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As agricultural areas expand, interactions between wild animals and farmland are increasing. Understanding the nature of such interactions is vital to inform the management of human–wildlife coexistence. We investigated patterns of space use of two Critically Endangered Galapagos tortoise species, Chelonoidis porteri and Chelonoidis donfaustoi, on privately owned and agricultural land (hereafter farms) on Santa Cruz Island, where a human–wildlife conflict is emerging. We used GPS data from 45 tortoises tracked for up to 9 years, and data on farm characteristics, to identify factors that influence tortoise movement and habitat use in the agricultural zone. Sixty-nine per cent of tagged tortoises used the agricultural zone, where they remained for a mean of 150 days before returning to the national park. Large male tortoises were more likely to use farms for longer periods than female and smaller individuals. Tortoises were philopatric (mean overlap of farmland visits = 88.7 ± SE 2.9%), on average visiting four farms and occupying a mean seasonal range of 2.9 ± SE 0.3 ha. We discuss the characteristics of farm use by tortoises, and its implications for tortoise conservation and coexistence with people.

Emerging infectious diseases (EIDs) have been reported as causes of morbidity and mortality in free-living animal populations, including turtles and tortoises, and they have even resulted in species extinctions, with human activities contributing to the spread of many of these diseases. In the Galapagos, giant tortoises are endangered due to habitat change, invasive species, and other human impacts; however, the impact of EIDs on Galapagos tortoise conservation remains understudied. To fill this gap, we conducted health assessments of five tortoise species from the islands of Santa Cruz, Isabela and Española. We performed health evaluations of 454 animals and PCR testing for pathogens known to be relevant in other tortoise species. We identified two novel sequences of adenoviruses and four of herpesviruses. Based on alignments of the DNA polymerase gene and maximum likelihood phylogenetic analyses, we found both novel adenoviruses to be most closely related to red footed tortoise adenovirus 2, by nucleotide sequence and red footed tortoise adenovirus 1, based on amino acid sequence. Three of the herpesvirus sequences translated into the same deduced amino acid sequence; therefore, they may be considered the same viral species, closely related to terrapene herpesvirus 2. The fourth herpesvirus sequence was highly divergent from any sequence previously detected and is related to an eagle owl herpesvirus based on nucleotide sequence and to loggerhead oro-cutaneous herpesvirus based on amino acids. These novel viruses may be pathogenic for giant tortoises under specific conditions (e.g., stress). Continued screening is crucial to determine if these viruses play a role in tortoise fitness, morbidity and survival. This information allows us to provide recommendations to the Galapagos National Park Directorate and other institutions to improve the management of these unique species both in Galapagos and globally, and for tortoise reintroduction plans throughout the archipelago.

International audience; This paper conceptualises replication research as being one of the most needed areas of ongoing academic activity. Using George the Galapagos tortoise as a metaphor for the lack of replication research, it is argued that only by replicating research studies over time can solid theory be developed. For the most part, advertising and marketing communication research consists of non-replicated, one-shot, point-in-time experiments which, once accepted and published by a journal, becomes the litany of the academic community and is then deified by the citation process. The paper begins by reviewing the background of replication research in the marketing communication domain and applies it to current thinking and publication trends. Reasons for the lack of replication research are presented and some conclusions are drawn for those seeking to confirm or challenge existing research. An agenda is provided for the development and publication of replication research.

Hybridization poses a major challenge for species conservation because it threatens both genetic integrity and adaptive potential. Yet, hybridization can occasionally offer unprecedented opportunity for species recovery if the genome of an extinct taxon is present among living hybrids such that selective breeding could recapture it. We explored the design elements for establishing a captive-breeding program for Galapagos tortoises (Chelonoidis spp.) built around individuals with admixed ancestry involving an extinct species. The target individuals were hybrids between the extinct species from Floreana Island, C. niger, and an extant species, C. becki, which were recently found in the endemic range of C. becki, from Wolf Volcano on Isabela Island. We combined genotypic data from 35 tortoises with high ancestry from C. niger with forward-in-time simulations to explore captive breeding strategies that maximized overall genetic diversity and ancestry from C. niger while accommodating resource constraints, species biology, and the urgency to return tortoises to Floreana Island for facilitating ecosystem restoration. Overall genetic diversity was maximized when in the simulation tortoises were organized in relatively small breeding groups. Substantial amounts of the C. niger genome were captured despite limited resources available for selectively breeding tortoises in captivity. Genetic diversity was maximized when captive-bred offspring were released to the wild rather than being used as additional breeders. Our results provide genetic-based and practical guidance on the inclusion of hybrids with genomic representation from extinct taxa into species restoration programs and informs the ongoing debate on the value of hybrids in biodiversity conservation.Reproducción en Cautiverio Informada Genéticamente de Híbridos de una Especie Extinta de Tortuga de las Galápagos Resumen La hibridación representa un obstáculo importante para la conservación de especies ya que amenaza tanto a la integridad genética como al potencial adaptativo. Aun así, la hibridación ocasionalmente puede ofrecer una oportunidad sin precedentes para la recuperación de una especie si el genoma de un taxón extinto está presente entre los híbridos vivientes de tal manera que la reproducción selectiva pudiera recuperarlo. Exploramos los elementos de diseño para el establecimiento de un programa de reproducción en cautiverio de la tortuga de las Galápagos (Chelonoidis spp.) construido en torno a los individuos con linajes mixtos que incluyeran una especie extinta. Los individuos fueron los híbridos de la especie extinta en la Isla Floreana, C. niger, y la especie viviente C. becki, encontrados recientemente en la distribución geográfica endémica de la segunda especie en el Volcán Wolf (Isla Isabela). Combinamos los datos genotípicos de 35 tortugas con un linaje cargado de C. niger usando simulaciones futuras de la descendencia generada por el programa para explorar las estrategias de reproducción en cautiverio que maximizaran en general la diversidad genética y el linaje de C. niger a la vez que se ajustaba a las restricciones de recursos, la biología de la especie y la urgencia por regresar las tortugas a la Isla Floreana para facilitar la restauración del ecosistema. En general, la diversidad genética se maximizó cuando en la simulación las tortugas estuvieron organizadas en grupos de reproducción relativamente pequeños y cuando cantidades sustanciales del genoma de C. niger fueron capturados con base en los recursos disponibles para reproducir selectivamente a las tortugas en cautiverio. La diversidad genética se vio especialmente maximizada cuando las crías reproducidas en cautiverio fueron liberadas en lugar de ser utilizadas como reproductoras adicionales. Nuestros resultados proporcionan una guía práctica y basada en la genética para la inclusión de híbridos con representación genómica de un taxón extinto en los programas de restauración de especies. Cuando incorporamos a los híbridos con diversidad genética que previamente se creía perdida en los programas con el propósito de la reintroducción de especies, nuestro estudio informa al debate continuo sobre el valor de los híbridos para la conservación de la biodiversidad.杂交对物种保护提出了重大挑战, 因为它威胁着物种的遗传完整性和适应性潜力。然而, 如果一个已灭绝类群的基因组存在于现存的杂交种中, 那么杂交也可以为物种恢复提供前所未有的机遇, 通过选择性育种重新获得灭绝物种的基因组。本研究探讨了如何利用含有已灭绝物种基因组的混合血统个体, 为加拉帕戈斯陆龟 （Chelonoidis spp.） 建立圈养繁殖计划。我们的目标个体是弗洛里安娜岛灭绝物种 C. niger 与近期在其分布范围内伊莎贝拉岛沃尔夫火山发现的现存物种 C. becki 的杂交后代。我们将 35 只含有较高比例 C. niger 血统的乌龟的基因型数据与对该计划获得后代的前进式模拟相结合, 在满足总体遗传多样性和 C. niger 血统最大化, 且考虑资源限制、物种生物学特性和弗洛里安娜岛急需重引入乌龟来促进生态系统恢复的情况下, 分析了可能的圈养繁殖策略。在模拟实验中, 建立相对较小的乌龟繁殖群时的总体遗传多样性最高, 且根据已有资源对圈养乌龟进行选择性育种可以捕获大量的 C. niger 基因组。若将圈养繁殖的后代释放到野外而不是继续用于繁殖, 则遗传多样性会特别高。我们的研究结果为将携带已灭绝类群的代表性基因组的杂交种纳入物种恢复计划提供了基于遗传学的实践指导。我们的研究还表明, 可以在物种重引入项目中纳入携带了被认为已经丢失的遗传多样性的杂交种, 这也为目前杂交种在生物多样性保护中的价值的争论提供了信息。【翻译: 胡怡思; 审校: 聂永刚】.

