Understanding spatial distribution patterns is a key component in predicting community structural changes and preserving biodiversity. Within the subtropical forest ecosystems of China, the spatial interrelations between raptors and pheasants, and their respective roles and functions in community structures, remain inadequately studied. Through niche modeling, we examined the spatial distribution relationships between three large raptor species—the Black Eagle (Ictinaetus malaiensis), the Black Kite (Milvus migrans), and the Crested Serpent Eagle (Spilornis cheela) and three prevalent pheasant species—the Silver Pheasant (Lophura nycthemera), the Common Pheasant (Phasianus colchicus), and Elliot’s Pheasant (Syrmaticus ellioti). The results showed that the Black Eagle and Elliot’s Pheasant displayed localized distribution patterns, the Black Kite and Silver Pheasant demonstrated widespread distribution, and the Crested Serpent Eagle and Common Pheasant exhibited broader patchy distributions. Significant differences were observed in the potential suitable habitat areas among the raptor species pairs, with the Black Kite having the largest potential suitable habitat area and the Black Eagle the smallest. While the habitat area differences between the Silver Pheasant and Elliot’s Pheasant were not significant, both species significantly exceeded the Common Pheasant in potential suitable habitat area. The Silver Pheasant held the largest area within the raptors’ potential suitable habitat, and the Black Kite dominated within the pheasants’ habitats. These results indicated a higher sensitivity of the Black Eagle and Crested Serpent Eagle to human disturbances and potential coexistence among the pheasant species through spatial niche differentiation. The distribution patterns underscored the spatial interplay between raptors and pheasants, unveiling their individual survival strategies and functional roles within the ecosystem. This study offers insights into the ecological processes behind species distribution patterns.
Rat control using anticoagulant rodenticides on livestock farms is a widely applied practice worldwide. Birds can be exposed to rodenticides through direct ingestion or secondary poisoning, resulting in mortality or sublethal health effects. While impacts on raptors and owls are well documented, potential effects on songbird communities in farmland settings have received limited empirical investigation. To address this gap, avifaunal surveys were conducted on 12 livestock farms in the Münsterland, Germany, during 2021–2022, comparing farms with and without rodenticide application to assess impacts on songbird and farmland bird communities. In addition, farm structures, such as the proportions of grassed areas and buildings, were quantified using spatial analysis (linear mixed-effects model). Farm structure showed patterns in bird abundance and community composition, with the proportion of buildings and grassed area showing the most notable associations with bird abundance and ground-nesting species respectively. Rodenticide application showed possible associations with the number of individual birds. However, none of those patterns reached statistical significance, and causal mechanisms remain unclear due to the observational design. Larger-scale studies are needed to assess population-level consequences and optimize rodenticide use alongside habitat management.
The Western House Martin Delichon urbicum is a trans-Saharan migrant whose Iberian winter distribution is concentrated mainly in southern and coastal areas. We document repeated winter occurrence and roost use at the Almirante Sarmento Rodrigues bridge in Barca d'Alva, north-eastern Portugal, approximately 200 km from the Atlantic coast. Five opportunistic fixed-point surveys were conducted between November 2021 and January 2022. Birds were recorded on five dates, with a maximum of 20 individuals on 6 December, and repeatedly entered cavities and old nests beneath the bridge during late-afternoon visits. Repeated presence over nearly two months, before the expected spring arrival period, strongly indicates local winter occupancy, although intermittent surveys and the absence of marked birds preclude confirmation that the same individuals remained continuously. The site lies in a sheltered, sun-exposed gorge within the thermomediterranean bioclimatic belt, where favourable foraging conditions and protected bridge cavities may facilitate winter persistence. This single-site observation cannot establish a causal relationship with climate change. Continued standardised monitoring, complemented by citizen-science data, is required to determine whether the event is exceptional or part of an emerging redistribution of wintering ranges.
Plumage anomalies in owls range from common color polymorphisms to rare, extreme aberrations such as leucism, albinism, and melanism, yet systematic syntheses across taxa are scarce. In this review, we collate recent genomic, ecological, and environmental research (2017–2025) on owl plumage anomalies and combine it with new field observations from Israel to examine how depigmentation and hyperpigmentation arise and what their ecological consequences may be. We highlight the exceptional rarity of familial leucism by presenting a brood of Eurasian Eagle Owls (Bubo bubo) from Mount Gilboa containing two Ino and one normally colored fledgling—the first family-level record in this species and only the second wild case of extreme depigmentation in Eurasian Eagle Owls following a leucistic fledgling reported in Spain. We complement this with another sporadic color anomaly in a Little Owl (Athene noctua) from the Galilee and one from Shoham, Central Israel, both exhibiting unusually dark plumage with reduced pale spotting. Together, these records illustrate that owls may show pronounced reductions or alterations in melanin-based plumage coloration. However, the underlying mechanisms—including possible melanin-synthesis defects, altered melanin deposition, and external staining—cannot always be determined from photographs or opportunistic observations alone. By integrating these examples with broader evidence on climate, habitat, diet, and urbanization as drivers of plumage variation, we argue that rare pigment anomalies, although individually exceptional, provide disproportionate insight into camouflage, signaling, fitness, and potential bioindicator roles in owl populations facing rapid environmental change.
Understanding how historical climatic oscillations and contemporary dispersal interact to shape genetic diversity is central to interpreting population structure in long-distance migratory birds. The White Stork (Ciconia ciconia) has a broad trans-Eurasian distribution, yet populations from the Caucasus region remain underrepresented in population genetic studies. Here, we investigate mitochondrial and nuclear genetic variation in breeding populations from Armenia, a region located at the junction of Europe and Southwest Asia. We analyzed sequence variation in the mitochondrial control region and COI gene together with a nuclear intron (SPIN) from 102 individuals sampled across northern, central, and southern Armenia and integrated these data with publicly available Eurasian sequences. Genetic diversity indices, haplotype networks, mismatch distributions, and hierarchical analyses of molecular variance were used to evaluate spatial genetic structure and demographic history. Armenian populations exhibited high mitochondrial haplotype diversity but heterogeneous nucleotide diversity, consistent with complex demographic histories. AMOVA revealed no significant genetic differentiation among Armenian populations (FST = 0.019, p = 0.226) or between Armenia and Europe (FCT = −0.021, p = 0.754), indicating that Armenian breeding populations form part of a single, well-connected Western Palearctic mitochondrial gene pool. Mismatch distributions revealed a consistent secondary peak across all three populations, suggesting demographic complexity that may reflect the retention of older mitochondrial lineage diversity, though this interpretation remains tentative given the limited discriminatory power of mismatch analyses alone and requires confirmation through expanded sampling and complete mitogenome sequencing. These results indicate that Armenian White Stork populations are genetically diverse and well-connected to the broader Western Palearctic population, while also carrying signatures of a complex demographic history potentially shaped by Pleistocene lineage divergence and post-glacial admixture. Our findings provide a regional genetic baseline for an understudied part of the species’ range and highlight the South Caucasus as a candidate area for future genomic studies integrating complete mitogenomes and genome-wide nuclear markers.
