• Age-dependent, negative heterozygosity-fitness correlations and local effects in an endangered Caribbean reptile, Iguana delicatissima

      Judson, Jessica L Martin; Knapp, Charles R.; Welch, Mark E. (2018)
      Inbreeding depression can have alarming impacts on threatened species with small population sizes. Assessing inbreeding has therefore become an important focus of conservation research. In this study, heterozygosity-fitness correlations (HFCs) were measured by genotyping 7 loci in 83 adult and 184 hatchling Lesser Antillean Iguanas, Iguana delicatissima, at a communal nesting site in Dominica to assess the role of inbreeding depression on hatchling fitness and recruitment to the adult population in this endangered species. We found insignificant correlations between multilocus heterozygosity and multiple fitness proxies in hatchlings and adults. Further, multilocus heterozygosity did not differ significantly between hatchlings and adults, which suggests that the survivorship of homozygous hatchlings does not differ markedly from that of their heterozygous counterparts. However, genotypes at two individual loci were correlated with hatching date, a finding consistent with the linkage between specific marker loci and segregating deleterious recessive alleles. These results provide only modest evidence that inbreeding depression influences the population dynamics of I. delicatissima on Dominica.;
    • Biosphere reserve to transshipment Port: Travesty for Jamaica's Goat Islands.

      Grant, Tandora D. (2014)
      You know what is a huge bummer? Being a part of an amazing conservation success story to recover a species, only to reach the point where all those efforts appear lost. I know I’m not the only conservationist who has fought similar battles — many losing, but occasionally winning. I still have hope that reason will prevail and my colleagues and I can make further progress toward true recovery and the long-term goals of sustainability. The Jamaican Iguana (Cyclura collei) is a really big lizard that was thought to have been extinct for 40-something years when a small number of individuals were found in the rugged limestone interior of the Hellshire Hills on the southern coast of Jamaica…
    • Conservation genetics of Roatán Spiny-tailed Iguanas, Ctenosaura oedirhina.

      Pasachnik, Stesha A.; Hudman, S.; Iverson, John B.; Grant, Tandora D.; Knapp, Charles R.; Pasachnik, Stesha A. (2016)
      Roatán Spiny-tailed Iguanas, Ctenosaura oedirhina, are assessed as Endangered by the IUCN Red List of Threatened Species and listed in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Occurring in less than 1% of the available habitat on Roatán, due primarily to hunting... pressure, this species faces severe fragmentation.
    • Contrasting patterns of movement across life stages in an insular iguana population

      Moss, Jeanette B.; Gerber, Glenn P.; Goetz, Matthias; Haakonsson, Jane E.; Harvey, Jessica C.; Laaser, Tanja; Welch, Mark E. (2020)
    • Cyclura carinata. The IUCN Red List of Threatened Species 2020

      Gerber, Glenn P.; Colosimo, G.; Grant, Tandora D. (2020)
      Due to the persistent threat of invasive alien species, and habitat loss and degradation, Turks and Caicos Rock Iguanas currently occupy an area of about 37.1 km2 distributed among approximately 75 small islands with very little gene flow between them. This represents less than 10% of their historic range (500 km2 , >250 islands). Further, islands with abundant iguana subpopulations and no current anthropogenic threats total only 15.6 km2 . The total area of occupancy is estimated at 200 km2 using a 2x2 km grid, overlaying 20 clusters of iguana-inhabited islands. Over the last three generations (42 years), at least 11–20 island subpopulations of iguanas (including some very large islands) have been extirpated. The largest subpopulation is found on Big Ambergris Cay and is currently estimated at 6,000–7,000 mature adults (ca 25% of the total population). However, this represents a decline of 30–40% from this subpopulation's size prior to development in 1995.
    • Cyclura pinguis. The IUCN Red List of Threatened Species 2020

      Grant, Tandora D.; Bradley, K. A. (2020)
      Although it is believed the Anegada Rock Iguana population size has increased somewhat since the headstarting programme began releasing subadults, the habitat is continuing to be degraded. The significant population reduction (> 80%) for this species occurred over a much longer time period than three generations (66 years) ago due to the introduction of invasive alien species and human settlement. Most of these threats have not ceased for the remnant population and habitat destruction for development has increased. Natural juvenile recruitment is nearly zero due to feral cats preying on hatchlings. This invasive predator must be eradicated in order to solidify the iguana’s long-term future and eliminate the need for continued headstarting. This iguana's estimated extent of occurrence is 56.7 km2 , is endemic to only one island, and qualifies for listing as Critically Endangered.
    • Cyclura stejnegeri. The IUCN Red List of Threatened Species 2020