The tortoises of Galapagos are vestiges of a once impressive, widely distributed lineage of land tortoises that declined during the period when humans expanded across the planet. Galapagos tortoises are remarkable for many reasons. They include the greatest number of surviving giant tortoises anywhere, with diverse morphological forms. These tortoises, ensconced in their island refuges, have persisted through global tortoise catastrophe, although 3 of the 15 putative species are now extinct, and surviving species are under varying levels of threat. Tortoises have played diverse ecological roles in various ecosystems around the world, often acting as ecological engineers, Through long-term, ongoing conservation efforts several populations of Galapagos tortoise species are beginning to recuperate, and many are expected to recover to the point of population self-sufficiency. Some tortoise populations may return to being the dominant herbivore within their native range.

The conservation and recovery of Galapagos giant tortoise populations began in earnest in the 1960s following the establishment of the Galapagos National Park and the Charles Darwin Foundation in 1959. Decade by decade scientists, park rangers, students, and volunteers filled knowledge gaps and incorporated new methodologies, technologies, and evolving conservation strategies into their ongoing efforts to restore tortoise species and populations. This chapter covers each decade of the 60 years of giant tortoise conservation, describing the initial search and rescue, the initiation and expansion of the tortoise breeding programs, the incorporation of tortoise genetics into tortoise conservation, control and eradication of invasive mammals that impact tortoises, and the recently established Giant Tortoise Restoration Initiative, which builds on five decades of conservation with a focus on the next half century, with a goal of restoring tortoise populations to their historical range and numbers.

Nothing was known about the source of the specimen that was the basis for Richard Harlan's description of the tortoise Testudo elephantopus beyond the facts that it was from the Galapagos and was alive in the possession of Philadelphia businessman Whitton Evans before 5 September 1826. From published and archival sources we propose that there is compelling circumstantial evidence that this tortoise was taken on Charles (Floreana, Santa Maria) Island, Galapagos, in September 1825 by Evans's ship America, Isaiah Eldredge master, on its way to Honolulu and Canton. The historically important name Testudo elephantopus Harlan 1826 should therefore take precedence for the extinct tortoise of Charles Island.

When you think of the Galapagos Islands, you perhaps think of their unique wildlife, the giant Galapagos tortoise, for example, or its pioneering research into conservation, or you could even imagine the finches made famous by Charles Darwin’s theory of evolution. When I arrived in the Galapagos in early 2019 to take on the management of a charitable veterinary clinic, I found that this reputation was entirely genuine, accurate and magical. However, my preconceived perceptions of the islands missed another part of the reality altogether; …

Reptile hematologic data provide important health information for conservation efforts of vulnerable wildlife species such as the Galapagos tortoise (Chelonoidis spp.). Given the reported discrepancies between manual leukocyte counts for nonmammalian species, two manual leukocyte quantification methods, the Natt and Herrick's (NH) and the Eopette (EO), were compared to white blood cell (WBC) estimates from blood films of 42 free-living, clinically healthy, adult female Galapagos tortoises. To investigate the effects of delay in sample processing, estimated WBC counts and leukocyte differentials were compared for blood films prepared at time of collection under field conditions (T0) to blood films prepared from samples that were stored for 18-23 hr at 4°C in the laboratory (T1). Passing-Bablok regression analysis revealed no constant or proportional error between the NH and WBC estimates (T0 and T1) with slopes of 1.1 and 0.9, respectively. However both constant and proportional errors were present between EO and WBC estimates (T0 and T1) with slopes of 3.1 and 2.7, respectively. Bland Altman plots also showed agreement between the NH and WBC estimates where the points fell within the confidence-interval limit lines and were evenly distributed about the mean. In contrast, the EO and WBC estimate comparisons showed numerous points above the upper limit line, especially at higher concentrations. WBC estimates obtained from T0 and T1 films were in agreement, whereas heterophil and monocyte percentages based on differentials were not. Cell morphology and preservation were superior in T0 blood films because thrombocytes exhibited swelling after storage, becoming difficult to differentiate from lymphocytes. In this study, the highest quality and most reliable hematologic data in Galapagos tortoises were obtained by combining immediate blood film preparation with the NH leukocyte quantification method and a confirmatory WBC estimate from the blood film.

