Tortoises Research Papers - Academia.edu (original) (raw)

From the northern Negev Desert of Israel three new localities for land tortoises are reported: Be'er Mash'abim, the Mash'abim Sands Nature Reserve for Testudo kleinmanni and T. graeca; approximately 2 km south of Lahav (southwest of... more

From the northern Negev Desert of Israel three new localities for land tortoises are reported: Be'er Mash'abim, the Mash'abim Sands Nature Reserve for Testudo kleinmanni and T. graeca; approximately 2 km south of Lahav (southwest of Eshkolot) for T. graeca and approximately 6 km northeast of Nizzana for T. kleinmanni. Be'er Mash'abim is the first sympatric occurrence of T. kleinmanni and any other tortoise species. Further Israeli localities for T. kleinmanni are discussed.

From total 21 individuals of Painted Terrapin (Batagur borneoensis) found – accidentally caught and field survey – it can be concluded that female is heavier, wider and longer curve carapace than male. Male is experiencing sexual... more

From total 21 individuals of Painted Terrapin (Batagur borneoensis) found – accidentally caught and field survey – it can be concluded that female is heavier, wider and longer curve carapace than male. Male is experiencing sexual dichromatism during six months or from April to September. The movement of Painted Terrapin is related to tides and they are inhabit in rivers stream that has water salinity level is 0 and high density of Berembang (Sonneratia sp).

It is shown that the location data for the terra typica restricta of Testudo graeca and for the terra typica designata for Testudo graeca are based on an incorrectly assigned location. In fact, the original place corresponds to Santa... more

It is shown that the location data for the terra typica restricta of Testudo graeca and for the terra typica designata for Testudo graeca are based on an incorrectly assigned location. In fact, the original place corresponds to Santa Cruz, known today as Agadir (Morocco) and not the old Spanish fortress of Santa Cruz near Oran in Algeria. Accordingly, populations of Testudo graeca from the Agadir environment have to be named Testudo graeca graeca instead of Testudo graeca soussensis. For the populations of Testudo graeca from the vicinity of Algiers, "mauritanica" is the next available name for this subspecies of graeca. Therefore, Testudo graeca mau-ritanica has to be used instead of Testudo graeca graeca. For Testudo graeca mauritanica, a lectotypus is designated.

Dietary habits of tortoises in Croatia and Montenegro

We provide a first checklist and review of all recognized taxa of the world’s extinct Pleistocene and Holocene (Quaternary) turtles and tortoises that existed during the early rise and global expansion of humanity, and most likely went... more

We provide a first checklist and review of all recognized taxa of the world’s extinct Pleistocene and Holocene (Quaternary) turtles and tortoises that existed during the early rise and global expansion of humanity, and most likely went extinct through a combination of earlier hominin (e.g., Homo erectus, H. neanderthalensis) and later human (H. sapiens) exploitation, as well as being affected by concurrent global or regional climatic and habitat changes. This checklist complements the broader listing of all modern and extant turtles and tortoises by the Turtle Taxonomy Working Group (2014). We provide a comprehensive listing of taxonomy, names, synonymies, and stratigraphic distribution of all chelonian taxa that have gone extinct from approximately the boundary between the Late Pliocene and Early Pleistocene, ca. 2.6 million years ago, up through 1500 AD, at the beginning of modern times. We also provide details on modern turtle and tortoise taxa that have gone extinct since 1500 AD. This checklist currently includes 100 fossil turtle and tortoise taxa, including 84 named and apparently distinct species, and 16 additional taxa that appear to represent additional valid species, but are only identified to genus or family. Modern extinct turtles and tortoises include 8 species, 3 subspecies, and 1 unnamed taxon, for 12 taxa. Of the extinct fossil taxa, terrestrial tortoises of the family Testudinidae (including many large-bodied island forms) are the most numerous, with 60 taxa. When the numbers for fossil tortoises are combined with the 61 modern (living and extinct) species of tortoises, of the 121 tortoise species that have existed at some point since the beginning of the Pleistocene, 69 (57.0%) have gone extinct. This likely reflects the high vulnerability of these large and slow terrestrial (often insular) species primarily to human exploitation. The other large-bodied terrestrial turtles, the giant horned turtles of the family Meiolaniidae, with 7 taxa (also often insular), all went extinct by the Late Holocene while also exploited by humans. The total global diversity of turtles and tortoises that has existed during the history of hominin utilization of chelonians, and that are currently recognized as distinct and included on our two checklists, consists of 336 modern species and 100 extinct Pleistocene and Holocene taxa, for a total of 436 chelonian species. Of these, 109 species (25.0%) and 112 total taxa are estimated to have gone extinct since the beginning of the Pleistocene. The chelonian diversity and its patterns of extinctions during the Quaternary inform our understanding of the impacts of the history of human exploitation of turtles and the effects of climate change, and their relevance to current and future patterns.

