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Skeletal ontogeny of xenarthrans is poorly known, especially because of the paucity of study specimens from distinct developmental stages. Here, we investigate morphometric aspects of the mandible ontogeny in the two-toed sloths, Choloepus spp. We examined mandibles of infant, juveniles and subadult sloths that were present in kill assemblages of harpy eagles, Harpia harpyja, and complemented our study with adult museum specimens. We carried out uni- and multivariate linear morphometric analyzes to assess the growth pattern of the mandible. Harpy eagles did not prey on adult two-toed sloths, preferring younger individuals. We found an overall strong correlation between the total length of the mandible and other mandibular measurements across age classes, with some of them scaling isometrically, and others presenting allometric growth. Also, morphometric data correlated with patterns of symphysial fusion across ontogenetic stages, rendering the latter a reliable indicator of the animal's age category. Although it was necessary to complement our sample with museum material, individuals obtained from the harpy eagle kill assemblage proved to be a valuable complementary source of specimens to be studied. [ABSTRACT FROM AUTHOR]

Mylodon darwinii is an extinct terrestrial species of sloth with a wide fossil record in South America, the record of the skin and hairs found from "La Cueva del Milodón", Chile. More than a century after the first studies on its hair, we aimed to redescribe the morphological characteristics of the hairs of M. darwinii by applying modern protocols of trichology and microscopy. Hair patterns were also compared with those of two other extinct species of sloths available in the literature. Hairs from mummified specimen housed in Museo de La Plata (Argentina) were analyzed through light and scanning electron microscopy to identify their cuticular and medullary patterns. Guard hairs lack medulla and have a wavy cuticle with irregular scale orientation, while underhairs have an amorphous cuticle pattern and no medulla. Hence, the former ones help in the diagnosis of the hair morphology of the species, while the latter ones do not. Differences found in the final product of each microscopy technique are discussed and should be considered in future research. The outcomes presented herein are a step further toward the understanding of evolutionary processes within Xenarthra, providing important data for such a poorly studied group that has only been recorded in Central and South America. [ABSTRACT FROM AUTHOR]

Nutrient foramina are small openings in the periosteal surface of the mid-shaft region of long bones that traverse the cortical layer and reach the medullary cavity. They are important for the delivery of nutrients and oxygen to bone tissue and are crucial for the repair and remodeling of bones over time. The nutrient foramina in the femur's diaphysis are related to the energetic needs of the femur and have been shown to be related to the maximum metabolic rate (MMR) of taxa. Here, we investigate the relationship between nutrient foramen size and body mass as a proxy to the aerobic capacity of taxa in living and extinct xenarthrans, including living sloths, anteaters, and armadillos, as well as extinct xenarthrans such as glyptodonts, pampatheres, and ground sloths. Seventy femora were sampled, including 20 from extant taxa and 50 from extinct taxa. We obtained the blood flow rate (Q̇) based on foramina area and performed PGLS and phylogenetic ANCOVA in order to explore differences among mammalian groups. Our results show that, among mammals, taxa commonly associated with lower metabolism like living xenarthrans showed relatively smaller foramina, while the foramina of giant extinct xenarthrans like ground sloths and glyptodonts overlapped with non-xenarthran placentals. Consequently, Q̇ estimations indicated aerobic capacities comparable to other placental giant taxa like elephants or some ungulates. Furthermore, the estimation of the MMR for fossil giant taxa showed similar results, with almost all taxa showing high values except for those for which strong semi-arboreal or fossorial habits have been proposed. Moreover, the results are compatible with the diets predicted for extinct taxa, which indicate a strong consumption of grass similar to ungulates and in contrast to the folivorous or insectivorous diets of extant xenarthrans. The ancestral reconstruction of the MMR values indicated a lack of a common pattern for all xenarthrans, strongly supporting the occurrence of low metabolic rates in extant forms due to their particular dietary preferences and arboreal or fossorial habits. Our results highlight the importance of considering different evidence beyond the phylogenetic position of extinct taxa, especially when extinct forms are exceptionally different from their extant relatives. Future studies evaluating the energetic needs of giant extinct xenarthrans should not assume lower metabolic rates for these extinct animals based solely on their phylogenetic position and the observations on their extant relatives. [ABSTRACT FROM AUTHOR]

The first step towards understanding the conservation situation and informing conservation decision‐making is to identify the habitat loss drivers. However, for nearly all tropical biota, there is a glaring lack of information on the spatiotemporal patterns of anthropogenic drivers.Our objective was to analyse the spatial and temporal distribution of the main anthropogenic drivers of habitat loss for Bradypus torquatus and Bradypus crinitus, two endangered and endemic species to the Brazilian Atlantic Forest.We used land‐use information associated with seven major IUCN‐based threats to sloths, covering a three‐generation time window (1988–2020), to quantify the current area occupied, temporal changes, heterogeneity, and intensity of drivers across species distributions.We found that cattle farming and ranching dominate the range of both species (from 49% to 56%) and cover an area larger than the remaining native forest. Other drivers also represent important spatial and temporal features of land conversion across species distributions.Driven mainly by livestock expansion, both sloth species have experienced a significant loss of forest cover (Bradypus torquatus – 659098.70 ha; Bradypus crinitus – 139013.20 ha) in the Brazilian Atlantic forest. Overall, Bradypus torquatus showed a higher rate of deforestation than forest regeneration, whereas forest gains outweighed habitat loss for Bradypus crinitus.Our results show that a substantial area of native forest – essential for strictly arboreal species – is being continuously replaced by cattle ranching and agricultural activities, which may lead to population isolation and decline, threatening the long‐term population viability. [ABSTRACT FROM AUTHOR]

This study comprises a comparative description of the skull anatomy in the basal megatherioid sloth Schismotherium fractum, based on specimens from the Santa Cruz Formation (late early Miocene; Santacrucian SALMA) in southern Argentine Patagonia. We provide more detailed descriptions and illustrations of the skull bones and their sutural connections, as well as the cranial foramina and their contents, than have previously been available. The anatomy in S. fractum is compared to contemporaneous basal megatherioids from Santa Cruz, Hapalops elongatus and Pelecyodon cristatus. The latter is a close relative of S. fractum in several phylogenetic analyses, but given the high levels of anatomical variation and other taxonomic uncertainties that surround these sloths, previous authors have suggested that the two may not represent distinct taxa. Our observations demonstrate that although the skulls of S. fractum do indeed exhibit variation in a broad variety of features, there are invariant, apomorphic features that consistently distinguish Schismotherium and Pelecyodon from one another, including at least 17 features derived from virtually every region of the skull. While supporting the current taxonomic status of these important, basal-most megatherioids, the present study highlights the need for further anatomical and phylogenetic investigations of Santacrucian sloths. [ABSTRACT FROM AUTHOR]