Genome-wide assessments allow for fuller characterization of genetic diversity, finer-scale population delineation, and better detection of demographically significant units to guide conservation compared with those based on "traditional" markers. Galapagos giant tortoises (Chelonoidis spp.) have long provided a case study for how evolutionary genetics may be applied to advance species conservation. Ongoing efforts to bolster tortoise populations, which have declined by 90%, have been informed by analyses of mitochondrial DNA sequence and microsatellite genotypic data, but could benefit from genome-wide markers. Taking this next step, we used double-digest restriction-site associated DNA sequencing to collect genotypic data at >26000 single nucleotide polymorphisms (SNPs) for 117 individuals representing all recognized extant Galapagos giant tortoise species. We then quantified genetic diversity, population structure, and compared results to estimates from mitochondrial DNA and microsatellite loci. Our analyses detected 12 genetic lineages concordant with the 11 named species as well as previously described structure within one species, C. becki. Furthermore, the SNPs provided increased resolution, detecting admixture in 4 individuals. SNP-based estimates of diversity and differentiation were significantly correlated with those derived from nuclear microsatellite loci and mitochondrial DNA sequences. The SNP toolkit presented here will serve as a resource for advancing efforts to understand tortoise evolution, species radiations, and aid conservation of the Galapagos tortoise species complex.

Zooarchaeological investigations at Thompson’s Cove, San Francisco, a Gold Rush-era site located on the original shoreline of Yerba Buena Cove, provide evidence of the maritime California hide and tallow trade, consumption of abundant wild game, including seasonal hunting of migratory ducks and geese, and importation of non-native species into Alta California, specifically Galapagos tortoise (Chelonoidis sp.) and sea turtle (Family Cheloniidae). This abundant and diverse assemblage (NISP = 8661, NTAXA = 50) dating primarily to the 1840s–60s allows rigorous investigations into the economic and subsistence activity of San Francisco in a stratified context encompassing the California Gold Rush-era.

As part of a planned introduction of captive Galapagos tortoises (Chelonoidis chathamensis) to the San Cristobal highland farms, our veterinary team performed thorough physical examinations and health assessments of 32 tortoises. Blood samples were collected for packed cell volume (PCV), total solids (TS), white blood cell count (WBC) differential, estimated WBC and a biochemistry panel including lactate. In some cases not all of the values were obtainable but most of the tortoises have full complements of results. Despite a small number of minor abnormalities this was a healthy group of mixed age and sex tortoises that had been maintained with appropriate husbandry. This work establishes part of a scientific and technical database to provide qualitative and quantitative information when establishing sustainable development strategies aimed at the conservation of Galapagos tortoises.

Critically endangered wildlife species typically require intensive management using a variety of in situ and ex situ approaches. Yet, despite broad application of ex situ conservation strategies, comparatively few programs incorporate genetic tools into management decisions and monitoring efforts. This is the case with the giant Galapagos tortoise endemic to Pinzon Island (Chelonoidis ephippium); a head-start program has been in place for 50 years without an evaluation of whether this conservation intervention has captured the breadth of diversity present in the wild population. Here we used microsatellite genotypic data to reconstruct patterns of within- and among-population genetic variation in the wild and captivity, and to assess the degree to which head-start cohorts and adult captive founders are representative of the gene pool in situ. We found that Pinzon giant tortoises maintain high levels of variation in situ despite their well-documented decline and that the founders of the captive population are a reasonably diverse and representative group. However, we also found that the head-start cohorts are not representative of the wild population, as evidenced by significant genetic differentiation between the in situ and ex situ samples and by the private alleles detected in both. Future head-start activities should broaden the source locations of eggs and hatchlings to more comprehensively capture the extent and distribution of genetic variation in this critically endangered keystone herbivore. More broadly, this study further highlights the utility of integrating genetic information within ex situ conservation programs.

The San Cristóbal Galapagos tortoise, Chelonoidis chathamensis, is native to San Cristóbal, the most eastern and oldest island of the Galapagos Archipelago. Although numerous studies on the ecology, behavior and genetics of Galapagos tortoises have been published, little is known about the health status of these animals. Here we report blood values from clinically healthy tortoises., As part of a planned introduction of captive Galapagos tortoises (Chelonoidis chathamensis) to the San Cristóbal highland farms, our veterinary team performed thorough physical examinations and health assessments of 32 tortoises. Blood samples were collected for packed cell volume (PCV), total solids (TS), white blood cell count (WBC) differential, estimated WBC and a biochemistry panel including lactate. In some cases not all of the values were obtainable but most of the tortoises have full complements of results. Despite a small number of minor abnormalities this was a healthy group of mixed age and sex tortoises that had been maintained with appropriate husbandry. This work establishes part of a scientific and technical database to provide qualitative and quantitative information when establishing sustainable development strategies aimed at the conservation of Galapagos tortoises.

Although Galápagos giant tortoises are an icon for both human-mediated biodiversity losses and conservation management successes, populations of two species on southern Isabela Island (Chelonoidis guntheri, and C. vicina) remain threatened by hunting and persistence of feral animals. Conservation management of these tortoises has been hampered by lack of clarity regarding their taxonomy, ecological and morphological diversity, and the spatial distribution of evolutionarily significant units that may exist. Analyses of 16 microsatellite loci did not group samples according to current taxonomy. Instead, three (rather than two) genetic clusters were revealed. We show that the three regions of southern Isabela associated with these genetic clusters are significantly different in their ecological niches, which could suggest that ecological divergence may have shaped patterns of genetic differentiation in these tortoises. Furthermore, results suggest limited recent gene flow among sampled localities and between each of the three regions associated with genetic clusters. We discuss the need for further research on the ecological factors shaping the genetic and morphological diversity of southern Isabela tortoises. We suggest that current strategies whereby populations are managed separately are warranted pending further study, but due to mixed ancestry we recommend that Cerro Paloma tortoises be excluded from management programs.

During January 1994, feces from a captive juvenile Galápagos tortoise, Chelonoidis sp., from the Dallas Zoo, Dallas County, Texas was examined for coccidia. The tortoise was found to harbor an eimerian which is described as new. Sporulated oocysts of Eimeria iversoni n. sp. were ovoidal with a smooth, single-layered wall (∼ 0.5-0.8) that measured (L × W) 13.5 × 10.3 μm, with a length/width (L/W) ratio of 1.3; micropyle, oocyst residuum, and polar granule(s) were all absent; 2 conical projections were present on 1 end of oocyst and measured 1.0-1.5. Sporocysts were elongate-ellipsoidal and measured 8.3 × 4.5 μm, with L/W of 1.8; a Stieda body (∼ 0.5 high) was present, but substieda and parastieda bodies were absent; a sporocyst residuum was composed of 2-5 granules in a compact mass between sporozoites; sporozoites were banana-shaped and measured 9.5 × 2.5 in situ, with an ellipsoidal posterior refractile body and a spheroidal anterior refractile body. This is only the second time an eimerian has been reported from Galápagos tortoises.

