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1.
Mov Ecol ; 12(1): 19, 2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38429836

ABSTRACT

BACKGROUND: Understanding how to connect habitat remnants to facilitate the movement of species is a critical task in an increasingly fragmented world impacted by human activities. The identification of dispersal routes and corridors through connectivity analysis requires measures of landscape resistance but there has been no consensus on how to calculate resistance from habitat characteristics, potentially leading to very different connectivity outcomes. METHODS: We propose a new model, called the Time-Explicit Habitat Selection (TEHS) model, that can be directly used for connectivity analysis. The TEHS model decomposes the movement process in a principled approach into a time and a selection component, providing complementary information regarding space use by separately assessing the drivers of time to traverse the landscape and the drivers of habitat selection. These models are illustrated using GPS-tracking data from giant anteaters (Myrmecophaga tridactyla) in the Pantanal wetlands of Brazil. RESULTS: The time model revealed that the fastest movements tended to occur between 8 p.m. and 5 a.m., suggesting a crepuscular/nocturnal behavior. Giant anteaters moved faster over wetlands while moving much slower over forests and savannas, in comparison to grasslands. We also found that wetlands were consistently avoided whereas forest and savannas tended to be selected. Importantly, this model revealed that selection for forest increased with temperature, suggesting that forests may act as important thermal shelters when temperatures are high. Finally, using the spatial absorbing Markov chain framework, we show that the TEHS model results can be used to simulate movement and connectivity within a fragmented landscape, revealing that giant anteaters will often not use the shortest-distance path to the destination patch due to avoidance of certain habitats. CONCLUSIONS: The proposed approach can be used to characterize how landscape features are perceived by individuals through the decomposition of movement patterns into a time and a habitat selection component. Additionally, this framework can help bridge the gap between movement-based models and connectivity analysis, enabling the generation of time-explicit connectivity results.

2.
Genet Mol Biol ; 47(1): e20230252, 2024.
Article in English | MEDLINE | ID: mdl-38446984

ABSTRACT

The progressive fragmentation and loss of habitats represent the main threats for endangered species, causing genetic consequences that may have potential implications for a population's long-term persistence. Large mammals are the most affected species among vertebrates. The giant armadillo Priodontes maximus is a large South American mammal threatened species, showing nocturnal, solitary and fossorial behavior, occurring at low population densities, and its population dynamics are still poorly known. In this study, we carried out the first assessment of genetic variability and population genetic structure of the species, using a panel of 15 polymorphic microsatellites developed by high-throughput genome sequencing. The spatial Bayesian clustering, Fst and Dest results indicated the presence of two genetic clusters (K = 2) in the study area. These results suggest a reduction in gene flow between individuals inhabiting the Brazilian savanna (Cerrado) and the Pantanal wetlands, with the increased human-driven habitat modifications possibly contributing for this scenario. A bottleneck signal was detected in both populations, and a subpopulation structuring in the Cerrado may also be reflecting consequences of the extensive habitat modifications. Findings from this study provide important and useful information for the future maintenance of genetic diversity and long-term conservation of this flagship species.

