Mangrove Habitats in Zhanjiang of South China: A Potentially High‐Risk Environment for Breeding Birds

Nest predation is one of the most important causes of breeding failure in birds, and the risk of predation is closely related to nest site selection. To maximize site suitability, birds should choose safe locations for nest site to reduce the risk of nest predation. Mangroves and mudflats are very important feeding and wintering grounds for many birds; however, we still know little about the risk of nest predation experienced by birds breeding in mangrove habitats. From August to December 2019, we studied nest predation rates and predator types in mangroves by setting up artificial nest experiments in the Zhanjiang Mangrove National Nature Reserve in Guangdong Province, south China. The results showed that the nest predation rates in the Jiulongshan mangrove area in the reserve were substantially higher than those in the Caoyang mangrove area during the first 3 days for both the artificial nests on trees and on the ground. However, the nest predation rates were 100% for the experimental nests in both mangroves within 7 days. There were diverse predators, including the greater coucal (<i>Centropus sinensis</i>), Oriental magpie-robin (<i>Copsychus saularis</i>), white-breasted waterhen (<i>Amaurornis phoenicurus</i>), mangrove crabs (<i>Chiromantes dehaani</i>), and rats. We recorded a total of 44 nests. The predation rate of the greater coucal on the experimental nests was as high as 70.45%, while the predation rates of the mangrove crabs and rats on the experimental nests were both 20.45%. Our research indicates that birds breeding in mangrove habitats of the Zhanjiang Mangrove in south China face a relatively high risk of nest predation.