Spotting a sea turtle or Galapagos tortoise on the early wharfs and streets of San Francisco or Sacramento, California during the Gold Rush (1848-1855) would not have been a rare event. Massive population influx into the San Francisco Bay region during this time resulted in substantial impacts to native species and habitats of all taxa, but the demand for food resulted in many resources, turtles and tortoises included, being imported into the cities. Providing a fresh and delectable food source, these terrapin were brought to San Francisco and Sacramento to feed the hungry Gold Rush populous. Their taste, popularity and demand also resulted in small numbers being imported into gold mining towns in the San Joaquin Valley and foothills of the Sierra Nevada’s. Remarkable as this process was, the consumption and importation of both sea turtles and Galapagos tortoises during the Gold Rush pushed native populations of these species to the brink of extinction during the mid to late-nineteenth century. Declining numbers of terrapin and increased scientific curiosity, with a desire to safeguard these creatures for future generations, resulted in their eventually legal protection and conservation. In many ways the impacts of the decimation of terrapin in the eastern Pacific during the Gold Rush are still felt today, as conservation and breeding efforts continue in an attempt to return native turtle and tortoise populations to pre-Euro-American contact levels. This research describes the historical, and new archaeofaunal, evidence of the terrapin import market in San Francisco, Sacramento and beyond during the dynamic period of the California Gold Rush.

Galapagos giant tortoises (Chelonoidis nigra ssp.) are widely known for both the role played in evolutionary theory and their precarious conservation status. Thirteen nuclear microsatellite loci were isolated and tested on 60 individuals from Cinco Cerros, Isabela Island. The mean number of alleles per locus was 5.5 (range between 2 and 12) while mean observed and expected heterozygosity were 0.417 and 0.426, respectively. A single marker statistically deviated from Hardy–Weinberg equilibrium. These markers represent a valuable addition to the molecular tools available for studying the taxonomic affiliation and relatedness of individuals in captive management plans, crucial for the maintenance of several subspecies.

article i nfo The retention time of food in the digestive tract of animals has important implications for digestive physiology. Retention time impacts digestive efficiency and among herbivores affects plant-animal interactions including herbivory and seed dispersal. Poorly studied yet iconic Galapagos tortoises are large- bodied generalist herbivores and ecosystem engineers which migrate seasonally. Potentially variable digesta retention times due to strong seasonal and altitudinal temperature gradients may influence tortoise seed dispersal abilities and rates of herbivory. We fed captive adult tortoises living in semi-natural conditions on Galapagos with inert particles and seeds from locally available fruits to determine whether seed size and ambient temperature influenced retention time. Median retention time varied from 6 to 28 days, with a mode of 12 days. Seed size had no effect on any of our measures of retention time, but ambient temperature was inversely correlated with retention times. Long retention time facilitates long distance seed dispersal by Galapagos tortoises, which may improve effectiveness. The effect of temperature, which may double from hot lowlands to cold highlands through the seasonal cycle, on tortoise digesta retention time will strongly influence seed dispersal efficiency and may influence patterns of food selection and migration in this species.

Galapagos tortoises are a symbolic animal in terms of conservation biology as well as evolutionary biology, and both in situ and ex situ conservation programs are currently underway. For endangered species, captive individuals can perform a certain role as genetic reservoirs for ongoing and future breeding programs We examined the genetic identities of two giant tortoises in Ueno Zoo, Japan. The mitochondrial genotype of the older tortoise, Taro, as appeared to be that of Chelonoidis porteri from Santa Cruz island. The mitochondrial genotype of the younger tortoise, Kamekichi, was identified as either C. becki from the northern area of Isabela island, or C. darwini from Santiago island. These genetic analyses serve as reference data for the future conservation management of captive Galapagos tortoises.

Galapagos tortoises possess two main shell forms, domed and saddleback, that correlate with the biogeographic history of this species group. However, the lack of description of morphological shell variation within and among populations has prevented the under- standing of the contribution of evolutionary forces and the potential role of ontogeny in shaping morphological shell differences. Here, we analyze two lineages of Galapagos tortoises inhabiting Santa Cruz Island by applying geometric morphometrics in combination with a photogrammetry 3D reconstruction method on a set of tortoises of different ages (from juvenile to adult). The aim of this study is to describe morphological features on the carapace that could be used for taxonomic recog- nition by taking into account confounding factors, such as the morphological changes occurring during growth. Our results indicate that despite the shared similarities of growth patterns and of morphological changes observed during growth, the two lineages and the differ- ent sexes can be distinguished on the basis of distinct carapace features. Lineages differ by the shape of the vertebral (especially concerning their width) and pleural scutes, with one lineage having a more compressed carapace shape, whereas the other possesses a carapace that is more elongated and expanded toward the sides as well as an higher positioning of the first vertebral scute. Furthermore, females have a more elongated and wider carapace shape than males. Finally, carapace shape changes with growth, with vertebral scutes becoming narrower and pleural scutes becoming larger during late ontogeny. J. Morphol. 272:379-386, 2011. 2011 Wiley-Liss, Inc.

During the voyage of the Beagle, Charles Darwin collected a single juvenile tortoise from James (San Salvador or Santiago) Island in the Galapagos Archipelago. This specimen, often referred to as Darwin's “pet” tortoise was returned alive to England along with 3 other small tortoises and examined by J.E. Gray. The subsequent fate of the specimen has been the source of much speculation, and recent popular publications have variously proposed that the tortoise was transported to Australia (where it supposedly lived to an age of more than 175 years) or that it remained in England but disappeared without a trace. We discovered that Darwin's pet was indeed registered into the British Museum collection in 1837 and that it is still extant and clearly labeled on the inner face of the plastron as BMNH 1837.8.13.1 from James Island. These data were overlooked for more than 170 years, and 3 curators (Gray, Gunther, and Boulenger) who published chelonian catalogues between 1844 and 1889 all failed to recogni...

