• Advances in conservation endocrinology: The application of molecular approaches to the conservation of endangered species

      Tubbs, Christopher W.; McDonough, C. E.; Felton, Rachel G.; Milnes, M. R. (2014)
      …In this review we examine various in vitro approaches we have used to compare estrogen receptor binding and activation by endogenous hormones and phytoestrogens in two species of rhinoceros; southern white and greater one-horned. We have found many of these techniques valuable and practical in species where access to research subjects and/or tissues is limited due to their conservation status....
    • Advancing laboratory-based zoo research to enhance captive breeding of southern white rhinoceros

      Tubbs, Christopher W.; Minteer, Ben A.; Maienschein, Jane; Collins, James P. (University of Chicago PressChicago, IL, 2018)
      The captive southern white rhinoceros (SWR) is not currently self-sustaining because of low fertility of captive-born females. The cause of this phenomenon is believed to be high dietary levels of phytoestrogens; endocrine disrupting chemicals (EDCs) produced by plants that can mimic the reproductive hormone estrogen....
    • After the installation

      Maschinski, Joyce; Albrecht, Matthew A.; Font, Jeremie; Monks, Leonie; Lange, Jimmy; Coffey, Emily; Forbes, Holly; Ceska, Jennifer; Haskins, Kristin E.; Center for Plant Conservation (CPC) (Center for Plant ConservationEscondido, California, 2019)
      A reintroduction will have a higher chance of successful establishment if it receives water and weeding after installation. Keeping land managers apprised of the performance of the rare species and engaging them in active site management is critical for long-term population persistence.
    • 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.;
    • Age-related patterns of neophobia in an endangered island crow: implications for conservation and natural history

      Greggor, Alison L.; Masuda, Bryce M.; Flanagan, Alison M.; Swaisgood, Ronald R. (2020)
      Theory suggests that the balance between unknown dangers and novel opportunities drives the evolution of species-level neophobia. Juveniles show lower neophobia than adults, within mammals and birds, presumably to help minimize the costs of avoiding beneficial novelty, and adults tend to be more neophobic, to reduce risks and focus on known stimuli. How these dynamics function in island species with fewer dangers from predators and toxic prey is not well understood. Yet, predicting neophobia levels at different age classes may be highly valuable in conservation contexts, such as species' translocation programmes, where responses to novelty can influence the effectiveness of prerelease training and animals' survival postrelease. To better understand how neophobia and its age-related patterns are expressed in an island corvid, we surveyed object neophobia in 84% of the world's critically endangered ‘alal?, Corvus hawaiiensis. Individuals repeatedly demonstrated high neophobia, suggesting that neither captivity nor their island evolution has erased this corvid-typical trait. Unexpectedly, juveniles were exceedingly more neophobic than adults, a pattern in stark contrast to common neophobia predictions and known mammalian and avian studies. We discuss the potential conservation ramifications of this age-structured result within the larger context of neophobia theory. Not only may the expression of neophobia be more complicated than previously thought but predicting such responses may also be important for conservation management that requires exposing animals to novelty.
    • Alaotra reed lemur (Hapalemur alaotrensis). The IUCN Red List of Threatened Species 2020

      Ralainasolo, F.B; Raveloarimalala, M.L; Randrianasolo, H.; Reuter, K.E; Heriniaina, R; Clarke, T; Ravaloharimanitra, M.; Volampeno, S.; Donati, G; Razafindramanana, J.; et al. (2020)
      Listed as Critically Endangered as the species has been observed to have undergone a population reduction of greater than or equal to 80% over a period of 27 years (three generations), due primarily to continuing decline in area, extent and quality of habitat, in addition to exploitation through unsustainable hunting pressure. These causes have not ceased, and will to a large extent not be easily reversible.
    • Allen Cays Rock Iguana, Cyclura cychlura ssp. inornata. IUCN Red List of Threatened Species

      Iverson, John; Grant, Tandora D.; Buckner, Sandra (IUCN, 2019)
      Only two natural breeding subpopulations of the Allen Cays Rock Iguana have ever been known (U and Leaf Cays), with a combined population of less than 500 mature animals inhabiting only seven total hectares (0.07 km2). Those two subpopulations have recovered from near extinction in the early 1900s to current levels that are near the limit of the resources available on those two cays (carrying capacity). Human-assisted translocations to other Bahamian islands over the past two decades has decreased the number of large adults on the source cays, and although these moves have increased the number of subpopulations, without reproduction almost all are considered not viable....
    • Alternatives to conventional seed banking: Introduction

      Maschinski, Joyce; Pence, Valerie; Center for Plant Conservation (CPC) (Center for Plant ConservationEscondido, California, 2019)
      For exceptional (or non-orthodox) plants that cannot be conserved long-term using conventional seed banking methods, three alternatives traditionally used by botanical gardens are tissue culture, cryogenic storage, and field genebanks. (See Overview.) Each requires different institutional commitment to space, resources, staff time, and expertise....
    • Amblyrhynchus cristatus. The IUCN Red List of Threatened Species 2020

