Search Results (5)

The Yancheng coastal wetlands serve as a crucial stopover site along the East Asian–Australasian Flyway. The rapid expansion of aquaculture has led to a significant decline in natural wetlands, impacting both the distribution and quality of waterbird habitats. Following the designation of the region as a World Natural Heritage site in 2019, the local government has prioritized the protection of waterbird habitats, leading to the large-scale withdrawal of aquaculture from the region. Nevertheless, the impact of the fishing withdrawal on waterbird habitat selection and the ecological benefits it brought remain unknown. In this study, based on the identification of fishing withdrawal zones in the Yancheng coastal area, six waterbird groups, Anatidae, Ardeidae, Charadriiformes, Laridae, Gruidae and Ciconiidae, were selected to construct an evaluation index system for habitat suitability. The Biomod2 ensemble model was employed to analyze the spatial differences of suitable habitats for waterbirds within the fishing withdrawal zones. The result revealed the following: (1) As of 2022, the area of fishing withdrawal zones had reached 2.23 × 10⁴ ha, primarily distributed in Beihuan and Nanhuan. Among these, the area of fishing withdrawal zones in Nanhuan was the largest, reaching 6.78 × 10³ ha. (2) Unsuitable area for waterbirds was largest in the fishing withdrawal zones, with a proportion of 60% and 58% for Gruidae and Ciconiidae, respectively. (3) The rich nutrients, high coverage and tall stature of emergent vegetation in the fishing withdrawal zones led to a reduction in water surface area, resulting in significant adverse effects on the suitable habitats for Charadriiformes and Gruidae. Therefore, the results suggest that most areas after fishing withdrawal were still not suitable habitats for waterbirds. The implementation of scientific fishing withdrawal practices, along with ecological restoration and management, is crucial for improving the habitat suitability in fishing withdrawal zones. This study provides valuable insights for more purposeful selection of fishing withdrawal sites, and more scientific management and restoration of these areas to enhance their ecological benefits. Full article

The retinal structure is generally conserved across vertebrates; however, variations occur due to the relationship between environmental factors and visual perception. Birds have adapted to diverse ecological contexts, evolving specialized visual characteristics. In this study, we examined the retina of Audouin’s Gull (Larus audouinii) using light and transmission electron microscopy. This species is particularly intriguing as it is considered an outlier within the Laridae family: despite being a diurnal bird, it exhibits nocturnal/crepuscular foraging behaviour. Our analysis revealed a retina well adapted for diurnal activity, with features such as a retinal thickness comparable to that of other diurnal birds, a well-developed retinal pigment epithelium, and a high cone-to-rod density ratio. However, we also observed characteristics aligned with nocturnal or crepuscular activity, including a slightly increased rod density in central regions and the presence of two distinct types of horizontal cells in the inner nuclear layer. Additionally, the inner retina showed evidence of complex visual processing. These findings suggest that Audouin’s Gull is an excellent model for visual ecology studies due to its specialized adaptations. Full article

The cosmopolitan genus Streptocara Railliet, Henry and Sisoff, 1912 (Nematoda: Acuariidae) comprises parasites of the upper alimentary tract of aquatic and, rarely, terrestrial birds. Two species of the genus Streptocara are redescribed from Bulgaria by means of light and scanning electron microscopy: Streptocara crassicauda (Creplin, 1829), based on specimens from Larus genei, Larus minutus (Laridae) and Aythya ferina (Anatidae), and Streptocara recta (von Linstow, 1879) from Podiceps nigricollis (Podicipedidae). This is the first record of S. recta from Bulgaria. The host and distribution records of the species of the genus Streptocara are reviewed. Six species are recognised as valid. Streptocara crassicauda (Creplin, 1829), S. californica (Gedoelst, 1919), S. formosensis Sugimoto, 1930 and S. incognita Gibson, 1968, seem to be parasites well-adapted to birds of the family Anatidae (Anseriformes) and occasionally found in other birds, whereas S. recta (von Linstow, 1879) and S. longispiculata Gibson, 1968, are specialists of Podicipediformes and Gaviiformes, respectively. Streptocara indica Fotedar and Chishti, 1974, is recognised as a junior synonym of S. crassicauda, and Schistogendra oligopapillata Zhang and An, 2002, is considered as a junior synonym of Streptocara formosensis Sugimoto, 1930. An identification key to the species of the genus Streptocara is proposed. Full article

Campylobacteriosis is the most common gastrointestinal bacterial disease in the European Union (EU). Wild birds are one of the natural reservoirs of these pathogens. In this study we tested cloacal swabs of 643 gulls captured on rubbish tip in Zagreb, Croatia for the presence of Campylobacter spp. and found 168 Campylobacter positive samples. We used multilocus sequence typing (MLST) to genotype 62 random C. jejuni isolates from gulls, 24 isolates from broiler caeca, 27 isolates from broiler neck skins and 23 human isolates. Altogether, we identified 44 different STs, from which 19 were newly described. Most of the new STs (14) originate from gulls. Although humans and broilers share the majority of STs and isolates from gulls are separated from these, there was one ST present in all three hosts: 45. Additionally antimicrobial susceptibility to six antimicrobials was performed on 123 C. jejuni strains isolated from broiler caeca (n = 22), neck skins of broilers (n = 20), gulls cloacal swabs (n = 50) and human faeces (n = 31) by the broth microdilution method. Results show lower resistance of gull isolates to NAL and CIP, while resistance to TET was as high as in human and broiler isolates. Full article

Domestic cats have a cosmopolitan distribution, commonly residing in urban, suburban and peri-urban environments that are also critical for biodiversity conservation. This study describes the impact of a desexed, free-roaming cat on the behavior of a threatened coastal seabird, the Australian Fairy Tern, Sternula nereis nereis, in Mandurah, south-western Australia. Wildlife cameras and direct observations of cat incursions into the tern colony at night, decapitated carcasses of adult terns, dead, injured or missing tern chicks, and cat tracks and scats around the colony provided strong evidence of cat predation, which led to an initial change in nesting behavior and, ultimately, colony abandonment and the reproductive failure of 111 nests. The death of six breeding terns from the population was a considerable loss for this threatened species and had the potential to limit population growth. This study highlights the significant negative impacts of free-roaming cats on wildlife and the need for monitoring and controlling cats at sites managed for species conservation. It also provides strong evidence against the practice of trap-neuter-release programs and demonstrates that desexed cats can continue to negatively impact wildlife post-release directly through predation, but also indirectly through fundamental changes in prey behavior and a reduction in parental care. Full article