Stesha Pasachnik

• Doctor of Philosophy
• Conservation Biologist at Fort Worth Zoo

We highlight the smuggling of Galápagos iguanas in Africa, Asia, Europe, and the Pacific region. Wild caught Galapagos iguanas are laundered into international trade declared as captive-bred. The offspring of such animals receive CITES permits in violation of CITES regulations. We urge CITES Parties to transfer all four species of Galápagos iguanas...

We created a database of lost and rediscovered tetrapod species, identified patterns in their distribution and factors influencing rediscovery. Tetrapod species are being lost at a faster rate than they are being rediscovered, due to slowing rates of rediscovery for amphibians, birds and mammals, and rapid rates of loss for reptiles. Finding lost s...

The genus Cyclura includes nine extant species and six subspecies of West Indian Rock Iguanas and is one of the most imperiled genera of squamate reptiles globally. An understanding of species diversity, evolutionary relationships, diversification, and historical biogeography in this group is crucial for implementing sound long-term conservation st...

Extinctions and population decline of species on islands are often attributed to invasive alien species (IAS). Predation from IAS, such as the Small Indian Mongoose (Urva auropunctata) drove the Critically Endangered Jamaican Rock Iguana (Cyclura collei) to near extinction. Historical and ongoing conservation efforts have restored the population to...

Trauma, uveitis, cataracts, glaucoma, and neoplasia are common diagnoses in avian eyes and in domestic species have been associated with increases in intraocular pressure (IOP). IOP have been established for various avian species using applanation and rebound tonometry, but few studies have calibrated the tonometer readings with manometry to determ...

The global trade in wildlife affects most major taxonomic groups (Fukushima et al., 2020; Scheffers et al., 2019). Managing wildlife trade requires an accurate understanding of the dimensions of trade and its impacts (positive, neutral, or negative) on the conservation of native wildlife populations. We are concerned that assertions made by Natusch...

Recognizing the imperative to evaluate species recovery and conservation impact, in 2012 the International Union for Conservation of Nature (IUCN) called for development of a “Green List of Species” (now the IUCN Green Status of Species). A draft Green Status framework for assessing species’ progress toward recovery, published in 2018, proposed 2 s...

The Roatán Spiny-tailed Iguana (Ctenosaura oedirhina) is an endangered species endemic to only two islands in the Bay of Honduras and a few of its surrounding cays. Ctenosaura oedirhina is currently threatened by different impacts, including habitat modification, invasive predators, and illegal collection and harvesting. Although previous work has...

The Útila spiny-tailed iguana, Ctenosaura bakeri (Stejneger, 1901), is a Critically Endangered iguana endemic to the island of Útila, in the Bay Islands archipelago of Honduras. The species occurs almost exclusively in the highly dynamic mangrove habitat on Útila (Gutsche, 2005), and is threatened by the encroachment of anthropogenic activities, as...

Common Green Iguanas (Iguana iguana) and Spiny-tailed Iguanas (Ctenosaura similis and C. pectinata) are native to Neotropical regions. These reptiles have been redistributed beyond their native ranges primarily via the pet trade, for human consumption, or as unintended commensals in horticultural and construction shipments (IUCN SSC Iguana Speciali...

Hispaniola is the second largest island in the Caribbean and harbors an extensive amount of biodiversity. The geologic history and resulting complex topography of the island has led to significant differentiation across various taxonomic groups. Hispaniola is the only Caribbean Island with two species of Rock Iguanas, genus Cyclura. Rhinoceros Rock...

Context Organisms living in small, isolated populations with very restricted ranges are at high risk of extirpation due to various direct and indirect forces than mainland populations. Roatán spiny-tailed iguanas (Ctenosaura oedirhina) are endemic to the 146-km² island of Roatán, Honduras. Harvesting for consumption, fragmentation of habitat and pr...

Cyclura ricordii is an endemic iguana from Hispaniola Island and is threatened on the IUCN Red List. The main threats are predation by introduced mammals, habitat destruction, and hunting pressure. The present study focused on two nesting sites from Pedernales Province in the Dominican Republic. The hypothesis that natal philopatry influences dispe...

Invasive alien species are a major threat to native insular species. Eradicating invasive mammals from islands is a feasible and proven approach to prevent biodiversity loss. We developed a conceptual framework to identify globally important islands for invasive mammal eradications to prevent imminent extinctions of highly threatened species using...

Table of islands, country or territory of ownership, invasive mammals and highly threatened species occurring on island, island rank reflecting conservation value, and timeframe assessed by socio-political survey in which an eradication could feasibly be initiated. Invasive mammal species listed are only those identified as having negative impact o...

Table of islands where no socio-political feasibility data was available during this study, country or territory of ownership, invasive mammals and highly threatened species occurring on island. Invasive mammal species listed are only those identified as having negative impact on highly threatened species and fall below island area and human popula...

Additional figures, tables and text supporting the main paper. (DOCX)

The Útila Spiny-tailed Iguana is known only from the island of Útila, Honduras. Total known extent of occurrence is 41 km2. The iguana and its eggs are harvested heavily and sold both locally and on the adjacent mainland. Other primary threats to the population are habitat loss and fragmentation associated with development for tourism; decreasing q...

Ctenosaura bakeri is a Critically Endangered Iguana endemic to the small Honduran island of Utila. Utila is the smallest of the three bay islands in Honduras at 41km². As a mangrove specialist, Ctenosaura bakeri likely only inhabits less than 25% of the island and is threatened by habitat loss and fragmentation, hunting of adults and eggs, invasive...