3.
Animals (Basel) ; 13(23)2023 Nov 22.
Article in English | MEDLINE | ID: mdl-38066956

ABSTRACT

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

4.
Parasitol Res ; 122(12): 3169-3180, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37848747

ABSTRACT

Xenarthra mammals can be found from southern North America to southern South America, including all Brazilian biomes. Although it has been shown that Xenarthra mammals can play a role as reservoirs for several zoonotic agents, few studies investigate the diversity of piroplasmids (Apicomplexa: Piroplasmida) in this group of mammals. Taking into account that piroplasmids can cause disease in animals and humans, understanding the prevalence and diversity of piroplasmids in Xenarthra mammals would contribute to conservation efforts for this group of animals as well as to infer risk areas for transmission of emergent zoonosis. The present study aimed to investigate the occurrence and molecular identity of piroplasmids in free-living mammals of the Superorder Xenarthra from four Brazilian states (Mato Grosso do Sul, São Paulo, Rondônia, and Pará). For this, DNA was extracted from blood or spleen samples from 455 animals. A nested PCR based on the 18S rRNA gene was used as screening for piroplasmids. Of the 455 samples analyzed, 25 (5.5%) were positive. Additionally, PCR assays based on 18S rRNA near-complete, cox-1, cox-3, hsp70, cytB, ß-tubulin genes and the ITS-1 intergenic region were performed. Five out of 25 positive samples also tested positive for ITS-1-based PCR. The phylogenetic analysis positioned three 18S rRNA sequences detected in Priodontes maximus into the same clade of Babesia sp. detected in marsupials (Didelphis albiventris, Didelphis marsupialis, and Monodelphis domestica) and Amblyomma dubitatum collected from opossums and coatis in Brazil. On the other hand, the 18S rRNA sequence obtained from Dasypus novemcinctus was closely related to a Theileria sp. sequence previously detected in armadillos from Mato Grosso State, grouping in a subclade within the Theileria sensu stricto clade. In the phylogenetic analysis based on the ITS-1 region, the sequences obtained from Myrmecophaga tridactyla and Tamandua tetradactyla were placed into a single clade, apart from the other piroplasmid clades. The present study demonstrated the molecular occurrence of Piroplasmida in anteaters and Babesia sp. and Theileria sp. in armadillos from Brazil.


Subject(s)
Babesia , Didelphis , Marsupialia , Piroplasmida , Theileria , Xenarthra , Animals , Humans , Brazil/epidemiology , Armadillos , Phylogeny , RNA, Ribosomal, 18S/genetics , Theileria/genetics , Babesia/genetics , Piroplasmida/genetics
5.
Science ; 380(6649): 1059-1064, 2023 06 09.
Article in English | MEDLINE | ID: mdl-37289888

ABSTRACT

COVID-19 lockdowns in early 2020 reduced human mobility, providing an opportunity to disentangle its effects on animals from those of landscape modifications. Using GPS data, we compared movements and road avoidance of 2300 terrestrial mammals (43 species) during the lockdowns to the same period in 2019. Individual responses were variable with no change in average movements or road avoidance behavior, likely due to variable lockdown conditions. However, under strict lockdowns 10-day 95th percentile displacements increased by 73%, suggesting increased landscape permeability. Animals' 1-hour 95th percentile displacements declined by 12% and animals were 36% closer to roads in areas of high human footprint, indicating reduced avoidance during lockdowns. Overall, lockdowns rapidly altered some spatial behaviors, highlighting variable but substantial impacts of human mobility on wildlife worldwide.


Subject(s)
Animal Migration , Animals, Wild , COVID-19 , Mammals , Quarantine , Animals , Humans , Animals, Wild/physiology , Animals, Wild/psychology , COVID-19/epidemiology , Mammals/physiology , Mammals/psychology , Movement
6.
PeerJ ; 11: e14726, 2023.
Article in English | MEDLINE | ID: mdl-36691484

ABSTRACT

Advances in biologging have increased the understanding of how animals interact with their environment, especially for cryptic species. For example, giant armadillos (Priodontes maximus) are the largest extant species of armadillo but are rarely encountered due to their fossorial and nocturnal behavior. Through the analysis of speed, turning angles, and accelerometer activity counts, we estimated behavioral states, characterized activity budgets, and investigated the state-habitat associations exhibited by individuals monitored with GPS telemetry in the Brazilian Pantanal from 2019 to 2020. This methodology is proposed as a useful framework for the identification of priority habitat. Using the non-parametric Bayesian mixture model for movement (M3), we estimated four latent behavioral states that were named 'vigilance-excavation', 'local search', 'exploratory', and 'transit'. These states appeared to correspond with behavior near burrows or termite mounds, foraging, ranging, and rapid movements, respectively. The first and last hours of activity presented relatively high proportions of the vigilance-excavation state, while most of the activity period was dominated by local search and exploratory states. The vigilance-excavation state occurred more frequently in regions between forest and closed savannas, whereas local search was more likely in high proportions of closed savanna. Exploratory behavior probability increased in areas with high proportions of both forest and closed savanna. Our results establish a baseline for behavioral complexity, activity budgets, and habitat associations in a relatively pristine environment that can be used for future work to investigate anthropogenic impacts on giant armadillo behavior and fitness. The integration of accelerometer and GPS-derived movement data through our mixture model has the potential to become a powerful methodological approach for the conservation of other cryptic species.


