Nest site selection and breeding ecology of the red-billed blue magpie Urocissa erythrorhyncha in central China

While knowledge on birds’ breeding ecology is essential for understanding avian adaptation and managing conservation, it is poorly studied for many species, even for some common species. The knowledge of the natural history of the red-billed blue magpie (Urocissa erythrorhyncha), a species widely distributed in China and Southeast Asia, is sketchy. Here we present detailed data of nest site selection and the breeding ecology of red-billed blue magpie in central China, and of the effects of nest predation and brood parasitism on reproductive strategies. Most nests were built on Phyllostachys sulphurea and Quercus acutissima. Breeding season ranged from March to August. The first egg was laid between early April and late July. The incubation period lasted 15 days and the nestling period, 18 days. Average clutch size was 4.6 eggs, and brood size at fledging was 3.3 young. Overall, 43.8% of nesting attempts successfully produced at least one fledged young. Nest predation and brood parasitism were the two main reasons for fledging failure, which mainly occurred after April. Correspondingly, U. erythrorhyncha showed a tendency to build nests higher up and have a smaller clutch size in late stages of the breeding season. This study provides the first reliable and comprehensive information on the reproductive parameters of U. erythrorhyncha, which will lay a foundation for further understanding this species’ biology and opens up an avenue for large-scale comparative studies of the Urocissa genus or higher-level taxa.