomal RNAs (12S rRNA and 16S rRNA), 22 transfer RNA genes, and a D-loop region. The overall nucleotide composition was A: 31.0%, T: 25.6%, C: 29.5%, and G: 13.9%. Twenty-eight genes were encoded on the heavy strand, while the remaining nine genes were encoded on the light strand. The common start codon was ATG, and three stop codons and an incomplete stop codon (T–) were used in PCGs. This study improves our comprehension of the mitogenomic characteristics and its phylogenetic relationships within Scolopacidae.