Bird Conservation International最新文献

Migratory birds are experiencing widespread population declines, underscoring the urgency of effective conservation actions. Long-term monitoring of migratory birds, especially during migration, is crucial for such actions yet remains technically challenging. Bioacoustic monitoring of nocturnal flight calls (NFCs) constitutes a promising technique to monitor migratory birds during migration. Such monitoring has increased in North America and Europe, but its application on the East Asian–Australasian Flyway (EAAF) remains limited. Here, we present findings from an NFC monitoring project conducted at a recording station in central Beijing, China over four migration seasons. From around 3,350 hours of recording effort, we manually extracted and identified 84,135 NFCs, involving at least 111 species or species groups that are associated with a wide range of habitat types. We also found that NFCs provided additional information on species’ migration phenology in comparison with citizen science observation data. To our knowledge, this study is the first formal investigation of bird migration using NFC monitoring on the EAAF, serving as a proof-of-concept case for wider, long-term monitoring efforts in this traditionally understudied region. Our findings also highlight the significance of incorporating migratory bird conservation into urban planning and land management practices.

The endemic Little Vermilion Flycatcher (LVF) Pyrocephalus nanus has suffered a drastic decline on Santa Cruz Island, Galapagos, where it was common 30 years ago. Currently, fewer than 40 individuals remain in the last remnants of natural humid forest in the Galapagos National Park on the island. This small population has low reproductive success, which is contributing to its decline in Santa Cruz. Previous studies have identified Avian Vampire Fly Philornis downsi parasitism, changes in food sources, and habitat alteration as threats to this species. In Santa Cruz, invasive plants may strongly affect the reproductive success of LVF because they limit accessibility to prey near the ground, the preferred foraging niche of these birds. Since 2019, we restored the vegetation in seven plots of 1 ha each by removing invasive blackberry plants and other introduced plant species. In all nests that reached late incubation, we also reduced the number of Avian Vampire Fly larvae. In this study, we compared foraging and perch height, pair formation, incubation time, and reproductive success between managed and unmanaged areas. As predicted, we found significantly lower foraging height and perch height in 2021 in managed areas compared with unmanaged areas. In 2020, the daily failure rate (DFR) of nests in the egg stage did not differ between management types; however, in 2021, the DFR in the egg stage was significantly lower in managed areas than in unmanaged areas. The DFR during the nestling stage was similar between managed and unmanaged areas in 2020, but in 2021, only nests in managed areas reached the nestling stage. Females brooded significantly more during the incubation phase in managed areas. Additionally, we found significantly higher reproductive success in managed areas compared with unmanaged areas in 2021, but not in 2020. Habitat restoration is a long-term process and these findings suggest that habitat management positively affects this small population in the long term.