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Purpose: In the Agriculture industry, tortoises may not have a great commercial value compared with chicken and hoofed mammals; nevertheless, they have a substantial economic value for food, medicine, and ecological services. The empirical work was conducted at the Departmental Research Center (DRC), to investigate the impact of growth phases on body weight (BW) and morphometrics of different age groups. Design/ Methodology/ Approach: Eighty freshwater tortoises of 4 age groups (20 hatchlings, 20 juveniles, 20 sub-adults and 20 adults) were obtained from the Ministry of Forestry and Wildlife in Nigeria. A deep litter housing system was used for the present study. Tortoises were fed with cooked meat, concentrate, fermented cassava, and palm fruits. Findings: The mean BW ranged from 41.00g - 848.00g. The result revealed that the mean BW of the tortoise value (503g). The Coefficient of Variance (CV) of morphometrics ranged from 9.73% - 15.63%. The straight carapace length (SCL) had a higher CV value (15.63%), followed by plastron length (PL) (12.90%) and least value (9.73%) for carapace width (CW). There was a huge difference in all the morphometrics except SCL and CW for sub-adult and adult tortoises. The result revealed that SCL, CW, PL and plastron width (PW) differed distinctly from BW. The correlation coefficient of BW and morphometric of juvenile growth phase (JGP) and sub-adult phase (SAGP) ranged from (0.326 - 0.964) and (0.275 - 0.953) respectively. Research Limitation/Implications: This research focused on Nigeria's availability and sustainability of freshwater tortoises. Practical Implication: This paper has potential implications for understanding the management and improvement of the freshwater tortoise in Nigeria. Social Implication: This study will enhance the availability and development of freshwater tortoise for policy-makers in addressing sustainable food security through social, economic and environmental stability for the present and future generations. Originality/Value: This study is based on the data collected on body weight and morphometric traits during growth phases. [ABSTRACT FROM AUTHOR]

Freshwater turtles and tortoises are highly threatened by illegal and unsustainable wildlife trade. The trade has been thriving online, particularly on social media platforms, in recent decades. We conducted a two-year online survey on 20 Facebook groups in 2019-2020 and reviewed CITES trade data from 1990-2019 (30 yr) to elucidate chelonian trade dynamics in the Philippines. A total of 5,801 individuals representing 77 taxa were documented for sale on Facebook in 2019-2020. The 10 most commonly traded species represented 79% of the total quantity, and Centrochelys sulcata (n = 1,211) was the most offered for sale. The analysis of 307 CITES trade records showed that the Philippines imported between 3,365 (importer-reported) and 4,279 (exporter-reported) live chelonians of 39 species from 21 countries and territories during the 30-yr period. There were 23 CITES Appendix-listed species, including six species listed on Appendix I, documented for sale on Facebook but without import records from the CITES Trade Database such as Astrochelys radiata (n = 47), Astrochelys yniphora (n = 2), Geochelone platynota (n = 30), Geoclemys hamiltonii (n = 30), Pangshura tecta (n = 42), and Pyxis arachnoides (n = 3). Whereas the origins of these species were uncertain (e.g. pre-CITES convention; smuggled), some individuals may be poached from the wild, recently smuggled, and illegally offered in the country. Our results show that the wildlife trade continues to thrive on Facebook. Greater cooperation among conservation groups, wildlife authorities, and social media platforms and appropriate actions are urgently needed to curtail illegal online wildlife trade proliferation. [ABSTRACT FROM AUTHOR]

Sequences of ribosomal internal transcribed spacers ( ITS s) are of great importance to molecular phylogenetics and DNA barcoding, but remain unstudied in some large taxa of Deuterostomia. We have analyzed complete ITS1 and ITS2 sequences in 62 species from 16 Deuterostomia classes, with ITS sequences in 24 species from 11 classes initially obtained using unannotated contigs and raw read sequences. A general tendency for both ITS length and GC-content increase from interior to superior Deuterostomia taxa, a uniform GC-content in both ITS s within the same species, thymine content decrease in sense DNA sequences of both ITS s are shown. A possible role of GC-based gene conversion in Deuterostomia ITS evolutionary changes is hypothesized. The first example of non-LTR retrotransposon insertion into ITS sequence in Deuterostomia is described in turtle Geochelone nigra . The roles of mobile genetic element insertions in the evolution of ITS sequences in some Sauropsida taxa are discussed as well. [ABSTRACT FROM AUTHOR]