The Author has been traveling Morocco since 1977, mainly in search for lizards and snakes. He also encountered turtles and tortoises and eventually came to know some localities rather intimate, because he visited them several times and... more

The Author has been traveling Morocco since 1977, mainly in search for lizards and snakes. He also encountered turtles and tortoises and eventually came to know some localities rather intimate, because he visited them several times and during different seasons. Even in January he could observe tortoises. So his paper is centered around those habitats, which are presented in a detailed manner, that also includes accompanying herpetofauna and sometimes even flora. He starts by listing the taxa of chelonians that are supposed to inhabit Morocco. Recently an abundance of subspecies were described and not so long after largely synonymized again. This especially happened to Mauremys leprosa, but also, in a lesser degreem to Testudo graeca. So one purpose of the author's research was to test the validity of the supposed diagnostic features, that were used to describe those taxa: colour traits, shape of the carapax and so on. He often noticed, that the variability within one population might transcend the limits of the diagnosis. So Mauremys leprosa zizi should lack lateral keelings on the carapax, but in Ziz River SCHWEIGER encountered specimens that showed a broad spectrum, from no lateral keelings at all to well developed ones. SCHWEIGER proceeds by outlining ecological changes that took place during the decades he was visiting Morocco: Mayor parts of the Meseta were turned into agricultural areas, the Rif mountains suffered environmental degradation by getting used as pastures and some locations are in danger to fall victim to real estate development (among them „ Marios Private Oasis "). Subsequently the locations are introduced, starting with Larache in the North and ending with the surroundings of Tiznit at the outmost southern part of Morocco (West Sahara excluded). In Larache Mauremys l. atlantica should occur, but the specimens found considerably differ from the description. Tortoises (T. g. marokkensis) were found at nearby hills. In Volubilis also T. g. marokkensis were found, but showed only light, non contrasting markings on the carapax. In El Hajeb one Testudo graeca was found, together with the very rare lizard Psammodromus microdactylus. Farther south, in M'Rirt, Mauremys were found. They should belong to the subspecies M l. wemerkaestlei, but they didn't match the description of this subspecies. 30 km farther south, in Khenifra, M. l. wemerkaestlei still should occur, but here the turtles also differ significantly from the description and resemble the subspecies M. l. marokkensis as defined in the description. The River Oued Zate, crossing the road from Marrakech to Ouarzazate, is home to turtles that meet the description of M. l. marokkensis, especially concerning the markings on the forelegs, but still the variability of the carapax-coloration within the population is considerable. Near the town Ouarzazate the author learned to know many promising locations, among them " Mario's Private Oasis". Here Mauremys l. saharica should occur, but again the specimens differ greatly from the subspecies-description, especially regarding the markings on the forelegs: They show leopardoise pattern, but should show a clear line separating orange areas from dark ones. At the Ziz-River. M. l. zizi should occur. Here SCHWEIGER encountered specimens that showed variability in the shape of the carapax and therefore didn't mutch the description of M. l. zizi perfectly. In the Souss-Valley Testudo graeca soussensis were found. But many of them had tubercles at the upper tights, which T. g. soussensis shouldn't show. Near the town Tiznit, the River Oued Massa meets the shore. There M. l. saharica occur, and the specimens actually meet the description. The paper concludes with remarks concerning the usage of turtles and tortoises as medical
remedies by the local people.

La iguana y el morrocoy sabanero están entre las especies de fauna silvestre más buscadas y utilizadas por la población venezolana, principalmente con fines alimenticios (obtención de carne y huevos), aunque también como animales de... more

La iguana y el morrocoy sabanero están entre las especies de
fauna silvestre más buscadas y utilizadas por la población venezolana,
principalmente con fines alimenticios (obtención de carne y huevos),
aunque también como animales de compañía, para la obtención de
medicina tradicional y en la elaboración de artesanías. Este hecho, sumado
al deterioro del hábitat y al aumento en la demanda de sus productos, ha
causado el declive drástico de algunas poblaciones, lo que en el mediano
y largo plazo pudiere ocasionar su vulnerabilidad hacia la extinción a nivel
local y regional.