Understanding the diet of endangered species can benefit conservation efforts that involve habitat preservation and restoration. Caribbean rock iguanas, Cyclura spp., are among the most endangered lizards in the world, yet little is known about the diets of many of these species. In particular, the diets of the Rhinoceros rock iguana, Cyclura cornu...

For species living in naturally fragmented habitats, the identification of conservation units is particularly challenging. Turks and Caicos Rock Iguanas, Cyclura carinata, are endemic to the Turks and Caicos Islands (TCI). These Critically Endangered lizards inhabit less than 5% of their historic range. A complete study of the geographic distributi...

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 speci...

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 ph...

This annotated checklist of the world's iguanas (Iguanidae; Iguaninae) represents an update by the Iguana Taxonomy Working Group (ITWG) of its 2011 list. We recognize 44 extant species (19 subspecies across six species) in eight genera. Ctenosaura (as currently recognized) is the most diverse, with 18 species, and Amblyrhynchus is the least diverse...

Of the 10,272 currently recognized reptile species, fewer than 8% are regulated by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and the European Wildlife Trade Regulations (EWTR). However, The International Union for Conservation of Nature (IUCN) Red List has assessed 45% of the world’s reptile species...

RationaleStable isotope analysis is a powerful tool for reconstructing trophic interactions to better understand drivers of community ecology. Taxon-specific stable isotope discrimination factors contribute to the best use of this tool. We determined the first C-13 and N-15 values for Rock Iguanas (Cyclura spp.) to better understand isotopic fracti...

Abnormal colouration has been reported in both wild and captive reptile populations. In wild populations, piebaldism is a type of leucism where individuals have normal-coloured eyes, but exhibit white patches, giving them a blotched or mottled appearance. It is a common form of abnormal colouration. Some species show an ontogenetic shift in this pa...

The harvesting of wildlife has had a devastating effect on global biodiversity. Here we investigate the perceived status of the Critically Endangered Valle de Aguán Spiny-tailed Iguana, Ctenosaura melanosterna. We interviewed 132 residents of the Valle de Aguán, Honduras to: (1) examine their knowledge of the range and habitat preference; (2) docum...

We examined aspects of natural history and ecology of the black-chested spiny-tailed iguana, Ctenosaura melanosterna, on Cayo Cochino Menor, Honduras, over 6 years to provide baseline data to assist in management of this critically endangered species. Size of territory is resource-dependent, and the species seems to prefer habitats with open canopy...

Roatan Spiny-tailed Iguanas, Ctenosaura oedirhina, are listed as Endangered by the IUCN Redlist Assessment and under Appendix II of Convention on International Trade of Endangered Species of Wild Fauna and Flora (CITES). These iguanas occur primarily on Roatan and Barbaretta, off the Caribbean coast of Honduras. Habitat destruction associated with...

Effective and targeted conservation action requires detailed information about species, their distribution, systematics and ecology as well as the distribution of threat processes which affect them. Knowledge of reptilian diversity remains surprisingly disparate, and innovative means of gaining rapid insight into the status of reptiles are needed i...

Utila Spiny-tailed Iguanas, Ctenosaura bakeri, are listed as Critically Endangered by the IUCN Redlist Assessment and are listed under Appendix II of CITES. This species occupies a portion of Utila, a small continental island located off the northern coast of Honduras, in the Bay Islands chain. Habitat destruction and overharvesting for consumption...

The Black-chested Spiny-tailed Iguana, Ctenosaura melanosterna, is listed as Endangered by the IUCN Redlist Assessment and under Appendix II of CITES. The species has two evolutionarily significant units (ESUs), found in the Valle de Aguán and the Cayos Cochinos Archipelago, Honduras. Each ESU has been shown to be genetically distinct and each is l...

Work Assignments: • Site visits to open markets and breeding facilities. Interviews with interested government, NGO, and education stakeholders -CLS, LF, SP, LR. • Compilation of legal instruments per country. Data analyses of export and import activities -AR, PM.

In conservation, difficult decisions concerning prioritization of different geographic areas must be made. Large-scale prioritization methods such as defining biodiversity hotspots and crisis ecoregions have paved the way; however, these efforts then need to be localized. Various approaches have been taken, such as defining evolutionarily significa...

The Ctenosaura palearis complex (C. bakeri, C. melanosterna, C. palearis and C. oedirhina) comprises four endangered species. We isolated 22 polymorphic microsatellites from C. melanosterna and evaluated them for amplification success and polymorphism in the source population, two non-source populations, the three remaining C. palearis complex taxa...

The growing use of molecular systematics in conservation has increased the importance of accurate resolution of taxonomic units and relationships. DNA data relate most directly to genealogies, which need not have perfect relationships with species limits and phylogenies. We used a multilocus gene tree approach to elucidate the relationships between...

The island endemic Ctenosaurabakeri was listed as critically endangered by the IUCN Redlist Assessment in 2004, 7years after it was recognized as a distinct species. C.bakeri occupies a portion of Utila, a small continental island located off the northern coast of Honduras. Habitat destruction and over-harvesting are among the top threats facing th...

Eurycea cirrigera, a relatively small species that occurs in the Allegheny Mountains, appears to fill in the gaps along the aquatic-terrestrial gradient that are left by two sympatric salamander species; the terrestrial Plethodon cinereus and semiaquatic Desmognathus fuscus. To better understand the local distribution of these three species we test...