The present work concerns xenarthrans from the collection of Santiago (Kaspar Jakob) Roth (1850–1924) housed at the Palaeontological Institute and Museum of the University of Zurich, one of the most important collections of Pleistocene mammals from Argentina in Europe. Roth was a paleontologist originally from Switzerland who prospected and collected a large amount of Pleistocene megafauna of the Pampean Region of Argentina. The xenarthrans are the main representatives of this collection in Zurich, with 150 specimens. Since 1920, this material has not been revised and is under studied. The present investigation corresponds to a taxonomic revision resulting in 114 reassignments, leading to document xenarthran diversity and discuss their paleoecologies. The high diversity reflects the paleoecology of the Pampean Region during the Pleistocene, with the various abiotic events that impacted the paleoenvironment of this region. Within the Cingulata, the Pampean Region fauna was probably dominated by glyptodonts with a high representation of Glyptodontinae and Neosclerocalyptinae while within the sloths the highest diversity and abundance is found in the Mylodontinae and Scelidotheriinae. These four clades represent both species with high ecological tolerance (e.g., Glyptodon munizi; Catonyx tarijensis) and ecologically highly specialized species (e.g., Neosclerocalyptus paskoensis; Scelidotherium leptocephalum). The presence of such ecological diversity underlines the status of the Pampean Region as a major interest for paleoecological and paleoenvironmental reconstruction. [ABSTRACT FROM AUTHOR]

Simple Summary: Anteaters are insectivores, consuming diets consisting primarily of termites and ants in the wild; therefore, feeding them under human care has been a challenge and frequently leads to nutritional disorders. Through analysis of free-ranging giant anteaters' stomach content, the findings of this study provide valuable information for optimizing anteater nutrition in zoological institutions and rehabilitation centers causing a significant impact on the welfare of the species. Using the stomach contents of 24 wild road-killed giant anteaters as proxies for their diet, we found that estimated wild diets were much lower in calcium (about ten times less) and phosphorus compared with manufactured feeds commonly fed to anteaters under human care. Indicators of soil consumption, such as ash, iron, and manganese were higher in the stomach contents than in either wild termites or manufactured diets, likely due to high levels of soil ingestion during feeding in the wild. Protein and fat levels in insects, stomach contents, and commercial diets all met carnivore recommendations. Both giant anteaters and tamanduas in managed care often develop hypercalcemia, perhaps because these taxa have an enhanced ability to retain calcium allowing them to survive on such low calcium diets. Results from this study indicate that, for anteaters in managed care, it is important to keep dietary calcium and vitamins D and K within recommended levels to prevent nutritional diseases such as hyper- and hypocalcemia and vitamin K deficiency. [ABSTRACT FROM AUTHOR]

Anthropogenic disturbances affecting forest areas can increase disease prevalence and susceptibility in several species of arboreal mammals, such as sloths. Thus, this study aimed to evaluate the most common conditions in body systems of free-ranging sloths admitted at the Wildlife Triage and Rehabilitation Center of Amazonas of the Institute of Environment and Renewable Natural Resources. A total of 227 individuals (139 retrospective cases from 2015 to 2019, and 88 prospective cases from July 2020 to July 2021) were evaluated over a six-year period. Cases from the genus Bradypus showed involvement of the following body systems: 44% respiratory, 29% integumentary, 15% musculoskeletal, 5% digestive, 3% visual, 2% auditory, 1% circulatory and 1% genitourinary, while that distribution in the genus Choloepus was: 39% musculoskeletal, 27% integumentary, 19% respiratory, 9% digestive, 3% circulatory, 1% visual, 1% auditory and 1% genitourinary. The results reveal significant differences between the condition detected and the genus (Bradypus and Choloepus), age and case outcome. These results can provide data for future investigations of sloth diseases, confirming lesions, as well as motivating and suggesting adequate management methods. [ABSTRACT FROM AUTHOR]

Abstract The present work concerns xenarthrans from the collection of Santiago (Kaspar Jakob) Roth (1850–1924) housed at the Palaeontological Institute and Museum of the University of Zurich, one of the most important collections of Pleistocene mammals from Argentina in Europe. Roth was a paleontologist originally from Switzerland who prospected and collected a large amount of Pleistocene megafauna of the Pampean Region of Argentina. The xenarthrans are the main representatives of this collection in Zurich, with 150 specimens. Since 1920, this material has not been revised and is under studied. The present investigation corresponds to a taxonomic revision resulting in 114 reassignments, leading to document xenarthran diversity and discuss their paleoecologies. The high diversity reflects the paleoecology of the Pampean Region during the Pleistocene, with the various abiotic events that impacted the paleoenvironment of this region. Within the Cingulata, the Pampean Region fauna was probably dominated by glyptodonts with a high representation of Glyptodontinae and Neosclerocalyptinae while within the sloths the highest diversity and abundance is found in the Mylodontinae and Scelidotheriinae. These four clades represent both species with high ecological tolerance (e.g., Glyptodon munizi; Catonyx tarijensis) and ecologically highly specialized species (e.g., Neosclerocalyptus paskoensis; Scelidotherium leptocephalum). The presence of such ecological diversity underlines the status of the Pampean Region as a major interest for paleoecological and paleoenvironmental reconstruction.

The species Myrmecophaga tridactyla, Myrmecophagidae, is widely distributed in the Neotropics regions and is popularly known as the giant anteater. It is considered a generalist species regarding habitat and can be found in human-modified areas such as pastures and crops. However, there is limited information about the species in agricultural ecosystems. Due to its threatened status and the absence of records in the Campos das Vertentes region, which has only 1.04% of its area included in Conservation Units, this study aimed to report the unprecedented occurrence of M. tridactyla in the municipality of Ritápolis, Campos das Vertentes, Minas Gerais, in a transitional region between the Atlantic Forest and the Cerrado. Two occasional records were made on a rural road in this municipality. Therefore, this record increases our knowledge about the spatial distribution of M. tridactyla in the state of Minas Gerais, provides information about the species in human-modified landscapes, and supports the need for more Conservation Units in the Campos das Vertentes region.

The giant anteaters (Myrmecophaga tridactyla) belong to the superorder Xenarthra, they have low metabolism and anatomical features distinct from other groups of mammals. The species is classified as vulnerable by the IUCN Red List and ICMBio, being commonly found participating in ex situ conservation programs or received in wildlife rescue centers. The objective of this paper is to compile retrospective data and analyze the effectiveness of using ketamine associated with midazolam for the chemical restraint of giant anteaters. Fifty-five anesthetic files were selected from a heterogeneous group of giant anteaters, anesthetized between 2006 and 2023, at Sorocaba Zoo, and whose anesthetic protocol consists in the association between ketamine and midazolam in different doses, intramuscularly (IM). The ketamine dose ranged from 4 -12 mg/kg, and of midazolam, from 0,27 - 1 mg/kg. During anesthetic maintenance, the mean physiological parameters were 78 ± 32 bpm of heart rate, 10 ± 7 bpm of respiratory rate, and 33,9 ± 1°C of rectal temperature. The working time was, on average, 56 minutes and only 11 animals showed prolonged recovery, above 2 hours and 30 minutes. The protocol analyzed produced rapid induction and adequate working time, even with the possibility of extending the anesthetic protocol with isoflurane. There were no episodes of apnea or severe depression of the parameters during the procedures. [ABSTRACT FROM AUTHOR]

New remains of a relatively plesiomorphic nothrotheriid sloth have been recovered from upper Miocene-aged deposits near the village of Achiri in the Altiplano of Bolivia. The new specimens appear allied to other middle and late Miocene remains from Argentina and Bolivia that have been assigned to the pseudo-genus 'Xyophorus'. 'Xyophorus' has not previously been recognised as a distinct genus because of the paucity of material it encompasses. The new specimens, however, include a well-preserved squamosal with attached auditory region and an isolated astragalus. These elements, which are described in detail, provide a sufficient number of distinctive characters to place the previous fossils assigned to 'Xyophorus' into a new monotypic genus. Beyond exhibiting a suite of distinctive autapomorphies which justify its formal taxonomic designation, the new taxon not only shares several synapomorphies with more derived members of Nothrotheriidae but also retains a number of plesiomorphies characteristic of basal megatherioid taxa and shows a number of intermediate features. Although the new taxon is too incomplete to justify a full phylogenetic analysis, it appears to represent a basal member of Nothrotheriidae. Resolution of the taxonomic status of the genus Xyophorus awaits a better understanding of the taxonomy of early Miocene-aged basal megatherioids. [ABSTRACT FROM AUTHOR]

