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Sloth Ecology: an overview of field studies
... They are considered feeding generalists at the population level, but because the individual diets vary considerably in terms of plant species, they have been reported as specialists at the individual level (Montgomery and Sunquist 1978;Chiarello 1998b;Giné et al. 2022). Although untested, the individual diet specialization of these sloths has been explained as a consequence of distinct individual preferences for plant species, associated with processes passed through generations such as, mother-infant learning and symbiotic gut microbiota sharing (Montgomery and Sunquist 1978;Chiarello 1998bChiarello , 2008. Moreover, individual diet specialization may accrue from differences in the local floristic compositions among different home ranges that result in distinct availability of resources even for individuals inhabiting the same forest fragment. ...
... The latter is reasonable, considering the sessile habits and small home range (usually less than 10 ha) of these mammals, combined with the high changes in floristic compositions within and between patches characteristic of Neotropical forests (Arroyo-Rodríguez et al. 2013). An optimal foraging perspective would predict that for energy-saving mammals such as three-toed sloths (Chiarello 2008;Pauli et al. 2016), the search for near food sources would be more advantageous than the search for a more distant specific plant species with better nutritional quality (Stephens and Krebs 1986). ...
... Despite the evidence for individual diet specialization in sloths, its magnitude and variation according to the environmental context have never been studied systematically. Individual specialization has been evidenced in highly diverse forests (Montgomery and Sunquist 1978;Chiarello 2008;Giné et al. 2022), but it may not occur in less diverse forested environments, where sloths consume fewer plant species (Urbani and Bosque 2007;Vaughan et al. 2007;Ramirez et al. 2011;Mendoza et al. 2015). Comparisons among studies are limited because the sampling effort on less diverse environments is not always reported and diets have been rarely described at the individual level. ...
Individual diet specialization is commonly found in generalist species but has been little studied in folivore mammals. Empirical evidence shows that the diversity of food resources in the habitat affects the degree of this specialization, by influencing among-individual diet variation (diet similarity) and individual niche breadth (diet diversity). We aim to evaluate the diet composition and selection of maned sloths (Bradypus torquatus, Illiger 1811) in two distinct ecological contexts; test whether the diet similarity between individuals and populations is explained by changes in the local floristic compositions and/or by a differentiated selection of tree species, and evaluate the effect of the local tree diversity on the diet diversity and similarity across individuals. We monitored 13 individuals in northern Bahia and Rio de Janeiro and accessed the tree species diversity and availability within each home range. We identified 67 tree species consumed, most of which were consumed in higher proportion than their availability in the home ranges, indicating high selectivity by the individuals. Diet similarity decreased with greater differences in the local floristic composition and higher tree diversity, but was also influenced by individual selection. Together, our results evidence that the maned sloth is specialist and selective at the individual level, and the lower tree diversity reduces individual diet specialization, revealing tree species that are commonly preferred at the population level under such condition. Our results can be directly applied to feeding protocols of captive populations, and ecological restoration initiatives focusing on the conservation of this threatened species.
... Sloths, Bradypus, are among the most lethargic species in the world (Eisenberg 1978;Giné et al. 2015). They are inactive during most of the time of their 24-h cycles, and can rest in up to 90% of the time (Beebe 1926;Queiroz 1995;Chiarello 1998;Consentino 2004;Cassano 2006;Urbano and Bosque 2007;Ginè et al. 2015) They are cathemeral heterothermic animals that can be active at any time of their 24-h cycle, which is dictated by ambient temperature, food acquisition, competition, and predation (Queiroz 1995;Chiarello 1998Chiarello , 2008Urbano and Bosque 2007;Ginè et al. 2015), and exhibit a circadian rhythm (Duarte et al. 1982;Chiarello 1998;Ginè et al. 2015). ...
... In most studies carried out to date, Bradypus spp. have been observed as active mostly during the day and the night, and have been considered cathemeral creatures (Queiroz 1995;Chiarello 1998Chiarello , 2008Giné et al. 2015). In cases in which competitors and/or predators were absent, however, sloths apparently adopted a pronounced diurnal feeding habit (Consentino 2004). ...
... Interestingly, none of these studies considered the effects that the various forms of human impacts present would have on the ecology and behavior of the sloths, despite the potential impacts that they might exert on the species (Mendes Pontes et al. 2007, 2016Pinheiro and Mendes Pontes 2015). Furthermore, it has been postulated that colder or hotter seasons, altitudinal, or latitudinal range, or montane or lowland forests with colder or hotter ambient temperatures are the best predictors of sloth activity (Chiarello 1998(Chiarello , 2008Urbani and Bosque 2007;Giné et al. 2015). ...
Previous studies exploring the rhythmic activity of sloths of the Bradypus genus in undisturbed forests revealed cathemeral patterns of activity. In the current study we wished to examine sloth behavior in a highly disturbed secondary forest habitat. We evaluated activity pattern, time budget and rhythmic activities of brown-throated three-toed sloths (B. variegatus) living in the border of a highly disturbed forest fragment in northeastern Brazil. Three adults (2 females and 1 male) and 2 infants were studied over 29 days. Observational data were collected in 15 min increments over the 24-h day in the following categories: resting, moving, travelling, eating and grooming. Time series data were subjected to X2 periodogram, Fourier (Fast Fourier Transformation, FFT), cosinor and CircWave circadian rhythm analysis, and revealed significant 24-h rhythms in all behaviors in most circumstances. Unlike sloths located in an undisturbed forest, this population exhibited primarily diurnal activity patterns of behavior, with the center of gravity for each behavior occurring in the middle of the day. Furthermore, several behaviors were expressed in a bimodal pattern, with a morning and a late afternoon peak of activity. These data suggest that with decreased predator presence and with a more ubiquitous food source, sloths adjust their temporal niche to daytime.
... Marmosets (body weight around 0.3 kg) are generalists occurring in different types of habitats and benefiting from disturbed and edge habitats (Rylands 1996;Hue et al. 2017;Secco et al. 2018), whereas the three-toed sloth (body weight around 4 kg) is a habitat specialist, with low vagility, a high reliance on forest cover and specialization on a few tree species for feeding (Garcés-Restrepo et al. 2018;Garcés-Restrepo et al. 2019;Mendoza et al. 2015). Nonetheless, this species seems to be resilient to habitat disturbance (Chiarello 2008). Sloths have extremely low metabolic rates compared to other mammals and can subsist on a low-energy diet composed mostly of leaves (Chiarello 2008;Garcés-Restrepo et al. 2019). ...
... Nonetheless, this species seems to be resilient to habitat disturbance (Chiarello 2008). Sloths have extremely low metabolic rates compared to other mammals and can subsist on a low-energy diet composed mostly of leaves (Chiarello 2008;Garcés-Restrepo et al. 2019). Although marmosets and three-toed sloths occur in some urban parks and other disturbed environments (Chiarello 2008;Duarte et al. 2011;Teixeira et al. 2015), it is unlikely that urban forest fragments might constitute as good a habitat as less disturbed non-urban areas due to the effects of urban stressors. ...
... Sloths have extremely low metabolic rates compared to other mammals and can subsist on a low-energy diet composed mostly of leaves (Chiarello 2008;Garcés-Restrepo et al. 2019). Although marmosets and three-toed sloths occur in some urban parks and other disturbed environments (Chiarello 2008;Duarte et al. 2011;Teixeira et al. 2015), it is unlikely that urban forest fragments might constitute as good a habitat as less disturbed non-urban areas due to the effects of urban stressors. ...
Urbanization is a major threat to wildlife with its cohort of environmental stressors. Urban remnant vegetation can help mitigate these impacts, but such remnants are subject to stressors that might be detrimental for some species. Habitat generalists have flexible diets and broader habitat tolerances that could favour their persistence in these remnants. Marmosets (Callithrix jacchus) and sloths (Bradypus variegatus) differ in their ecological and behavioural plasticity and both occur in urban areas. We predict marmosets to be less affected than sloths, a specialist species, by anthropogenic disturbance. We estimated their densities in urban forest fragments of semi-deciduous Atlantic forest in Paraiba, NE Brazil, with contrasting levels of urbanization. Using the distance sampling methodology, we surveyed 12 trails in a larger and less impacted fragment (515 ha) and 13 trails across nine smaller forest patches (2.1–8.0 ha) with a greater level of anthropogenic disturbance. Density of marmoset’s groups was higher in the area with lower anthropogenic disturbance, whereas sloths’ density was significantly higher in the more urbanized fragments. Marmosets seemed to be more impacted by noise than sloths. The density of both species in forest patches with higher level of anthropogenic disturbance was similar or even higher than densities from non-urban and less disturbed areas. Despite the negative impacts on wildlife, urbanization seems to cause a reduction of predators and an increase in availability of food resources that favour some species. Our results show the importance of small urban forest fragment for the persistence of marmosets and sloths in Neotropical cities.
... However, representatives of both extant sloth genera (i.e. Bradypus, the three-toed sloth, and Choloepus, the two-toed sloth) show the opposite condition: females tend to be heavier and larger than males (Lara-Ruiz & Chiarello, 2005;Chiarello, 2008), which is uncommon among mammals (Isaac, 2005;Fairbairn et al., 2007) [data for B. torquatus Illiger, 1811, in Lara-Ruiz & Chiarello (2005 and for B. tridactylus Linnaeus, 1758 andC. didactylus (Linnaeus, 1758) in Richard- Hansen et al. (1999)]. ...