Specimens of Galapagos tortoises ( Testudo, now Chelonoidis) obtained by scientific institutions up to and including the voyage of the Beagle (1835) are reviewed, along with the scientific literature of that period. The idea that all giant tortoises (Galapagos and Indian Ocean) were a single species ( Testudo indica) was challenged as early as 1817 by Amasa Delano and refuted scientifically by Harlan in 1826, although his publication was widely ignored; some authors continued to use T. indica for Galapagos tortoises at least until 1855. That Galapagos tortoises varied from island to island was reported first by David Porter in 1815, but such differences continued to be in the realm of hearsay until well after the publication of the second edition of Darwin's Journal of researches in 1845. Contrary to what has been written by modern authors, Darwin did not think that tortoises had been introduced to the Galapagos from elsewhere. Also contrary to popular mythology, tortoises did not play an important role in the development of Darwin's evolutionary theories. [ABSTRACT FROM AUTHOR]

Over a half-century ago, C. W. Hibbard proposed a climate theory based on imported living giant tortoises ("Geochelone") as proxies that suggested the climate adaptations of giant fossil tortoises of the Cenozoic Era (65.5 million years ago to present) were subtropical or tropical across much of North America. This has been a prominent and enduring paleoclimate theory. We show that incorrect assumptions and other problems invalidate this theory. Seven alternative concepts are presented that suggest North American fossil giant tortoises could have evolved necessary adaptations including cold-adaptive morphology, behavioural thermoregulation, burrowing, use of caves as shelters, tolerance of prolonged cessation of food consumption, cryoprotection and supercooling (protection from freezing), and gigantothermy (metabolic and structural thermoregulation) to survive northern winters and in montane areas. This study illustrates the potential danger of using an inappropriate proxy to predict past climates. [ABSTRACT FROM AUTHOR]

Illegal trade in tortoises and freshwater turtles (TFTs) for pet, meat and traditional medicine markets in East and Southeast Asia poses significant threats to wild TFTs globally. South Asian countries such as India are believed to be disproportionately large sources of wild TFTs in illegal international markets, but the nature and dynamics of this trade in India are poorly understood. Using data from 223 enforcement seizure reports obtained through systematic online searches, we show that at least 15 of India's 28 TFT species, including 10 IUCN Threatened species, are illegally harvested, with over 58,000 live individuals seized during 2011–15. Geochelone elegans , Geoclemys hamiltonii and Lissemys punctata were recorded in the largest number of seizures and comprised the largest numbers of TFTs seized overall. Nearly 90% of all seizures were from illegal commercial trade, and there were numerous reports of Indian TFTs being transported by road, rail and air within India, as well as to known pet and meat trading hubs in Bangladesh, Thailand, and four other East/Southeast Asian countries. Commercial trade of live TFTs now targets twice as many Indian species as reported in the 1990s. Alongside illegal harvests for local consumption and TFT body parts for traditional East Asian medicines, this illegal trade poses a growing threat to Indian TFTs. Our findings indicate that building awareness and capacity for handling TFT seizures among enforcement agencies, and strengthening international cooperation for law enforcement, are important steps needed for conserving India's endangered tortoises and freshwater turtles. [ABSTRACT FROM AUTHOR]

Information on geochelone platynota from Myanmar including information related to topics like morphomeric measurements and reproductive output for large female Burmese star tortoise is presented.

This study assesses the rate and pattern of variation of allometric shell growth in Indian star tortoise Geochelone elegans. Morphometric measurements of 83 Indian star tortoises were taken over 6 months. The anal notch measurements correctly classified the sex of the individuals based on the results of multiple regression analysis and chi-square test. Discriminant analysis clustered the growth rates into three age groups. The shell growth across sexes varied with age and morphometric measurements of the shell characters (length in males; width in females). The increase in straight carapace width and plastron length (PL) was significantly different across sexes (females > males and males > females respectively) in 5-7 years age class only. A pronounced increase in PL in males and overall width in females only in the age class of 7-9 years may indicate the influence of sexual selection. The difference in allometric shell growth (in males and females) may thus lead to sexually dimorphic adults. [ABSTRACT FROM AUTHOR]

