Abstract

The gopher tortoise (Gopherus polyphemus) is a vulnerable terrestrial tortoise native of the southeastern United States, and is a frequent victim of direct and indirect human activity. The need for understanding the factors causing morbidity and mortality is of primary importance for conservation efforts. The medical records of 490 wild gopher tortoises admitted to the University of Florida Zoological Medicine Service over a 16-yr period (1998–2014) were reviewed to determine common causes of morbidity and mortality, and to determine the effects of season and animal size on their outcome. Negative outcomes included death and euthanasia, and positive outcomes included rehabilitation, release, or permanent captivity. The two most common clinical presentations were dog predation (39.8%, n=195) and vehicular trauma (35.7%, n=175). More tortoises presented during the summer months (74.3%, May–October) than during the winter months (25.7%, November–April). Of all gopher tortoises presented for dog attack between 2007 and 2014, 30.6% died or were euthanized within 3 days of presentation, whereas 59.2% had a positive outcome. Of all gopher tortoises presenting with vehicular trauma between 2007 and 2014, 56.9% died or were euthanized within 3 days of presentation, whereas 34.3% had a positive outcome. The average body sizes at presentation of gopher tortoises attacked by dogs and hit by vehicles were 1.97 kg and 2.69 kg respectively. Human activities, in particular vehicular trauma and predation by domestic dogs, were significant causes of morbidity and mortality of wild gopher tortoises in north-central Florida.