... In Bradypus, males also differ from females in pelage traits. Males of B. tridactylus and B. variegatus Schinz, 1825 present a speculum, a patch of orange or yellowish hairs surrounded by black hairs located on the dorsum, a feature that is absent in females (Lara-Ruiz & Chiarello, 2005;Chiarello, 2008). Males of B. torquatus are characterized by longer and darker manes than those of the females (Lara-Ruiz & Chiarello, 2005;Chiarello, 2008), whereas secondary dimorphic features have not been observed in the pelage of species in Choloepus (Goffart, 1971;Lara- Ruiz & Chiarello, 2005). ...
... Males of B. tridactylus and B. variegatus Schinz, 1825 present a speculum, a patch of orange or yellowish hairs surrounded by black hairs located on the dorsum, a feature that is absent in females (Lara-Ruiz & Chiarello, 2005;Chiarello, 2008). Males of B. torquatus are characterized by longer and darker manes than those of the females (Lara-Ruiz & Chiarello, 2005;Chiarello, 2008), whereas secondary dimorphic features have not been observed in the pelage of species in Choloepus (Goffart, 1971;Lara- Ruiz & Chiarello, 2005). ...
Sexual dimorphism (SD) is extremely common in species that have reproductive roles segregated into separate sexes, and it has been recognized in several mammalian lineages, both extant and extinct. Sexual dimorphism is low to moderate in living sloths, but it had a more important role for extinct sloth taxa. The presence of SD in extinct sloths was first suggested at the end of the 19 th century and it is now commonly advocated as a possible explanation of high intraspecific variation in many extinct sloth species. In this paper, we report the presence of SD in Simomylodon uccasamamensis, a Late Miocene to Late Pliocene sloth from the Bolivian Altiplano. We present evidence of SD in the morphology of cranial and postcranial remains, representing the earliest unequivocal occurrence of size-based SD in an extinct sloth species. Differences between sexes are mainly observed in the morphology of the feeding apparatus and general body size. Comparisons with extant large mammals allow us to hypothesize different food selection between the two sexes, with probable divergent habitat use and concomitant niche separation. This, in turn, could have represented an important selective factor for adaptation to environmental changes experienced by the Bolivian Altiplano in Late Neogene times.
... As preguiças possuem baixa detectabilidade em seu ambiente natural, consequência principalmente de suas características comportamentais e de seu hábito arborícola (Chiarello 2008). Estas características dificultam trabalhos que abordem parâmetros demográficos, e assim, pesquisas nessa área são escassas e incipientes (Montgomery & Sunquist, 1975, Queiroz 1995, Taube et al. 1999, Cassano 2006, Chiarello 2008, Dias 2008), e podem requerer o dobro de esforço ou resultar em grandes falhas na amostragem (MacKenzie et al. 2006). ...
... As preguiças possuem baixa detectabilidade em seu ambiente natural, consequência principalmente de suas características comportamentais e de seu hábito arborícola (Chiarello 2008). Estas características dificultam trabalhos que abordem parâmetros demográficos, e assim, pesquisas nessa área são escassas e incipientes (Montgomery & Sunquist, 1975, Queiroz 1995, Taube et al. 1999, Cassano 2006, Chiarello 2008, Dias 2008), e podem requerer o dobro de esforço ou resultar em grandes falhas na amostragem (MacKenzie et al. 2006). Os estudos com modelagem de ocupação surgem, assim, como uma alternativa para avaliar o status de conservação atual da espécie diante das recentes transformações ambientais. ...
... Os (Chiarello 1998b). Em menor frequência, as preguiças também fazem uso de espécies arbóreas pertencentes a florestas avançadas, permitindo-as, assim, ocupar diferentes tipos florestais (Montgomery & Sunquist 1978, Chiarello 1998b, Chiarello 2008, Cassano et al. 2011. ...
The study of occupancy patterns is essential to understand species ecological strategies.
Our main goal was identify variables that could influence the maned sloth (Bradypus
torquatus) occupancy in re-emerging Atlantic forest fragments. We conducted the
research in the municipality of Santa Maria de Jetibá, Espírito Santo, Brazil. We
selected 33 points distributed in all landscape, distant 500 m and we plotted two
perpendicular trails. We conducted five surveys to verify the presence or absence of the
species and collect ten local variable data. We performed two moving windows – 500m
and 1000m – at each sampling station in order to perform the landscape analysis. We
choose ten of the 25 variables generated to conduct the occupancy estimates. We
calculated the dynamic model and the median c-hat to test the assumptions of closed
population and independent points. We performed the model selection using the Akaike
Information Criteria. To increment the results, we calculated the model averaging and
the accumulative weight. We detected the sloth in 48% of points. The dynamic model
indicates the population is closed (γ=ε=0) and the median c-hat shows a data
overdispersion (1.79). In both approaches, we used the ad hoc tests. Only local variables
act as environmental filters, with positive associations with the important trees and
canopy high and negative with the Habitat Complexity Index (ICH), whereas IT had the
higher accumulative weight ((w+(j) = 0.64249). With regard to landscape, the Null
model was the better-ranked model (QAICc=78.2979), following by the edge
disponibility (QAICc=80.584), with a positive association. Our results demonstrated
that the presence of essentials trees to food and rest are extremely, in addition to high
canopy are very important to sloths and landscape traits have no influence in sloths
occupancy, included the regrowth patches, probably consequence of a landscape with a
high forest cover (> 30%) such as Santa Maria de Jetibá. This is a very important
evidence that the sloth are flexible in occupy degraded environments and that the
secondary growth forest are important to species’s conservation projects.
... As preguiças possuem baixa detectabilidade em seu ambiente natural, consequência principalmente de suas características comportamentais e de seu hábito arborícola (Chiarello 2008). Estas características dificultam trabalhos que abordem parâmetros demográficos, e assim, pesquisas nessa área são escassas e incipientes (Montgomery & Sunquist, 1975, Queiroz 1995, Taube et al. 1999, Cassano 2006, Chiarello 2008, Dias 2008), e podem requerer o dobro de esforço ou resultar em grandes falhas na amostragem (MacKenzie et al. 2006). ...
... As preguiças possuem baixa detectabilidade em seu ambiente natural, consequência principalmente de suas características comportamentais e de seu hábito arborícola (Chiarello 2008). Estas características dificultam trabalhos que abordem parâmetros demográficos, e assim, pesquisas nessa área são escassas e incipientes (Montgomery & Sunquist, 1975, Queiroz 1995, Taube et al. 1999, Cassano 2006, Chiarello 2008, Dias 2008), e podem requerer o dobro de esforço ou resultar em grandes falhas na amostragem (MacKenzie et al. 2006). Os estudos com modelagem de ocupação surgem, assim, como uma alternativa para avaliar o status de conservação atual da espécie diante das recentes transformações ambientais. ...
... Os (Chiarello 1998b). Em menor frequência, as preguiças também fazem uso de espécies arbóreas pertencentes a florestas avançadas, permitindo-as, assim, ocupar diferentes tipos florestais (Montgomery & Sunquist 1978, Chiarello 1998b, Chiarello 2008, Cassano et al. 2011. ...
... Because they are generally stationary, freeze in response to loud sounds, avoid predators by moving slowly, and are extremely silent when making rare and careful movements (Chiarello, 2008), sloths are difficult to locate, even when they are gregarious in anthropogenic habitats (Silva et al., 2013). Consequently, studies of the ecology, abundance, and density of B. tridactylus are lacking. ...
... Studies reporting abundance and density estimates of B. tridactylus are scarce, perhaps because stationary sloths are hard to detect in the forest canopy (Laufer et al., 2012), even by trained observers (Chiarello, 2008). Our estimate of 20.1 animals/ha represents the greatest documented population density of this species. ...
... In our study, the unique opportunity offered by the animal rescue effort to determine the density of the B. tridactylus population by capturing or observing virtually every animal present might, by itself, have resulted in the "higher than normal" estimate. If so, then perhaps earlier studies simply missed large numbers of these extraordinarily cryptic animals (Chiarello, 2008;Voirin et al., 2009) or perhaps the paucity of comprehensive field studies just did not include such an aggregated population. Regardless, our results suggest that past studies may have substantially underestimated pale-throated three-toed sloth population densities. ...
In October 2012 individuals associated with the Green Heritage Fund Suriname organized a rescue of arboreal mammals displaced during deforestation of a 6.8 ha plot in northwest Paramaribo. Rescued or observed animals included 137 pale-throated three-toed sloths (Bradypus tridactylus), eight two-toed sloths (Choloepus didactylus), three Brazilian porcupines (Coendou prehensilis), and three silky anteaters (Cyclopes didactylus). In addition, two lesser anteaters (Tamandua tetradactyla) – a mother and baby – were seen but not rescued. Due to their lack of speed and inability to escape, it is likely that almost all of the pale-throated sloths in the forested plot were captured during the thirty-day period of clear-cutting. Comprising 91% of the total rescued animals, the 137 B. tridactylus included 61 males, 56 females, 15 juveniles, and ve adults that could not be sexed. Data on body mass, length, and other features reveal a population of reasonably healthy but smaller animals at a population density of 20.1 animals/ha that far exceeds any previous reports for this species.
... In French Guiana, C. didactylus has been found at densities of 0.9 animals per hectare (Taube et al. 1999). In the Brazilian Amazon, estimated densities range from 0.13 individuals per hectare (Manaus region) to 0.88 animals per hectare in the flooded forests (Mamirauá Reserve;Queiroz 1995, Chiarello 2008). ...
... There is little information on the diet of wild individuals (Chiarello 2008). A rather unusual observation in the Amazon of north-eastern Peru recorded an adult individual descending to the forest floor to feed on a human latrine (Heymann et al. 2011). ...
... In Costa Rica, anthropogenically changed landscapes have grown to unprecedented levels [93,94]. The negative effects of this tropical deforestation and habitat fragmentation have been documented for multiple sloth species, including C. hoffmani, in terms of altered dispersal, behavior, and survival [82,89,[95][96][97][98][99]. ...
