Status of a Relocated Population of Endangered Iguana pinguis on Guana Island, British Virgin Islands

Abstract

Eight individual rock iguanas (Iguana pinguis) from Anegada Island were relocated to Guana Island by Lazell, 1984–1987, in order to establish a second population reservoir for this endangered species. The species may have originally occupied the entire Puerto Rico Bank. The relocation has been successful and, in the area currently providing the best habitat, we estimate a density of 9 or 12 animals of various age classes per 19 ha. The optimal area contains a sheep exclosure with relatively dense understory vegetation and numerous exotic as well as native species of plants. Iguana activity is concentrated on east facing slopes and ridge‐tops that get morning sun. Outside the exclosure most edible ground cover and shrubs have been eaten by sheep, leaving toxic or noxious species, such as Croton or Lantana, in the understory where I. pinguis adults generally forage. Removal of sheep may be critical to continued population growth of these reptiles. Views on relocation or repatriation of other endangered Antillean Iguana species are advanced, with some ideas on minimum viable population sizes and a possible explanation for the extirpation of I. pinguis from much of its former range.

Life History of a Fossorial Lizard, Neoseps reynoldsi

“…Past studies of Cyclura populations have reported home-range sizes varying by one order of magnitude among individuals (Carey, 1975;Iverson, 1979;Goodyear and Lazell, 1994;Mitchell, 1999;Knapp, 2000), rather than the two orders of magnitude reported here. Our minimum overall home-range sizes for iguanas are not attributable to inadequate sampling as the two smallest home ranges for 2002 (100% MCPs with all data of , 0.7 ha; both females) were based on 273 and 327 locations collected over a 185-day period, which are large sample sizes compared to most studies in Cyclura.…”

Microhabitats and Population Densities of California Legless Lizards, with Comments on Effectiveness of Various Techniques for Estimating Numbers of Fossorial Reptiles

“…Among iguanid lizards, males typically have larger home ranges than females (reviewed in Perry and Garland, 2002), and this is true of most species of Cyclura that have been studied (Carey, 1975;Iverson, 1979;Goodyear and Lazell, 1994;Mitchell, 1999;Knapp, 2000; but see Alberts et al, 2002). Similarly, male C. lewisi in this study had larger home ranges than females during the entire study period.…”

Home range and habitat associations of a Bahamian iguana: implications for conservation

“…This study represents the longest telemetry investigation on a natural Cyclura population in the West Indies. The relatively few studies that have attempted to estimate Cyclura home ranges were hampered with transmitter attachment failures and thus occurred only over limited time periods ranging from days to ≈ 4 weeks (Wiewandt, 1977;Iverson, 1979;Goodyear & Lazell, 1994;Mitchell, 1999;Hayes et al, 2004). Accurate estimates should improve in the future as attachment technologies are refined and tested.…”

“…Home-range estimates for the Andros iguana are considerably larger than previously published for natural populations of West Indian iguanas. An inadequate number of re-location sightings via telemetry are most probably responsible for the low estimates on some islands (see Carey, 1975;Wiewandt, 1977;Goodyear & Lazell, 1994;Mitchell, 1999), or for other estimates this phenomenon is probably an artifact of island size and population density (see Knapp, 2000;Hayes et al, 2004). West Indian iguanas inhabit islands ranging from < 1 ha cays in the Bahamian Archipelago to the > 110 000 km 2 landmass of Cuba.…”