Living sloths exhibit numerous anatomical specializations towards inverted quadrupedalism, however, previous studies have noted a more varied locomotor repertoire than previously anticipated. In this study, we present spatiotemporal gait characteristics and triaxial kinetic data from the brown‐throated three‐toed sloth (Bradypus variegatus) across three locomotor modes: terrestrial quadrupedal "crawling", suspensory walking, and vertical climbing. Compared to quadrupedal crawling and suspensory walking, B. variegatus adopted longer contact times and stride durations, larger duty factors, and greater speed during vertical climbing. Net fore‐aft impulses were significantly greater during vertical climbing in both limb pairs than in quadrupedal crawling and suspensory walking. Functionally, during quadrupedal crawling and vertical climbing, both limb pairs served propulsive roles, while differentiation between a propulsive forelimb and braking hindlimb was observed during suspension. Net tangential forces differentiated vertical climbing kinetics from the other modes of locomotion, with the introduction of bidirectional pulling and pushing forces in the forelimb and hindlimb, respectively. The net mediolateral impulses were similar in vertical climbing and quadrupedal crawling as both limb pairs directed forces in one direction, whereas during suspensory walking, the laterally dominant forelimb was opposed by the medially dominant hindlimb. In total, this study provides novel data on the diverse locomotor dynamics in a slow‐moving arboreal tetrapod and posits new testable hypotheses about the neuroplasticity and ease of transitioning between locomotor behaviors. The strikingly similar kinetic profiles of quadrupedal crawling and suspensory walking compared to vertical climbing suggest shared neuromuscular and mechanical demands between these mirrored locomotor modes. Research highlights: Besides suspensory locomotion, sloths climb vertically and crawl terrestrially. We compared kinetic profiles and gait characteristics among these three locomotor modes and found that quadrupedal crawling and suspensory walking share several overlapping characteristics, whereas vertical climbing is more distinctive in both gait and limb loading patterns. [ABSTRACT FROM AUTHOR]

The Amazon Forest comprises one of the richest biodiversities area on the planet, but is highly threatened from habitat fragmentation and loss. Among its inhabitants is the magna-order Xenarthra, which includes the armadillos, sloths and anteaters. Five protected areas within the Amazon forest of Brazil were surveyed with camera traps following the TEAM protocol between the years 2015 and 2019. A total of 4044 independent records were examined to identify the richness, detection rate and activity patterns of xenarthrans in Brazilian rainforest. A total of seven Xenarthra species were obtained during 57,805 camera-trap days. Two threatened xenarthrans, Myrmecophaga tridactyla and Priodontes maximus, were present in all surveyed sites. Activity patterns were similar to those found in other biomes, with most species being mainly nocturnal; however, M. tridactyla and Cabassous unicinctus exhibited marked diurnal activity. Data were obtained from species at risk of extinction, such as P. maximus, and species rarely seen in the region, such as C. unicinctus. This study provides one of the most important datasets for the magna-order Xenarthra in areas of predominantly primary vegetation and the first activity pattern and richness of xenarthras in different areas of the Amazon biome. [ABSTRACT FROM AUTHOR]

The giant anteater (Myrmecophaga tridactyla) is classified as a vulnerable species but is commonly received in rescue centers and zoos. Establishing hematological and biochemical reference intervals of free-ranging animals is an important tool to assess the health of both captive and wild populations. Reference values for 53 free-ranging giant anteaters in the Cerrado savanna of Mato Grosso do Sul state were established and differences across sexes and age groups were tested. Significant differences (p ≤ 0.05) between age groups (juvenile and adult) were found for hematocrit, mean corpuscular hemoglobin concentration (MCHC), lymphocytes, monocytes, platelets, total protein, globulin, alkaline phosphatase (ALP), glutamyl transpeptidase (GGT), and phosphorus. Between sexes, the only value that showed a significant difference was platelets. The data from the present study were also compared with previous studies and a worldwide zoological databank (ZIMS). White blood cell values were higher in all the studies with free-ranging giant anteaters compared to captive individuals. The relative eosinophils reference interval from our study was the highest ever reported for the species. This paper is the first published study with biochemical values for free-ranging giant anteaters and provides important reference intervals for future giant anteater in situ and ex situ conservation initiatives and highlights the importance of more veterinary research with comparative aspects between wild and captive animals. [ABSTRACT FROM AUTHOR]

In the fossil record of South America, both ground sloths and their tracks are well known. However, most tracks described were assignable to megatherians and mylodontids, while tracks assignable to scelidotheriines show a very scarce record. In this contribution, we present new records of fossil tracks assignable to scelidotheriines and review and expand the original description of the ichnotaxon Acugnaichnum dorregoensis. In addition, we explored the correlation between track features and limb morphology, finding that the tracks can help to better understand the posture and function of scelidotheriine limbs. Features of the handprint suggest that these ground sloths would not rest hands in the substrate by its palmar aspect, but on the knuckles or its lateral aspect, similar to the extant giant and lesser anteaters. Concerning the foot tracks, their features indicate that digits V and IV rested on the substrate in a different orientation than the digit III, whose large ungual phalanx provided additional support by resting of its lateral side, which is biomechanically coherent with the stability of the foot. In addition, some kind of soft tissue cushion would be present below the main arch of the foot. Evidence for locomotion style and bipedalism is discussed. [ABSTRACT FROM AUTHOR]

Climate change and habitat loss have been identified as the main causes of species extinction. Forest regeneration and protected areas are essential to buffer climate change impacts and to ensure quality habitats for threatened species. We assessed the current and future environmental suitability for the maned sloth, Bradypus torquatus , under both future climate and forest restoration scenarios, using ecological niche modeling. We compared environmental suitability for two Evolutionarily Significant Units (ESUnorth and ESUsouth) using two climate change scenarios for 2070, and three potential forest regeneration scenarios. Likewise, we evaluated the protection degree of the suitable areas resulting from the models, according to Brazilian law: PA—Protected Areas; PPA—Permanent Protection Areas (environmentally sensitive areas in private properties); and LR—Legal Reserves (natural vegetation areas in private properties). Finally, we calculated the deficit of PPA and LR in each ESU, considering the current forest cover. Forest regeneration might mitigate the deleterious effects of climate change by maintaining and increasing environmental suitability in future scenarios. The ESUnorth contains more suitable areas (21,570 km²) than the ESUsouth (12,386 km²), with an increase in all future scenarios (up to 45,648 km² of new suitable areas), while ESUsouth might have a significant decrease (up to 7,546 km² less). Suitable areas are mostly unprotected (ESUnorth—65.5% and ESUsouth—58.3%). Therefore, PPA and PA can maintain only a small portion of current and future suitable areas. Both ESUs present a high deficit of PPA and LR, highlighting the necessity to act in the recovery of these areas to accomplish a large-scale restoration, mitigate climate change effects, and achieve, at least, a minimum forested area to safeguard the species. Notwithstanding, a long-term conservation of B. torquatus will benefit from forest regeneration besides those minimum requirements, allied to the protection of forest areas. [ABSTRACT FROM AUTHOR]

Using the stomach contents of 24 wild road-killed giant anteaters as proxies for their diet, we found that estimated wild diets were much lower in calcium (about ten times less) and phosphorus compared with manufactured feeds commonly fed to anteaters under human care. Indicators of soil consumption, such as ash, iron, and manganese were higher in the stomach contents than in either wild termites or manufactured diets, likely due to high levels of soil ingestion during feeding in the wild. Protein and fat levels in insects, stomach contents, and commercial diets all met carnivore recommendations. Both giant anteaters and tamanduas in managed care often develop hypercalcemia, perhaps because these taxa have an enhanced ability to retain calcium allowing them to survive on such low calcium diets. Results from this study indicate that, for anteaters in managed care, it is important to keep dietary calcium and vitamins D and K within recommended levels to prevent nutritional diseases such as hyper- and hypocalcemia and vitamin K deficiency.