... In the face of habitat fragmentation, food becomes diminished through loss of tree diversity and less accessible through reduced canopy connectivity [103,104]. As a result, C. hoffmanni is forced to travel further distances, enter unfavorable and novel environments, and modify their means of locomotion by climbing on the ground to navigate between trees [82,98]. ...
Human-introduced predators, primarily the domestic dog (Canis lupus familiaris), and human-modified landscapes conjointly threaten wildlife across Costa Rica. For arboreal species, including the two-fingered sloth (Choloepus hoffmani), the impact of domestic dogs is amplified in areas of habitat fragmentation. In efforts to navigate discontinuous canopies associated with urban development and human encroachment, C. hoffmani is forced to utilize terrestrial locomotion. This unnatural behavior leaves sloths increasingly vulnerable to predation by domestic dogs, which occupy altered landscapes in high densities. In this report, we detail the ante and postmortem findings associated with C. hoffmani following an extensive attack by three large-breed dogs. The patient sustained severe and fatal polytraumatic injuries targeting the abdominothoracic region. Gross lesions were not readily evident, obscured by unique anatomical characteristics of the species. This report aims to highlight the threat imposed by dogs to sloths and the severity of injuries, with considerations for clinical management in light of C. hoffmani morphology. We review the scope of domestic dog–wildlife conflict in Costa Rica, and propose collaborative mitigation strategies including habitat preservation, domestic dog population control, installation of wildlife corridors, policy initiatives, and dog owner education and public outreach.
... Successful conservation actions rely on well-founded knowledge of species' life history to guide effective strategies. However, natural history information for most of the Xenarthra species is scarce and, when available, often limited to a few short-term studies or based on captive animals (Chiarello, 2008;McDonough & Loughry, 2008;Superina et al., 2014). Even for widespread taxa, available data are mostly derived from studies from few localities or a particular biome and may not reflect how the species respond under distinct environmental conditions (Diniz & Brito, 2012;Loughry & McDonough, 2013). ...
... This uneven spatial aggregation echoes knowledge shortfalls at the species level. For example, ecological aspects of the Amazonian endemics two-toed sloths (Choloepus hoffmanni and Choloepus didactylus) and greater long-nosed armadillos (Dasypus kappleri, Dasypus pastasae and Dasypus beniensis) are largely unknown (Chiarello, 2008;Superina et al., 2014). On the other hand, species whose distribution includes areas with high collection efforts tend to be better known. ...
Aim
Limited funds for conservation and research require the development of prioritization schemes. Traditionally, biodiversity metrics were used to delineate priority areas; however, a growing realization emphasizes that logistic factors should be also considered. Here, we combine species richness, past collection efforts, degree of habitat loss and accessibility to define priority areas and spatially orient fieldwork in a cost-effective manner for xenarthrans.
Location
Neotropics.
Methods
We assessed spatial patterns of species richness in Xenarthra and identified diversity hotspots based on species distribution models. Spatial patterns and biases in the Xenarthra past collection efforts were analysed using a comprehensive database including 33,464 individual records for 34 species of Xenarthra. Finally, we produced priority area indices relating species richness and collection efforts with levels of habitat loss and accessibility (roads and rivers network) to highlight important but neglected areas.
Results
Collection efforts were concentrated to a small portion of the Neotropics (central-western Brazil, eastern Bolivia and north-western Argentina) and were biased towards access routes. Only 4% of the Neotropics can be considered well sampled. Major xenarthran diversity hotspots include the Amazonian lowlands of Bolivia and the dry Chaco of Paraguay and Argentina. Priority areas for research varied depending on the metric analysed. Amazon holds a high diversity that remains poorly explored. Central Argentina and eastern Brazil are priority areas for research and conservation given the low sampling efforts, high diversity and endemic species, high levels of habitat loss and a dense road network.
Main conclusions
Most areas of the Neotropics lack a proper assessment of the xenarthran assemblage, reflecting extensive knowledge shortfalls. Sites close to roads tend to be better sampled, but many areas with a dense road network are undersampled, being good candidates for low-cost studies. Xenarthra diversity hotspots facing the highest levels of habitat alteration are the least protected and are priority for both research and conservation. Simultaneous efforts of data collection and conservation actions across most of the xenarthran range should be stimulated.
... I.V.I., Importance Value Index. higher digestibility and nutritional content than mature leaves (Chiarello 1998(Chiarello , 2008Montgomery and Sunquist 1975). The plant species consumed shows a resistant epidermis that was difficult to digest, which allowed identifying food plants based on their histological characteristics. ...
... In north-eastern Costa Rica, three-toed sloths showed strong dependence to use this genus, while two-toed sloths were more flexible and used a greater diversity of tree species (Mendoza et al. 2015). Reports from captive individuals also indicate that two-toed sloths consume a much more varied diet than three-toed sloths (Chiarello 2008). ...
The Hoffmann’s two-toed sloth ( Choloepus hoffmanni ) is a species which could potentially be evaluated as threatened, but data on its natural history in wild conditions are still insufficient. The diet in wildlife of C. hoffmanni was studied through of microhistological analysis of indigestible fragments of leaves found in 43 feces samples collected of the 47 samples found in an Andean forest reserve south of Bogotá, Colombia. Four samples were highly decomposed and were not collected. A reference collection was made of 29 tree species where the feces were found or two-toed sloth were observed, to compare with the plant fragments found in the feces. Seventeen species and six fragments of foliar epidermis of undetermined species were identified in sloth diet. Based on this analysis, C. hoffmanni is a generalist folivore, ingesting a wide variety of plant leaves. Based on frequency of occurrence, relative frequency, and percent cover by volume, Brunellia sibundoya, Cordia cylindrostachya, Citharexylum sp. , Quercus humboldtii, and Clethra fagifolia made up most (74%) of the diet of C. hoffmanni in an Andean forest. Comparing the plant species found in the feces with the reference collection, C. hoffmanni appears to deposit feces at the base of the trees that it consumes.
... They spend prolonged periods inactive, and when movement does occur, it is slow and deliberate to conserve energy and avoid predator detection (Goffart, 1971;Montgomery & Sunquist, 1975). As a consequence of their slow nature and highly specific arboreal lifestyle, sloths have a poor dispersal ability compared to other mammal species and are likely to be particularly sensitive to the fragmentation and disturbance of neotropical rainforests (Chiarello, 2008;Garcés-Restrepo, Pauli, & Peery, 2018;. Annually, the deforestation rate for neotropical forests is 0.5%, with currently 55.8 million forest fragments existing across the Americas (Taubert et al., 2018). ...
... Sloths are physically unable to traverse gaps in the canopy by jumping, and moving on the ground is a laborious and dangerous strategy. As a result, even small levels of habitat fragmentation that cause a loss in canopy connectivity can hinder sloth dispersal and movement (Chiarello, 2008). In this context, the large-scale fragmentation due to monoculture plantations, agriculture and widespread rainforest urbanization is of particular concern due to the complete isolation of sloth populations, which arises as a result (Sanchez-Azofeifa, Harriss, & Skole, 2001). ...
Sloths are notoriously slow and consequently have limited dispersal ability, which makes them particularly vulnerable to the effects of habitat fragmentation and degradation. Sloths in Costa Rica are considered of conservation concern due to habitat loss, livestock production and increasing urbanisation. Reintroductions from rescue centres are commonplace across the country, yet their genetic diversity and population structure are unknown, and there is currently little consideration of the genetic background prior to intervention or releases. We used microsatellite analysis to undertake the first exploratory investigation into sloth population genetics in Costa Rica. Using data from 98 two‐fingered sloths (Choloepus hoffmanni) from four different geographic regions, we determined the presence of four potential genetic groups, three of them with minimal population structuring despite the limited dispersal ability and presence of physical barriers. Sloths from the North appear to represent a highly distinct population that we propose may require management as a discrete unit for conservation. We stress the need for additional analyses to better understand the genetic structure and diversity of North and West regions and suggest that rescue facilities in Costa Rica should consider the genetic background of rehabilitated sloths when planning future reintroductions. Our results also highlight the threat posed by physical isolation due to widespread urbanisation and agriculture expansion for a species with a weak dispersal ability.
... Bouts of awake activity are reported to rarely last more than 6 h (60) and mainly involve feeding, grooming, and/or scratching. Moreover, even when searching for a mate (47), individuals may not leave their home range, which typically consists of 7-12 trees used for foraging (11). Their collective physiological and behavioral features, in addition to their adaptive slow movements (17,31), are therefore expected to correlate with a skeletal muscle composition capable of providing energy savings. ...
... Though evaluation of these parameters is beyond the scope of the current study, the muscle enzymatic profile of sloths is consistent with their ability to survive at the extremes of metabolic function by subsistence on poor quality forage (12). Moreover, our interpretations may be particularly important for Bradypus that selectively consumes only leaves (11,38) and is nearly half the adult body mass of Choloepus (7), which has a more diverse diet (35,36). Irrespective of these subtle differences, it is notable that both genera share a primary reliance on anaerobic pathways associated with the slow fiber phenotype. ...
... 6,11,21,30,31 An increasing number of studies have reported unique trends in the ecology, anatomy, physiology, and behavior of sloths. 5,8,12,13,31 Three-toed sloths (Bradypus spp.) are heterothermic 14,20 and are considered one of the most lethargic mammals, 9 with activity dependent on ambient temperature. 13 Species within this group have a specialized gastrointestinal tract to fit their strictly folivorous diet 20 ; however, unlike most folivores, they feed on a large number of plant species. ...