Giant Galapagos tortoises represent an interesting model for the study of patterns of genetic divergence and adaptive differentiation related to island colonization events. Recent mitochondrial DNA work elucidated the evolutionary history of the species and helped to clarify aspects of nomenclature. We used 10 microsatellite loci to assess levels of genetic divergence among and within island populations. In particular, we described the genetic structure of tortoises on the island of Isabela, where discrimination of different taxa is still subject of debate. Individual island populations were all genetically distinct. The island of Santa Cruz harboured two distinct populations. On Isabela, populations of Volcan Wolf, Darwin and Alcedo were significantly different from each other. On the other hand, Volcan Wolf showed allelic similarity with the island of Santiago. On Southern Isabela, lower genetic divergence was found between Northeast Sierra Negra and Volcan Alcedo, while patterns of gene flow were recorded among tortoises of Cerro Azul and Southeast Sierra Negra. These tortoises have endured heavy exploitation during the last three centuries and recently attracted much concern due to the current number of stochastic and deterministic threats to extant populations. Our study complements previous investigation based on mtDNA diversity and provides further information that may help devising tortoise management plans.

Giant tortoises, a prominent symbol of the Galápagos archipelago, illustrate the influence of geological history and natural selection on the diversification of organisms. Because of heavy human exploitation, 4 of the 15 known species ( Geochelone spp.) have disappeared. Charles Darwin himself detailed the intense harvesting of one species, G. elephantopus , which once was endemic to the island of Floreana. This species was believed to have been exterminated within 15 years of Darwin's historic visit to the Galápagos in 1835. The application of modern DNA techniques to museum specimens combined with long-term study of a system creates new opportunities for identifying the living remnants of extinct taxa in the wild. Here, we use mitochondrial DNA and microsatellite data obtained from museum specimens to show that the population on Floreana was evolutionarily distinct from all other Galápagos tortoise populations. It was demonstrated that some living individuals on the nearby island of Isabela are genetically distinct from the rest of the island's inhabitants. Surprisingly, we found that these “non-native” tortoises from Isabela are of recent Floreana ancestry and closely match the genetic data provided by the museum specimens. Thus, we show that the genetic line of G. elephantopus has not been completely extinguished and still exists in an intermixed population on Isabela. With enough individuals to commence a serious captive breeding program, this finding may help reestablish a species that was thought to have gone extinct more than a century ago and illustrates the power of long-term genetic analysis and the critical role of museum specimens in conservation biology.

Although the killing of giant tortoises in the Galapagos Islands has been prohibited since 1933, poaching of tortoises still occurs. Personnel of the Galapagos National Park Service and the Charles Darwin Research Station regularly survey populations of tortoises throughout the archipelago and report all dead tortoises found. For the 10-year period 1995–2004 the field personnel reported evidence of 190 giant tortoises killed, primarily on the southern portion of Isabela Island. For the first 6 years the number of tortoises found killed was

Ex situ conservation strategies may be substantially informed by genetic data, and yet only recently have such approaches been used to facilitate captive population management of endangered species. The Galapagos tortoise Geochelone nigra is an endangered species that has benefited greatly from the application of molecular and population genetic data, but remains vulnerable throughout its range. The geographic and evolutionary origins of 98 tortoises in private collections and zoos on three continents were identified using mitochondrial DNA (mtDNA) control region sequences and multi-locus microsatellite genotype data relative to a large database of representative samplings from all extant populations, including historical population allele frequency data for the Geochelone nigra abingdoni taxon on Pinta by way of museum specimens. All but six individuals had mtDNA haplotypes previously sampled, with the novel haplotypes identified as most closely related to robust populations on the islands of Santa Cruz and Isabela. Multi-locus genotypic assignments corroborated the results obtained from the mtDNA analyses, with 83.7% of individuals consistently assigned to the same locality by both datasets. Overall, the majority of captive unknowns sampled were assigned to the La Caseta Geochelone nigra porteri population, with no fewer than six individuals of hybrid origin detected. Although a purported Pinta individual was revealed to be of Pinzon ancestry, the two females currently housed with Lonesome George exhibited haplotypic and genotypic signatures that indicate that they are among the most appropriate matches for captive breeding. More generally, molecular approaches continue to represent important tools for assessing conservation value, minimizing hybridization and guiding management programs for preserving the distinctiveness of G. nigra taxa in captivity.

Phaeohyphomycosis is an infection caused by brown to black fungi presenting in tissue sections as dark walled septate hyphae, dark walled yeast, or both. Disseminated phaeohyphomycosis in reptiles has rarely been reported in the literature. An adult Galapagos tortoise, Geochelone nigra, presented with unilateral ocular lesions consisting of buphthalmia and a posterior chamber density. Clinical progression, diagnostics, and therapeutics are discussed. Diagnosis of phaeohyphomycosis was made on histopathology of the enucleated eye. Eventual euthanasia and necropsy revealed widespread granulomatous inflammation with fungal invasion. Dissemination was likely hematogenous. Culture and molecular analyses determined the etiologic agent to be an Exophiala species not previously seen. A species name has not been determined for this fungus.

A group of five, related captive born juvenile Galapagos tortoises, Geochelone nigra, presented with cervical neck swellings (6 – 20 cm) of greater than one year of duration. Thyroid hormones, plasma triiodothyronine (T3) and thyroxine (T4) were normal range or slightly elevated. Surgical biopsy and histologic and immunohistochemical evaluation of the masses revealed thymic hyperplasia. Thymic hyperplasia should be included as a differential diagnosis, in addition to goiter, for neck swelling in tortoises.

Island radiations can offer challenging systemsfor the implementation of conservation policiesbecause descendent populations may exhibitdifferent levels of adaptive divergence,reproductive isolation, and phylogeneticdistinctiveness. This seems particularly truefor the endangered Galapagos gianttortoises (Geochelone nigra), whichcomprise a lineage that radiated rapidly andconcomitantly with the evolution of thearchipelago. We used mitochondrial DNAsequences and microsatellite markers toinvestigate the genetic structure, and toreconstruct genealogical relationships and thehistory of population colonization of gianttortoises from the Islands of Santa Cruz andPinzon, including samples of a basal taxonfrom the Island of San Cristobal.Populations displayed marked geneticdivergence, contrasting demographic histories,and deep phylogeographic structure. The patternof diversification among populations wasconsistent with geological and biogeographichistory, and to some extent, with adaptive andmorphological divergence. Results stronglyindicate the presence of a minimum of fourconservation units with long-standingevolutionary separation: two in Santa Cruz, onein Pinzon, and one in San Cristobal. Wepropose that these findings be effectivelyintegrated with other existing data by theappropriate environmental agencies to evaluatecurrent conservation efforts and implement newstrategies aimed at protecting the integrityand diversity of giant tortoise populations.