Additional archival information on the history of the holotype of Testudo nigra (¼T. californiana) confirms that there is probably no possibility of establishing its island of origin within the Galapagos. Both names should be suppressed as nomina dubia, despite the fact that T. nigra was relatively recently resurrected as the species name for all Galapagos tortoises. The status of the name Testudo nigrita as a nomen dubium is here further confirmed by the fact that its lectotype no longer exists. [ABSTRACT FROM AUTHOR]

A female Indian star tortoise (Geochelone elegans) was evaluated for anorexia and suspected coelomic masses. Clinical examination indicated follicular stasis. The tortoise was anesthetized and placed in dorsal left lateral recumbency for a right prefemoral approach. The ovaries and oviducts were exposed through the right prefemoral incision. The ovarian vasculature, the mesovarium, the oviduct, mesosalpinx and associated vasculature were ligated and transected. Bilateral oophorosalpingectomy was performed through the incision, without coelioscopy. Since then, the same procedure has been performed in five other tortoises, and all recovered well. These results suggest that bilateral oophorosalpingectomy, performed through a prefemoral incision, without coelioscopy, is a safe and practical approach for treating follicular stasis in tortoises. [ABSTRACT FROM AUTHOR]

We used automatic game-cameras to document the consumption of desert gourds (Cucurbita foetidissima) by collared peccary (Pecari tajacu) during 2009-2011 at a wildlife feeding station near Alpine, Texas. Our observations constitute the first report of the fruit of C. foetidissima in the diet of collared peccary. Seeds probably escape damage during mastication and chemical digestion owing to their small size, and we, therefore, consider collared peccary to be potential dispersal agents of C. foetidissima. Although extinct megafauna (e.g., probiscideans, equids, and Geochelone) also may have dispersed seeds of C. foetidissima, the contention that its fruit is an ecological anachronism warrants reconsideration. [ABSTRACT FROM AUTHOR]

The article presents the ruling of the International Commission on Zoological Nomenclature on an application to conserve the specific name Testudo gigantea for the giant land tortoise found on Aldabra Atoll in the western Indian Ocean. It provides a background of the application which was submitted by J. Frazier on April 17, 2008. The commission has reportedly decided to conserve the use of the specific name by maintenance of a designated neotype and suppression of Testudo dussumieri which is currently called Dipsochelys dussumieri. The application has received 19 affirmative votes and four negative votes.

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The article discusses a study that examined the social learning abilities of the non-social red-footed tortoise, Geochelone carbonaria, which inhabits the tropical forests in Central America and South America. The material and methods used in the study are discussed, including the subjects, apparatus and successive approximation procedure. The study showed that the solitary tortoise can learn to solve a task by observing the actions of a conspecific demonstrator. Furthemore, all observer tortoises successfully achieved a goal.

The article provides information on a study which examined the body size development of captive and free-ranging African spurred tortoises, Geochelone sulcata, over a period of nearly 18 years. It explains that the tortoises were kept in outdoor enclosures with natural vegetation during the summer and indoors on hemp in winter. Researchers found that the logistic growth model best described growth in body mass of African spurred tortoises and produced accurate estimated ages at sexual maturity. They also suggest that faster growing tortoises reach sexual maturity earlier than slower growing individuals, based on the growth-curve-based estimates of sexual maturity.

An adult specimen of "Jaboty-piranga" (Geochelone carbonaria), female, weighing 3.5 kg, was attended in the Doctor-school Dr. Luiz Cataldi de Souza of the University Centre Serra dos Órgãos - Teresópolis, Rio de Janeiro, presenting historically of eggs retention. By means of physical and radiografic examination the presence of three eggs was noted in normal positions. Because of being a reproductive station, the observation of the animal was advised to the owner, a year later, the tortoise was returned to the clinic because of not having expelled the eggs. After new radiografic examination, the presence of three eggs in the same positions was diagnosed, and 0.03 mL of oxitocine was applied, for subcutaneous road in the previous appendix of the animal. Passed three hours of the application of the hormone, the female of giant tortoise-pauper expelled the eggs naturally, no surgical intervention was needed. [ABSTRACT FROM AUTHOR]

The article offers information on an application under Article 75.8 of the International Code of Zoological Nomenclature created to conserve the specific name Testudo gigantea in its customary usage for the giant land tortoise (Testudinidae) found on Aldabra Atoll in the western Indian Ocean. Taxonomic and nomenclature confusion during the 19th and early 20th centuries led to contradictory proposals to supplant Testudo gigantea between 1982 and 2006. It is noted that the neotype Testudo gigantea was created in an effort to stabilize the accustomed name for the Aldabra tortoise species as Geochehme (Aldabrachelys) gigantea.