... 13 Species within this group have a specialized gastrointestinal tract to fit their strictly folivorous diet 20 ; however, unlike most folivores, they feed on a large number of plant species. 5 Research on the health status and diseases of this genus are only available for Bradypus variegatus, 2,23,27, 33 whereas hematologic values have been published for Choelopus spp. and B. variegatus. ...
Bradypus torquatus is a rare and endemic sloth species from the Atlantic Forest, Brazil. Due to a lack of medical information including hematologic reference parameters for the species, hematologic baseline values were determined using samples from 14 clinically healthy B. torquatus, under captive (n = 7) and free-living (n = 7) conditions in Bahia State, Brazil. Additionally, the morphology of the blood cells is presented, with a demonstration that the Barr body chromosome may assist with sex determination of the species. The Barr body chromosome was present in all seven females and absent in all males. Many erythrocytes were approximately the size of small lymphocytes, with red blood cells exhibiting anisocystosis, normochromia, and apparent macrocytosis, compared with domestic animals. This study provides the first published hematologic values and cell morphology for B. torquatus. However, further studies are suggested using an automated hematology analyzer with larger sample sizes so that reference intervals may be established and hematologic values better understood for sex, habitat type, and age cohorts.
... Sloths are represented nowadays by two diphyletic genera: the two-toed sloth Choloepus (Megalonychidae) and the three-toed sloth Bradypus (monogeneric family Bradypodidae). They are nearly exclusively arboreal and folivorous mammals living in the dense tropical rainforests of Central and South America (Reid 1997;Chiarello 2008), and range from about 4 kg to 6 kg in body mass (Nowak 1999), which represents a remarkable instance of convergent evolution (Patterson & Pascual 1968;Webb 1985;Gaudin 2004;Nyakatura et al. 2010). However, in the past, sloths constituted a rich and diverse clade known since the early Oligocene (Gaudin & McDonald 2008;McDonald & De Iuliis 2008;Pujos et al. 2012). ...
... All sloths are hypselodont (see Vizcaíno 2009, for a review of xenarthran dental features) and, in general, are reconstructed as herbivorous animals (but see Fariñ a 1996;Fariñ a & Blanco 1996;Bargo 2001;Vizcaíno 2009). Extant sloths are folivorous (Bradypus) and frugivorousfolivorous (Choloepus) browsers (Chiarello 2008). They carry out foregut fermentation in complex chambered stomachs (Montgomery & Sunquist 1975) and food undergoes a long transit time, not only in the stomach but also in the intestines (Gilmore et al. 2008). ...
Pilosa include anteaters (Vermilingua) and sloths (Folivora). Modern tree sloths are represented by two genera, Bradypus and Choloepus (both around 4–6 kg), whereas the fossil record is very diverse, with approximately 90 genera ranging in age from the Oligocene to the early Holocene. Fossil sloths include four main clades, Megalonychidae, Megatheriidae, Nothrotheriidae, and Mylodontidae, ranging in size from tens of kilograms to several tons. Modern Vermilingua are represented by three genera, Cyclopes , Tamandua and Myrmecophaga , with a size range from 0.25 kg to about 30 kg, and their fossil record is scarce and fragmentary. The dependence of the body size on phylogenetic pattern of Pilosa is analysed here, according to current cladistic hypotheses. Orthonormal decomposition analysis and Abouheif C-mean were performed. Statistics were significantly different from the null-hypothesis, supporting the hypothesis that body size variation correlates with the phylogenetic pattern. Most of the correlation is concentrated within Vermilingua, and less within Mylodontidae, Megatheriidae, Nothrotheriidae and Megalonychidae. Influence of basal metabolic rate (BMR), dietary habits and substrate preference is discussed. In anteaters, specialised insectivory is proposed as the primary constraint on body size evolution. In the case of sloths, mylodontids, megatheriids and nothrotheriids show increasing body size through time; whereas megalonychids retain a wider diversity of sizes. Interplay between BMR and dietary habits appears to be the main factor in shaping evolution of sloth body size.
... Armadillos include omnivorous and insectivorous species, occurring from southern Patagonia, Argentina into the United States (Wetzel et al. 2008). Modern sloths are solitary, generalist folivores, with a strictly arboreal lifestyle (Chiarello 2008). These sloths are restricted to Neotropical forested biomes and are represented by two families (Bradypodidae and Megalonychidae). ...
Here, I summarize the recent changes in xenarthran taxonomy, analyze past collection efforts, and discuss knowledge gaps in Amazonian xenarthrans. Currently, there are 39 extant species of xenarthrans, represented by 22 armadillos, 10 anteaters, and 7 sloths: an increase in richness by 18% in the last 15 years. The majority of the new xenarthran species recently recognized have geographic ranges within Amazonia, highlighting the importance of this biome to the evolution of this autochthonous South American group. Nevertheless, studies on Brazilian xenarthrans have been conducted mainly in the Cerrado and Pantanal (for armadillos and anteaters), and Atlantic Forest (for sloths). In the Brazilian Amazon, where fully half of the xenarthran species occur, natural history information is based on few unquantified observations and short-term studies. Past research has concentrated on widely distributed species and in areas close to roads and rivers in the eastern and central portions of the biome. The knowledge gaps are even more alarming when we consider the accelerated deforestation rate in the eastern Amazon, where at least three xenarthran species are endemic. There is vast potential for future projects aiming to explore the taxonomy and ecology of xenarthrans, particularly those studies focusing on Amazonian populations.
... Sloth genera differ in ecological behavior, which may have influenced the differences in lesion percentages, especially in the integumentary, musculoskeletal, and respiratory systems. While sloths of the Bradypus genus move less often, staying for a prolonged period in a tree and with both daytime and nighttime activity in less frequency, sloths of the Choloepus genus present strictly nocturnal activities spending little time at a single location (Sunquist & Montgomery 1973, Chiarello 2008. In addition, a study showed that activity patterns in Bradypus variegatus are influenced by environmental temperature, besides nutritional requirements and protection against predators (Chiarello 1998, Castro-Sá et al. 2021, Lopes et al. 2023). ...
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.
... Not only do sloths contribute to energy flow in the forest by providing nutrients and minerals to trees via fecal deposition, they also harbor a complex ecosystem within their fur, comprised of pyralid moths (Cryptoses spp.), microorganisms, and green algae (Trichophilus spp.) (Montgomery and Sunquist 1975;Pauli et al. 2014). One of the more disadvantageous characteristics of sloths is their incredibly low rate of movement due to their low metabolism and energypoor diet, making them especially sensitive to deforestation and human development (Montgomery and Sunquist 1978;Chiarello 2008). In Latin America, sloths are frequently admitted to rescue centers for medical treatment from trauma, relocation from urban areas, and as orphans requiring long-term care in captivity (Chiarello et al. 2004;Larrazábal 2004;Martínez et al. 2004;Plese et al. 2016). ...
The field of wildlife rescue and rehabilitation continues to grow as human expansion increases the rate of deforestation in Latin America. Sloths (Bradypus spp. and Choloepus spp.) are often admitted to rescue centers throughout Latin America due to their poor dispersal abilities and vulnerability to anthropogenic impacts. Although post-release monitoring is fundamental to measuring the success of wildlife rescue programs, few studies have assessed the outcomes of releasing hand-reared sloths back into the wild. We studied the ecology of rehabilitated and relocated Hoffmann’s two-toed sloths (Choloepus hoffmanni) in central Panamá during 2019- 2020. Eleven two-toed sloths rescued from the wild were hand-reared in captivity for 727±193 days and then radiomarked, placed in an outdoor 500 m2 soft-release enclosure for 3 months, and released in a nearby national park. While in the softrelease enclosure, two-toed sloths spent 80.0% of their time resting and became active and more alert in the evening (p=0.01). Upon release into the wild, two-toed sloths traveled a mean linear distance of 82.3±21.6 m and a mean distance of 25.6±9.5 m between successive radiolocations. The mean home range size was 2.92±1.19 ha, with females occupying larger areas than males. Two-toed sloths used trees with a smaller dbh than available (p≤0.001; p≤0.015) and selected trees with dense crowns and ≥50% lianas. Eight mortalities were recorded, with predation and natural causes being the main causes of mortality. Monthly survival was 0.72±0.14 and did not differ (p≤0.30) between males (1.00±0.00) and females (0.44±0.22). Rehabilitated two-toed sloths exhibited behavioral and space use patterns similar to wild two-toed sloths, with the exception of having lower survival rates following release in the wild. Our study provides information that can be useful in evaluating the efficacy of sloth rescue and rehabilitation programs throughout Latin America.
... It feeds on a wide variety of leaves in the canopy, where it prefers to forage in high areas between 24 and 30 m (Tirira, 2007). Very few studies on the natural history of sloths are available (e.g., Plese et al., 2016), and information on their biology, activity patterns, and behavior is still scant (Chiarello, 2008;Mosquera et al., 2019;Peery and Pauli, 2012). However, previous studies have shown that two-toed sloths exhibit temporal variation in their visits to mineral licks, over both hourly and monthly scales (Mosquera et al., 2019). ...
Two-toed sloths (genus Choloepus) are almost exclusively arboreal. However, they often descend to the ground in places known as mineral licks or “saladeros'' and feed from soil, which presumably enhances their digestion of toxins and helps them obtain minerals not readily available in their diet. Mineral licks are risky areas which may increase their visitors’ vulnerability to predators. Here, we report a predation attempt on an adult Linnaeus two-toed sloth (Choloepus didactylus) by an adult ocelot (Leopardus pardalis) at a mineral lick at the Tiputini Biodiversity Station in the Ecuadorian Amazon. Predation events are rarely recorded in camera traps, and this particular predation event can be considered unusual, given that sloths usually come down to mineral licks during the night. Also, it is not clear how ocelots are able to capture sloths, and other arboreal animals and this record evidence that predation of arboreal vertebrates by ocelots may also take place in the ground. Finally, the anti-predatory behavior displayed by the two-toed sloth demonstrates that there are intrinsic risks for predators while attempting to capture prey.