Cyclopes didactylus , the smallest of all anteaters, inhabits Amazonian and Atlantic forests with an apparently disjunct distribution. Yet, phylogeography reveals historical connections through the forests of the Northeast Region of Brazil. Its populations in this region are classified by the Red List of Threatened Species as Data Deficient and with a trend towards decline. However, Northeast Brazil has a large sampling gap, and the potential distribution of this species has yet to be evaluated. We investigated the potential distribution of C. didactylus to evaluate the hypothesis of a disjunct distribution between Amazonian and Atlantic forests and estimate the amount of protected area in its predicted distribution. We generated a Maxent distribution model using occurrence records, according to the new taxonomic revision of Cyclopes , and selected current bioclimatic variables to evaluate the continuity of the predicted distribution of the species in Northeast Brazil. We also performed past projections to assess historical connections and overlapped maps of protected areas onto their current distribution. Although its distribution is probably disjunct, at least one as-yet-unknown population may be present in the forests of Northeast Brazil, an area poorly protected. The results are useful for targeting field efforts in this under-sampled region. [ABSTRACT FROM AUTHOR]

Simple Summary: In recent years, the use of technologies to remotely monitor animal behaviour has increased. However, when they are used for the first time in a new species, validation is needed. Therefore, a tri-axial accelerometer was used to monitor lesser anteater (Tamandua tetradactyla) behaviour. First, the influence of using a vest on the animals' behaviour was evaluated. Second, correlations between video recordings and accelerometer data were made, allowing the researchers to obtain summary measures for each behaviour and a threshold to discriminate activity/inactivity events. Sensitivity and precision variables revealed the robustness of accelerometer monitoring. Third, animals responded to a reduction in enclosure complexity by increasing their activity. The relevance of the accelerometer was determined comparing data (activity level and activity cycle) with video recordings. The results indicate that an accelerometer attached to a vest is a reliable technology for monitoring the activity pattern of T. tetradactyla under semi-controlled environmental conditions. Accelerometers are a technology that is increasingly used in the evaluation of animal behaviour. A tri-axial accelerometer attached to a vest was used on Tamandua tetradactyla individuals (n = 10) at Biodiversity Park. First, the influence of using a vest on the animals' behaviour was evaluated (ABA-type: A1 and A2, without a vest; B, with a vest; each stage lasted 24 h), and no changes were detected. Second, their behaviour was monitored using videos and the accelerometer simultaneously (experimental room, 20 min). The observed behaviours were correlated with the accelerometer data, and summary measures (X, Y and Z axes) were obtained. Additionally, the overall dynamic body acceleration was calculated, determining a threshold to discriminate activity/inactivity events (variance = 0.0055). Then, based on a 24 h complementary test (video sampling every 5 min), the sensitivity (85.91%) and precision (100%) of the accelerometer were assessed. Animals were exposed to an ABA-type experimental design: A1 and A2: complex enclosure; B: decreased complexity (each stage lasted 24 h). An increase in total activity (%) was revealed using the accelerometer (26.15 ± 1.50, 29.29 ± 2.25, and 35.36 ± 3.15, respectively). Similar activity levels were detected using video analysis. The results demonstrate that the use of the accelerometer is reliable to determine the activity. Considering that the zoo-housed lesser anteaters exhibit a cathemeral activity pattern, this study contributes to easily monitoring their activities and responses to different management procedures supporting welfare programs, as well as ex situ conservation. [ABSTRACT FROM AUTHOR]

We present the first records of the post-release follow-up and monitoring of a rehabilitated two-toed sloth (Choloepus hoffmanni) as well as freezing behavior and an inferred antagonistic interaction for this species. Two-toed sloths are nocturnal and arboreal mammals whose survival relies on their capability to remain undetected by predators. Nevertheless, in the Guayas province of Ecuador, they are among the most common mammal species in rehabilitation centers. The liberation of animals back to the forest is the main goal of rehabilitation, while the follow-up of post-release human support of animals facilitates their re-establishment in their natural habitat. Follow-up, direct observation, and Bluetooth-based monitoring of the two-toed sloths secured the survival of this species in this part of Ecuador. The range of detectability of the device used indicates its suitability for tracking low-mobility animals. After the first five days, the number of trees used per day increased, and 19 trees within 1152 m² were visited. Daylight and movement time range showed a correlation towards detectability. The follow-up effort allowed for keeping the two-toed sloth safe for 10 days after release. Due to the difficulty monitoring nocturnal animals, economic constraints in conservation, accessibility, and safety of the animals, biodegradable Bluetooth-based backpacks are recommended to ease the location of the animal and support its survival in the wild. [ABSTRACT FROM AUTHOR]

Simple Summary: Monitoring diseases and lesions in free-ranging and captive wild animals is important for biodiversity conservation and for understanding factors that can impact not only animal health but also human and environmental health. Here, we report for the first time a case of liver cancer in a free-ranging three-toed sloth (Bradypus variegatus) and describe the gross, microscopic, and immunohistochemical features of the lesion. The tumor was identified during the necropsy of a three-toed sloth that had to be euthanized due to serious consequences of an accident in the electrical network. Despite not being related to the cause of death of the animal, the type of tumor observed, a hepatocellular carcinoma (HCC), is one of the most frequent hepatic neoplasms in the liver of humans and domestic animals. The increasing interest of tumors in wildlife is important for biodiversity conservation and for monitoring environmental agents and/or contaminants with potential impact on human health. Here we described the occurrence of hepatocellular carcinoma (HCC) in noncirrhotic liver of a free-ranging three-toed sloth (Bradypus variegatus) from the Atlantic Forest biome in Brazil. The HCC showed a moderate mononuclear inflammatory infiltrate within the tumor tissue but with no inflammation and fibrosis in the adjacent liver tissue. Upon immunohistochemistry, neoplastic cells were diffusely positive for HepPar-1 and glutamine-synthetase presenting an irregular and random immunostaining pattern; β-catenin was positive in the cytoplasmic membrane of malignant hepatocytes; and cytokeratin 19 immunostaining was restricted to bile duct epithelial cells. The liver tissue was negative for HBV-like and HCV-like viruses assessed by molecular tests. The potential similarity of pathogenesis may reinforce the need for research on environmental and/or infectious agents associated with HCC that may contribute to the understanding of cancer in wildlife. [ABSTRACT FROM AUTHOR]