      Garcia, M.A.; Figuerola, C.; Grant, Tandora D. (2020)
      Although it is believed that the Mona Rhinoceros Iguana population size has increased somewhat since the last systematic survey of 2000 due to initial conservation efforts, the habitat is continuing to be degraded. Juvenile recruitment is impacted by the combined effects of feral pigs eating incubating eggs and cats preying on hatchlings. These invasive predators must be eradicated in order to solidify the longterm future of the iguana. In addition, removal of the Australian Pine plantation is necessary to restore prime nesting areas. The significant population reduction (>75%) for this species occurred much longer than three generations ago due to the introduction of invasive alien species and periods of settlement for mining, agriculture, and fishing. Some of these threats have not ceased for the remnant population, particularly the impacts of predators. The iguana is endemic to only one island, with an estimated extent of occurrence of 80 km², and qualifies for listing as Critically Endangered.
    • Ecological specialization and morphological diversification in Greater Antillean boas

      Reynolds, R. Graham; Collar David C.; Pasachnik, Stesha A.; Niemiller Matthew L.; Puente-Rolón, Alberto R.; Revell, Liam J. (2016)
      Colonization of islands can dramatically influence the evolutionary trajectories of organisms, with both deterministic and stochastic processes driving adaptation and diversification. Some island colonists evolve extremely large or small body sizes, presumably in response to unique ecological circumstances present on islands. One example of this phenomenon, the Greater Antillean boas, includes both small (<90 cm) and large (4 m) species occurring on the Greater Antilles and Bahamas, with some islands supporting pairs or trios of body‐size divergent species. These boas have been shown to comprise a monophyletic radiation arising from a Miocene dispersal event to the Greater Antilles, though it is not known whether co‐occurrence of small and large species is a result of dispersal or in situ evolution. Here, we provide the first comprehensive species phylogeny for this clade combined with morphometric and ecological data to show that small body size evolved repeatedly on separate islands in association with specialization in substrate use. Our results further suggest that microhabitat specialization is linked to increased rates of head shape diversification among specialists. Our findings show that ecological specialization following island colonization promotes morphological diversity through deterministic body size evolution and cranial morphological diversification that is contingent on island‐ and species‐specific factors.
    • Evidence for dominant males but not choosy females in an insular rock iguana

      Moss, Jeanette B.; Gerber, Glenn P.; Schwirian, Aumbriel; Jackson, Anna C.; Welch, Mark E. (2018)
      In natural populations susceptible to inbreeding depression, behaviors such as female promiscuity and disassortative mating may enhance the production of outbred progeny and help maintain genetic variation at the population-level. However, empirical tests of such hypotheses have largely focused on mating systems in which female choice is known to play a large role....
    • First evidence for crossbreeding between invasive Iguana iguana and the native rock iguana (Genus Cyclura) on Little Cayman Island

      Moss, Jeanette B.; Welch, Mark E.; Burton, Frederic J.; Vallee, Michael V.; Houlcroft, Edward W.; Laaser, Tanja; Gerber, Glenn P. (2017)
      Green iguanas (Iguana iguana) are invasive throughout the West Indies and co-occur on several islands with native rock iguanas (Genus Cyclura). In August 2016, three hybrid hatchlings were captured on Little Cayman Island, providing the first evidence for a successful crossbreeding event between I. iguana and any Cyclura rock iguana species in the wild.....
    • Growth, coloration, and demography of an introduced population of the Acklins Rock Iguana (Cyclura rileyi nuchalis) in the Exuma Islands, The Bahamas

      Iverson, John B.; Smith, G.R.; Pasachnik, Stesha A.; Hines, K.N.; Pieper, L.; Iverson, John B.; Grant, Tandora D.; Knapp, Charles R.; Pasachnik, Stesha A. (2016)
      In 1973, five Acklins Rock Iguanas (Cyclura rileyi nuchalis) from Fish Cay in the Acklins Islands, The Bahamas, were translocated to Bush Hill Cay in the northern Exuma Islands. That population has flourished, despite the presence of invasive rats, and numbered > 300 individuals by the mid-1990s....
    • Habitat utilization of Roatán Spiny-tailed Iguanas (Ctenosaura oedirhina) and its implications for conservation

      Goode, A.B.C.; Pasachnik, Stesha A.; Maple, T.L.; Iverson, John B.; Grant, Tandora D.; Knapp, Charles R.; Pasachnik, Stesha A. (2016)
      ...With data gathered from use/availability surveys, resource selection functions can identify habitats and environmental variables associated with the presence of a species. Herein, we used these techniques to better understand the distribution of the Roatán Spiny-tailed Iguanas (Ctenosaura oedirhina), a narrow-range endemic on the island of Roatán, Honduras....
    • Heterozygosity–Fitness Correlations Reveal Inbreeding Depression in Neonatal Body Size in a Critically Endangered Rock Iguana