Keywords: Ocelot, Predation, Mineral lick, Sloth, Behavior, Amazonia.
... Although B. torquatus can find and consume young leaves throughout the year, despite the seasonal variation, typically strongest in the ESUsouth region (Chiarello 1998b), this flexibility might be compromised with the expected increase in seasonality, as possible adaptations in the physiology of the species may not keep pace with climatic changes (Schloss et al. 2012). Further, present and future suitable areas in the ESUsouth have a greater proportion of hilly areas that might not constitute adequate habitats for B. torquatus, particularly those located higher than 1,000 m of altitude given the poor ability of the species to endure cold (Chiarello 2008;. Future climate change may impose several nonanalog (novel) conditions to B. torquatus, particularly to ESUsouth populations. ...
Improving coexistence between humans and large predators is one of the foremost issues for the survival of large carnivores, especially in the Neotropics, where
conflicts for retaliation are still frequent. This problem was increased due to the expansion of agricultural areas, settlements, roads, and the loss of natural habitats.
Therefore, a key component in the long-term conservation of carnivores is to reduce animal-human conflicts. We aimed to assess multi-scale habitat selection models,
exploring specificities in the selection for each sex and variation for the circadian period. We found that jaguars live in real landscapes of fear with high human and
livestock density, where the perception of risk related to humans governed the selection of their resources. However, depending on the sex of individuals and the
circadian period, jaguars positively selected some anthropic structures, such as areas of crops and human settlements. This selection suggested an aptitude to use
various human-dominated structures and indicated jaguars could locally perceive risks in different ways, depending of sex and day period. Unexpectedly, jaguars
presented attraction to roads, sexual or circadian related, regardless of the natural environments. Our results demonstrate that male and female jaguars could use
some anthropic features differently in the distinct circadian periods. In addition, we conclude that the knowledge of the habitat selection for jaguars is a crucial
component to the structure of the landscape of coexistence of this species and can give us efficient guidance to better comprehend the behavior through different
scales of selection and through different periods of the day. Finally, our results show fundamental observations on the movement plasticity of this species for the
construction of conservation plans focusing on the coexistence in different landscapes of the Neotropics dominated by humans.
... Several adaptations of Bradypus, making it more specialized compared to the other 'tree sloth' Choloepus, have been already pointed out. Bradypus exclusively feeds on leaves (Montgomery 1983b;Chiarello 2008) compared to Choloepus that conversely consumes more diverse food (Miller 1935;Meritt 1985). ...
Ecomorphological convergence occurs when similar morphological traits are independently evolved by species with the same lifestyle. Novel case studies can help to elucidate the underlying mechanisms of this process. This work addresses some convergent slow arboreal mammals, i.e. two lineages of ‘tree sloths’, the silky anteater, ‘Lorisidae’, two clades of extinct lemurs, i.e. palaeopropithecids and Megaladapis, and the koala. Functional morphological convergences are searched in these taxa, studying their humerus and femur as well as those of their closely related ecologically distinct taxa. For the first time, bones are analyzed at four anatomical levels, i.e. external shape, diaphyseal microstructure and anatomy and epiphyseal trabecular architecture, through phylogenetic comparative methods. Many slow arboreal mammals share a low cortical compactness, probably related to their extremely low metabolic rate and biomechanical demands. Slow arboreal xenarthrans, i.e. ‘tree sloths’ and the silky anteater, exhibit a pattern of incomplete convergence for a set of external and internal anatomical features, possibly explained by the relatively distinct ecology of the silky anteater. On a wider mammalian scale, other traits possibly related to slow arboreal ecology converge in some of the studied taxa, although with complex patterns also explained by other evolutionary processes. Only suspensory taxa significantly contribute to convergence. This thesis highlights the stronger convergence reflected by bone internal structure. By providing potential explanations for convergence in slow arboreal mammals, the inherent complexity of this process is here emphasized.
... Some of the vegetation consumed may be toxic. However, due to the low metabolism of these mammals the absorption of these toxic substances is minimized (Britton and Atkinson, 1938;Macnab, 1985;Gilmore et al., 2001;Chiarello, 2008). Within the representatives of the genus Bradypus the brownthroated sloth is the most abundant, falling into the least threatened category of the red list of threatened species (Silva, 2013;Moraes-Barros et al., 2014). ...
Bradypus variegatus, the common sloth, belongs to the Bradypodidae family, being considered a biological model to be applied in multidisciplinary research. This study was developed with the aim of being applied to clinical medicine and to the adequate management of the common sloth. Ten sloths were utilized, obtained post-natural death. The animals were fixed and to obtain the results, they were submitted to the dissection technique. For 80% of the animals, the portal vein originated from five tributaries, which were: the resulting vein from the anastomosis of the cardia vein, fundic vein, and the pyloric branches; the mesenteric trunk; the vein formed by the confluence of the stomach body branches and the cranial portion of the cavity of the cardia; the pyloric vein and splenic vein. While in 20% of the animals, the portal vein was comprised of six tributaries, because the fundic vein and cardia vein form two direct anastomoses, arriving at the portal vein two tributary vessels. This pattern differs in number and arrangement of branches when compared to the main domestic species. Therefore, the hepatic portal system is responsible for the drainage of the stomach, spleen, pancreas and intestines.
Keywords:
Blood vessels; vascularization; liver; venal drainage; hepatic portal system
... Although B. torquatus can find and consume young leaves throughout the year, despite the seasonal variation, typically strongest in the ESUsouth region (Chiarello 1998b), this flexibility might be compromised with the expected increase in seasonality, as possible adaptations in the physiology of the species may not keep pace with climatic changes (Schloss et al. 2012). Further, present and future suitable areas in the ESUsouth have a greater proportion of hilly areas that might not constitute adequate habitats for B. torquatus, particularly those located higher than 1,000 m of altitude given the poor ability of the species to endure cold (Chiarello 2008;. Future climate change may impose several nonanalog (novel) conditions to B. torquatus, particularly to ESUsouth populations. ...
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.
... Ficus ssp.) are commonly reported in their diet, but the diet of all animals represents only a small portion of the available species (Chiarello 1998;Chiarello et al. 2004). Maned sloths have been considered feeding specialists at the individual level, but generalists at the population level (Chiarello 2008). Nevertheless, the current paucity of information and the few individuals monitored in the wild highlight the need for further studies of their feeding ecology. ...
Aspects of the feeding ecology of the threatened maned sloth (Bradypus torquatus Illiger, 1811) are poorly understood. Here, we evaluate the diet composition and the influence of leaf chemical compounds on the consumption of plant species by 10 radio‐tracked individuals in southern Bahia and construct a list of plants consumed by the species based on our data and the available literature. We confirmed that the maned sloth is a strict folivore and consumes predominantly young leaves. We reported the consumption of 39 species, from 32 genera and 20 families of plants in southern Bahia, and provide an updated list of 68 species so far reported as consumed by maned sloths. The most frequently consumed species in southern Bahia belong to the genera Emmotum, Inga, Ficus and Brosimum, totalling almost half of the maned sloth's diet. Nevertheless, only Ficus spp. were widely consumed by maned sloths elsewhere. The low consumption of Cecropia spp. suggests that maned sloth's diet is not strongly linked to these taxa as reported for other Bradypus. None of the evaluated chemical compounds had a significant effect on the choice of plants consumed. Altogether, the available data indicated that the maned sloth is a generalist at the species level. In addition to morphological and physiological adaptations, it deals with the challenges of a foliage‐based diet by selecting young leaves. Our update on maned sloth's diet may be used to overcome the difficulties of keeping and reproducing them in captivity and support actions that aim to recover their habitat.
... São animais de baixo metabolismo e hábito arborícola, passando a maior parte do tempo em repouso na copa das árvores, se deslocando pelas extremidades dos galhos, com movimentos muito lentos, descendo ao solo geralmente apenas para defecar a cada sete dias ou quando estão em áreas abertas, sem conexão entre as árvores. Além disso, nadam muito bem (CASSANO, 2006) e podem estar ativas tanto durante o dia quanto à noite (CHIARELLO, 2008) Outro fator que explica a preferência pela copa das árvores é a capacidade de termorregulação das preguiças, que têm seu comportamento diretamente ligado às alterações climáticas, ficando imóveis nas primeiras horas da manhã e passando a se movimentar, gradativamente, conforme a temperatura se eleva, buscando a parte mais alta das árvores, ficando expostas ao sol, para se aquecer (MIRANDA et al., 2007). ...
A preguiça-comum (Bradypus variegatus) ocorre nas Américas Central e do Sul, estando presente na maior parte dos estados do Brasil. Ocorre em florestas tropicais e subtropicais e possui uma alimentação restrita a folhas (94%). Esse animal passa a maior parte do tempo na copa das árvores, indo ao solo apenas para defecar (a cada sete dias) ou quando não encontra possibilidade de atravessar de uma árvore para outra. Possui hábitos solitários, se associando a outro indivíduo apenas na época de acasalamento e durante os primeiros seis meses do filhote. O status da espécie é de menos preocupante, porém, vem sendo ameaçada por diversas formas de fragmentação de seu habitat, além do aumento do número de acidentes por choques elétricos, apanhe ilegal e atropelamentos. Devido à necessidade de conhecimento técnico sobre particularidades na anatomia dessa espécie, para enfrentar os desafios que as ameaças ocasionam ao resgate e reabilitação desses animais, este trabalho teve como objetivo estudar a dentição da espécie Bradypus variegatus, uma vez que a mesma tem sido vítima frequente de traumas que dificultam ou impossibilitam sua recuperação e retorno à natureza.