The Amazonian tortoise Geochelone denticulata may play an important role in forest dynamics due to its highly frugivorous diet, ability to disperse viable seeds, and predilection for resting in forest gaps for thermoregulation. The purpose of our study was to evaluate the species' effectiveness as a seed disperser. We measured dispersal quantity (abundance of seeds in feces, frequency of droppings, and population density of the disperser) and dispersal quality (movement patterns, habitat use, germination rates of dispersed seeds, and recruitment probabilities of seedlings) in a SW Amazonian forest, in Peru. Population density was calculated by mark-recapture and line-transect methods. Eight individuals were radio-tracked to monitor habitat use. Diet was described from fecal samples, which were washed to count seeds and for germination experiments. Seedling survival in different environmental conditions was monitored for three plant species. Population densities with mark-recapture estimates (0.15-0.31 individuals/ha) were much higher than with line transects estimates (0.0025 individuals/ha). Diet included fruit of 55 different plant species. Dispersed seeds had high germination rates (average 76%). In spite of their low activity, we documented long seed dispersal distances (average 89.6 m). Tortoises showed a marked preference for the open-canopy swampy forest, where long term recruitment was not favorable for seedlings of the species examined. However, the high solar radiation in this forest type promoted survival of pioneer seedlings in the short term. In conclusion, while G. denticulata did not perform a very efficient role in terms of the quantity of seed dispersal, the species can be considered efficient in many aspects of dispersal quality. [ABSTRACT FROM AUTHOR]

Abstract: Leopard tortoises (Stigmochelys pardalis) experience wide fluctuations in environmental conditions and unpredictable availability of food and water within the Nama-Karoo biome. It was hypothesised that tortoises fed two diets differing in preformed water and fibre content would have differing food intake, gut transit rate, assimilation efficiency, faecal and urinary water loss, and urine concentrations. It was predicted that tortoises fed these contrasting diets would attempt to maintain energy and water balance by altering their digestive parameters. Leopard tortoises fed lucerne (Medicago sativa) had a low food intake coupled with long gut transit times, which resulted in the lowest amount of faecal energy and faecal water lost. Tortoises fed tomatoes (Solanum lycopersicum) had higher food intake and faster gut transit times, but more energy and water was lost in the faeces. However, daily energy assimilated and assimilation efficiency were comparable between tortoises fed the two diets. Urine osmolality was significantly different between tortoises on the two diets. Results indicate that leopard tortoises can adjust parameters such as transit rate, food intake, water loss and urine osmolality to maintain body mass, water and energy balance in response to a high fibre, low water content and a low fibre, high water content diet. This study suggests that this digestive flexibility allows leopard tortoises in the wild to take advantage of unpredictable food and water resources. [Copyright &y& Elsevier]