En el área ecobiológica es bien sabido que cada especie, sobre todo las correspondientes a los reinos biológicos eucariotas, se comporta en su medio natural como ecosistemas para otras especies. Este concepto no está tan bien comprendido... more

En el área ecobiológica es bien sabido que cada especie, sobre todo las correspondientes a los reinos biológicos eucariotas, se comporta en su medio natural como ecosistemas para otras especies. Este concepto no está tan bien comprendido para las ciencias veterinarias para las cuales el concepto de individuo sano corresponde a aquel que no posee mayormente ningún parásito ó comensal; situación muy alejada de la realidad de la situación real. En tal sentido, el asimilar el concepto de especie como ecosistema ayudará tanto a biólogos como a veterinarios a comprender mejor los problemas que conlleva la rehabilitación de especies en la naturaleza, la contaminación genética, entre otros problemas. En este ensayo tomamos como ejemplo, dentro de los reptiles, a las tortugas y analizamos brevemente algunas de las implicancias veterinarias y en los procesos de rehabilitación derivadas del dicho concepto

We provide a first checklist and review of all recognized taxa of the world’s extinct Pleistocene and Holocene (Quaternary) turtles and tortoises that existed during the early rise and global expansion of humanity, and most likely went... more

We provide a first checklist and review of all recognized taxa of the world’s extinct Pleistocene and Holocene (Quaternary) turtles and tortoises that existed during the early rise and global expansion of humanity, and most likely went extinct through a combination of earlier hominin (e.g., Homo erectus, H. neanderthalensis) and later human (H. sapiens) exploitation, as well as being affected by concurrent global or regional climatic and habitat changes. This checklist complements the broader listing of all modern and extant turtles and tortoises by the Turtle Taxonomy Working Group (2014). We provide a comprehensive listing of taxonomy, names, synonymies, and stratigraphic distribution of all chelonian taxa that have gone extinct from approximately the boundary between the Late Pliocene and Early Pleistocene, ca. 2.6 million years ago, up through 1500 AD, at the beginning of modern times. We also provide details on modern turtle and tortoise taxa that have gone extinct since 1500 A...

We provide a first checklist and review of all recognized taxa of the world’s extinct Pleistocene and Holocene (Quaternary) turtles and tortoises that existed during the early rise and global expansion of humanity, and most likely went... more

We provide a first checklist and review of all recognized taxa of the world’s extinct Pleistocene and Holocene (Quaternary) turtles and tortoises that existed during the early rise and global expansion of humanity, and most likely went extinct through a combination of earlier hominin (e.g., Homo erectus, H. neanderthalensis) and later human (H. sapiens) exploitation, as well as being affected by concurrent global or regional climatic and habitat changes. This checklist complements the broader listing of all modern and extant turtles and tortoises by the Turtle Taxonomy Working Group (2014). We provide a comprehensive listing of taxonomy, names, synonymies, and stratigraphic distribution of all chelonian taxa that have gone extinct from approximately the boundary between the Late Pliocene and Early Pleistocene, ca. 2.6 million years ago, up through 1500 AD, at the beginning of modern times. We also provide details on modern turtle and tortoise taxa that have gone extinct since 1500 A...

El consum de quelonis per part d'homínids està testimoniat des de fases molt antigues, però és especialment al llarg del Paleolític Mitjà i lligat a contexts neandertals quan les evidències es multipliquen, sobre testudínids terrestres a... more

El consum de quelonis per part d'homínids està testimoniat des de fases molt antigues, però és especialment al llarg del Paleolític Mitjà i lligat a contexts neandertals quan les evidències es multipliquen, sobre testudínids terrestres a la conca mediterrània. No obstant, Mauremys leprosa és una tortuga d’aigües continentals de distribució iberomagrebina, de caràcter termòfil, que actualment encara es consumeix per l'ésser humà a determinades comarques andaluses i extremenyes. Al registre zooarqueològic valencià apareix a partir de l’Holocè postglacial, als jaciments de l’Ereta del Pedregal, Cova de l’Or, Lloma de Betxí i Pic dels Corbs, en ambients que, exceptuant el primer jaciment (a una antiga zona lacustre), es troben fora dels hàbitats naturals d’aquesta tortuga (cova i poblats elevats). En aquest treball analitzem les restes assignades a Mauremys leprosa recuperades en aquests llocs i vinculem la seua aparició amb un possible consum humà, entre el Neolític i l’Edat del Bronze.