Located in the Northeast of Brazil, the city of Paripiranga, State of Bahia, is situated in a karst region called Supergrupo Canudos. The locality boasts a high number of natural cavities, some of which contain Pleistocene mammal fossils and remains of contemporary vertebrates. The cave locally known as Furna do Cazuza is a deep natural cavity in Proterozoic limestone, with a vertical entrance of 16 m in depth, resembling an abyss, serving as natural traps for many animals, especially mammals. The cave has a large area at its entrance, with a significant influx of sediment and a considerable quantity of bones, some of which have already been collected. The collected bone material (appendicular and part of a skull) belongs to three individuals: an armadillo and two giant ground sloths. The osteoderms were attributed to the Pampatheriidae Holmesina sp., and the most abundant bone material to the Megatheriidae Eremotherium laurillardi and the Scelidotheriidae Catonyx cuvieri. This study presents the largest number of bones of C. cuvieri attributed to a single individual in a cave. As paleontological research advances, the understanding of the diversity of the past fauna during the Pleistocene in the municipality of Paripiranga and the surrounding region continues to expand. The caves are still under study, and their fossiliferous richness has not been fully measured and identified. • Solid description of fossils in Furna do Cazuza Cave. • The addition of three new taxa - E. laurillardi , Holmesina sp. and the confirmation of C. cuvieri - to the paleobiodiversity. • The most complete Catonyx cuvieri skeleton found in the municipality of Paripiranga to date. • Amplification of the paleobiogeography of extincted taxons. [ABSTRACT FROM AUTHOR]

Objective: To describe ophthalmic examination and diagnostic values for Schirmer tear test (STT), intraocular pressure (IOP), corneal horizontal diameter (CHD), palpebral fissure length (PFL), fundoscopy, and palpebral conjunctiva microbiota from healthy giant anteaters. Animals studied: Twelve giant anteaters (Myrmecophaga tridactyla), 11 adults and one juvenile, five males and seven females. Procedures: The animals were submitted to general anesthesia and ophthalmic evaluation with portable slit‐lamp biomicroscope, Finoff transilluminator, and fundoscopy, as well as STT, bacterial culture from palpebral conjunctiva, rebound tonometry IOP, and measurement of PFL and CHD. Data compiled were analyzed with ANOVA and Tukey tests. Results: The results (mean ± standard deviation) were as follows: STT 8.04 ± 6.21 mm/min; IOP 10.92 ± 2.45 mmHg; PFL 0.75 ± 0.11 cm; CHD 0.96 ± 0.10 cm. Out of the 24 eyes swab samples for bacterial culture, 17 were positive, with three genera of Gram‐positive bacteria identified Staphylococcus spp., Bacillus sp., and Corynebacterium sp. Gram‐negative bacteria were not isolated from any of the samples. Conclusions: As conservation work in this vulnerable species continues, this report on basic ophthalmic examination and diagnostic parameters will be helpful improve their treatment and care. More ophthalmic studies are encouraged in animals within the Pilosa order. [ABSTRACT FROM AUTHOR]

The brown‐throated sloth, Bradypus variegatus, is a common species endemic to South and Central America. Nonetheless, maintaining these animals in captivity can be challenging, and very few institutions manage to do so. The São Paulo Zoological Park Foundation is in a remnant of the Atlantic rainforest in the middle of São Paulo, the largest city in Brazil. This forest fragment has a population of B. variegatus that is geographically isolated and yet to be studied. Assessing the health status of individuals remains difficult due to the lack of reference intervals (RIs) for hematologic and biochemical variables for this species. We aimed to establish hematologic and biochemical RIs in a population of wild B. variegatus living in the largest remnant of Atlantic rainforest in São Paulo city, Brazil. Blood samples from 25 individuals of wild B. variegatus were collected and analyzed for 20 hematologic and 21 biochemical variables, using standard laboratory techniques. Each variable was statistically analyzed according to the American Society for Veterinary Clinical Pathology guidelines. The results obtained for each variable were statically analyzed, making it possible to obtain descriptive statistics for all hematologic and biochemical variables. RIs were determined for 16 hematologic variables. During the microscopic analysis, we observed anisocytosis, polychromatophils, Howell‐Jolly bodies, macroplatelets, and reactive lymphocytes. The RIs and descriptive statistics described here establish important baseline numbers that could be essential for the management and treatment of both captive and wild B. variegatus sloths. [ABSTRACT FROM AUTHOR]

Stereotypic behavior has been studied in various species, but little information exists on stereotypies in giant anteaters (Myrmecophaga tridactyla) under professional care. Giant anteaters are known for their solitary nature and well-developed sense of smell. This study examined the effect of conspecifics who were housed off-exhibit on a male giant anteater’s rate of pacing and pacing intensity when he was on-exhibit. Instantaneous sampling was used to determine the percentage of time pacing, the number of pacing bouts and pacing bout duration. Randomization tests determined that the reduction in the male giant anteater’s rate of pacing significantly decreased after conspecifics were relocated to a different building. Pacing bout duration, a potential measure of intensity, also significantly decreased during the treatment phase. In addition, the giant anteater changed his pacing location after the removal of conspecifics. He transitioned from pacing near the conspecifics’ off-exhibit location during the baseline to the opposite quadrant of the exhibit after their departure. These results suggest that keeping a male giant anteater in proximity to conspecifics without the ability to interact with them had an impact on his behavior. Better understanding the motivations for stereotypic behaviors of giant anteaters will better inform housing decisions made by zoo professionals.

Abstract Spatial ecology data are essential for conservation purposes, especially when extinction risk is influenced by anthropogenic actions. Space use can reveal how individuals use the habitat, how they organize in space, and which components are key resources for the species. We evaluated the space use and multiscale habitat selection of giant anteaters (Myrmecophaga tridactyla), a vulnerable Neotropical mammal, in a Cerrado site within a human‐modified landscape in southeastern Brazil. We used GPS transmitters to track eight anteaters in the wild. With the resulting dataset, we estimated home range and core‐area sizes and then used two overlap indexes. We assessed habitat selection by compositional analysis and analyzed events of spatio‐temporal proximity. The average Brownian bridge kernel estimate of home range size was 3.41 km2 (0.92–7.9). Regarding home range establishment, five individuals showed resident behavior. Males (n = 4) had larger home ranges and were more active than females (n = 4). Despite the spatial overlap of home range (above 40% in four dyads), maximum temporal space sharing was 18%. Giant anteaters were found in proximity. Habitat selection favored savanna, and exotic timber plantation was always avoided. Roads and built‐up areas were selected secondarily at the landscape level. The selection of anthropogenic sites denotes behavioral plasticity regarding modified habitats. However, the high selectivity for savanna, at all levels, demonstrates a high dependence on natural habitats, which provide the necessary resources for the species. The recurrent proximity of male–to‐female anteaters may indicate reproductive behavior, which is essential for maintaining this isolated population.

RESUMO Bradypus variegatus, espécie pertencente à família Bradypodidae e à superordem Xenarthra, pode ser considerada modelo biológico de caráter multidisciplinar. Assim, realizou-se um trabalho de descrição anatômica da artéria carótida externa (ACE) e dos seus ramos no bicho-preguiça B. variegatus. Utilizaram-se 10 animais adultos, sendo todos fêmeas, que foram submetidos à dissecação, constatando-se que a artéria (a.) carótida comum se bifurca, em externa e interna, no nível do primeiro anel traqueal. A ACE, então, segue estendendo-se até a maxila, onde emite ramos para a região temporal e para o polo posterior do olho. Em todos os animais estudados, foram observados sete ramos principais da ACE, que, segundo a sua origem e localização, foram denominados como a. auricular, a. lingual, a. facial, a. alveolar, a. inferior, a. temporal, a. maxilar e a. oftálmica. Os ramos maxilar e oftálmico correspondem aos terminais e os demais são ramos colaterais. Em 50% dos animais analisados, foi verificada a presença de anastomoses arteriais e 40% deles apresentaram o acréscimo de um ramo aos principais. Desses, 30% demonstraram a presença de um ramo traqueal e 10% de um ramo sublingual, sendo esses ramos colaterais.