We compared the muscular anatomy of the distal front limb in terrestrial and aquatic chelonians to test whether observed differences between the two groups are associated with their divergent lifestyles and locomotor modes. Given the different use of the forelimb in the two environments (body support and propulsion on land vs. mainly propulsion in water) we expected that: (1) aquatic and terrestrial turtles would show differences in their muscular anatomy, with aquatic species having more individualized muscle bundles to allow for the complex forearm movements observed during swimming, and (2) that terrestrial turtles would have more robust muscles to support their body weight against gravity. To address these questions, we examined the forelimb myology and associated tissues in six aquatic or semi-aquatic turtles ( Phyrnops hilarii, Podocnemis unifilis, Trachemys scripta, Sacalia bealei, Cuora amboinensis and Mauremys caspica) and six terrestrial or semi-terrestrial turtles ( Geochelone chilensis, Testudo graeca, Cuora galbinifrons, Glyptemys insculpta, Terrapene carolina and Rhinoclemmys pulcherrima). This paper describes the general structure of the forelimb musculature in all species, and quantifies muscle masses in those species with more than five specimens available ( Ph. hilarii, Po. unifilis and Ge. chilensis). The general structure of the forelimb muscles in the strictly terrestrial species Ge. chilensis and Tes. graeca was found to be notably different from the pattern of the aquatic and semi-aquatic species examined, showing a distinct fusion of the different muscular bodies. Ter. carolina also show a distinctly terrestrial pattern, but a less extensive tendon development. R. pulcherrima and Gl. insculpta were found to be morphologically intermediate; in the geoemydids the strictly terrestrial bauplan never appears. Quantitative differences in the robustness or mass of the distal forelimb muscles were also observed for the species investigated, supporting our prediction that the extensor muscles are more robust in terrestrial turtles. However, in contrast to our expectations, not only the extensor muscles of the distal forelimb (which are crucial in providing both body support and propulsion), but all muscles acting around the wrist were found to be heavier in terrestrial turtles. [ABSTRACT FROM AUTHOR]

We evaluated the role that endangered species reintroduction efforts can play in the larger context of ecosystem restoration. To do so, we examined interactions between endangered giant tortoises ( Geochelone nigra hoodensis), currently being reintroduced to Isla Española, Galápagos, and an arboreal cactus ( Opuntia megasperma var. megasperma), which is itself endangered and a keystone resource for many animals on the island. We collected information on spatial patterns of occurrence of cacti, tortoises, and woody vegetation and compared recruitment of juvenile cacti in areas occupied versus unoccupied by tortoises. Reintroduced tortoises appeared to suppress cactus recruitment near the few remaining adult cacti at the study site, but facilitate it at longer distances, with tortoise–cactus interactions mediated by the presence of woody vegetation, which likely alters tortoise movements and thereby patterns of cactus seed dispersal. The net effect of tortoises on cacti appeared to be positive insofar as tortoise presence was associated with greater recruitment of juveniles into cactus populations. Our study provides support for reintroducing endangered reptiles and other animals to aid ecosystem restoration in areas where they might once have played an important role in grazing upon and dispersing plants. [ABSTRACT FROM AUTHOR]

A single tortoise (Geochelone carbonaria) was trained in an eight-arm radial maze, with the apparatus and general procedures modeled on those used to demonstrate spatial learning in rats. The tortoise learned to perform reliably above chance, preferentially choosing baited arms, rather than returning to arms previously visited on a trial. Test sessions that examined control by olfactory cues revealed that they did not affect performance. No systematic, stereotyped response patterns were evident. In spite of differences in brain structure, the tortoise showed spatial learning abilities comparable to those observed in mammals. [ABSTRACT FROM AUTHOR]

Abstract: We used a five-gene data set (mtDNA: 12S rRNA, 16S rRNA, cyt-b; nDNA: Cmos, Rag2) comprising approximately two-thirds of all extant testudinid species and, for the first time, including all five Testudo species to investigate the question of whether all western Palaearctic testudinids are monophyletic. Further, we examined whether the recently suggested allocation of the African Geochelone pardalis in the otherwise exclusively South African genus Psammobates and of the Malagasy G. yniphora in the monotypic genus Angonoka is justified in the face of considerable morphological evidence against such placements. Our phylogenetic analyses do not support the paraphyly and generic break-up of Testudo, as suggested by previous papers using a smaller taxon sampling and mtDNA data only. We propose a continued usage of the generic name Testudo for all five western Palaearctic tortoise species. Within Testudo, two monophyletic subclades are present, one containing T. hermanni+T. horsfieldii, and the other comprising (T. kleinmanni+T. marginata)+T. graeca. Nomenclaturally, we demonstrate that Eurotestudo Lapparent de Broin et al., 2006, which was recently erected with the type species T. hermanni, is an objective junior synonym of Chersine Merrem, 1820 and Medaestia Wussow, 1916. Recognition of a monotypic genus Angonoka for G. yniphora is unwarranted according to both our re-analysis of sequence data and morphological data. Acknowledging the strong morphological similarity between G. yniphora and G. radiata, we suggest placing both species into the genus Astrochelys. Although sequence data for only one of the three Psammobates species was available for analysis, there is currently no cause to challenge the monophyly of this genus as established on the basis of morphological evidence. Thus, we hypothesize that G. pardalis is sister to a monophyletic Psammobates. In light of the clear morphological gap between G. pardalis and Psammobates species, the recognition of a distinct genus Stigmochelys for the former seems justified. [Copyright &y& Elsevier]

