Short-term effects of camera trap installation on incubation constancy in cranes

Abstract

Research regarding how birds respond to the installation of cameras at nest sites is limited. We installed cameras at nests of Sandhill Cranes Antigone canadensis ( Linnaeus, 1758 ) and federally endangered Whooping Cranes Grus americana Linnaeus, 1758 in Juneau County, WI, as part of an ongoing study monitoring the reproductive success of Whooping Cranes in WI. The eastern population of Sandhill Cranes has grown, while Whooping Crane population growth has been slow, prompting the need to monitor the reproductive success of cranes on the refuge. We recorded the flight initiation distance during camera installation, the return time after camera installation, as well as measured the distance at which cameras were placed from each nest. We included temperature at camera deployment, age of nest, mode of access, ordinal date, and year in statistical regression models. We found an apparent difference in the observed flight initiation distances between the two species. Sandhill Cranes allowed researchers to approach their nests closer than Whooping Cranes prior to flushing. The post-disturbance return time was influenced by how far away the cameras were placed from the nest and the ambient temperature during camera deploy. Our study may help inform decisions regarding species response to methods and distance when deploying cameras, especially for endangered or disturbance-sensitive species.