... For instance, B. variegatus climbs more slowly and frequently, and it goes as high as the emergent level of the rainforest versus C. hoffmanni that engages in more frequent suspensory locomotion/posture (Urbani & Bosque, 2007) and has the capacity to move quicker with greater muscle power (Spainhower et al., 2021). Bradypus is also more selective with the types cecropia trees that it will inhabit (Chiarello, 2008) and prefers larger diameter substrates than does Choloepus (Mendel, 1985). ...
Tree sloths rely on their limb flexors for bodyweight support and joint stability during suspensory locomotion and posture. This study aims to describe the myology of three-toed sloths and identify limb muscle traits that indicate modification for suspensorial habit. The pelvic limbs of the brown-throated three-toed sloth (Bradypus variegatus) were dissected, muscle belly mass was recorded, and the structural arrangements of the muscles were documented and compared with the available myological accounts for sloths. Overall, the limb musculature is simplified by containing muscles with generally long and parallel fascicles. A number of specific and informative muscle traits are additionally observed in the pelvic limb of B. variegatus: well-developed hip flexors and hip extensors each displaying several fused bellies; massive knee flexors; two heads of the m. adductor longus and m. gracilis; robust digital flexors and flexor tendons; m. tibialis cranialis muscle complex originating from the tibia and fibula and containing a modified m. extensor digitorum I longus; appreciable muscle mass devoted to ankle flexion and hindfoot supination; only m. extensor digitorum brevis acts to extend the digits. Collectively, the findings for tree sloths emphasize muscle mass and organization for suspensory support namely by the hip flexors, knee flexors, and limb adductors, for which the latter two groups may stabilize suspensory postures by exerting appreciable medially-directed force on the substrate. Specializations in the distal limb are also apparent for sustained purchase of the substrate by forceful digital flexion coupled with strong ankle flexion and supination of the hind feet, which is permitted by the reorganization of several digital extensors. Moreover, the reduction or loss of other digital flexor and ab-adductor muscles marks a dramatic simplification of the intrinsic foot musculature in B. variegatus, the extent to which varies across extant species of two- and three-toed tree sloths and likely is related to substrate preference/use.
... Although Choloepus spp. are primarily nocturnal, they have a strictly arboreal lifestyle and spend the daylight hours sleeping high in the forest canopy where they are exposed to the sun (Chiarello, 2008;Sunquist & Montgomery, 1973). In captivity, especially in temperate regions at high latitudes, sloths are commonly housed indoors year-round with no exposure to unfiltered sunlight. ...
Hoffmann's two-toed sloths (Choloepus hoffmanni) are unique animals popular in zoological settings. The role of vitamin D in the maintenance of calcium homeostasis in this species is unexplored, although disorders of calcium homeostasis have been reported in managed sloths, including urolithiasis and soft tissue mineralization. This study assessed cutaneous concentrations of 7-dehydrocholesterol (7-DHC) in nine indoor-housed Hoffmann's two-toed sloths, as a means of evaluating the potential for cutaneous photobiosynthesis of vitamin D3. Samples were obtained from both abdominal and lumbar regions of the skin to assess for regional variation in 7-DHC concentration. The average concentration of 7-DHC in the sloth skin was low (0.197 ± 0.02 nmol/cm²). Location had a significant effect on 7-DHC level only when concentrations were expressed based on the wet weight of the sample (ng/g), but levels were similar when values were normalized to biopsy surface area (nmol/cm²).
Research Highlights
• 1. Indoor-housed Choloepus hoffmanni have a low cutaneous concentration of 7-dehydrocholesterol.
• 2. No significant difference in cutaneous 7-DHC concentrations (nmol/cm²) was found between abdominal and dorsal lumbar locations.
... Like trees that are colonized by microbes in their phyllosphere (leaves) (Vacher et al., 2016) and by lichens in their dermosphere (bark) (Lambais, Lucheta & Crowley, 2014), slow-moving sloths may be reservoirs of similar types of microbes that colonize substrates with low levels of movement-based disturbance. Moreover, as sloths move from tree to ground and tree to tree in the forest canopy (Montgomery & Sunquist, 1975;Vaughan et al., 2007; see online Supporting Information, Supplementary Videos S1-S4), they may acquire epibionts from interacting with hundreds of species of trees, each of Biological Reviews (2021) Aiello (1985), Anderson & Handley (2001), Britton (1941), Chiarello (2008), Falconi et al. (2015), Feldhamer et al. (2015), Goodwin & Ayres (2014), Higginbotham et al. (2014), Mendoza et al. (2015), Montgomery & Sunquist (1978), Nie et al. (2015), Nyakatura (2012), , Pauli et al. (2014Pauli et al. ( , 2016, , Ramirez et al. (2011), Sunquist & Montgomery (1973, Taube et al. (2001), Urbani & Bosque (2007, Vaughan et al. (2007), andWetzel (1985). It should be noted that Choloepus hoffmanni and Bradypus variegatus home range sizes were based largely on observations in mixed-cacao plantation agroecosystems and thus may not truly represent native home ranges for these species (Montgomery & Sunquist, 1978;Vaughan et al., 2007;Ramirez et al., 2011). ...
Sloths are unusual mobile ecosystems, containing a high diversity of epibionts living and growing in their fur as they climb slowly through the canopies of tropical forests. These epibionts include poorly studied algae, arthropods, fungi, and bacteria, making sloths likely reservoirs of unexplored biodiversity. This review aims to identify gaps and eliminate misconceptions in our knowledge of sloths and their epibionts, and to identify key questions to stimulate future research into the functions and roles of sloths within a broader ecological and evolutionary context. This review also seeks to position the sloth fur ecosystem as a model for addressing fundamental questions in metacommunity and movement ecology. The conceptual and evidence-based foundation of this review aims to serve as a guide for future hypothesis-driven research into sloths, their microbiota, sloth health and conservation, and the coevolution of symbioses in general.
... Some sloths descend to defecate and urinate on the ground, increasing the risk of predation by ground animals. At least, five hypotheses have been proposed to explain this behavior: to fertilize trees, because feces are deposited at the tree base (Montgomery & Sunquist, 1975); to avoid predation, by covering the feces and reducing smells, as occurs in some other mammals (see Bailey, 1974;Liberg, 1980;Pauli et al., 2014); to communicate with chemical messages because direct interactions among individuals are rare, as implied by Chiarello (2008); to pick trace nutrients from the ground when they lick mud from their claws, as observed by Voirin, Kays, Wikelski, & Lowman (2013); and to increase moth populations, a mutualistic model (Voirin et al., 2013) for which Pauli et al. (2014) published some experimental support. ...
Introduction:
Sloths are arboreal mammals that defecate on the ground, increasing the risk of predation. There are several hypotheses that try to explain why they undergo this risk.
Objective:
To critically review all the hypotheses and to propose a new hypothesis that is compatible with all known data.
Methods:
I verified the assumptions and implications of five hypotheses against the literature available February, 2021.
Results:
Previous hypotheses either lack reliable supporting data, or are contradicted by published data. Here I propose that defecation on the ground is an ancestral behavior that persists in all sloth species because there has not been enough natural selection against it.
Conclusions:
Current knowledge of sloth biology is compatible with the hypothesis that there has not been enough selective pressure for sloths to abandon defecation on the ground.
... As the cryptic habits of sloths make them difficult to observe in general (Queiroz, 1995;Chiarello, 2008;Castro-Vásquez et al., 2010), the probability of recording relatively rare and brief activities, such as licking water from a substrate, during monitoring in the field may be greatly reduced, a problem exacerbated by the huddled posture typically adopted by these animals during much of their activity time. In addition, any observations during rainy weather presents specific challenges for the use of binoculars (lens fogging or damage) or data-logging devices (field books or audio-recorders), which may often force the observer to pause data collection. ...
... Preguiças atuais estão distribuídas nas famílias Bradypodidae (três dedos) e Megalonychidade (dois dedos), cuja distribuição geográfica está restrita as florestas neotropicais da América Central e do Sul (WETZEL, 1982(WETZEL, ,1985CHIARELLO, 2008 Brasil (FONSECA et al., 1996;MEDRI et al., 2006). ...