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 <15 per year, but since 2001 the number killed has increased dramatically, with 49 tortoises poached in 2004. During the same 10 years the number of tortoises found dead from natural causes was 131. Many of these deaths can be attributed to events associated with the 1997–1998 El Niño or with outbreaks of disease on Santa Cruz Island in 1996 and 1999. The results indicate that poaching exceeds natural mortality, and is a significant factor affecting these long-lived and slow-reproducing animals. Environmental education efforts in the human population of southern Isabela appear to have had little effect. Because tortoise poaching takes place at a small number of sites, effective enforcement at those sites could reduce killing of tortoises. [ABSTRACT FROM AUTHOR]

The Indian Star tortoise (Geochelone elegans) belongs to the family Testunidae and is distributed in southwest India and Sri Lanka. In addition to facing loss of its natural habitat, the species is also illegally traded as food and as an exotic pet internationally. Here we report DNA-based analyses for identification and repatriation of these tortoises into their natural habitat. We have attempted to establish the geographical origin of these tortoises rescued from smugglers, by comparing the microsatellite and mitochondrial markers of rescued animals with animals of known provenance. Star tortoises exhibited strong genetic structure in india. The populations from western India were genetically distinct at microsatellite and mitochondrial loci from southern populations. The rescued individuals had similar multilocus genotypes and mitochondrial DNA haplotypes as the reference individuals from south India. However, the precise geographic origin of many of the rescued samples remains unresolved, because we could not assign them to southern populations and the Neighbor-Joining cluster analysis indicated that some of rescued tortoises formed distinct clusters. These data strongly suggest that the rescued group of tortoises is composed of a mix of individuals from differentiated source populations that are probably located in southern India and possibly Sri Lanka. Our study provides valuable information based on molecular markers for the assessment of genetic diversity in Indian Star tortoises. [ABSTRACT FROM AUTHOR]

We studied reproduction of wild Geochelone radiata at the Cap Sainte Marie Special Reserve in southwestern Madagascar to gain insight into life history traits related to reproductive success. Reproductive behaviour was observed over two nesting seasons and egg production was studied by radiographing telemetered females at regular intervals. We captured and marked 1438 radiated tortoises of which 26% were adults. Mating and nesting coincided with the rainy season, and mating events peaked in December, shortly before females started nesting in January. The incubation period was approximately 263-342 days, and hatchlings emerged after the onset of the rainy season when new plant growth became available. Hatching success was high and incidental destruction by humans rather than predation had the greatest impact on tortoise nests. Individual females produced from 0-3 clutches per season with 1-5 eggs per clutch. Body size had a weak effect on clutch size, but clutch size was lower in the dry year (2000) than in the wet year (1999) and appears to reflect resource availability. Mean egg size per clutch increased significantly with increasing body size. These findings emphasize that protection of large females should be considered in the conservation of this species. [ABSTRACT FROM AUTHOR]

The radiated tortoise ( Geochelone radiata) is an endangered endemic species from Madagascar that inhabits the semiarid spiny forest of the southern part of the island. Habitat destruction and illegal harvesting greatly threaten this species, as attested by the significant reduction of its distribution area in the past 30 years. In order to undertake appropriate conservation actions, it is essential to acquire a better knowledge of its genetic structure. For this study, 145 blood samples were collected from three populations of radiated tortoises in southwestern Madagascar. Eight microsatellite loci were found to be polymorphic, and allelic diversity and observed heterozygosity were high for all markers. [ABSTRACT FROM AUTHOR]