Newly described specimens of North American Eocene turtles provide valuable information on their morphology and, more specifically, variation, both intraspecific and ontogenetic. We describe several complete and nearly complete... more

Newly described specimens of North American Eocene turtles provide valuable information on their morphology and, more specifically, variation, both intraspecific and ontogenetic. We describe several complete and nearly complete testudinoid (Testudinoidea) specimens, including juvenile specimens of Hadrianus corsoni, H. majusculus, Echmatemys haydeni and E. naomi. These specimens help us determine that the oldest and most basal tortoises are from the western United States, suggesting Testudinidae evolved in North America from one of the geoemydid-like forms in the genus Echmatemys, which have their lowest stratigraphic occurrence in the earliest Wasatchian North American land-mammal “age” (early Eocene, Ypresian, ~53 Ma).

This work is a synthesis about the distribution of the Mediterranean tortoise (Testudo hermanni Gmelin 1789) in the Valencian area (Eastern Iberian Peninsula) during the Middle Palaeolithic. Furthermore, we have compiled available... more

This work is a synthesis about the distribution of the Mediterranean tortoise (Testudo hermanni Gmelin 1789) in the Valencian area (Eastern Iberian Peninsula) during the Middle Palaeolithic. Furthermore, we have compiled available published data related to the origin of tortoise accumulations in the archaeological sites. Also, we present new information about tortoise consumption by Neanderthals from the preliminary study of Abric del Pastor bone sets.

This study assesses the rate and pattern of variation of allometric shell growth in Indian star tortoise Geoche-lone elegans. Morphometric measurements of 83 Indian star tortoises were taken over 6 months. The anal notch measurements... more

This study assesses the rate and pattern of variation of allometric shell growth in Indian star tortoise Geoche-lone 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 dimor-phic adults. IN some animal species, variation in size with growth is often associated with a proportional change in the body shape. Allometry is the study of this relationship of body size to various aspects of anatomy, physiology and even behaviour. Chelonian shell shows allometry and thus becomes an ideal group/system to conduct morphometric studies 1. These studies have been used for investigating taxonomy 2–4 , describing the intra-specific distinction between closely related species or subspecies 5–7 , and assessing morphometric variation among and within populations 8–10. Another aspect of the chelonian shell is sexual size dimorphism (SSD): the size difference between males and females of the same species (steppe tortoises (Testu-do horsfieldi) 3 , slider turtle (Trachemys scripta) 11 , African tortoise (Geochelone pardalis) 12 , angonoka tortoise (Geochelone yniphora) 13 , etc.). SSD is known to be driven by the following: (1) sexual selection – size and shape will provide better reproductive success 14 ; (2) fe-cundity selection – favours larger female size allowing them to have more offspring 15 , and (3) competitive displacement – size related to resource use to reduce inter-sexual competition 15–17. This in turn is affected by the genetic make-up, physiological requirements and environmental factors. In case of chelonians, SSD occurs in both extremes with individuals of either sex being larger than those of the opposite sex 18,19. Allometric growth in shell is closely associated with SSD and this association can be used to explain the direction and intensity of SSD. For example, in Malayemys macrocephala, Brophy 15 observed that while females grew proportionally with respect to most of the shell characters, males selectively grew longer, wider and higher giving them flat and narrow shell compared to that of females. The tortoise shell serves a variety of physiological (thermoregulation, fat and water reserves, mating and reproduction) and environmental (self-righting, locomo-tor performance and physical protection) functions. Its shape and size is governed by both intrinsic (genetic and physiology) and extrinsic (environmental) factors 20. The plastron itself is known to be highly variable with respect to its shape, which makes the overall shell shape variable as well 21,22. This versatility of morphometric/phenotypic variation is due to the complexity and interaction of the genetic make-up that is under pressure from both natural and sexual selection. Analysis of this variation of shell shape can: (a) provide precise quantification; (b) provide information about the pattern of inheritance and genetic variation (indirectly the effect of sexual selection), and (c) act as a proxy for determining the ability of a population to adapt to external stress (indirectly indicating influence of natural selection) 21. The present study aims at assessing the interrelation ship of SSD and allometry in one chelonian species, the Indian star tortoise (Geochelone elegans). This is a terrestrial member of Testudinidae and one of the four known species of tortoises found in the drier regions of the Indian subcontinent. It is distributed in three regions: northwest India (Rajasthan, Gujarat continuing to Pakistan),

