Reducing the primary exposure risk of Henderson crakes (Zapornia atra) during aerial broadcast eradication by selecting appropriate bait colour

Research indicates that Henderson crakes (Zapornia atra), a globally threatened island endemic, are significantly less likely to consume blue bait pellets compared to green ones. This finding suggests a potential strategy to reduce non-target mortality during rat eradication efforts on Henderson Island. The study involved 22 captive Henderson crakes, which were observed over five days in 2015, with consumption measured and analyzed using linear mixed models. Results showed that females consumed 24% less blue bait than green, while males consumed 77% less. Notably, the crakes did not consume dry pellets, highlighting the importance of wet bait conditions. The study recommends using blue baits during future rat eradication to minimize exposure risk for Henderson crakes.

Oppel, S., Lavers, J. L., Bond, A. L., & Harrison, G. (2016). Reducing the primary exposure risk of Henderson crakes (Zapornia atra) during aerial broadcast eradication by selecting appropriate bait colour. Wildlife Research, 43(4), 298–303. https://doi.org/10.1071/wr15198