Tolerance to, and Metabolism of, Fluoroacetate in the Emu

Compared with most other birds, the emu, Dromaius novaehollandiae Vieillot, has unusually high tolerance to fluoroacetate (1080). The LD*5O for emus with evolutionary exposure to fluoroacetatebearing vegetation in the south-west of Western Australia was 102 mg of 1080 per kilogram. This tolerance appears to result from: the substantial capacity of emus to detoxify fluoroacetate by defluorination; the limited conversion of fluoroacetate into fluorocitrate by emus; and/or their possession of an aconitate hydratase which is relatively insensitive to fluorocitrate.