Abstract: The radiated tortoise, Geochelone radiata, one of Madagascar’s four endemic tortoises, occupies a narrow band of xeric spiny forest along the island’s southwest coast. Traditionally avoided by indigenous tribes, these tortoises are now routinely harvested for food. An accurate assessment of human exploitation remains problematic, however, hindered by limited, dated statistics available on tortoise populations. To update the radiated tortoise’s status and distribution, we established a series of line transects at seven localities across its range and implemented a mark-recapture study at one of these localities (Cap Sainte Marie). Tortoises currently range from south of Tulear to east of Cap Sainte Marie, at density estimates spanning 27–5744 tortoises/km2. The mark-recapture estimate for Cap Sainte Marie (1905–2105 tortoises/km2) was substantially higher than its transect estimate (654 tortoises/km2) though comparable to actual tortoise captures (1438) there. Thus, our transect density values probably err as underestimates, and from these data, we calculate a conservative total population size of 12 million radiated tortoises. We also examined mitochondrial DNA sequences (ND4 gene) for two individuals/locality in a preliminary assessment of genetic variation across the species’ range. Only two ND4 haplotypes were recovered, the more common haplotype representing 13 of the 14 individuals. We offer several conservation recommendations in light of our survey results. [Copyright &y& Elsevier]

Twenty-four juvenile leopard tortoises were divided into tour groups of six, one group was fed a basic low-calcium feed for six months, and the other three groups were fed the same basic diet supplemented with one, three and nine times the amount of calcium recommended as a supplement to the diet of reptiles. The animals' bone mineral content and bone mineral density were estimated by dual energy x-ray absorptiometry, and blood samples were taken at the start and at the conclusion of the study. One tortoise from each group was examined postmortem. There was a clear depletion of calcium in the body of the tortoises receiving no calcium supplement, and the shell of the tortoises receiving the recommended calcium supplement did not calcify to the extent expected. The tortoises that received three times the recommended calcium supplementation had the highest growth rate and were thriving. However, metastatic calcifications were observed postmortem in the two groups that were given the highest doses of calcium. [ABSTRACT FROM AUTHOR]

Heterophylly is present in many plant species on oceanic islands. Almost all of these plants are island endemics, and heterophylly may have evolved as a response to feeding from large insular browsers such as giant tortoises and flightless birds. We tested this anti-browser hypothesis by feeding Aldabra giant tortoises (Geochelone gigantea) with leaves of native Mauritian plants to see if they distinguished between juvenile and adult leaves and between heteophyllous and homophyllous species.Mauritius.In a choice experiment we recorded feeding response of four captive Aldabra giant tortoises to 10 species of Mauritian plants, of which seven were heterophyllous and three homophyllous.In general, juvenile leaves of heterophyllous species showed convergence in shape and midrib coloration. Homophyllous foliage was preferred to heterophyllous, and among heterophyllous species adult foliage was preferred to juvenile.Several Mascarene heterophyllous plants show convergence in morphology of juvenile leaves and these are avoided by giant tortoises. This indicates a strong selection history from large browsers such as the giant tortoises. The Mascarene example is in accordance with several other comparable cases of plant-large browser interactions from other archipelagos. [ABSTRACT FROM AUTHOR]

We developed an interactive management model for wild and captive populations of the ploughshare tortoise or angonoka, Geochelone yniphora. Interactive management is based on the translocation of individuals between wild and captive populations to simulate a metapopulation. Demographic parameters of one captive and two wild populations of this rare tortoise were used to conduct a metapopulation viability analysis (MVA). The effectiveness of the conservation strategy proposed for this species was then evaluated by modifying the probability of extinction and growth of the metapopulation over a fixed period of time. Several alternative scenarios of interactive management were then tested and ranked in terms of their effect on the viability of the metapopulation. The model predicted that catastrophic events such as bush fires would likely have a negative effect on the future of remaining wild populations. However, the model also predicted that the use of captive-born offspring to establish additional wild populations would decrease the risk of extinction of the metapopulation as a whole. We believe that, when supported by sound knowledge of the demographic parameters of a species, the use of MVA as part of an interactive management program can be an effective conservation tool that allows assessment of the probable response of both captive and wild populations to different management alternatives. One of the most interesting aspects of this interactive management approach is the link between in situ and ex situ conservation. [Copyright &y& Elsevier]