We examined the phylogeography and history of giant Galapagos tortoise populations based on mito- chondrial DNA sequence data from 161 individuals from 21 sampling sites representing the 11 currently recognized extant taxa. Molecular clock and geological considerations indicate a founding of the monophyletic Galapagos lineage around 2-3 million years ago, which would allow for all the diversification to have occurred on extant islands. Founding events generally occurred from geologically older to younger islands with some islands colonized more than once. Six of the 11 named taxa can be associated with monophyletic maternal lineages. One, Geochelone porteri on Santa Cruz Island, consists of two distinct populations connected by the deepest node in the archipelago-wide phylogeny, whereas tortoises in northwest Santa Cruz are closely related to those on adjacent Pinzon Island. Volcan Wolf, the northernmost volcano of Isabela Island, consists of both a unique set of maternal lineages and recent migrants from other islands, indicating multiple colonizations possibly due to human transport or multiple colonization and partial elimination through competition. These genetic findings are consistent with the mixed morphology of tortoises on this volcano. No clear genetic differentiation between two taxa on the two southernmost volcanoes of Isabela was evident. Extinction of crucial populations by human activities confounds whether domed versus saddleback carapaces of different populations are mono- or polyphyletic. Our findings revealed a complex phylogeography and history for this tortoise radiation within an insular environment and have implications for efforts to conserve these endangered biological treasures.

Galagete, gen. n. (type species: Gelechia protozona Meyrick) is described to include 11 species of Autostichidae apparently endemic to the Galapagos Islands. This group represents the first recognised case of an extensive radiation of endemic Lepidoptera in the archipelago. The following species are described as new: Galagete cinerea, G. consimilis, G. cristobalensis, G. darwini, G. espanolaensis, G. levequei, G. pecki, G. seymourensis, and G. turritella. Gelechia gnathodoxa Meyrick and Gelechia protozona Meyrick, both described from the Galapagos Islands, are transferred to Galagene and redescribed. Galagete is closely related to Taygete Chambers, a taxon previously placed in the Gelechiidae. Specimens of Galagete were reared from twigs and dead leaves of Scalesia species (Asteraceae) and from Galapagos tortoise (Geochelone elephantopus) scats.

A species of giant tortoise unique to Floreana Island in the Galapagos and considered extinct since the 19th century could soon be brought back from the dead. Galapagos giant tortoises are often divided into 15 species, 11 of which survive today. The tortoise populations on all the islands were decimated after humans arrived in the archipelago and began loading them onto ships for their meat. Sailors also brought animals such as rats, which can eat young tortoises, and goats, which destroy the reptiles' habitat.

The reproductive physiology of nine Galapagos tortoises (Geochelone nigra) was studied from February 1988 to May 1989. The study encompassed the annual reproductive cycle to include complete mating and nesting sequences. Male (n = 4) and female (n = 5) seasonal reproductive changes were determined throughout the study with endocrine analysis and ultrasonographic examinations. Males displayed a prenuptial rise in serum testosterone (x― ±SE = 6.62 ± 0.92 ng/ml in August) during which gonadal maturation and spermatogenesis are thought to occur. The male reproductive cycle appears consistent with the prenuptial spermatogenic pattern exhibited by other tropical turtles. In the females, testosterone rose during the mating period (x― ± SE = 499.3 ± 124.6 pg/ml in October) prior to ovulation and is probably related to receptivity in the females. Progesterone was more variable, but also peaked during the mating period (x― ± SE = 1,017.2 ± 220.6 pg/ml in October) and appears related to ovulation. Estradiol rose several months prior to mating (x― ± SE = 75.5 ± 11.9 pg/ml in July) and was correlated with increased serum calcium levels. This increase in estradiol is thought to stimulate vitellogenesis several months prior to mating. Nesting occurred from November 1988 to April 1989, during which six clutches were laid. Clutch size ranged from eight to 17 eggs. Both male and female Galapagos tortoises display seasonal physiological changes that function to regulate annual reproductive patterns. Zoo Biol 17:505–517, 1998. © 1998 Wiley-Liss, Inc.

A new fungal genus and species, Aphanoascella galapagosensis, recovered from carapace keratitis in a Galapagos tortoise residing in a south Texas zoological collection, is characterized and described. The presence of a pale peridium composed of textura epidermoidea surrounded by scarce Hulle cell-like chlamydospores, and the characteristic reticulate ascospores with an equatorial rim separates it from other genera within the Onygenales. The phylogenetic tree inferred from the analysis of D1/D2 sequences demonstrates that this fungus represents a new lineage within that order. As D1/D2 and ITS sequence data also shows a further separation of Aphanoascus spp. into two monophyletic groups, we propose to retain the generic name Keratinophyton for species whose ascospores are pitted and display a conspicuous equatorial rim, and thereby propose new combinations in this genus for four Aphanoascus species.

Seasonal migration has evolved in many taxa as a response to predictable spatial and temporal variation in the environment. Individual traits, physiology and social state interact with environmental factors to increase the complexity of migratory systems. Despite a huge body of research, the ultimate causes of migration remain unclear. A relatively simple, tractable system - giant tortoises on Santa Cruz Island, Galapagos, was studied to elucidate the roles of environmental variation and individual traits in a partial migratory system. Specifically, we asked: (i) do Galapagos tortoises undergo long-distance seasonal migrations? (ii) is tortoise migration ultimately driven by gradients in forage quality or temperature; and (iii) how do sex and body size influence migration patterns? We recorded the daily locations of 17 GPS-tagged tortoises and walked a monthly survey along the altitudinal gradient to characterize the movements and distribution of tortoises of different sizes and sexes. Monthly temperature and rainfall data were obtained from weather stations deployed at various altitudes, and the Normalized Difference Vegetation Index was used as a proxy for forage quality. Analyses using net displacement or daily movement characteristics did not agree on assigning individuals as either migratory or non-migratory; however, both methods suggested that some individuals were migratory. Adult tortoises of both sexes move up and down an altitudinal gradient in response to changes in vegetation dynamics, not temperature. The largest tagged individuals all moved, whereas only some mid-sized individuals moved, and the smallest individuals never left lowland areas. The timing of movements varied with body size: large individuals moved upward (as lowland forage quality declined) earlier in the year than did mid-sized individuals, while the timing of downward movements was unrelated to body size and occurred as lowland vegetation productivity peaked. Giant tortoises are unlikely candidates for forage-driven migration as they are well buffered against environmental fluctuations by large body size and a slow metabolism. Notably the largest, and presumably most dominant, individuals were most likely to migrate. This characteristic and the lack of sex-based differences in movement behaviour distinguish Galapagos tortoise movement from previously described partial migratory systems. published