Subject(s)
Armadillos , Ecosystem , Animals , Bayes Theorem , Forests , Brazil
7.
Integr Zool ; 18(1): 129-142, 2023 Jan.
Article in English | MEDLINE | ID: mdl-35278278

ABSTRACT

Understanding of resource requirements of vulnerable species is key for conservation planning. Here, we used stable carbon (δ13 C) and nitrogen isotopes (δ15 N) of hair from giant armadillos (Priodontes maximus) to understand individual resource use. We collected hair from 19 giant armadillos analyzing 34 samples from the Brazilian Pantanal and compared the resource use between sexes and age classes. We also assessed the relationship of isotopic values with individuals' body mass and the habitat type used. We observed a wide variation in resource use by giant armadillos, showing that individuals consume prey that feeds on distinct resources and occupies different habitat types, indicating that there is individual variation in foraging behavior. Most giant armadillos presented a mixed diet (C3 /C4 resources, forests/open areas), but a quarter of individuals had strictly C4 diets (open areas). Males are more prone to forage on C4 resources, presenting an isotopic niche 2.6-times larger than that of females. Subadults presented diets more associated with habitats with high arboreal cover (C3 resources, forests), while adults foraged more in open areas (C4 resources). This result is mirrored by the positive relationship between δ13 C values and body mass, suggesting that larger giant armadillos tend to feed more in open areas. We observed that δ13 C values decreased as individuals increased the use of habitats with high arboreal cover. We stress the importance of conserving the natural mosaic in the Pantanal landscape for the species persistence, given that giant armadillos require all habitat types to fulfill their dietary, spatial, and developmental needs.


Subject(s)
Armadillos , Ecosystem , Female , Male , Animals , Carbon Isotopes/analysis , Forests , Diet , Hair/chemistry , Nitrogen Isotopes/analysis
8.
Glob Ecol Biogeogr ; 31(8): 1526-1541, 2022 Aug.
Article in English | MEDLINE | ID: mdl-36247232

ABSTRACT

Aim: Macroecological studies that require habitat suitability data for many species often derive this information from expert opinion. However, expert-based information is inherently subjective and thus prone to errors. The increasing availability of GPS tracking data offers opportunities to evaluate and supplement expert-based information with detailed empirical evidence. Here, we compared expert-based habitat suitability information from the International Union for Conservation of Nature (IUCN) with habitat suitability information derived from GPS-tracking data of 1,498 individuals from 49 mammal species. Location: Worldwide. Time period: 1998-2021. Major taxa studied: Forty-nine terrestrial mammal species. Methods: Using GPS data, we estimated two measures of habitat suitability for each individual animal: proportional habitat use (proportion of GPS locations within a habitat type), and selection ratio (habitat use relative to its availability). For each individual we then evaluated whether the GPS-based habitat suitability measures were in agreement with the IUCN data. To that end, we calculated the probability that the ranking of empirical habitat suitability measures was in agreement with IUCN's classification into suitable, marginal and unsuitable habitat types. Results: IUCN habitat suitability data were in accordance with the GPS data (> 95% probability of agreement) for 33 out of 49 species based on proportional habitat use estimates and for 25 out of 49 species based on selection ratios. In addition, 37 and 34 species had a > 50% probability of agreement based on proportional habitat use and selection ratios, respectively. Main conclusions: We show how GPS-tracking data can be used to evaluate IUCN habitat suitability data. Our findings indicate that for the majority of species included in this study, it is appropriate to use IUCN habitat suitability data in macroecological studies. Furthermore, we show that GPS-tracking data can be used to identify and prioritize species and habitat types for re-evaluation of IUCN habitat suitability data.