      MacLeod, A.; Nelson, K.; Grant, Tandora D. (2020)
      Marine Iguanas occur on the large islands of Española, Fernandina, Floreana, Genovesa, Isabela, Marchena, Pinta, San Cristobál, Santa Cruz, Santa Fé, and Santiago, the mid-sized islands of Baltra, Bartolomé, Pinzón, Plaza Norte, Plaza Sur, Rábida, and Seymour Norte, smaller key populations on Darwin, Roca Redonda, and Wolf, as well as many satellite islets of the Galápagos Archipelago, Ecuador. The estimated extent of occurrence is 56,647 km2 by minimum convex polygon and the area of occupancy is estimated at 42,155 km2 using a 2x2 km grid overlay within a coastal buffer 2 km from the shore. The population size is poorly known and crudely estimated as low as 33,000 total iguanas after a strong El Niño famine and as many as 350,000 after several years of La Niña abundant food conditions, with fewer than 210,000 mature individuals. Current taxonomy describes eleven subspecies. Only one subspecies has a genetically resilient effective population size, and only one more is close to the threshold to be considered healthy; the remaining are critically low to moderate. Overall population trend is unknown, but is subject to extreme fluctuations and reductions during El Niño events (10–90% mortality), which are predicted to intensify in the future with ongoing climate change. Marine Iguana populations have been reduced by invasive alien predators such as feral cats, rats, and free-roaming pigs and dogs on five of the 13 main islands (ca 30% of the total population)....
    • Amblyrhynchus cristatus ssp. cristatus. The IUCN Red List of Threatened Species 2020

      MacLeod, A.; Nelson, K.; Grant, Tandora D. (2020)
      The Fernandina Marine Iguana is found on the islands of Fernandina, Isabela, Tortuga, and very likely other satellite cays in the Galápagos Islands, Ecuador. The estimated extent of occurrence is 8,845 km2 by minimum convex polygon and the area of occupancy is estimated at 2,288 km2 . The population size is poorly known and crudely estimated at 20,000–160,000 total iguanas with fewer than 96,000 mature individuals. Overall population trend is unknown, but is subject to extreme reductions and fluctuations during El Niño events, which are predicted to intensify in the future with ongoing climate change. This iguana is threatened by invasive alien Black Rats, feral cats, and free-roaming pigs and dogs on Isabela Island. Fernandina Marine Iguanas are threatened by a region-wide increase in human population and visitation that has multiplied the impacts from stress, marine pollution, habitat degradation, and chance of further invasive species introductions and emergent diseases. Land-based tourist presence and intensity has been shown to have a significant overall negative effect on iguana health. The population is estimated to have been reduced by at least 20–40% over the last three generations (18–24 years) due to the impacts of invasive alien predators, oil spills and urban pollution, and cyclic feast/famine fluctuations. Without significant invasive species control, declines are projected to continue in the near future, with a per cent reduction of at least 20–40% estimated over the past two generations and one generation into the future. This subspecies qualifies for listing as Vulnerable.
    • Amblyrhynchus cristatus ssp. hassi. The IUCN Red List of Threatened Species 2020

      MacLeod, A.; Nelson, K.; Grant, Tandora D. (2020)
      The Santa Cruz Marine Iguana is found on the islands of Santa Cruz, Baltra, Seymour Norte, Plaza Sur, Plaza Norte, and very likely other satellite cays in the Galápagos Islands, Ecuador. The estimated extent of occurrence is 1,439 km2 by minimum convex polygon and the area of occupancy is estimated at 580 km2 . The population size is poorly known and crudely estimated at 2,000–13,000 total iguanas with fewer than 7,800 mature individuals. Genetic data indicate a small effective population size. Overall population trend is unknown, but is subject to extreme reductions and fluctuations during El Niño events, which are predicted to intensify in the future with ongoing climate change. This iguana is threatened by invasive alien Black Rats, Norway Rats, feral cats, and free-roaming pigs and dogs. Santa Cruz Marine Iguanas are threatened by a region-wide increase in human population and visitation that has multiplied the impacts from stress, marine pollution, habitat degradation, and chance of further invasive species introductions and emergent diseases. Land-based tourist presence and intensity has been shown to have a significant overall negative effect on iguana health. The population is estimated to have been reduced by at least 30–40% over the last three generations (18–24 years) due to the impacts of invasive alien predators, oil spills, low effective population size, and cyclic feast/famine fluctuations. Without significant invasive species and pollution control, declines are projected to continue in the near future, with a percent reduction of at least 20–30% estimated over the past two generations and one generation into the future. This subspecies qualifies for listing as Endangered
    • Amblyrhynchus cristatus ssp. godzilla. The IUCN Red List of Threatened Species 2020