Figure 1. The morphology of eosinophils in different reptile species. Wright–Giemsa stain. 9100 objective. From left to right (A) Red-footed tortoise (Chelonoidis carbonaria), (B) Cayman lizard (Dracaena guianensis), (C) Gopher tortoise (Gopherus polyphemus), (D) Pancake tortoise (Malacochersus tornieri), (E) Desert tortoise (Gopherus agassizii), (F) Green iguana (Iguana iguana), (G) Northern red bellied turtle (Pseudemys rubriventris), (H) Galapagos tortoise (Chelonoidis nigra), (I) Rainbow boa (Epicrates cenchria), (J) American crocodile (Crocodylus acutus), (K and L) Kemp’s ridley turtle (Lepidochelys kempii), (M–O) Green sea turtle (Chelonia mydas), (P) Loggerhead sea turtle (Caretta caretta).

Galápagos tortoises represent the only surviving lineage of giant tortoises that exhibit two different types of shell morphology. The taxonomy of Galápagos tortoises was initially based mainly on diagnostic morphological characters of the shell, but has been clarified by molecular studies indicating that most islands harbor monophyletic lineages, with the exception of Isabela and Santa Cruz. On Santa Cruz there is strong genetic differentiation between the two tortoise populations (Cerro Fatal and La Reserva) exhibiting domed shell morphology. Here we integrate nuclear microsatellite and mitochondrial data with statistical analyses of shell shape morphology to evaluate whether the genetic distinction and variability of the two domed tortoise populations is paralleled by differences in shell shape. Based on our results, morphometric analyses support the genetic distinction of the two populations and also reveal that the level of genetic variation is associated with morphological shell shape variation in both populations. The Cerro Fatal population possesses lower levels of morphological and genetic variation compared to the La Reserva population. Because the turtle shell is a complex heritable trait, our results suggest that, for the Cerro Fatal population, non-neutral loci have probably experienced a parallel decrease in variability as that observed for the genetic data.

This study demonstrates the efficacy of using ultrasound to determine the presence of ovarian developing, preovulatory, and atretic follicular structures and oviductal eggs in the Galapagos tortoise, Geochelone elephantopus spp. Ultrasound was effective in locating both right and left ovarian structures in 92% (n = 100 ovaries) of the trials. Developing and preovulatory follicles and oviductal eggs were echogenically visualized and had measurements ranging from 18 to 44 mm (n = 93) and 55 to 68 mm (n = 9), respectively. Atretic follicles ranged in size from 10 to 38 mm (n = 10). In one trial with four G. elephantopus, ultrasound observations were validated with the use of laparoscopy. All procedures were accomplished without general anesthesia on a specifically designed restraining table. Ultrasound provides an effective, safe modality for determining the reproductive status of adult female tortoises.

As once boldly stated, ‘bad taxonomy can kill’, highlighting the critical importance of accurate taxonomy for the conservation of endangered taxa. The concept continues to evolve almost 15 years later largely because most legal protections aimed at preserving biological diversity are based on formal taxonomic designations. In this paper we report unrecognized genetic divisions within the giant tortoises of the Galápagos. We found three distinct lineages among populations formerly considered a single taxon on the most populous and accessible island of Santa Cruz; their diagnosability, degree of genetic divergence and phylogenetic placement merit the recognition of at least one new taxon. These results demonstrate the fundamental importance of continuing taxonomic investigations to recognize biological diversity and designate units of conservation, even within long-studied organisms such as Galápagos tortoises, whose evolutionary heritage and contribution to human intellectual history warrant them special attention.

Perhaps the most enduring debate in reptile systematics has involved the giant Galápagos tortoises ( Geochelone nigra ), whose origins and systematic relationships captivated Charles Darwin and remain unresolved to this day. Here we report a phylogenetic reconstruction based on mitochondrial DNA sequences from Galápagos tortoises and Geochelone from mainland South America and Africa. The closest living relative to the Galápagos tortoise is not among the larger-bodied tortoises of South America but is the relatively small-bodied Geochelone chilensis , or Chaco tortoise. The split between G. chilensis and the Galápagos lineage probably occurred 6 to 12 million years ago, before the origin of the oldest extant Galápagos island. Our data suggest that the four named southern subspecies on the largest island, Isabela, are not distinct genetic units, whereas a genetically distinct northernmost Isabela subspecies is probably the result of a separate colonization. Most unexpectedly, the lone survivor of the abingdoni subspecies from Pinta Island (“Lonesome George”) is very closely related to tortoises from San Cristóbal and Española, the islands farthest from the island of Pinta. To rule out a possible recent transplant of Lonesome George, we sequenced DNA from three tortoises collected on Pinta in 1906. They have sequences identical to Lonesome George, consistent with his being the last survivor of his subspecies. This finding may provide guidance in finding a mate for Lonesome George, who so far has failed to reproduce.

The Galapagos Islands are home to 11 subspecies of large terrestrial tortoises (Geochelone nigra). All Galapagos tortoises are considered endangered and approximately 12,000 animals still exist. Until now, the reproductive cycle of the Galapagos tortoise has been studied only in captive animals, and no data from free-ranging tortoises have been available. During a one-year period, blood samples were collected from male and femaleG. nigraliving under seminatural conditions on Santa Cruz Island, Galapagos. Plasma steroid hormones were measured by radioimmunoassays (RIAs). In males, plasma testosterone and corticosterone increased a few months before the onset of the mating season. Peak levels were observed while most copulations occurred and environmental temperatures were highest. Both testosterone and corticosterone showed low levels during the cold and dry nesting season and high levels during the hot and rainy mating season. In females, testosterone and corticosterone also rose during the hot and rainy mating season. Both hormones peaked during the second half of the mating season and decreased during the cooler dry season. Female estradiol levels increased at the onset of the mating season, reaching the highest level at the peak of the mating season, which coincided with the highest annual temperatures measured. Estradiol slowly decreased within the next months and rapidly dropped at the onset of the nesting season when temperatures decreased. Progesterone levels were high close to the time of ovulation and showed clearly elevated levels at the beginning of the nesting season after some females had laid their first clutch. Progesterone decreased during the nesting season, when ambient temperatures began to decrease, and reached minimal levels in the postbreeding period shortly before the onset of the next mating season. There were significant annual variations in plasma testosterone in both males and females. Plasma corticosterone was generally higher in males than in females and varied throughout the year in both sexes.