9.
J Comp Pathol ; 197: 1-18, 2022 Sep.
Article in English | MEDLINE | ID: mdl-36089291

ABSTRACT

Motor vehicle collisions (MVCs) are a severe threat to wildlife biodiversity worldwide and most vertebrate species are at risk. However, there is a considerable knowledge gap on the traumatic features and potential patterns of MVCs in wildlife. We investigated traumatic injuries (TIs) caused by MVCs (MVCs-TIs) in 430 neotropical wild mammals representing 44 species from Brazil. Injuries were classified topographically into four categories: abdomen/pelvis (AP), chest (TX), head/neck (HN) and extremities (EX). We also determined the prevalence of pathological changes in MVC fatalities. AP (n = 381; 89%) was the most affected body segment, followed by TX (n = 372; 87%), HN (n = 363; 84%) and EX (n = 288; 67%). The most prevalent gross pathological findings were single or multiple bone fractures (n = 397; 92%), visceral organ rupture (n = 371; 86%), haemothorax (n = 220; 51%) and pulmonary haemorrhage (n = 212; 49%). Microscopically, pulmonary oedema (n = 324; 82%) and haemorrhage (n = 272; 69%) were the most prevalent lesions. No distinct TI patterns were evident across the various taxonomic groups, although trends were found in some taxa, such as armadillos. These results may help clinicians performing emergency care on MVC wildlife patients and may be of value in pathological and forensic investigations where a MVC has been deemed a likely contributory factor to death.


Subject(s)
Accidents, Traffic , Mammals , Animals , Brazil/epidemiology , Motor Vehicles , Prevalence
10.
Pathogens ; 11(8)2022 Aug 15.
Article in English | MEDLINE | ID: mdl-36015039

ABSTRACT

Knowledge of reproductive health in wild southern tamanduas (Tamandua tetradactyla; Mammalia: Myrmecophagidae) is fragmentary. During necropsies of roadkill xenarthran species in Brazil, a case of ovarian filariasis in an adult female southern tamandua was observed. Macroscopically, both ovaries were irregularly enlarged and had numerous smooth protuberances. Histologically, the affected ovarian parenchyma presented adult nematodes (including females with microfilaria) surrounded by pleocellular inflammatory infiltrates. The morphological characteristics of the nematodes were consistent with the superfamily Filarioidea (order Spirurida). The adjacent ovarian parenchyma had developing and atretic follicles at different stages of maturation. Filarial nematodes were not observed in other tissues. The cause of death of this tamandua was fatal acute polytrauma as a consequence of the motor vehicle collision. This case adds to a prior report of ovarian filariasis in two southern tamanduas in Nicaragua and Guatemala, dating back almost 100 years, and suggests filarial infections could potentially have an impact on reproductive success in southern tamanduas and possibly other xenarthrans. Several xenarthran species are under different levels of threat and knowledge of their basic reproductive health is crucial for conservation programs.