Wildlife managers face complex problems in attempting to achieve contemporary conservation goals while maintaining ecosystem function. Anthropogenically altered environments can subsidize certain species, causing them to become... more

Wildlife managers face complex problems in attempting to achieve contemporary conservation goals while maintaining ecosystem function. Anthropogenically altered environments can subsidize certain species, causing them to become overabundant and straining the remaining natural system. Such is the case with the widespread avian generalist and subsidized predator, the common raven (Corvus corax). Ravens depredate nests and prey on small animals, with locally focused high impacts to the ecosystem during rearing of their nestlings. Limiting predator abundance reduces the spatially concentrated preda-tion rates by eliminating nestling provisioning needs. We investigated avenues to limit the reproduction of common raven using customized theoretical and practical tools. Specifically, we developed an online interactive tool, a mathematical model, that calculates the predator's population growth rate under any given proportion of reproductive management. This quantitative tool models an assessment of ravens in a defined area and results in the degree to which raven fitness would need to be reduced to control their populations. To implement the model's results in a field-practical way and manage reproduction with minimal disturbance, we developed novel technology, a Remote Fluid Application System (RFAS). The RFAS applies the egg addling technique of egg oiling to high (usually out of reach) nesting situations. We tested these tools in the Mojave Desert, CA, where the raven is a heavily human-subsidized predator. We mounted our RFAS on telescoping poles and unmanned aerial vehicles (UAVs; drones) and found that we were able to aerially, and precisely, spray-oil eggs high in trees or cliffs/rock faces, halting 100% (n = 46) of raven nesting events. With these tools, we enable managers to calculate the intensity of, and the ability to carry out, egg addling needed to stem or halt predator population growth. We conclude that the combination of the interactive software (StallPOPd Interactive Tool, https://cwhl.vet.cornell.edu/tools/stallpopd; publicly available at https://ecommons.cornell.edu/handle/1813/65718) and the RFAS is the most effective wildlife management strategy to date for the offset or control of undesirable population growth in high-nesting avian predators.

This essay explores the provenance of the tortoise metaphor in Andrew Marvell's “Upon Appleton House, To My Lord Fairfax” (1652). It discusses the degree to which the tortoise metaphor celebrates the classical architecture of the estate.... more

This essay explores the provenance of the tortoise metaphor in Andrew Marvell's “Upon Appleton House, To My Lord Fairfax” (1652). It discusses the degree to which the tortoise metaphor celebrates the classical architecture of the estate. It identifies a thread of testudinal imagery originating in the architectural writings of Vitruvius (fl. 70–15 BCE), who invokes the tortoise metaphor to describe both primitive dwellings and siege weapons. It also traces the thread of influence through the various revivals of Vitruvian theory, including Leonardo da Vinci's “Vitruvian Man” (1490), Palladio's “I quattro libri dell'architettura” (1570), Inigo Jones's architectural designs (1614–17), and John Webb’s design for Appleton House (1650).

This paper aimed to examine the management of urinary calculi of a sulcata tortoise. A 5-year-old Sulcata tortoise (Geochelon sulcata) was presented with a history of dehydration, loss of appetite, and lameness. Clinical signs and... more

This paper aimed to examine the management of urinary calculi of a sulcata tortoise. A 5-year-old Sulcata tortoise (Geochelon sulcata) was presented with a history of dehydration, loss of appetite, and lameness. Clinical signs and radiographic examination indicated urinary calculi in the urinary bladder. Radiographic results revealed that there was a radiopaque urinary calculi mass. Plastron osteotomy and cystotomy techniques were used to remove urinary calculi. The appetite of the tortoise returned to normal in a week after the surgery. The lateral plastron is an appropriate osteotomy technique, especially for the immediate opening of the plastron with a stone-filled bladder. This was a safe area to open plastron since it was far from the heart. This method was not beneficial for the tortoise in their infancy since it would interrupt the development of plastron formation resulting in the postoperative asymmetrical plastron structure.