The Parisian comparative anatomist Claude Perrault, dissecting an Indian giant tortoise in 1676, was the first to observe that the urinary bladder is of an extraordinary size in terrestrial tortoises. In 1799, the English comparative physiologist Robert Townson suggested that the bladder functioned as a water reservoir, as he had shown previously for frogs and toads. However, these observations went unnoticed in subsequent reports on tortoise water economy that were made by travellers and naturalists visiting the Galapagos Archipelago and marvelling over the huge numbers of giant tortoises that inhabited these desert-like islands. The first such report was by an American naval officer, David Porter, who was a privateer in the 1812-15 war with England. In his journal he referred to the constant supply of water which the Galapagos tortoises carried with them. References to the location in the body, as well as the amounts and quality of the water stored, were, however, contradictory. The confusion concerning the anatomical identity of the water reservoir in the Galapagos tortoise, Geochelone elephantopus, persisted throughout the nineteenth century, and continued when studies of tortoise water economy and drinking behaviour in arid environments were taken up independently in the desert tortoise, Gopherus agassizii, which inhabits the desert regions in the south-western United States. In 1881 Cox found large sacs filled with clear water under the carapace, but it was half a century later that these sacs were identified as the large bilobed bladder; references to specific water sacs continued to appear in the literature until the 1960s. Since 1970, information on the water economy of desert tortoises has been obtained from extensive field studies. Rates of disappearance of tritiated water injected into the body have shown that during the drought periods of the summer, water turnover (intake) rates do not differ from the rates of metabolic water production. Under these conditions urine is not voided, but is stored in the large bladder. During a drought period the bladder urine increases from initially low osmolality finally to reach isosmolality with the blood plasma. Soluble K+ is the major cation of the urine, but large amounts of K+ are also present as precipitated urates. During a drought period the body is in negative water balance, but despite substantial losses of total body water, the plasma concentrations of Na+ and Cl- can remain constant for many months, indicating regulation of the extracellular fluid and water content of the body tissues by reabsorption of water from the urinary bladder. The bladder thus acts both as a store for nitrogenous waste and K+ and as a water reservoir during droughts. Following rain showers, there is a sharp decline in tritium activity correlated with copious drinking from temporary pools of rain water. The old bladder urine is voided and most of the water drunk is stored as a highly dilute urine. In 1676 Perrault observed that in a freshwater turtle, Emys orbicularis, but not in the giant tortoise, two other bladders opened into the cloaca. By the mid-twentieth century it had been established that these cloacal bladders typically were restricted to species of chelonians that led a semi-terrestrial or semi-aquatic life. The function of the bladders has been debated since Townson observed in 1799 that dehydrated freshwater turtles took up water by anal drinking, suggesting that anal drinking served in the water economy of semi-terrestrial turtles. Since then, the bladders have been ascribed hydrostatic and respiratory functions, but the recent literature mostly argues for a respiratory function. The possible role of the cloacal bladders as a water reservoir in amphibious turtles is still open. Terrestrial amphibians and tortoises are unique among vertebrates in possessing large urinary bladders that may function as water reservoirs in dry environments. (ABSTRACT TRUNCATED)

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In comparison with other animals, human beings are relatively slow and ineffective. Our physical strength and general performance fall far below that of animals of our own size. The human life-span is also short when compared with such different animals as the elephant or the Galapagos tortoise which limits the amount of human accumulated experience. We cannot remain in water for a long time, or fly; our body can only survive within a very limited internal and external temperature range and we must have oxygen to breathe.

Background The giant Galápagos tortoise, Chelonoidis nigra, is a large-sized terrestrial chelonian of high patrimonial interest. The species recently colonized a small continental archipelago, the Galápagos Islands, where it has been facing novel environmental conditions and limited resource availability. To explore the genomic consequences of this ecological shift, we analyze the transcriptomic variability of five individuals of C. nigra, and compare it to similar data obtained from several continental species of turtles. Results Having clarified the timing of divergence in the Chelonoidis genus, we report in C. nigra a very low level of genetic polymorphism, signatures of a weakened efficacy of purifying selection, and an elevated mutation load in coding and regulatory sequences. These results are consistent with the hypothesis of an extremely low long-term effective population size in this insular species. Functional evolutionary analyses reveal a reduced diversity of immunity genes in C. nigra, in line with the hypothesis of attenuated pathogen diversity in islands, and an increased selective pressure on genes involved in response to stress, potentially related to the climatic instability of its environment and its elongated lifespan. Finally, we detect no population structure or homozygosity excess in our five-individual sample. Conclusions These results enlighten the molecular evolution of an endangered taxon in a stressful environment and point to island endemic species as a promising model for the study of the deleterious effects on genome evolution of a reduced long-term population size.

Background Although not unusual to find captive relicts of species lost in the wild, rarely are presumed extinct species rediscovered outside of their native range. A recent study detected living descendents of an extinct Galapagos tortoise species (Chelonoidis elephantopus) once endemic to Floreana Island on the neighboring island of Isabela. This finding adds to the growing cryptic diversity detected among these species in the wild. There also exists a large number of Galapagos tortoises in captivity of ambiguous origin. The recently accumulated population-level haplotypic and genotypic data now available for C. elephantopus add a critical reference population to the existing database of 11 extant species for investigating the origin of captive individuals of unknown ancestry. Methodology/Findings We reanalyzed mitochondrial DNA control region haplotypes and microsatellite genotypes of 156 captive individuals using an expanded reference database that included all extant Galapagos tortoise species as well as the extinct species from Floreana. Nine individuals (six females and three males) exhibited strong signatures of Floreana ancestry and a high probability of assignment to C. elephantopus as detected by Bayesian assignment and clustering analyses of empirical and simulated data. One male with high assignment probability to C. elephantopus based on microsatellite genotypic data also possessed a “Floreana-like” mitochondrial DNA haplotype. Significance Historical DNA analysis of museum specimens has provided critical spatial and temporal components to ecological, evolutionary, taxonomic and conservation-related research, but rarely has it informed ex situ species recovery efforts. Here, the availability of population-level genotypic data from the extinct C. elephantopus enabled the identification of nine Galapagos tortoise individuals of substantial conservation value that were previously misassigned to extant species of varying conservation status. As all captive individuals of C. elephantopus ancestry currently reside at a centralized breeding facility on Santa Cruz, these findings permit breeding efforts to commence in support of the reestablishment of this extinct species to its native range.