Abstract A radiation of five species of giant tortoises (Cylindraspis ) existed in the southwest Indian Ocean, on the Mascarene islands, and another (of Aldabrachelys ) has been postulated on small islands north of Madagascar, from where at least eight nominal species have been named and up to five have been recently recognized. Of 37 specimens of Madagascan and small-island Aldabrachelys investigated by us, 23 yielded significant portions of a 428-base-pair (bp) fragment of mitochondrial (cytochrome b and tRNA-Glu), including type material of seven nominal species (A. arnoldi , A. dussumieri , A. hololissa , A. daudinii , A. sumierei , A. ponderosa and A. gouffei ). These and nearly all the remaining specimens, including 15 additional captive individuals sequenced previously, show little variation. Thirty-three exhibit no differences and the remainder diverge by only 1–4 bp (0.23–0.93%). This contrasts with more widely accepted tortoise species which show much greater inter- and intraspecific differences. The non-Madagascan material examined may therefore only represent a single species and all specimens may come from Aldabra where the common haplotype is known to occur. The present study provides no evidence against the Madagascan origin for Aldabra tortoises suggested by a previous molecular phylogenetic analysis, the direction of marine currents and phylogeography of other reptiles in the area. Ancient mitochondrial DNA from the extinct subfossil A. grandidieri of Madagascar differs at 25 sites (5.8%) from all other Aldabrachelys samples examined here. [ABSTRACT FROM AUTHOR]

Uses mitochondrial DNA sequences and microsatellite markers to investigate the genetic structure, and to reconstruct genealogical relationships and the history of population colonization, of giant tortoises from the Islands of Santa Cruz and Pinzón, including samples of a basal taxon from the Island of San Cristóbal, Galápagos Islands. Notion that island radiations can offer challenging systems for the implementation of conservation policies because descendent populations may exhibit different levels of adaptive divergence, reproductive isolation, and phylogenetic distinctiveness; Finding that results strongly indicate the presence of a minimum of four conservation units with long-standing evolutionary separation: two in Santa Cruz, one in Pinzón, and one in San Cristóbal; Suggestion that these findings be effectively integrated with other existing data by the appropriate environmental agencies to evaluate current conservation efforts and implement new strategies aimed at protecting the integrity and diversity of giant tortoise populations.

Abstract Giant Galápagos 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. [ABSTRACT FROM AUTHOR]

Observations were made of growth rate and variation in colour pattern of the leopard tortoise (Geochelone pardalis babcocki ) in northern Tanzania between October 1993 and June 1996. Growth rate differed significantly between tortoises, with immature animals (6.9 ± 1.4 mm month-1 ) and females (5.7 ± 1.3 mm month-1 ) exhibiting higher rates of growth than adult animals (2.9 ± 0.8 mm month-1 ) and males (3.2 ± 1.1 mm month-1 ), respectively. The faster growth rate in immature animals suggested that growth rate declined with age. The difference in growth rates between the sexes was ascribed to sexual dimorphism, adult females being larger and therefore growing faster than males. The carapacial colour pattern observed in the northern Tanzanian tortoises was generally similar to that described elsewhere in the species' range. The colour pattern varied between Arusha and Serengeti District tortoises. Animals at the Arusha sites tended to be sparsely coloured (55.6%) compared to the Serengeti tortoises, which had a buff colouration with radiating spots (89.3%).; The sparse colouration provides effective camouflage in the drier Arusha habitats, as does the buff colouration with black spots in the wetter, darker habitats in the Serengeti. [ABSTRACT FROM AUTHOR]

Cirrhosis is the final stage of chronic hepatitis occurring diffusely in the liver, characterized by destruction of hepatic parenchymal cells, accompanied by increased fibrous tissue. A female of the species Geochelone carbonaria, approximately 16 years old, with a history of anorexia, lethargy, constant urination and watery stools for a period of 4 days of evolution and after death. At necropsy was observed, liver, firm irregular surface, the presence of diffuse nodules coalescing to about 0.5 cm to 4 cm, varying in color from yellow to light red, occupying all liver lobes. Histopathological examination of liver fragments revealed liver tissue architecture disorganized, intense proliferation of connective tissue enclosing "islands" of hepatocytes with vacuolated cytoplasm intensely and offset from the nucleus to the periphery (degeneration and necrosis). Histopathological findings and revealed the diagnosis of cirrhosis in Geochelone carbonaria. [ABSTRACT FROM AUTHOR]