Nest-site selection by Common Green Magpie (Cissa chinensis) in a tropical dry evergreen forest, northeast Thailand

The Common Green Magpie (Cissa chinensis) is a nest predator in tropical evergreen forests of Indomalaya and is likely impacting the reproductive success of other birds nesting in areas where it occurs. We studied the Common Green Magpie's nest-site selection in northeastern Thailand between March and July 2015. We actively searched for Common Green Magpie nests, recorded and compared vegetation variables such as vegetation cover and stem density at 32 nest sites with 64 randomly selected non-nest sites, and modeled nest-site selection using generalized linear models. The results indicated that vegetation cover (at heights 1-3 m, >3-5 m, and >5-7 m) and stem density (at heights >3-5 m and >5-7 m) were significantly greater at nest sites than at random sites. The GLM analysis indicated that vegetation cover at >5-7 m and stem density at >7 m were the most important vegetation variables influencing nest site selection by these magpies. Choice of sites with greater vegetation cover and stem density may be an anti-predator strategy that reduces nest predation risks and protects eggs and nestlings from harsh weather. Our findings add to our understanding of the ecology of a major nest predator in Asian tropical forests.