Flight response and human habituation in an insular endemic lizard

Authors: Goode, Ashley; PASACHNIK, STESHA - Fort Worth Zoo

Submitted to: Herpetological Review
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/26/2018
Publication Date: 6/1/2019
Citation: Goode, A.B., Pasachnik, S. 2019. Flight response and human habituation in an insular endemic lizard. Herpetological Review. 49(2):215-217.

Interpretive Summary: Flight distance and flight behavior have been used as a measure of wariness and risk-assessment in many species. Flight distance is an experience-dependent behavior, where the subject’s familiarity with intruders can alter their response to perceived threats. Even seemingly innocuous ecotourism can cause wildlife to lose their wariness of humans. This can be detrimental to populations that also face harvesting pressure, as the experiences result in conflicting outcomes. In other words, losing wariness of people due to habituation to non-lethal contact could make the subjects easier targets for poachers. The endangered Roatán Spiny-tailed Iguana (Ctenosaura oedirhina) is endemic to the island of Roatán, in the Bay Islands of Honduras. Previous studies have shown that the current distribution of this species across the island is the result of hunting pressure. High population densities are found only in locations that are protected by local landowners and managers. These privately protected areas are strongholds, ensuring the species remain extant; however, some populations now experience increased contact with tourists due to the nature of these areas. These increased non-predatory interactions may have desensitized the iguanas, making them more vulnerable to incursions by hunters or other introduced predators. Flight distance did not vary significantly across study sites. However, the responses are consistent with populations of other species that are accustomed to some degree of human interaction and thus exhibit decreased wariness. While protection, and subsequent human habituation, in tourist areas has been crucial to the survival of this species, these preliminary results suggest that there may be a cost to increased human interactions. Decreased flight response could result in increased susceptibility to hunting incursions, whereas increased response rate could results in elevated stress and a loss of resources.

Technical Abstract: Flight distance and flight behavior have been used as a measure of wariness and risk-assessment in many species. Flight distance is an experience-dependent behavior, where the subject’s familiarity with intruders can alter their response to perceived threats. Even seemingly innocuous ecotourism can cause wildlife to lose their wariness of humans. This can be detrimental to populations that also face harvesting pressure, as the experiences result in conflicting outcomes. In other words, losing wariness of people due to habituation to non-lethal contact could make the subjects easier targets for poachers. The endangered Roatán Spiny-tailed Iguana (Ctenosaura oedirhina) is endemic to the island of Roatán, in the Bay Islands of Honduras. Previous studies have shown that the current distribution of this species across the island is the result of hunting pressure. High population densities are found only in locations that are protected by local landowners and managers. These privately protected areas are strongholds, ensuring the species remain extant; however, some populations now experience increased contact with tourists due to the nature of these areas. These increased non-predatory interactions may have desensitized the iguanas, making them more vulnerable to incursions by hunters or other introduced predators. Flight distance did not vary significantly across study sites. However, the responses are consistent with populations of other species that are accustomed to some degree of human interaction and thus exhibit decreased wariness. While protection, and subsequent human habituation, in tourist areas has been crucial to the survival of this species, these preliminary results suggest that there may be a cost to increased human interactions. Decreased flight response could result in increased susceptibility to hunting incursions, whereas increased response rate could results in elevated stress and a loss of resources.