11.
J Environ Manage ; 321: 115903, 2022 Nov 01.
Article in English | MEDLINE | ID: mdl-35973292

ABSTRACT

For several species, roadkill is not spatially aggregated on hotspots, having instead a more diffuse pattern along the roads. For such species, management measures such as road passages may be insufficient for effective mitigation, since a large part of the road crossings is likely to occur outside the influence of those structures. One complementary approach could be to implement temporary mitigation actions, such as traffic calming. This requires understanding when roadkill peaks may occur. We tested the feasibility of predicting seasonal peaks of roadkill using data from a 3-year systematic monitoring (78 surveys over ca. 960 km of roads) from eight non-flying vertebrate species from Mato Grosso do Sul, Brazil, with different body size and life history traits (ca. 6400 records from focal species). We modelled the time-series of the roadkill of these species at large scale (state level) using generalized additive mixed models (GAMMs). We used the data of the first 2 years as training datasets, and the information from the third year of surveys as testing datasets to evaluate the prediction performance of models. Overall, the models of species feed with a higher number of records were able to follow reasonably well the variations of roadkill over time, although they were not able to correctly predict the number of collisions. For species with fewer observations, the models presented a poorer goodness-of-fit and prediction ability. Our results suggest that, at least for those species with higher roadkill rates, it can be possible to forecast periods of higher probability of occurring hot-moments of mortality. Such models can provide valuable information to implement seasonal management actions.


Subject(s)
Vertebrates , Animals , Brazil , Seasons
12.
Ecology ; 103(9): e3738, 2022 09.
Article in English | MEDLINE | ID: mdl-35567292

ABSTRACT

The Amazon forest has the highest biodiversity on Earth. However, information on Amazonian vertebrate diversity is still deficient and scattered across the published, peer-reviewed, and gray literature and in unpublished raw data. Camera traps are an effective non-invasive method of surveying vertebrates, applicable to different scales of time and space. In this study, we organized and standardized camera trap records from different Amazon regions to compile the most extensive data set of inventories of mammal, bird, and reptile species ever assembled for the area. The complete data set comprises 154,123 records of 317 species (185 birds, 119 mammals, and 13 reptiles) gathered from surveys from the Amazonian portion of eight countries (Brazil, Bolivia, Colombia, Ecuador, French Guiana, Peru, Suriname, and Venezuela). The most frequently recorded species per taxa were: mammals: Cuniculus paca (11,907 records); birds: Pauxi tuberosa (3713 records); and reptiles: Tupinambis teguixin (716 records). The information detailed in this data paper opens up opportunities for new ecological studies at different spatial and temporal scales, allowing for a more accurate evaluation of the effects of habitat loss, fragmentation, climate change, and other human-mediated defaunation processes in one of the most important and threatened tropical environments in the world. The data set is not copyright restricted; please cite this data paper when using its data in publications and we also request that researchers and educators inform us of how they are using these data.


Subject(s)
Forests , Mammals , Animals , Biodiversity , Birds , Brazil , Humans , Reptiles , Vertebrates
13.
Transbound Emerg Dis ; 69(5): e1877-e1891, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35298081

ABSTRACT

Although mammals of the superorder Xenarthra are considered hosts of a wide range of zoonotic agents, works aiming at investigating the role of these animals as hosts for bacteria with zoonotic potential are rare. The present study aimed to investigate the occurrence and molecularly characterize Coxiella burnetii and haemoplasma (haemotropic mycoplasmas) DNA in blood and spleen samples from 397 free-living Xenarthra mammals (233 sloths, 107 anteaters and 57 armadillos) in five Brazilian states (Mato Grosso do Sul, São Paulo, Pará, Rondônia and Rio Grande do Sul). All biological samples from Xenarthra were negative in the qPCR for Coxiella burnetii based on the IS1111 gene. The absence of C. burnetii DNA in blood and spleen samples from Xenarthra suggests that these mammals may not act as possible hosts for this agent in the locations studied. When performed conventional PCR assays for the endogenous (gapdh) mammalian gene, 386 samples were positive. When screened by molecular assays based on the 16S rRNA gene of haemoplasmas, 81 samples were positive, of which 15.54% (60/386) were positive by conventional PCR and 5.44% (21/386) were positive by real-time PCR; three samples were positive in both assays. Of these, 39.74% (31/78) were also positive for the 23S rRNA gene and 7.69% (6/78) for the haemoplasma RNAse P gene. Among the samples positive for haemoplasmas, 25.64% (20/78) were obtained from anteaters (Tamandua tetradactyla and Myrmecophaga tridactyla), 39.74% (31/78) from sloths (Bradypus tridactylus, Bradypus sp. and Choloepus sp.) 34.61% (27/78) from armadillos (Priodontes maximus, Euphractus sexcinctus and Dasypus novemcinctus). A haemoplasma 16S rRNA sequence closely related and showing high identity (99.7%) to Mycoplasma wenyonii was detected, for the first time, in B. tridactylus. Based on the low identity and phylogenetic positioning of 16S rRNA and 23S rRNA sequences of haemoplasmas detected in anteaters and armadillos, the present study showed, for the first time, the occurrence of putative new Candidatus haemotropic Mycoplasma spp. ("Candidatus Mycoplasma haematotetradactyla" and "Candidatus Mycoplasma haematomaximus") in Xenarthra mammals from Brazil.