RESUMO Preguiças servem de hospedeiros para uma grande variedade de artrópodes de pelo, destes destacam-se dois importantes grupos de macroparasitas, os hematófagos e os coprófagos. Dentre os hematófagos, estariam os carrapatos e as moscas picadoras, e no grupo coprófago, mariposas, besouros e ácaros, que utilizam a preguiça para forese. Embora os estudos sobre a distribuição de preguiças em vida livre tenham se concentrado na descrição das espécies vegetais e a área utilizada, quando comparadas a mamíferos de mesmo tamanho corpóreo, as preguiças possuem áreas de vida pequena, suportando modificações em escala de micro-hábitat, dependendo do local da copa a ser ocupado. Observações sobre a dieta e o comportamento alimentar para preguiças do gênero Bradypus demonstram adaptação da população às características de cada ambiente. Outro aspecto importante no estudo sobre área de uso dos indivíduos de B. variegatus é que a análise do volume das copas das árvores que são utilizadas, poderiam melhor representar o uso do espaço do que a área total que ocupada por tais árvores, incluindo dessa forma, a variável altura e o espaço ocupado de forma tridimensional. Este estudo pretende adicionar informações sobre aspectos da biologia de B. variegatus, tais como associações com artrópodes de pelo, comportamento alimentar e uso do hábitat, contribuindo para informação sobre as preguiças do Rio de Janeiro. A pesquisa foi realizada entre os meses de dezembro de 2007 e novembro de 2008, no Parque Natural Municipal da Prainha (PNMP) localizado dentro da cidade (22º59 23º04 S e 43º30' 43º34' W), no Recreio dos Bandeirantes, parte do Maciço da Pedra Branca. Os dados de campo foram obtidos de animais de vida livre, encontrados através de buscas ativas realizadas em trilhas da unidade de conservação (UC). Eventualmente, animais recebidos pelo corpo de bombeiros e/ou Patrulha Ambiental no Parque Natural Municipal Chico Mendes (PNMCM), oriundos da região, foram utilizados como amostras-piloto e complementares. Em cada ponto de avistamento foram registrados os dados da localidade, horário e espécie vegetal. Os pontos de avistamento foram marcados com GPS. Para a captura, foram utilizados técnicas e equipamentos de alpinismo. Uma vez capturado, o animal era trazido ao solo. Iniciando a triagem com a busca e coleta manual por artrópodes, o registro da biometria dos animais e a marcação com miçangas coloridas presas ao pelo. Cada morfotipo de artrópodes foi colocado em um pote de coleta com álcool 70%. Os artrópodes de pelo coletados foram descritos, e verificada sua prevalência, e intensidade. Foram registradas no PNMP 16 preguiças, 12 preguiças apenas avistadas e quatro capturadas. Foram coletados dois gêneros de artrópodes de pelo, representados pelas famílias Ixodidae e Pyralidae.
... On the contrary, other ground sloths were best adapted to a terrestrial lifestyle (Bargo et al., 2000;Vizcaíno et al., 2001;de Oliveira and Santos, 2018). Extant sloths (Bradypus and Choloepus) are known as tree sloths for their strictly arboreal lifestyle (Montgomery, 1985;Chiarello, 2008;Toledo et al., 2012), as well as the anteaters (White, 2010), but the latter are capable of above branch locomotion (Nyakatura, 2011). Locomotor categories were equally employed to test for convergence. ...
Three-dimensional (3D) models of fossil bones are increasingly available, thus opening a novel frontier in the study of organismal size and shape evolution. We provide an example of how photogrammetry can be combined with Geometric Morphometrics (GMM) techniques to study patterns of morphological convergence in the mammalian group of Xenarthra. Xenarthrans are currently represented by armadillos, sloths, and anteaters. However, this clade shows an incredibly diverse array of species and ecomorphotypes in the fossil record, including gigantic ground sloths and glyptodonts. Since the humerus is a weight-bearing bone in quadrupedal mammals and its morphology correlates with locomotor behavior, it provides an ideal bone to gain insight into adaptations of fossil species. A 3D sample of humerii belonging to extant and fossil Xenarthra allowed us to identify a significant phylogenetic signal and a strong allometric component in the humerus shape. Although no rate shift in the evolution of the humerus shape was recorded for any clade, fossorial and arboreal species humerii did evolve at significantly slower and faster paces, respectively, than the rest of the Xenarthran species. Significant evidence for morphological convergence found among the fossorial species and between the two tree sloth genera explains these patterns. These results suggest that the highly specialized morphologies of digging taxa and tree sloths represent major deviations from the plesiomorphic Xenarthran body plan, evolved several times during the history of the group.
... As preguiças estão entre as poucas espécies de mamíferos arborícolas com hábito alimentar estritamente folívoro (CORK;FOLEY, 1991), conhecido pelos movimentos lentos e baixa taxa metabólica, habitando lorestas e alimentando-se de folhas, ramos e brotos de várias plantas, frequentemente da família Moraceae (CHIARELLO, 2008), Cecropiaceae e Clethraceae (URBANI; BOSQUE, 2007), sendo que as folhas representam 94% dos itens consumidos (QUEIROZ, 1995). ...
Bradypus variegatus, vulgarmente conhecida como preguiça comum, pertence a um grupo individualizado de mamíferos, com peculiaridades morfológicas e biológicas já descritas, porém, pouco se sabe sobre questões estruturais do seu trato digestório, incluindo a morfologia do esôfago. Diferindo dos mamíferos em geral quanto ao trajeto completo do órgão, o esfíncter esofágico cranial localiza-se dorsalmente à laringe, desviando à esquerda da traqueia, mantendo-se adjacente a ela, ainda no antímero esquerdo, ao longo da porção cervical. No tórax, seguiu pelo mediastino, atravessou transversalmente o diafragma através do hiato esofágico, alcançando o estômago. Histologicamente, apresentou o mesmo padrão tecidual ao longo das três porções, destacando-se a presença de três camadas musculares, adensando na porção torácica, e na adventícia cercada pela cadeia nervosa simpática, adjacente à região cárdica. Essas características histológicas conferem ao esôfago dessa espécie arquitetura peculiar, que pode explicar o comportamento de deglutição destes indivíduos frente aos seus hábitos posturais.
... There are many factors that could lead to variation, including genetic, environmental and dietary factors, ontogenetic stage of the specimen and sexual dimorphism. With regard to sexual dimorphism, studies in living sloths such as Bradypus torquatus Illiger, 1811, indicate the existence of sexual dimorphism in body mass (females heavier than males) (see Lara-Ruiz and Chiarello, 2005;Chiarello, 2008). Fossil sloths do not have unequivocal anatomical features that indicate sexual dimorphism, as in living sloth Bradypus and Choloepus (Figure 4). ...
A skull of a ground sloth from the Pliocene San Gregorio Formation documents a northern neotropical occurrence of a megatheriine that addresses issues on intraspecific variation and biogeography. The new specimen is broadly similar in size and morphology to that of Proeremotherium eljebe from the underlying Codore Formation in the Urumaco Sequence, differing in several features such as a longer basicranial area and a more posteriorly projected basioccipital between the condyles. The living sloths species of Bradypus and Choloepus do not have unequivocal anatomical features that
indicate sexual dimorphism. Nevertheless, fossil sloths may have shown such dimorphism, and speculations on this subject are part of the considerations that can be made when allocating fragmentary fossils (e.g., in the new skull the presence of a long sagittal crest could indicate a male individual and the absence of an extended crest in Proeremotherium eljebe a female one). We speculate that as early as the late middle Miocene, two main lines of Megatheriinae had clearly separated in two geographic areas, one in the rising Andean area and one at low latitudes on the lowlands of central and northern South America.
... It belongs to one of the most representative families found in the diet of Bradypus species. The species Cecropia pachystachya (Urticaceae) also occurs in the area and is, along with other embaúbas (Cecropia spp.), among the most important species consumed by sloths (Chiarello, 2008). ...
... Sloths (Folivora), together with anteaters (Vermilingua), and armadillos (including glyptodonts) and pampatheres (Cingulata), form Xenarthra, one of the most prominent and conspicuous clades of South and Central American placental mammals. The present diversity of sloths comprises only two genera of medium-sized, suspensory forms (two-toed sloths Choloepus and three-toed sloths Bradypus: see Mendel 1985;Reid 1997;Chiarello 2008;Nyakatura et al. 2010) that are distantly related (Patterson and Pascual 1968;Webb 1985;Gaudin 2004). However, their fossil record reveals a considerable diversity including more than 90 genera documented since the early Oligocene (see McDonald and De Iuliis 2008;Pujos et al. 2012 for a review). ...
The concept of a pedolateral pes in many extinct sloths began effectively with Owen’s mid-nineteenth century descriptions of Glossotherium and Megatherium. Pedolaterality denotes a pes that is habitually inverted, with the digital plane oriented nearly vertically so that weight is borne largely by the lateral digits (mainly metatarsal V) and the plantar surface faces almost entirely medially. Subsequent researchers were strongly influenced by Owen’s interpretations. Astragalar morphology, with the medial and lateral portions of its trochlea forming, respectively, a peg-shaped odontoid process and a discoid facet, came to be viewed as a proxy for pedolaterality and, eventually, horizontal rotation around a nearly vertical axis as the main movement of the pes. Such motion necessitates a nearly vertical orientation for the odontoid process. However, analysis of the pes of the Pleistocene megatheriines Megatherium and Eremotherium, the astragalus of which conforms to the type usually interpreted in the literature as indicative of pedolaterality, suggests that the pes was not strongly inverted. Rather, the digital plane was about 35o to the horizontal plane, so that weight was borne largely by metatarsal V, but also by metatarsal IV and possibly the ungual phalanx of digit III. The astragalus was positioned so that the odontoid process was oriented obliquely to the vertical axis. With this element so positioned, mediolateral rotation in the horizontal plane was minor, and the main movement of the pes produced dorsiflexion and plantar flexion in nearly the parasagittal plane, the usual movement of the pes in terrestrial mammals.
... The extant species are often classified into five main dietary categories, which are: omnivores (sometimes called 'carnivore-omnivores', sensu Redford, 1985, although they mostly consume insects and plants; comprising euphractine armadillos), generalist insectivores (e.g. armadillos of the genus Dasypus), specialist insectivores (ant and termite eaters, such as the armadillos Cabassous and Priodontes), frugivore-folivores (two-toed sloths, genus Choloepus) and folivores (three-toed sloths, genus Bradypus) (Redford, 1985;Chiarello, 2008;Green, 2009). Note that none of the extant species is a specialised grazer, so for that dietary category there is no extant analogue among xenarthrans. ...
