Characteristics of American alligator bites on people in Florida

Abstract

Human–American alligator (Alligator mississippiensis) conflict in Florida, USA, has increased since the early 1970s, along with the recovery of the American alligator population. To better understand factors contributing to the risk of people being bitten by free‐ranging alligators in Florida, we evaluated the trend of alligator bites during 1971–2014 and examined characteristics associated with bites on people documented during 1948–2014. We classified 372 bites as either unprovoked or unintentionally provoked and used these in further analyses. Major injuries to victims occurred in 247 bite incidents. The estimated annual number of bites resulting in major injury to the victim increased from 3.5 to 7.0 during 1971–2014. The number of bites per Florida resident did not show a significant trend during 1971–2014. No significant change occurred in the frequency of fatal attacks during 1971–2014. Monthly frequency of bites was positively correlated with both mean maximum and mean minimum air temperatures but was not significantly correlated with testosterone concentration in adult male alligators, suggesting that bites are more likely related to feeding rates associated with seasonal fluctuations in ambient temperature than to aggression by male alligators during the breeding season. A high percentage of bites (41.8%) occurred in unnamed water bodies, which were generally small or man‐made. Most (93.7%) victims were Florida residents, and 58.7% resided close to the incident site. Victims were predominantly male (81.4%), and adults were more frequently victims than were adolescents or children. Most victims (93.9%) were in the water or near the shore when bitten. Victims were more likely to sustain major injuries if the bite occurred in deeper water. Male alligators were more frequently (76.9%) responsible for bites. We found only 1 instance in which a bite was associated with defense of eggs or young by an adult female alligator. Evidence of people feeding alligators before the bite was documented in 34.7% of bite incidents. Twenty‐two fatalities were attributed to alligator attacks, but we could not discern a pattern in the ages of victims. Alligators responsible for severe or fatal bites were predominantly in good condition with few deformities or injuries. Most alligator bites in Florida appeared to be attempts at feeding, although 36.8% of incidents entailed a single bite followed by immediate release, suggesting that alligators were unsure about their prey or were biting in defense. The risk of alligator bites can be reduced by educating people likely to interact with alligators and by selectively removing problem alligators in human residential areas and water bodies used regularly by people for swimming, wading, and shoreline activities. © 2019 The Wildlife Society.

Alligators in the big city: spatial ecology of American alligators (Alligator mississippiensis) at multiple scales across an urban landscape

“…Furthermore, alligators are a well-known indicator species that have been used to track the health of other ecosystems like the Everglades due to their ability to integrate changes in habitat and water quality within their tissues and behaviors 10 . To our knowledge no studies have yet been published that investigate alligator spatial ecology in a heavily urban landscape, despite relatively large increases in the number of reported nuisance alligator complaints and alligator bites on humans over the last few decades 11 . However, there have been two studies in “urban-influenced” areas: Eversole et al 12 investigated habitat selection and distribution of an alligator population in a nature preserve on the outskirts of Houston, TX and found that alligators tended to avoid areas with the highest levels of human activity.…”

Evaluating the efficacy of capture as aversive conditioning for American alligators in human‐dominated landscapes

“…Aversive conditioning may be useful for addressing the increasing number of human–alligator conflicts in coastal residential communities (Rhodes 1997, Eversole et al 2014, Hayman et al 2014, Skupien and Andrews 2017, Woodward et al 2019). In South Carolina, USA, a majority of nuisance alligator reports originate in populous areas (Rhodes 1997).…”

“…Managers often lethally remove alligators that are involved in attacks (i.e., when an alligator bites a human) or considered nuisances because of their behavior, location, and size (Rhodes 1997, Janes 2004, Hayman et al 2014). Lethal removal of target alligators, either reactive or proactive, may be ineffective at preventing future negative human–alligator interactions because it does not address the underlying causes of human–alligator conflict (Dickman 2010, Hayman et al 2014, Woodward et al 2019). Captive studies indicate that crocodilians are capable of learning stimulus‐response relationships (Davidson 1966, Augustine and Baumer 2012) and field observations suggest that crocodilians exposed to aversive experiences with humans exhibit greater avoidance of humans (Webb and Messel 1979, Pacheco 1996, Gramentz 2008, Marques et al 2016), providing evidence that alligators may respond to aversive conditioning when applied strategically.…”