Subject(s)
Coxiella burnetii , Mycoplasma Infections , Mycoplasma , Sloths , Xenarthra , Animals , Armadillos/genetics , Brazil/epidemiology , Coxiella burnetii/genetics , DNA , Mycoplasma/genetics , Mycoplasma Infections/epidemiology , Mycoplasma Infections/microbiology , Mycoplasma Infections/veterinary , Phylogeny , RNA, Ribosomal, 16S/genetics , RNA, Ribosomal, 23S , Real-Time Polymerase Chain Reaction/veterinary , Ribonuclease P/genetics
14.
Integr Zool ; 17(2): 285-296, 2022 Mar.
Article in English | MEDLINE | ID: mdl-33738919

ABSTRACT

Mammals can show conspicuous behavioral responses to thermal variation, including changes in movement patterns. We used an integrative approach to understand how environmental temperature can drive the movement behavior of a mammal with low capacity for physiological thermoregulation, the giant anteater (Myrmecophaga tridactyla). We tracked 52 giant anteaters in 7 areas throughout the Brazilian savannah. We estimated the distance moved, area used, use of forest areas, and mean environmental temperature for each monitoring day of each individual. We modeled these data with Mixed Structural Equations - considering the possible interactions between our variables and controlling for sex and body mass. Giant anteaters reduced displacement and increased forest use with decreasing environmental temperature, probably because of their low body heat production. It is possible that they reduce distance moved and area used by reducing the duration of activity. With decreasing temperature, forest habitats become warmer than open ones, besides buffer rain and chilly winds. Reducing displacement and using forests are important strategies to reduce body heat loss and the energetic costs of thermoregulation. However, decreasing movement can limit food access and, consequently, fitness. Therefore, we highlight the importance of forests as thermal shelters. With increasing frequency and intensity of extreme weather events, we showed the need to preserve forest patches to offer suitable conditions for tropical mammals' behavioral thermoregulation. In this context, policies favoring deforestation on Brazilian territory are especially worrisome. Finally, we emphasize the need of integrative approaches to understand the complex interactions between organisms and the environment.


Subject(s)
Ecosystem , Vermilingua , Animals , Body Temperature Regulation , Forests , Mammals , Temperature
15.
Transbound Emerg Dis ; 69(4): 2045-2051, 2022 Jul.
Article in English | MEDLINE | ID: mdl-34132049

ABSTRACT

The number of viral-associated neoplasms reported in wildlife has increased over the last decades, likely because of growing research efforts and a potentially greater burden of carcinogenic pathogens. Herein, we describe a primary gastric T-cell lymphoma in one free-ranging giant armadillo (Priodontes maximus) from Brazilian Pantanal infected by a novel gammaherpesvirus, proposed as Cingulatid gammaherpesvirus 1 (CiHV-1). By chromogenic in situ hybridisation against Epstein-Barr virus some neoplastic cells were labeled. Subsequently, a molecular screening was carried out to detect the occurrence of this pathogen in other giant armadillos in the same region. Overall, this novel virus was detected in 14.3% (3/21) of the tested giant armadillos. We suggest this herpesvirus, the first in Xenarthra, as a plausible aetiology of the neoplasm. The implications of CiHV-1 for this species are uncertain; while no outbreaks of disease have been recorded, the present study raises concerns. Further research is warranted to assess the real significance of CiHV-1 and its potential oncogenic role in this species.