      Moss, Jeanette B.; Gerber, Glenn P.; Welch, Mark E. (Oxford University Press (OUP), 2019)
      Inbreeding depression, though challenging to identify in nature, may play an important role in regulating the dynamics of small and isolated populations. Conversely, greater expression of genetic load can enhance opportunities for natural selection. Conditional expression concentrates these opportunities for selection and may lead to failure of detection. This study investigates the possibility for age-dependent expression of inbreeding depression in a critically endangered population of rock iguanas, Cyclura nubila caymanensis. We employ heterozygote-fitness correlations to examine the contributions of individual genetic factors to body size, a fitness-related trait. Nonsignificant reductions in homozygosity (up to 7%) were detected between neonates and individuals surviving past their first year, which may reflect natural absorption of inbreeding effects by this small, fecund population. The majority of variation in neonate body size was attributed to maternal or environmental effects (i.e., clutch identity and incubation length); however, heterozygosity across 22 microsatellite loci also contributed significantly and positively to model predictions. Conversely, effects of heterozygosity on fitness were not detectable when adults were examined, suggesting that inbreeding depression in body size may be age dependent in this taxon. Overall, these findings emphasize the importance of taking holistic, cross-generational approaches to genetic monitoring of endangered populations.
    • Jamaican Iguana: Species Recovery Plan, 2006-2013

      Grant, Tandora D.; Pagni, L; Wilson, B (IUCNGland, Switzerland, 2013)
      Thought to be extinct by the mid 1900s, the Jamaican Iguana was rediscovered in 1970, and again in 1990. The 1970 rediscovery generated surprisingly little interest, either within Jamaica or among international conservation organizations. But when pig hunter Edwin Duffus brought a live specimen to the Hope Zoo in 1990, the local Jamaican Iguana Research and Conservation Group (JIRCG) was rapidly formed, and international support quickly materialized. The renamed Jamaican Iguana Recovery Group (JIRG) is a consortium of local Jamaican organizations and international conservation groups that held a workshop in July 2006 to formulate the present Species Recovery Plan (SRP)...
    • Lost iguanas: Trouble in paradise

      Pasachnik, Stesha A.; Carreras De Leon, R. (2014)
      Hispaniola is second only to Cuba in size and biodiversity among West Indian islands, and is unique in being the only island with two native species of Rock Iguanas, the Rhinoceros Iguana (Cyclura cornuta; Fig. 1) and Ricord’s Iguana (C. ricordii). The island’s geologic history is likely responsible. Hispaniola was formed during the middle Miocene when North and South paleoislands joined (Graham 2003). A logical hypothesis suggests that each paleoisland held one species, and when the two islands joined, the ranges of both species shifted, eventually resulting in the distributions seen today. Cyclura ricordii is restricted to the southwestern Dominican Republic (DR) and just across the southern border into Haiti, whereas C. cornuta has a larger distribution throughout much of the arid lowlands across the entire island.
    • Phylogeography of the endangered Lesser Antillean iguana, Iguana delicatissima: a recent diaspora in an archipelago known for ancient herpetological endemism

      Martin, Jessica L.; Knapp, Charles R.; Gerber, Glenn P.; Thorpe, Roger S; Welch, Mark E. (2015)
      Iguana delicatissima is an endangered endemic of the Lesser Antilles in the Caribbean. Phylogeographic analyses for many terrestrial vertebrate species in the Caribbean, particularly lizards, suggest ancient divergence times. Often, the closest relatives of species are found on the same island, indicating that colonization rates are so low that speciation on islands is often more likely to generate biodiversity than subsequent colonization events…. Despite the great distances between islands and habitat heterogeneity within islands, this species is characterized by low haplotype diversity.
    • Qualitative impact evaluation of a social marketing campaign for conservation

      Salazar, Gabby; Mills, Morena; Veríssimo, Diogo (2019)
      Social marketing campaigns use marketing techniques to influence human behavior for the greater social good. In the conservation sector, social marketing campaigns have been used to influence behavior for the benefit of biodiversity as well as society....
    • The Jamaican Iguana (Cyclura collei): a report of 25 years of conservation effort

      Wilson, B.; Grant, Tandora D.; Van Veen, R.; Hudson, R.; Fleuchaus, D.; Robinson, O.; Stephenson, K.; Iverson, John B.; Grant, Tandora D.; Knapp, Charles R.; et al. (2016)
      Considered extinct by the late 1940s, the Jamaican Iguana (Cyclura collei) was re-discovered in 1970, and its existence confirmed in 1990. The 1970 re-discovery went largely unnoticed; in contrast, the 1990 “re-discovery” spawned a successful international recovery effort….
    • West Indian iguana Cyclura spp reintroduction and recovery programmes: Zoo support and involvement

      Grant, Tandora D.; Hudson, R. D. (2015)
      Many West Indian rock iguanas Cyclura spp comprise small restricted island populations that are threatened by habitat conversion and degradation, free-ranging domestic animals and invasive species. In the 1980s, concerted conservation efforts were initiated for Caribbean iguanas, using a combination of captive-breeding programmes and head-starting of wild-collected hatchlings for reintroduction, and habitat protection….
    • Where to now? An uncertain future for Jamaica's largest endemic vertebrate

      Veen, Rick van; Wilson, Byron S.; Grant, Tandora D.; Hudson, Richard (2014)