Hawksbill shell (tortoiseshell) is still commonly utilized in the Dominican Republic (DR) in the manufacture of hand crafts sold in tourist souvenir shops (locally known as gift shops). Through interviews conducted from January of 2001 to... more

Hawksbill shell (tortoiseshell) is still commonly utilized in the Dominican Republic (DR) in the manufacture of hand crafts sold in tourist souvenir shops (locally known as gift shops). Through interviews conducted from January of 2001 to January of 2002, we determined that 29% of gift shops from around the country openly offered this type of merchandise. Necklaces, hand bags, and bracelets were the most popular items. Additionally, we confirmed the existence of at least one gift shop in Santo Domingo in which unworked (raw) shell was stored in sacks of approximately 300 kg each. The owners of this shop indicated that they received this amount of shell every 15-20 days from local vendors. Using allometric growth equations on measures taken of shell scutes from 46 individual hawksbills, we estimated that these ranged in size from 69.9-97.7 cm straight carapace length, indicating that they were either adults or large juveniles. Given the depleted status of adult-sized hawksbills in the country, it is possible that significant amounts of tortoiseshell are being smuggled into the DR from other countries in the area. The importation of tortoiseshell by gift shops, as well as its exportation by customers (usually international tourists) constitute violations of the CITES. Furthermore, this trade, even on a domestic level, constitutes a violation of local legislation as well as a serious threat for the regional recovery of this critically endangered species.

The Critically Endangered ploughshare tortoise (Astrochelys yniphora) is Madagascar’s largest, rarest and most threatened of the island’s four endemic tortoises (Fig. 1) (Mandimbihasina & Currylow 2014). Madagascar supports two genera of... more

The Critically Endangered ploughshare tortoise (Astrochelys yniphora) is Madagascar’s largest, rarest and most threatened of the island’s four endemic tortoises (Fig. 1) (Mandimbihasina & Currylow 2014). Madagascar supports two genera of endemic tortoises. One is the Astrochelys genus, of which the radiated tortoise (A. radiata), endemic to the southern dry forests of Madagascar, is the ploughshare’s sister species. The other genus, Pyxis, supports two of the smallest species in the world: the spider tortoise (P. arachnoides), often sympatric in its range with A. radiata, and the flat tailed tortoise (P. planicauda), endemic to isolated parts of the western dry forests within the Kirindy region.
The ploughshare tortoise inhabits a number of isolated pockets of dry bamboo forest, palm savannah and thick scrub within the Baly Bay region of northwest Madagascar (Juvik et al. 1981). The bamboo forest is a fire-dependant transitional habitat. The species inhabits a region that is considered to be one of the driest within Madagascar (Mandimbihasina & Woolaver 2014).

The critically endangered Radiated Tortoise (Astrochelys radiata) is endemic to the southern coastlines of Madagascar. Once common, wild populations of this tortoise have undergone dramatic declines in recent years. Although there have... more

The critically endangered Radiated Tortoise (Astrochelys radiata) is endemic to the southern coastlines of Madagascar. Once common, wild populations of this tortoise have undergone dramatic declines in recent years. Although there have been studies documenting reproductive activities, reproductive physiological parameters are unknown yet may be crucial in the recovery of the species. Over four research seasons in remote field locations native to A. radiata, we surveyed for, radio-tracked, and sampled wild, free ranging tortoises. We sampled and measured stress and reproductive parameters (corticosterone [CORT], testos-terone [T], estradiol-17b [E2], and progesterone [P]) in 311 plasma samples from 203 wild A. radiata, capturing their active period. Generally, hormone concentrations were associated with body condition, temperature, and humidity. There was wide variation in CORT that varied monthly and by group. Juvenile tortoises maintained more than twice the mean basal CORT concentrations than either adult sex, with the most dramatic distinctions in the middle of the wet season. For adult sex hormones, the last months of the dry season and into the wet season when ground humidities are low and just begin to rise prior to temperature declines, male T concentrations gradually increased to a peak before returning to near undetectable values into the dry season. We had limited data for T concentrations in females, but found average T concentrations were much lower than in males and positively correlated with larger female home range sizes. For female hormone cycles, E2 also peaked in the early 1/3 of the wet season along with male T, and was followed by an uptick in P which correlates to the putative ovulatory cycle. Females tracked over four years showed variation in patterns of P, indicating that number and frequency of clutches vary. Our results suggest that 1) there is high species plasticity in response to stress; 2) A. radi-ata reproductive cycling is somewhat dissociated with courtship timing and is instead triggered by environmental cues; and 3) individual female reproductive output is irregular. This study is oone of the first to document and describe multi-year seasonal stress and reproductive hormones in a free-ranging Malagasy chelonian. These data may be used to identify key high-production habitats for conservation, and aide in captive management and reproduction in assurance colonies for species health and survival.