Subject(s)
Epstein-Barr Virus Infections , Gammaherpesvirinae , Lymphoma, T-Cell , Animals , Armadillos , Brazil/epidemiology , Epstein-Barr Virus Infections/veterinary , Gammaherpesvirinae/genetics , Herpesvirus 4, Human , Lymphoma, T-Cell/epidemiology , Lymphoma, T-Cell/veterinary
16.
PLoS One ; 16(8): e0253345, 2021.
Article in English | MEDLINE | ID: mdl-34407068

ABSTRACT

Knowing the influence of intrinsic and environmental traits on animals' movement is a central interest of ecology and can aid to enhance management decisions. The giant anteater (Myrmecophaga tridactyla) is a vulnerable mammal that presents low capacity for physiological thermoregulation and uses forests as thermal shelters. Here, we aim to provide reliable estimates of giant anteaters' movement patterns and home range size, as well as untangle the role of intrinsic and environmental drivers on their movement. We GPS-tracked 19 giant anteaters in Brazilian savannah. We used a continuous-time movement model to estimate their movement patterns (described by home range crossing time, daily distance moved and directionality), and provide an autocorrelated kernel density estimate of home range size. Then, we used mixed structural equations to integratively model the effects of sex, body mass and proportion of forest cover on movement patterns and home range size, considering the complex net of interactions between these variables. Male giant anteaters presented more intensive space use and larger home range than females with similar body mass, as it is expected in polygynous social mating systems. Males and females increased home range size with increasing body mass, but the allometric scaling of intensity of space use was negative for males and positive for females, indicating different strategies in search for resources. With decreasing proportion of forest cover inside their home ranges, and, consequently, decreasing thermal quality of their habitat, giant anteaters increased home range size, possibly to maximize the chances of accessing thermal shelters. As frequency and intensity of extreme weather events and deforestation are increasing, effective management efforts need to consider the role of forests as an important thermal resource driving spatial requirements of this species. We highlight that both intrinsic and environmental drivers of animal movement should be integrated to better guide management strategies.


Subject(s)
Eutheria/physiology , Homing Behavior , Animal Distribution , Animals , Brazil , Ecosystem , Female , Forests , Male , Models, Biological , Sexual Behavior, Animal
17.
PeerJ ; 9: e11945, 2021.
Article in English | MEDLINE | ID: mdl-34447632