Giant anteaters (Myrmecophaga tridactyla) are one of the most charismatic Neotropical mammals; however, the overall population trend for the species is decreasing due to numerous threats, including road kill. Population viability analysis (PVA) is an important tool to assess the viability of populations, rank alternative management scenarios and determine research priorities. A detailed baseline model for giant anteaters was developed using data from the literature, fieldwork, researcher expertise and captive populations. A sensitivity analysis was performed to evaluate the relative impact of each parameter on model results to prioritize potential threats and future research efforts. A case study based on three years of research in the Brazilian Cerrado on the impact of vehicle collisions on giant anteaters was tested. Model results showed a potential stochastic growth rate of 5% in the absence of significant threats, and sensitivity testing revealed that mortality rates and the percentage of females breeding are the most sensitive parameters of the model. Using real data for model inputs on road kill as well as sex ratio and age class showed that deaths of giant anteaters due to vehicle collisions decreases the stochastic growth rate of that population by half. Knowledge on the sex ratio of animals killed by vehicles is key to understanding the impact of roads in this polygynous species. This baseline model for giant anteaters can be adapted to populations throughout the species range and is valuable for use in conservation planning for the species.

Parocnus dominicanus sp. nov. represents a new species of megalonychid ground sloth from the Altagracia Province of southeastern Dominican Republic. Specimens of multiple individuals, including one associated partial skeleton, were recovered from two separate underwater caves in the Parque Nacional del Este through collaborations with museums and cave divers between 2009–2013. Parocnus dominicanus sp. nov. is distinguished by its small size compared to that of P. serus, with percent differences in limb element lengths ranging from 13−24%. Numerous cranial and post-cranial elements also exhibit morphological character states that are not attributable to size variations. The recovery of multiple individuals within each locality demonstrates a size dimorphism, possibly sexual, which parallels patterns exhibited by P. serus. The two species are also geographically distinct, with no examples of co-occurrence at any localities to date. Parocnus dominicanus sp. nov. and P. serus share character states that are distinct from those of the Cuban species, P. browni, and which suggest differential usage of the forelimb. The exact age of the specimens described here is unknown, however, Parocnus has been dated to the Holocene in Haiti. http://zoobank.org/urn:lsid:zoobank.org:pub:12E495D3-E261-4522-9854-D3B4C2D5FFB8

The giant anteater (Myrmecophaga tridactyla), the largest representative of the xenarthrans, is listed as Vulnerable-IUCN. Their unique anatomy and physiological characteristics, such as relatively low basal metabolic rates, make xenarthrans challenging to anesthetize and equip with tracking devices. This study evaluates and describes physical capture and chemical immobilization protocols for field conditions that enable the harnessing of free-ranging giant anteaters. A total of 51 wild giant anteaters were physically captured, and chemical immobilization was performed applying the combination protocol (BDM), butorphanol tartrate, detomidine hydrochloride, and midazolam hydrochloride, each at 0.1 mg/kg. Whenever extra time was necessary, supplementary doses of BDM were used (0.03 mg/kg of butorphanol, 0.03 mg/kg of detomidine, and 0.03 mg/kg of midazolam). Vital signs were monitored during anesthesia every 10 min. All individuals received the antagonist combination NYF: naloxone hydrochloride (0.02 mg/kg), yohimbine hydrochloride (0.125 mg/kg), and flumazenil (0.01 mg/kg). Average rectal temperature was 34.5 ± 2.52 °C, heart rate/min 43.47 ± 7.39, respiratory rate 8.49 ± 2.79, and oxygen saturation values (SpO2%) 90.1 ± 4.38. BDM protocol was considered satisfactory and provided enough time to complete the procedures. The total chemical immobilization time was 85.5 ± 16.8 min. This protocol provided rapid, smooth inductions, and a wide margin of safety. Recovery time varied according administration method lasting 2.55 ± 1.33 to 12 ± 5.39 min intravenous or intramuscular, respectively. Physical capture method and the chemical immobilization protocol were considered efficient, safe, highly feasible, and can be completely antagonized, promoting smooth and rapid recoveries. [ABSTRACT FROM AUTHOR]

The drastic reduction of the Brazilian Cerrado has transformed this savanna hotspot into vast swaths of commodity-based agriculture fields, mainly soybean, sugarcane, and beef-production pasturelands. The resulting habitat loss and fragmentation are the principal factors underlying population decline of native species inhabiting the Cerrado, particularly those with a high demand for space, low population density, and specialized diet, such as the endangered giant anteater (Myrmecophaga tridactyla). Although the species has been studied in protected areas, we know much less about its ability to endure in disturbed landscapes. Here, we analyzed camera-trapping data to estimate a proxy of habitat use (⁠ ψ ^ ⁠ ; occupancy) and detection probabilities of the giant anteater, identifying environmental covariates influencing these parameters in landscapes with intensive agriculture and commercial forestry. We found this species using about half of the study area (model average ψ ^ = 0.51, CI = 0.40–0.62), with two predictors strongly influencing habitat use: protected areas and unpaved roads. In turn, detection probability correlates positively with area of open Cerrado and negatively with area of settlements. The species is more likely to use unpaved roads inside protected areas (⁠ ψ ^ = 0.90, CI = 0.47–0.75), compared to off road sites in the surrounding areas (⁠ ψ ^ = 0.19, CI = 0.10–0.34). Our findings indicate that giant anteaters are dependent on nature reserves and native vegetation areas existing on private properties, whose protection is regulated by the Brazilian Native Vegetation Protection Law. Given the relative paucity of state-owned protected areas in the Brazilian Cerrado, increasing the adherence of rural owners to this law is, therefore, key for the conservation of the giant anteater. The intense use of unpaved roads might reflect travelling and/or foraging optimization, a behavioral response that, nevertheless, may compound this species' susceptibility to suffer mortality from roadkill. [ABSTRACT FROM AUTHOR]

ABSTRACT This work aimed to describe the origin, distribution, and ramifications of the ischiadicus nerve in the giant anteater and to provide anatomical data which could explain not only the evolutionary aspects but also provide important information for other related works. For the present study, four specimens were used, prepared by perfusion of 10% formaldehyde solution via the femoral artery, for conservation and dissection. The origin of the right and left ischiadicus nerves in the giant anteater from the ventral ramification of the third lumbar (L3) and the first (S1), second (S2), and third (S3) sacral spinal nerves. These nerves were symmetrical in all animals studied. The distribution and ramification occurred to the superficial, middle, and deep gluteal, gemelli, piriform, quadratus femoris, tensor fasciae latae, caudal crural abductor, cranial and caudal parts of the biceps femoris, adductor, semitendinous, and cranial and caudal parts of the semimembranous muscles. Based on the origins of the ischiadicus nerves, there is a caudal migration in the nerve location in animals in a more recent position on the evolutionary scale due to reconfiguration of the lumbosacral plexus, resulting from the increase in a number of lumbar vertebrae. There is no complete homology of the muscle innervation.