Xenarthrans comprised an ecologically significant and diverse group of small to gigantic sized terrestrial insectivorous, omnivorous and herbivorous mammals during the Cenozoic in South America and during the Pleistocene in North America. Their peculiar tooth morphology has proven to be challenging for palaeodietary analyses of this group. Here we introduce a new approach to this problem by utilising the recently developed mesowear angle analysis for xenarthran palaeodietary analyses. The method is based on recording the relief of worn teeth as angles measured from the occlusal surfaces. We compare our results with other lines of evidence of extant and fossil xenarthran diets, based on direct observation, orthodentine microwear analyses and analyses of fossilised faecal material. Our results support previous findings and hypotheses on fossil xenarthran diets, but also provide new information on the diversity of dietary preferences in the diverse assemblages of large Pleistocene xenarthrans such as ground sloths and glyptodonts.
... The algae in sloth fur are more abundant in Bradypus compared to Choloepus (Pauli et al., 2014). The benefit of algae to sloths is likely to be reduced predation from enhanced crypsis while occupying tree canopies (Chiarello, 2008). Also, this algae is highly digestible and has high carbohydrate and lipid content and could be a source of nutrition for the highly specialized Bradypus (Pauli et al., 2014). ...
Specialized species, like arboreal folivores, often develop beneficial relationships with symbionts to exploit ecologically constrained lifestyles. Although coevolution can drive speciation by specialization of a symbiont to a host, a symbiotic relationship is not indicative of coevolution between host and symbiont. We tested for coevolved relationships between highly specialized two- and three-toed sloths (Choloepus spp. and Bradypus spp., respectively) and their symbiotic algae using cophylogenies and phylogeography. Our phylogeographic analysis showed a biogeographic pattern for the sloth distribution that was not found in the algal phylogeny. We found support for congruence between the sloth and algae phylogenies, implying cospeciation, only in the Bradypus lineage. Algae host-switching occurred from Bradypus spp. to Choloepus spp. Our results support a previously hypothesized symbiotic relationship between sloths and the algae in their fur and indicate that coevolution may have played a role in algae diversification. More broadly, convergent evolution may facilitate host switching between deeply diverged host lineages.
Northern Maned Sloth Bradypus torquatus has most recently been assessed for The
IUCN Red List of Threatened Species in 2024. Bradypus torquatus is listed as
Endangered under criteria B2ab(ii,iii,iv,v).
Southern Maned Sloth Bradypus crinitus has most recently been assessed for The
IUCN Red List of Threatened Species in 2024. Bradypus crinitus is listed as Endangered
under criteria B2ab(ii,iii,iv,v).
Although extinct sloths exhibited a wide range of dietary habits, modes of locomotion, and occupied various niches across the Americas, modern sloths are considered quite similar in their habits. The dietary habits of living sloths can be directly observed in the wild, and understanding the mechanical behavior of their jaws during chewing through finite element analysis (FEA) provides a valuable validation tool for comparative analysis with their extinct counterparts. In this study, we used FEA to simulate the mechanical behavior of sloth mandibles under lateral mastication loads, using it as a proxy for oral processing. Our research focused on the six extant sloth species to better understand their diets and validate the use of FEA for studying their extinct relatives. We found that all living sloths have the predominancy of low‐stress areas in their mandibles but with significant differences. Choloepus didactylus had larger high‐stress areas, which could be linked to a reduced need for processing tougher foods as an opportunistic generalist. Bradypus variegatus and Choloepus hoffmanni are shown to be similar, displaying large low‐stress areas, indicating greater oral processing capacity in a seasonal and more competitive environment. Bradypus torquatus, Bradypus pygmaeus, and Bradypus tridactylus exhibited intermediary processing patterns, which can be linked to a stable food supply in more stable environments and a reduced requirement for extensive oral processing capacity. This study sheds light on extant sloths' dietary adaptations and has implications for understanding the ecological roles and evolutionary history of their extinct counterparts.
It is usually beneficial for species to restrict activity to a particular phase of the 24-hour cycle as this enables the development of morphological and behavioural adaptations to enhance survival under specific biotic and abiotic conditions. Sloth activity patterns are thought to be strongly related to the environmental conditions due to the metabolic consequences of having a low and highly variable core body temperature. Understanding the drivers of sloth activity and their ability to withstand environmental fluctuations is of growing importance for the development of effective conservation measures, particularly when we consider the vulnerability of tropical ecosystems to climate change and the escalating impacts of anthropogenic activities in South and Central America. Unfortunately, the cryptic nature of sloths makes long term observational research difficult and so there is very little existing literature examining the behavioural ecology of wild sloths. Here, we used micro data loggers to continuously record, for the first time, the behaviour of both Bradypus and Choloepus sloths over periods of days to weeks. We investigate how fluctuations in the environmental conditions affect the activity of sloths inhabiting a lowland rainforest on the Caribbean coast of Costa Rica and examined how this might relate to their low power lifestyle. Both Bradypus and Choloepus sloths were found to be cathemeral in their activity, with high levels of between-individual and within-individual variation in the amounts of time spent active, and in the temporal distribution of activity over the 24-hour cycle. Daily temperature did not affect activity, although Bradypus sloths were found to show increased nocturnal activity on colder nights, and on nights following colder days. Our results demonstrate a distinct lack of synchronicity within the same population, and we suggest that this pattern provides sloths with the flexibility to exploit favourable environmental conditions whilst reducing the threat of predation.
Linnaeus's two-toed sloth (Choloepus didactylus) is one of two extant neotropical species of the family Megalonychidae. Despite their being commonly kept under managed care, the digestive physiology of sloths remains poorly understood. Gastrointestinal disease has been reported as a primary or contributing cause of morbidity and mortality in captive two-toed and three-toed (Bradypus spp.) sloths. Gastric dilatation due to gas accumulation ("bloat") has been reported in sloths; however, a literature search failed to yield any published mention of gastric volvulus in any sloth species. Following an inquiry sent to the electronic mailing lists of the American Association of Zoo Veterinarians, the European Association of Zoo and Wildlife Veterinarians, and the LatinVets community, three cases of fatal gastric dilatation and volvulus (GDV) were identified in one male and two female Linnaeus's two-toed sloths from institutions in the United States, Canada, and Germany. All cases occurred in juvenile sloths <1 yr of age. Two animals were primarily hand reared, whereas one was reared primarily by its dam. Two animals were found dead with no overt premonitory signs, whereas one animal died following a 3-wk course of waxing and waning clinical signs consistent with gastric gas accumulation. In all cases, GDV was diagnosed on postmortem examination. Similar to other species, the condition is likely subsequent to a combination of host- and husbandry-related contributing factors. Further research into sloth husbandry is required in order to take an evidence-based approach to their management.
O Espaço Ciência é um museu contemporâneo localizado no Instituto de Biodiversidade e Sustentabilidade (NUPEM/UFRJ) que conta com a exposição “Diversidade dos Ecossistemas Costeiros do Norte Fluminense”. Portanto, pensando no isolamento social, o “ZooTrunfo Espaço Ciência NUPEM/UFRJ” foi criado para dar continuidade ao projeto e promover a aproximação da população com a diversidade biológica de um jeito fácil e divertido! O jogo é composto por 16 cartas que contém características e ilustrações sobre os animais representados no Espaço Ciência, para serem impressas e montadas em casa.
Sexual dimorphism (SD) is extremely common in species that have reproductive roles segregated into separate sexes, and it has been recognized in several mammalian lineages, both extant and extinct. Sexual dimorphism is low to moderate in living sloths, but it had a more important role for extinct sloth taxa. The presence of SD in extinct sloths was first suggested at the end of the 19th century and it is now commonly advocated as a possible explanation of high intraspecific variation in many extinct sloth species. In this paper, we report the presence of SD in Simomylodon uccasamamensis, a Late Miocene to Late Pliocene sloth from the Bolivian Altiplano. We present evidence of SD in the morphology of cranial and postcranial remains, representing the earliest unequivocal occurrence of size-based SD in an extinct sloth species. Differences between sexes are mainly observed in the morphology of the feeding apparatus and general body size. Comparisons with extant large mammals allow us to hypothesize different food selection between the two sexes, with probable divergent habitat use and concomitant niche separation. This, in turn, could have represented an important selective factor for adaptation to environmental changes experienced by the Bolivian Altiplano in Late Neogene times.
Esse livro tem como objetivo apresentar a importância de um dos mais significativos remanescentes de Mata Atlântica do município de São Paulo, o Parque Estadual das Fontes do Ipiranga – PEFI, tão pouco conhecido pela maioria da população.
A proposta surgiu de uma lacuna identificada durante uma pesquisa de mestrado realizada em parceria com a Divisão de Educação e Difusão da Fundação Parque Zoológico de São Paulo (FPZSP), que envolveu a elaboração de um curso de formação para professores do entorno do Parque. Produzido por uma equipe multidisciplinar que possui em comum o ideal de conservação da natureza, o livro é resultado do esforço de profissionais ligados ao Zoológico de São Paulo, ao Programa de Pós-Graduação em Conservação da Fauna (PPGCFau) e ao Instituto de Botânica de São Paulo.
Xenarthrans—anteaters, sloths, and armadillos—have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, 10 anteaters, and 6 sloths. Our data set includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the southern United States, Mexico, and Caribbean countries at the northern portion of the Neotropics, to the austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n = 5,941), and Cyclopes sp. have the fewest (n = 240). The armadillo species with the most data is Dasypus novemcinctus (n = 11,588), and the fewest data are recorded for Calyptophractus retusus (n = 33). With regard to sloth species, Bradypus variegatus has the most records (n = 962), and Bradypus pygmaeus has the fewest (n = 12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other data sets of Neotropical Series that will become available very soon (i.e., Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans data set. Please cite this data paper when using its data in publications. We also request that researchers and teachers inform us of how they are using these data.
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