ABSTRACT

BACKGROUND: The giant anteater belongs to the supraorder Xenarthra which occupies a systematically isolated position among placental mammals. The species is categorized as Vulnerable by the International Union for Conservation of Nature, and understanding its reproductive characteristics is critical for future conservation efforts. METHODS: Gross and microscopic anatomy of the genital organs of 23 male and 21 female adult and young roadkill giant anteaters in Brazil were studied. RESULTS: Male giant anteaters presented a short conical penis, intraabdominal testes, and prostate, vesicular and bulbourethral glands. A tubular remnant of the partially fused Müllerian ducts extended from the seminal colliculus through the prostate gland, continued cranially in the genital fold, bifurcated, and attached with one elongation each to the left and right epididymal corpus. The structure presented a total length of up to 10 cm and contained a yellowish liquid in its lumen. Histologically, the caudal section of this structure resembled the female vagina, the middle portion corresponded to the uterus, and the extensions showed characteristics of uterine tubes. In adult female giant anteaters, ovoid ovaries with occasional seminiferous cord-like structures were observed. The animals possessed a simple uterus, which was directly continuous with the vaginal canal. The caudal portion of the vagina had two lumina, separated by a longitudinal septum and opening into two apertures into the vaginal vestibule, cranial to the urethral opening. In the urethral and the lateral vestibular wall, glandular structures with characteristics of male prostate and bulbourethral glands, respectively, were found. The vestibule opened through a vertical vulvar cleft to the exterior. A pair of well-differentiated Wolffian ducts with a central lumen originated ventrally at the vaginal opening into the vestibule and passed in a cranial direction through the ventral vaginal and uterine wall. Each duct extended highly coiled along the ipsilateral uterine tube until the lateral pole of the ovaries where it merged with the rete ovarii. DISCUSSION: The reproductive morphology of giant anteaters reveals characteristics shared with other Xenarthrans: intraabdominal testes, a simple uterus, and a double caudal vagina. The persistence of well-differentiated genital ducts of the opposite sex in both males and females, however, singles them out among other species. These structures are the results of an aberration during fetal sexual differentiation and possess secretory functions. The possibility of a pathological degeneration of these organs should be considered in reproductive medicine of the species. CONCLUSION: Knowledge of the unique reproductive characteristics of the giant anteater is essential for future reproductive management of the species. Additionally, further research on the peculiarities of the persisting genital duct structures might help to understand sexual differentiation in placental mammals in general.

18.
Front Genet ; 12: 669350, 2021.
Article in English | MEDLINE | ID: mdl-34276776

ABSTRACT

In general, large mammal species with highly specialized feeding behavior and solitary habits are expected to suffer genetic consequences from habitat loss and fragmentation. To test this hypothesis, we analyzed the genetic diversity distribution of the threatened giant anteater inhabiting a human-modified landscape. We used 10 microsatellite loci to assess the genetic diversity and population structure of 107 giant anteaters sampled in the Brazilian Central-Western region. No genetic population structuring was observed in this region suggesting no gene flow restriction within the studied area. On the other hand, the moderate level of genetic diversity (Ho = 0.54), recent bottleneck detected and inbreeding (Fis, 0.13; p ≤ 0.001) signatures suggest potential impacts on the genetic variation of this Xenarthra. Additionally, a previous demographic reduction was suggested. Thus, considering the increased human-promoted impacts across the entire area of distribution of the giant anteater, our results can illustrate the potential effects of these disturbances on the genetic variation, allowing us to request the long-term conservation of this emblematic species.

19.
Pathogens ; 10(6)2021 Jun 11.
Article in English | MEDLINE | ID: mdl-34207936

ABSTRACT

Trypanosoma rangeli is a generalist hemoflagellate that infects mammals and is transmitted by triatomines around Latin America. Due to its high genetic diversity, it can be classified into two to five lineages. In Brazil, its distribution outside the Amazon region is virtually unknown, and knowledge on the ecology of its lineages and on host species diversity requires further investigation. Here, we analyzed 57 T. rangeli samples obtained from hemocultures and blood clots of 1392 mammals captured in different Brazilian biomes. The samples were subjected to small subunit (SSU) rDNA amplification and sequencing to confirm T. rangeli infection. Phylogenetic inferences and haplotype networks were reconstructed to classify T. rangeli lineages and to infer the genetic diversity of the samples. The results obtained in our study highlighted both the mammalian host range and distribution of T. rangeli in Brazil: infection was observed in five new species (Procyon cancrivorous, Priodontes maximum, Alouatta belzebul, Sapajus libidinosus, and Trinomys dimidiatus), and transmission was observed in the Caatinga biome. The coati (Nasua nasua) and capuchin monkey (S. libidinosus) are the key hosts of T. rangeli. We identified all four T. rangeli lineages previously reported in Brazil (A, B, D, and E) and possibly two new genotypes.

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