Giant tortoises are known from several remote islands in the Indian Ocean (IO). Our present understanding of ocean circulation patterns, the age of the islands, and the life history traits of giant tortoises makes it difficult to... more

Giant tortoises are known from several remote islands in the Indian Ocean (IO). Our present understanding of ocean circulation patterns, the age of the islands, and the life history traits of giant tortoises makes it difficult to comprehend how these animals arrived on such small, remote and geologically young (8–1.5 Ma) landmasses. For colonization to have occurred by dispersal, giant tortoises must either have originated in Madagascar or Africa and swum for hundreds of km against the ocean currents, or have launched themselves from the eastern IO margin and drifted with the currents over several thousands of km of open ocean. After these navigational feats, the tortoises would have needed to found new, viable populations on potentially inhospitable volcanic or coral outcrops. Geologically recent sea level changes are likely to have eliminated terrestrial life from islands like Aldabra, complicating the scenario. We reviewed information relating to IO geology, the evolution and ecology of giant tortoises, and the spread of humans within the region, and propose an alternative explanation: we posit that giant tortoises were introduced to the IO islands by early Austronesian sailors, possibly to establish provisioning stations for their journeys, just as European sailors did in more recent historical times.

Ecosystem engineers play an important ecological role because they modify habitats which are subsequently used by numerous other organisms (Dale and Beyeler, 2001; Wright and Jones, 2004). Burrowing tortoises are considered ecosystem... more

Ecosystem engineers play an important ecological role because they modify habitats which are subsequently used by numerous other organisms (Dale and Beyeler, 2001; Wright and Jones, 2004). Burrowing tortoises are considered ecosystem engineers because they construct burrows that are subsequently used by a multitude of heterospecifics (Jackson and Milstrey, 1989; Kaczor and Hartnett, 1990; Kinlaw and Grasmueck, 2012). The Desert Tortoise (Gopherus agassizii) is a large, semifossorial species which inhabits the Mojave Desert, one of the hottest and driest ecoregions in the North American southwest. The burrows of Desert Tortoises often reach lengths up to 2.0 meters (Burge, 1978) with dens being as long as 1.5–10 meters (Woodbury and Hardy, 1940) and can reach depths of >2 meters below the surface. These constructs provide refuge from the desert’s intense dryness, extreme high and low temperatures, and predators (Woodbury and Hardy, 1948; Luckenbach, 1982). Some species, such as Desert Woodrats (Packrat; Neotoma lepida) and Burrowing Owls (Athene cunicularia), are known to cohabitate or take over abandoned Desert Tortoise burrows, further excavating them and/or rearing young within (Woodbury and Hardy, 1948; Burge, 1978; Haug et al., 1993). In the closely related Gopher Tortoise (Gopherus polyphemus), more than 360 different species have been documented using or modifying tortoise burrows (Jackson and Milstrey, 1989; Lips, 1991; Kent and Snell, 1994; Heinrich et al., 1995). However, despite the large amount of literature on Desert Tortoises (Lovich and Ennen, 2013), only a few dozen heterospecifics have been reported using their burrows (Luckenbach, 1982; Walde and Lindey, 2009; Walde et al., 2009). Here, we report the first known use of a Desert Tortoise burrow by Long-nosed Leopard Lizards (Gambelia wislizenii), a relatively common habitat associate of the Desert Tortoise.

Las tortugas continentales son uno de los grupos de reptiles menos estudiados en Bolivia. La última revisión y evaluación de este grupo fue realizada el año 2009 para el Libro Rojo de la Fauna Silvestre de Vertebrados de Bolivia. En el... more

