Urbanization provides novel habitats for bird species, while simultaneously posing numerous threats to them. Although several bird species have successfully adapted to urbanization, the underlying adaptation mechanisms of reproductive success remain poorly understood in rapidly urbanizing areas. To this aim, a total of 168 breeding pairs of the Chinese Blackbird (Turdus mandarinus) were monitored during the breeding season (March–July) from 2018 to 2023. We used environmental factors (including nest tree variables, and concealment variables), phenotypic characteristics of nestlings, number of nest predation events, and quantified urbanization scores to understand the impact of urbanization on breeding performance of Chinese Blackbirds. In our study, generalized linear models and structural equation modeling showed that Chinese Blackbirds tended to initiate laying earlier and lay eggs with larger volume along an increasing urbanization gradient. We also found that urbanization did not affect the growth condition of nestlings, and the predation risk was lower in more urbanized habitats. Most importantly, urbanization did not have negative consequences on the reproductive success of Chinese Blackbirds. Our results show changes in the breeding behavior of Chinese Blackbirds as they adapt to rapid urbanization and suggest that certain more urbanized areas may be suitable for the breeding of bird populations.

Nest predation is a critical driver of avian reproductive success, yet its response to urbanization remains controversial. Using infrared camera traps to monitor 133 artificial nests and 32 natural nests of the Spotted Dove (Spilopelia chinensis) along an urbanization gradient in Nanchang and Shangrao, China, from 2021 to 2023, we examined spatiotemporal variation in predation pressure. We deconstructed predation pressure into risk (nest fate and survival time) and pattern (predation frequency, predator size, and predator–nest interaction duration). We found that higher urbanization and better nest concealment significantly reduced predation risk. The composition of the predator community did not change along the urbanization gradient, suggesting that the reduced nest predation risk in cities is likely driven by behavioral factors, such as the availability of alternative food or human shield effect, rather than by the filtering of predator species. In contrast, predation patterns were primarily moderated by season. The off-peak breeding season was characterized by more frequent but less severe predation events involving smaller predators and had shorter predator–nest interaction durations compared to the peak season. This seasonal shift opens a breeding window during the off-peak season, when lethal nest predation risk is reduced. The Spotted Dove's unique life-history traits enable it to capitalize on this opportunity by balancing environmental costs, enhancing its reproductive success and facilitating its colonization of urban environments.

For migratory waterbirds, the quality of wintering habitat is related to spring migration and successful breeding in the next year. The availability of food resources in the habitat is critical and varies within water levels. Although the water-level fluctuations in Poyang Lake have been extremely variable interannually in recent years, the wintering waterbird populations have remained relatively stable. Hence, the mechanism of maintaining the stability is worth exploring. This study aimed to compare the distribution of vegetation and herbivorous waterbirds in 2015–2016 and 2016–2017, focusing on three shallow sub-lakes and one main lake are. The results showed that the emergence of tubers and the growth of Carex spp. provided a continuous food supply and habitat for wintering waterbirds with a gradual decline in the water level. Shallow sub-lakes supported almost all of the tuber-eating waterbirds (1.42–1.62 × 10⁵) and most geese (1.34–1.53 × 10⁶). However, the main lake area, covered with Persicaria hydropiper, did not provide adequate and accessible food. This resulted in almost no distribution of tuber-eating waterbirds, with only a few geese congregating in early winter. Our results demonstrated that the shallow sub-lakes under human control provided a different environment from the main lake and are key to sustaining the successful wintering of hundreds of thousands of migratory waterbirds in Poyang Lake. Therefore, we recommend refining the anthropogenic management of the shallow sub-lakes to regulate the water level to ensure the carrying capacity of Poyang Lake.