The increasing interest of tumors in wildlife is important for biodiversity conservation and for monitoring environmental agents and/or contaminants with potential impact on human health. Here we described the occurrence of hepatocellular carcinoma (HCC) in noncirrhotic liver of a free-ranging three-toed sloth (Bradypus variegatus) from the Atlantic Forest biome in Brazil. The HCC showed a moderate mononuclear inflammatory infiltrate within the tumor tissue but with no inflammation and fibrosis in the adjacent liver tissue. Upon immunohistochemistry, neoplastic cells were diffusely positive for HepPar-1 and glutamine-synthetase presenting an irregular and random immunostaining pattern; β-catenin was positive in the cytoplasmic membrane of malignant hepatocytes; and cytokeratin 19 immunostaining was restricted to bile duct epithelial cells. The liver tissue was negative for HBV-like and HCV-like viruses assessed by molecular tests. The potential similarity of pathogenesis may reinforce the need for research on environmental and/or infectious agents associated with HCC that may contribute to the understanding of cancer in wildlife.

Zoological parks are an excellent source of biological material for research, as they often receive free-living wild animals. The present report discusses the occurrence of mites in the ear canal in a free-living anteater in the Metropolitan Region of Sorocaba, forwarded to the Sorocaba Zoo. During the clinical examination of the animal ectoparasites were located and collected. The mites were collected from the ear canal and were deposited in plastic pots with 70% alcohol, then sent to the National Reference Laboratory for Rickettsial Diseases Vectors (LIRN) of the Oswaldo Cruz Institute (IOC), Oswaldo Cruz Foundation (FIOCRUZ). Using taxonomic specific keys and with the aid of a microscope, the species Psoralges libertus Trouessart, 1896 was morphologically identified. This species was reported in another species from the Order Pilosa, but it is the first record of Psoralges libertus parasitizing a free-living Myrmecophaga tridactyla Linnaeus, 1758. [ABSTRACT FROM AUTHOR]

Although sex assignment is essential to study biology and ecology of an animal, in Xenarthra there is still no standardized assay for genetic sex identification. Here, we evaluate the potential of two nuclear fragments [Zinc finger (~ 400 bp) and Sex-determination region Y (~ 180 bp) genes] for sex identification of seven Xenarthra species. First, we amplified and sequenced both homologous segments of Zinc finger gene (Zfx and Zfy) in species from each suborder that represents the phylogenetic diversity in Xenarthra. Because of the absence of polymorphisms in the homologous segments in three species phylogenetically not closely related, we applied a multiplex polymerase chain reaction (multiplex PCR) approach using the genes described above. Finally, we performed a case study using tissue samples from the three most road-killed species of Xenarthra (Myrmecophaga tridactyla, Tamandua tetradactyla and Euphractus sexcinctus) to evaluate our multiplex PCR approach for sex identification in these individuals that have lost their morphological characteristics. The method proved to be efficient for molecular sex identification in the different types of samples and may be especially useful for studies using poor quality DNA. We discussed each approach with an applicability in genetic and ecological studies. [ABSTRACT FROM AUTHOR]

There is a growing ethical concern in modern society about animals' quality of life. We hypothesize that zoo visitors' perception of zoo animal welfare, particularly in the case of lesser anteaters, changes positively after listening to scientific information. Visitors observing active lesser anteaters in their enclosures at Córdoba Zoo (Argentina) were asked to respond to a questionnaire about animal welfare. The treatment group (T) answered the questionnaire after listening to a brief informative talk based on local scientific studies on lesser anteaters. The control group (C) answered the questionnaire without hearing the informative talk. Visitors (87.2%) considered biological, sanitary, and sociocultural aspects to be necessary conditions for optimum wild zoo‐housed animal welfare. The majority of visitors considered that natural surroundings provide the highest level of welfare for wild animals. Visitors in the T group ranked the zoo as providing a higher level of animal welfare than those in group C. In reference to management measurements, the T group agreed on the positive effect of the application of environmental enrichment (Likert Medians: C = 4 and T = 5; p =.0443). On the basis of their perception, most visitors in both groups stated that the lesser anteaters at Córdoba Zoo appeared to be in a good state of welfare. We interpret this as meaning that, what these Córdoba zoo visitors personally perceived while observing the lesser anteaters carried greater weight than what they learned from the informative talk, though the talk did slightly affect their opinion. Research Highlights: A scientific talk on the monitoring of lesser anteaters did not affect visitors' opinions about the welfare of these animals at Córdoba Zoo.Zoo visitors assessed lesser anteaters' welfare based on their perceptions. [ABSTRACT FROM AUTHOR]

Management procedures affect behavioural and physiological stress responses of wild mammals under human care. According to the Reactive Scope Model, normal values are presumed to exist within predictive and reactive ranges. First, stress parameters of zoo-housed adult Tamandua tetradactyla were evaluated in winter and summer (29 days each), determining the level of behaviour and/or physiological parameters needed to respond to predictable environmental changes. Secondly, the effects of veterinary procedures and transportation were studied in both seasons. Non-invasive methods were applied, assessing behaviour through videos and adrenocortical activity by faecal glucocorticoid metabolites (FGMs). Lesser anteaters exhibited seasonality (summer > winter) in some behavioural parameters, such as nocturnal activities, as well as in the activity cycle (e.g., acrophase) and FGMs. A veterinary check elicited an increase in total activity (TA), natural behaviours and repetitive locomotion and affected the activity cycle, particularly in summer. Transport produced changes in TA, nocturnal and natural activity and some variables of the activity cycle, mostly during summer. Although the effects of routine management procedures were different from each other and presumably stressful, they elicited changes only at the behavioural level, which was greater during summer. The differences observed according to non-invasive methodologies highlight the importance of a multidisciplinary approach in this context and suggest that it is unlikely that individual welfare was affected.

Spatial ecology data are essential for conservation purposes, especially when extinction risk is influenced by anthropogenic actions. Space use can reveal how individuals use the habitat, how they organize in space, and which components are key resources for the species.We evaluated the space use and multiscale habitat selection of giant anteaters (Myrmecophaga tridactyla), a vulnerable Neotropical mammal, in a Cerrado site within a human‐modified landscape in southeastern Brazil.We used GPS transmitters to track eight anteaters in the wild. With the resulting dataset, we estimated home range and core‐area sizes and then used two overlap indexes. We assessed habitat selection by compositional analysis and analyzed events of spatio‐temporal proximity.The average Brownian bridge kernel estimate of home range size was 3.41 km2 (0.92–7.9). Regarding home range establishment, five individuals showed resident behavior. Males (n = 4) had larger home ranges and were more active than females (n = 4). Despite the spatial overlap of home range (above 40% in four dyads), maximum temporal space sharing was 18%. Giant anteaters were found in proximity. Habitat selection favored savanna, and exotic timber plantation was always avoided. Roads and built‐up areas were selected secondarily at the landscape level.The selection of anthropogenic sites denotes behavioral plasticity regarding modified habitats. However, the high selectivity for savanna, at all levels, demonstrates a high dependence on natural habitats, which provide the necessary resources for the species. The recurrent proximity of male–to‐female anteaters may indicate reproductive behavior, which is essential for maintaining this isolated population. [ABSTRACT FROM AUTHOR]

