Captive Care and Treatment of Brodifacoum Toxicosis in a Vulnerable Shorebird, the Bristle-Thighed Curlew (Numenius tahitiensis), During a 2011 Rat Eradication Project, Palmyra Atoll
1Seattle Aquarium, Seattle, WA, USA; 2The Honolulu Zoo, Honolulu, HI, USA; 3USGS National Wildlife Health Center, Honolulu Field Station, Honolulu, HI, USA; 4Island Conservation, Hawai’i Program Office, Honolulu, HI, USA
During the 2011 Palmyra Atoll rat eradication project, a vulnerable shorebird, the bristle-thighed curlew (Numenius tahitiensis) (n=16), was captured and held in captivity as an attempt to reduce non-target mortality. Blood values (PCV, TP, cholesterol, triglycerides, albumin, calcium, uric acid, non-esterified fatty acids, and beta-hydroxybutyrate) were analyzed at capture and at 2 wk post captivity to evaluate the physiologic response to capture/captivity related stress and no statistically significant differences were found between time points or birds (p<0.05). A subset of birds were captured post bait application and with rodenticide (brodifacoum) bait in their crops and/or signs of bait stains around their cloaca. These birds were treated successfully with oral vitamin K during captivity and all were resighted >3 mo post-release. A novel avian ophthalmic trematode fluke was also discovered which caused clinical disease in captive birds. To the authors knowledge this is the first successful capture and captive maintenance of a shorebird species to reduce non-target mortality during a rat eradication project. Additionally, this is the first documentation of long-term survival of an avian species post-exposure to brodifacoum.
The authors thank Kate Stadler of The Nature Conservancy for her generous support of the researchers on this project.
1. Dowding JE, Murphy EC, Veitch CR. Brodifacoum residues in target and non-target species following an aerial poisoning operation on Motuihe Island, Hauraki Gulf, New Zealand. N Z J Ecol. 1999;2:207–214.
2. Eason CT, Murphy EC, Wright GRG, Spurr EB. Assessment of risks of brodifacoum to non-target birds and mammals in New Zealand. Ecotoxicology. 2002;11:35–48.
3. Howald G, Donlan CJ, Galvan JP, Russell JC, Parkes J, Samaniego A, Wang Y, Veitch D, Genovesi P, Pascal M, Saunders A, Tershy B. Invasive rodent eradication on islands. Conserv Biol. 2007;21:1258–1268.