Las tortugas continentales son uno de los grupos de reptiles menos estudiados en Bolivia. La última revisión y evaluación de este grupo fue realizada el año 2009 para el Libro Rojo de la Fauna Silvestre de Vertebrados de Bolivia. En el presente trabajo evaluamos tanto el estado de conocimiento como el nivel de las amenazas actuales, y determinamos las especies prioritarias para realizar investigación y acciones de conservación. El análisis se realizó durante un taller virtual en el cual participaron diferentes especialistas en base a experiencia propia, la revisión del conocimiento generado en artículos científicos, tesis y datos no publicados. La evaluación de las prioridades de conservación se realizó posterior al taller. En el marco de la evaluación realizada de prioridades de investigación, amenazas y prioridades de conservación, se determinó que hay diez especies con muy alta prioridad de investigación, tres con alta y dos con media. Las amenazas principales para este grupo de vertebrados en Bolivia son la pérdida de hábitat, cambio climático y los ilícitos de vida silvestre; cuatro especies tienen alto nivel de amenaza, una especie medianamente y diez sufren bajo impacto. En cuanto a las prioridades de conservación se determinaron tres especies con prioridad alta, diez con media y dos con baja; siendo las especies con mayor prioridad Podocnemis expansa, P. sextuberculata, y Acanthochelys pallidipectoris. Debido a la escasa investigación y al incremento del grado de las amenazas sobre estas especies, consideramos necesaria la reevaluación del estado de conservación de todas las especies, su priorización para la investigación y establecer medidas de conservación.

Introduction Information on the composition of natural diets in animals can provide insight into a species’ role in an ecosystem and contribute to effective captive husbandry and breeding programmes. Under natural conditions, a critical... more

Introduction Information on the composition of natural diets in animals can provide insight into a species’ role in an ecosystem and contribute to effective captive husbandry and breeding programmes. Under natural conditions, a critical aspect of nutritional behaviour is the level of energy expended to access food resources, which may vary depending on whether a species is a dietary generalist or specialist. For example, in herbivorous reptiles a generalist feeder will usually select a range of plants to satisfy overall dietary requirements, whilst a specialist may have to forage widely for a more limited food plant range (review in Stephens & Krebs, 1986). Additionally, herbivores must also be aware of plants that contain toxic substances, which if consumed, at the very least, may impose costs for digestion (Freeland & Janzen, 1974). Such plants are usually avoided but this is not always the case, particularly if they contain essential nutrients (Zahorik & Haupt, 1977). Foraging th...

Captive breeding is a vital conservation tool for many endangered species programs. It is often a last resort when wild animal population numbers drop to below critical minimums for natural reproduction. However, critical ecophysiological... more

Captive breeding is a vital conservation tool for many endangered species programs. It is often a last resort when wild animal population numbers drop to below critical minimums for natural reproduction. However, critical ecophysiological information of wild counterparts may not be well documented or understood, leading to years of minimal breeding successes. We collected endocrine and associated ecological data on a critically endangered ectotherm concurrently in the wild and in captivity over several years. We tracked plasma concentrations of steroid stress and reproductive hormones, body condition, activity, and environmental parameters in three populations (one wild and two geographically distinct captive) of ploughshare tortoise (Astrochelys yniphora). Hormone profiles along with environmental and behavioral data are presented and compared. We show that animals have particular seasonal environmental requirements that can affect annual reproduction, captivity affects reproductiv...

We investigated the acute stress response associated with animal personalities by measuring plasma glucocorticoids throughout handling and collected ~2 years of movement and behavioural data in a wild, Critically Endangered animal,... more

We investigated the acute stress response associated with animal personalities by measuring plasma glucocorticoids throughout handling and collected ~2 years of movement and behavioural data in a wild, Critically Endangered animal, Astrochelys radiata (radiated tortoise). To determine whether our standard, brief conscientious handling procedures induce a stress response in our target species, we applied a stressor by way of initial animal processing and deployment of telemetry equipment. During surveys and processing, we sampled animals immediately upon detection, again after completing transmitter attachment and processing, and a final time the following day. We then used radiotelemetry to follow a subset of the animals for 22 months while collecting behavioural, climatic and location data. We found that brief and conscientious handling did not illicit consistent changes in plasma concentrations of the stress hormone corticosterone (CORT) but did reveal tremendous individual variation in response. The CORT concentration ranged more than 200-fold after imposing the stressor and returned to near-baseline values by the following day. When we accounted for the wide variation by calculating the degree of each individual's stress response relative to its baseline over its processing time, we discovered two non-overlapping physiological response types; those in which CORT concentrations increased dramatically in response to handling (219 ± 89.8 pg/ml/min) and those in which CORT varied only slightly (5.3 ± 8.9 pg/ml/min). The response types (strong vs. mild) also predicted body condition, home range size, activity, and behavioural tendencies. The degree of the individual's stress response in this species may be one component of correlated physiological and behavioural traits (animal personalities), which have previously been obscured in other chelonian studies by the use of mean values and should be considered in future conservation management applications for chelonian species.