The Xenarthra, which are endemic to the Americas, consist of two distinct clades, the Pilosa (anteaters and sloths) and the Cingulata (armadillos). The association between xenarthrans and humans dates back to ancient times. Although these associations do not appear to have negatively impacted all wild populations, hunting probably contributed to the extinction of some xenarthrans in archaeological-geological times and, more recently, to the depletion or extinction of local populations. Undoubtedly, human activities are increasingly impacting the wild populations of many xenarthran species. According to the last assessment for the IUCN Red List of Threatened Species, 15 of the 30 species of Xenarthra are classified as Least Concern, five as Data Deficient, five as Near Threatened, and five are included in a threatened category, with one (Bradypus pygmaeus) being considered Critically Endangered, and four (Myrmecophaga tridactyla, Bradypus torquatus, Priodontes maximus, and Tolypeutes tricinctus) designated as Vulnerable. Here, we discuss the current taxonomic challenges of working with xenarthrans and the impacts of those challenges on the conservation of these animals. We evaluate the main threats affecting the Xenarthra now and in the future, we identify some successful conservation initiatives, and we highlight the importance of initiatives by individual experts. Our goals are to summarize the current status of xenarthrans and to facilitate the development and implementation of conservation strategies for these animals. [ABSTRACT FROM AUTHOR]

Collared anteater is present throughout the Brazilian territory, but its morphology is little known. This study aimed to trace its external biometric profile and its digestive system. Six cadavers (4 ± 0.16 kg) from Paraíba, Brazil, were used. The thoracic limbs were more robust when compared to pelvic. The length of the tail is below that described in specimens from south‐eastern Brazil, probably due to the greater use of the tail suspension function in the leafier forests in this region. The tongue had no papillae and had keratinized squamous epithelium. The oesophagus was tubular with keratinized squamous epithelium. The stomach was single‐chambered with simple prismatic epithelium and presence of tubular glands in the lamina propria. The pyloric region was thicker and had larger folds of mucosa; the greater curvature was approximately three times greater than the smaller. The small intestine was larger than that found in other Xernathra species such as sloth, an herbivore animal; in the large intestine, the caecum was small. The colon was subdivided ascending, transverse and descending, with simple prismatic epithelium. This study is the first to bring the description of the external and digestive system morphometrics of collared anteater adult and pup. The anatomical characteristics of the digestive system show that the digestion of the anteaters, although not using the fermentation, is not as rapid as in other Xenarthras, probably due to the material of the exoskeleton of the insects by them consumed. The data generate subsidies for the clinic, surgery, preservation and nutrition of this species. [ABSTRACT FROM AUTHOR]

Xenarthra is unique in having striking features in the axial skeleton, usually very different from the rest of the eutherian clades. Some of these features are widely spread among the members of the group (e.g., the presence of xenarthrales in most cingulates and all pilosans, and the synsacrum with sacroischial union to the pelvis in almost all xenarthrans) and others are restricted to some taxa (e.g., deviated number of cervical vertebrae in Bradypus and Choloepus). In this study, we aim to explore the great diversity of vertebral elements composing the xenarthran synsacrum within a phylogenetic framework. Vertebral counts of the adult synsacrum was obtained from almost all extant genera, with the exception of Calyptophractus, and several fossils. The modal number of vertebrae from the adult synsacrum was mapped onto a composite phylogeny of Xenarthra. The ancestral number of synsacrals for Xenarthra was recovered as ambiguous, although one of the optimizations recorded a number of six synsacrals, probably three iliac and three post-iliac vertebrae. The clade Cingulata is characterized by a high number of vertebrae forming the synsacrum (eight synsacrals), which is fused to the ischium through the tip of the transverse processes of the most posterior vertebrae. In pilosans, the ancestral number of synsacral vertebrae seems to be lower, probably formed by five or six vertebrae, and the union with the ischium is achieved through the base of the transverse processes of the most posterior vertebrae. Two exceptions stand out, one involving the extant suspensory sloths and Megalocnus, and the other involving a family of ground sloths, the Mylodontidae. A probable relationship of the synsacral number in the different taxa to the lifestyles is discussed. [ABSTRACT FROM AUTHOR]

Se actualiza la información taxonómica y geográfica de Ochthera para Colombia, un género con especies benéficas, reconocidas por sus hábitos depredadores de insectos pequeños terrestres y larvas de mosquitos. Se incluye el primer registro de Ochthera (O.) pilosa y nuevos datos de distribución para Ochthera (O.) regalis y Ochthera (O.) angustifacies. Se agregan ilustraciones, comentarios de su distribución y mapas.

• Twenty-nine ixodid tick species were recorded on Myrmecophagidae anteaters. • Amblyomma nodosum , A. calcaratum and A. auricularium are the most common ticks. • The northern anteater is the least studied with only 11 tick species registered. The family Myrmecophagidae contains three anteater species: Tamandua mexicana (Saussure, 1860), Tamandua tetradactyla (Linnaeus, 1758) and Myrmecophaga tridactyla (Linnaeus, 1758). These American anteater species currently face many conservation threats, among which road traffic accidents stand out. Parasitic studies on this family are scarce, and some of them include records of ectoparasites. Specifically for northern tamandua (T. mexicana), there is a lack of studies at population level. The objectives of the present research were to carry out an epidemiological study of tick species and its abundance on road-killed northern anteater specimens and, moreover, to perform a literature review of ticks collected from anteaters of Myrmecophagidae family. Five tick species were identified, including four Amblyomma spp. and Rhipicephalus sanguineus sensu lato, on 23 road-killed anteaters. Tick infestation prevalence was 43% (10/23), with a median tick infestation intensity of 3.5 per anteater (interquartile range 1–13.7). The bibliographic review highlighted the existence of twenty-nine ixodid species recorded on the three anteater species from 14 countries, mainly Brazil. The most common tick species on the Myrmecophagidae family are Amblyomma nodosum , A. calcaratum , A. cajennense sensu lato and A. auricularium. Some of these ixodids were also described as vectors of pathogens. Further studies are needed to evaluate the impact of ticks on anteater fitness, and to assess the role of these mammals as reservoirs of vector-borne diseases. [ABSTRACT FROM AUTHOR]

We characterized behavioral and adrenocortical activities of Tamandua tetradactyla under human care driven by the hypothesis that they vary between males and females. We also assessed the potential association between natural or abnormal behaviors and adrenocortical activity. We kept females and males T. tetradactyla in individual, contiguous enclosures at Córdoba Zoo (Argentina), under natural photoperiod and temperature. During 29 consecutive days we monitored the animals' behavior by recording their activity pattern every 5 min using infrared cameras (8352 records/individual). We collected all feces and measured fecal glucocorticoid metabolites (FGM) with an 11‐oxoaetiocholanolone enzyme immunoassay. We found individual differences in all behavioral variables. We detected that females exhibited lower total activity than males (23.8 ± 0.2% and 32.3 ± 0.3%, respectively; p = .005). Females were more active at night and males during the day (p < .05) and exhibited less abnormal behaviors than males (p = .05). Although we did not find sex‐related differences for average FGM, we detected individual differences (p < .0001). We found that daily FGM showed negative (−0.39) and positive (0.38) correlations with natural and abnormal behaviors, respectively (p < .0001). Thus, we consider that individual input and sex are factors to be considered in stress responses of the species in captivity. Natural and abnormal behaviors may demand different levels of adrenocortical activity. Our findings may prove useful as normative data for ex situ management of conservation programs. Research Highlights: Zoo‐housed lesser anteater females were less active than males.We found individual (but not sex) differences in levels of fecal glucocorticoid metabolites.Natural and abnormal behaviors were differently linked to adrenocortical activity. [ABSTRACT FROM AUTHOR]