      MacLeod, A.; Nelson, K.; Grant, Tandora D. (2020)
      The Punta Pitt Marine Iguana is found only on the northern and eastern part of San Cristóbal Island and very likely the satellite islets in this region in the Galápagos Islands, Ecuador. The estimated extent of occurrence is 257 km2 by minimum convex polygon and the area of occupancy is estimated at 188 km2. The population size is poorly known and was crudely estimated at 50–400 total iguanas on the entire island in 2004. A more recent mark-resight study calculated 147 mature adults at the largest subpopulation of this new subspecies designation. Genetic data indicate a critically low effective population size. Overall population trend is unknown, but is subject to extreme reductions and fluctuations during El Niño events, which are predicted to intensify in the future with ongoing climate change. This iguana is threatened by invasive alien Black Rats, Norway Rats, feral cats, and free-roaming pigs and dogs. Punta Pitt Marine Iguanas are threatened by a region-wide increase in human population and visitation that has multiplied the impacts from stress, marine pollution, habitat degradation, and chance of further invasive species introductions and emergent diseases. Land-based tourist presence and intensity has been shown to have a significant overall negative effect on iguana health.
    • Amblyrhynchus cristatus ssp. hayampi. The IUCN Red List of Threatened Species 2020

      MacLeod, A.; Nelson, K.; Grant, Tandora D. (2020)
      The Marchena Marine Iguana is found only on the island of Marchena in the Galápagos Islands, Ecuador. The extent of occurrence and area of occupancy is estimated at 140 km2 . The population size is poorly known and estimated at 1,000–40,000 total iguanas, with fewer than 6,000 mature individuals. Genetic data indicate a critically low effective population size. Overall population trend is unknown, but is subject to extreme reductions and fluctuations during El Niño events, which are predicted to intensify in the future with ongoing climate change. Marchena Marine Iguanas are threatened by a region-wide increase in human population and visitation that has multiplied the impacts from marine pollution, habitat degradation, and chance of invasive species introductions and emergent diseases. This subspecies qualifies for listing as Endangered.
    • Amblyrhynchus cristatus ssp. jeffreysi. The IUCN Red List of Threatened Species 2020

      MacLeod, A.; Nelson, K.; Grant, Tandora D. (2020)
      The Wolf Marine Iguana is found on the islands of Wolf, Darwin, and Roca Redonda in the Galápagos Islands, Ecuador. The estimated extent of occurrence is 1,058 km2 by minimum convex polygon and the area of occupancy is estimated at 16 km2 using a 2x2 km grid overlay. The population size is poorly known and estimated at 600–2,300 total iguanas, with fewer than 1,380 mature individuals. Overall population trend is unknown, but is subject to extreme reductions and fluctuations during El Niño events, which are predicted to intensify in the future with ongoing climate change. Wolf Marine Iguanas are threatened by a region-wide increase in human population and visitation that has multiplied the impacts from marine pollution, habitat degradation, and chance of invasive species introductions and emergent diseases. This subspecies qualifies for listing as Endangered.
    • Amblyrhynchus cristatus ssp. mertensi. The IUCN Red List of Threatened Species 2020

      MacLeod, A.; Nelson, K.; Grant, Tandora D. (2020)
      The San Cristóbal Marine Iguana is found only on the southern and western part of San Cristóbal Island and very likely the satellite islets in this region in the Galápagos Islands, Ecuador. The estimated extent of occurrence is 398 km2 by minimum convex polygon and the area of occupancy is estimated at 240 km2 . The population size is poorly known and was crudely estimated at 50–400 total iguanas on San Cristóbal in 2004, although this is under-estimated as a more recent mark-resight study calculated 300 mature adults at the largest subpopulation. Genetic data indicate a critically low effective population size. Overall population trend is unknown, but is subject to extreme reductions and fluctuations during El Niño events, which are predicted to intensify in the future with ongoing climate change. This iguana is threatened by invasive alien Black Rats, Norway Rats, feral cats, and free-roaming pigs and dogs. San Cristóbal Marine Iguanas are threatened by a region-wide increase in human population and visitation that has multiplied the impacts from stress, marine pollution, habitat degradation, and chance of further invasive species introductions and emergent diseases. Land-based tourist presence and intensity has been shown to have a significant overall negative effect on iguana health.
    •  Amblyrhynchus cristatus ssp. nanus. The IUCN Red List of Threatened Species 2020

