Habitat selection occurs at multiple spatial scales and affects demographic processes including reproductive success. Few studies, however, have linked multi-scale habitat selection to reproductive success. We investigated breeding habitat selection at three spatial scales (nest site, nest area and territory), and the consequences of habitat selection on reproductive success of four riverine sandbar-nesting bird species in Cambodia. All species generally selected larger habitat patches, in territories with higher proportions of bare ground substrates, including gravel and dry mud. Individuals generally selected areas with less vegetation; however, at smaller spatial scales, Small Pratincoles (Glareola lactea) and Little Ringed Plovers (Charadrius dubius) used sites with more vegetation. Vegetation generally had a negative effect on reproductive success. For River Terns (Sterna aurantia), nest success was lower in areas with a higher proportion of invasive Mimosa pigra, and chick survival decreased with vegetation height. River Lapwing (Vanellus duvaucelii) nest success decreased with more woody stems, and nest success of Small Pratincoles and Little Ringed Plovers decreased with more herbaceous vegetation. Negative effects of vegetation were likely due to reduced ability of incubating birds to detect predators, or increased cover or foraging efficiency of predators. Finally, proximity to the river channel reduced nest success; nests near the channel had a higher risk of flooding. This is the first study to identify variables associated with habitat selection for all species in this study and to relate habitat use to reproductive success. Results of this study will aid conservation efforts for these regionally threatened species.
Bibliographical noteFunding Information:
We thank our partner, the World Wildlife Fund (WWF – Cambodia country programme), especially Horm Chandet, Phan Channa, Gordon Congdon, Sok Ko, Saber Masoomi, and Gerry Ryan, for providing logistical support. Additionally, we are grateful to field assistants Trong Kam, You Bunthoeun, and Jeff Schwilk. This project would not have been possible without the support and hospitality of our network of community nest protectors. Juan Amat and an anonymous reviewer provided helpful comments that improved this manuscript. Financial support for this project was provided by the Critical Ecosystem Partnership Fund (CEPF), Conservation Sciences Graduate Program at University of Minnesota, Bell Museum of Natural History, McKinney Fellowship in Avian Ethology, and Huempfner Fellowship. Additionally, A.H.C. received support from the National Science Foundation (NSF-GRFP) and University of Minnesota Graduate School. F.J.C.’s contributions to this study were supported by the USDA National Institute of Food and Agriculture, Hatch project 1007020.
- Habitat change
- Mekong River
- Mimosa pigra
- Nest survival
- River Tern