      MacLeod, A.; Nelson, K.; Grant, Tandora D. (2020)
      The Genovesa Marine Iguana is found only on the island of Genovesa in the Galápagos Islands, Ecuador. The extent of occurrence and area of occupancy is estimated at 28 km2 . The population size is poorly known and estimated at 900–15,000 total iguanas, with fewer than 9,000 mature individuals. Genetic data indicate a moderate effective population size. Overall population trend is unknown, but is subject to extreme reductions and fluctuations during El Niño events, which are predicted to intensify in the future with ongoing climate change. Genovesa Marine Iguanas are threatened by a region-wide increase in human population and visitation that has multiplied the impacts from marine pollution, habitat degradation, and chance of invasive species introductions and emergent diseases. Land-based tourist presence and intensity has been shown to have a significant overall negative effect on iguana health. This subspecies qualifies for listing as Critically Endangered.
    • Amblyrhynchus cristatus ssp. sielmanni. The IUCN Red List of Threatened Species2020

      MacLeod, A.; Nelson, K.; Grant, Tandora D. (2020)
      The Pinta Marine Iguana is found only on the island of Pinta in the Galápagos Islands, Ecuador. The extent of occurrence and area of occupancy is estimated at 92 km2 . The population size is poorly known and estimated at 800–6,000 total iguanas with fewer than 3,600 mature individuals. Genetic data indicate a low to moderate effective population size. Overall population trend is unknown, but is subject to extreme reductions and fluctuations during El Niño events, which are predicted to intensify in the future with ongoing climate change. Pinta Marine Iguanas are threatened by a region-wide increase in human population and visitation that has multiplied the impacts from marine pollution, habitat degradation, and chance of invasive species introductions and emergent diseases. This subspecies qualifies for listing as Critically Endangered.
    • Amblyrhynchus cristatus ssp. trillmichi. The IUCN Red List of Threatened Species2020

      MacLeod, A.; Nelson, K.; Grant, Tandora D. (2020)
      The Santa Fé Marine Iguana is found only on the island of Santa Fé in the Galápagos Islands, Ecuador. The extent of occurrence and area of occupancy is estimated at 44 km2 . The population size is poorly known and estimated at 3,000–16,000 total iguanas with fewer than 9,600 mature individuals. Genetic data indicate a low to moderate effective population size. Overall population trend is unknown, but is subject to extreme reductions and fluctuations during El Niño events, which are predicted to intensify in the future with ongoing climate change. Santa Fé Marine Iguanas are threatened by a region-wide increase in human population and visitation that has multiplied the impacts from marine pollution, habitat degradation, and chance of invasive species introductions and emergent diseases. Land-based tourist presence and intensity has been shown to have a significant overall negative effect on iguana health.
    • Amblyrhynchus cristatus ssp. venustissimus. The IUCN Red List of Threatened Species2020

      MacLeod, A.; Nelson, K.; Grant, Tandora D. (2020)
      The Española Marine Iguana is found on the islands of Española, Floreana, Gardner-by-Floreana, Champion, and very likely their satellite cays in the Galápagos Islands, Ecuador. The estimated extent of occurrence is 1,184 km2 by minimum convex polygon and the area of occupancy is estimated at 308 km 2 . The population size is poorly known and crudely estimated at 3,700–37,000 total iguanas with fewer than 22,200 mature individuals. Genetic data indicate a small to moderate effective population size. Overall population trend is unknown, but is subject to extreme reductions and fluctuations during El Niño events, which are predicted to intensify in the future with ongoing climate change. This iguana is threatened by invasive alien Black Rats, feral cats, and free-roaming pigs and dogs. Española Marine Iguanas are threatened by a region-wide increase in human population and visitation that has multiplied the impacts from stress, marine pollution, habitat degradation, and chance of further invasive species introductions and emergent diseases. Land-based tourist presence and intensity has been shown to have a significant overall negative effect on iguana health. This subspecies qualifies for listing as Endangered.
    • Amblyrhynchus cristatus ssp. wikelskii. The IUCN Red List of Threatened Species 2020

      MacLeod, A.; Nelson, K.; Grant, Tandora D. (2020)
      The Santiago Marine Iguana is found on the islands of Santiago, Bartolomé, Pinzón, Rábida, and very likely nearby islets in the Galápagos Islands, Ecuador. The estimated extent of occurrence is 1,164 km2 by minimum convex polygon and the area of occupancy is estimated at 444 km2 . The population size is poorly known and estimated at 450–4,000 total iguanas, with fewer than 2,400 mature individuals. Genetic data indicate a critically low effective population size. Overall population trend is unknown, but is subject to extreme reductions and fluctuations during El Niño events, which are predicted to intensify in the future with ongoing climate change. Invasive Black Rats threaten this iguana more severely when compared to other subspecies, as the islands in its distribution have scarce food resources for rats. Santiago Marine Iguanas are threatened by a region-wide increase in human population and visitation that has multiplied the impacts from stress, marine pollution, habitat degradation, and chance of invasive species introductions and emergent diseases. Land-based tourist presence and intensity has been shown to have a significant overall negative effect on iguana health....