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Aim Land‐use change and overexploitation are major threats to biodiversity, and climate change will exert additional pressure in the 21st century. Although there are strong interactions between these threats, our understanding of the synergistic and compensatory effects on threatened species' range geography remains limited. Our aim was to disentangle the impact of habitat loss, hunting and climate change on species, using the example of the endangered Chacoan peccary (Catagonus wagneri). Location Gran Chaco ecoregion in South America. Methods Using a large occurrence database, we integrated a time‐calibrated species distribution model with a hunting pressure model to reconstruct changes in the distribution of suitable peccary habitat between 1985 and 2015. We then used partitioning analysis to attribute the relative contribution of habitat change to land‐use conversion, climate change and varying hunting pressure. Results Our results reveal widespread habitat deterioration, with only 11% of the habitat found in 2015 considered suitable and safe. Hunting pressure was the strongest single threat, yet most habitat deterioration (58%) was due to the combined, rather than individual, effects of the three drivers we assessed. Climate change would have led to a compensatory effect, increasing suitable habitat area, yet this effect was negated by the strongly negative and interacting threats of land‐use change and hunting. Main Conclusions Our study reveals the central role of overexploitation, which is often neglected in biogeographic assessments, and suggests that addressing overexploitation has huge potential for increasing species' adaptive capacity in the face of climate and land‐use change. More generally, we highlight the importance of jointly assessing extinction drivers to understand how species might fare in the 21st century. Here, we provide a simple and transferable framework to determine the separate and joint effects of three main drivers of biodiversity loss.

This study identifies gastrointestinal parasites in the feces of Pecari tajacu (caititu) and Sus scrofa domesticus (domestic pig) in southeastern Piauí, Brazil. The region covers 2 protected areas, Serra da Capivara National Park and Serra das Confusões National Park, and surrounding communities. Fecal samples from 64 animals, 42 from domestic swine and 22 from caititu, collected between 1985 and 2013, were analyzed by optical microscopy. Helminths and/or protozoa were found in 64% of the domestic pig samples and 27% of the caititu samples, totaling 18 morphospecies: Nematoda, Spirurida (2 morphospecies), Trichostrongyloidea, Eimeriidae, Aspidodera sp., Bertiella sp., Metastrongylus sp., Trichostrongylus sp., Moniezia sp., Gongylonema sp., Trichuris suis, Spirocerca lupi, Macracanthorhyncus hirudinaceus, Globocephalus urosubulatus, Strongyloides cf ransomi, Balantioides coli, and Eimeria cf scabra. The highest parasite diversity was obtained in the pig samples, totaling 15 morphospecies, compared to only 6 in caititus, with S. cf ransomi, G. urosubulatus, and S. lupi present in both hosts. We discuss the presence of parasites associated with domestic animals around the Protected Areas and potentially zoonotic parasites close to human communities, which raise concerns about the conservation of wildlife, human health, and livestock in the region.

Group living among ungulates has evolved mainly in species living in open habitats, such as grasslands and savannas, whereas in the forest, few ungulate species form groups and these tend to be small. Therefore, the white‐lipped peccary (Tayassu pecari), a Neotropical ungulate listed as Vulnerable by the IUCN, represents an almost unique social occurrence as it lives in large and cohesive groups, yet it inhabits dense tropical forests. Large variations in group sizes have been observed throughout the species range, with reports of herds with less than 10 to around 300 individuals. We examined factors that might cause variation in group size in white‐lipped peccary, including ecological and anthropogenic variables. We conducted an extensive literature review and used our original data to compile information on white‐lipped peccary's group size across its range. We built models to quantitate generalizations for group sizes distinguishing data from areas with high human influence, and areas that have not been significantly disturbed by humans for at least the last 20 years. We found that white‐lipped peccary's group size for all sites was most strongly predicted by a combination of the distances to the nearest human settlement and rainfall and its seasonality. Results from the undisturbed sites indicated that group size is positively influenced by rainfall. Our results contribute to understand why group size varies in different environments that are subjected to different ecological and human conditions. Information on these relationships is a key to advance our understanding of the socio‐ecological strategies of animal species living in groups.

More widespread farming of species not typically used as livestock may be part of a sustainable approach for promoting human health and economic prosperity in a world with an increasing population; a current example is peccary farming in the Neotropics. Others have argued that species that are local to a region and which are usually not farmed should be considered for use as livestock. They may have a more desirable nutrient profile than species that are presently used as livestock. It may also reduce the pressure from hunting on other wild species, and cause less environmental damage than exotic species. We propose a sentiocentric utilitarian framework that could be used to decide whether species that are local, but generally not used as livestock, should be farmed. To illustrate the use of our decision-making framework, we employ two contrasting neotropical case studies: the Spotted Paca (Cuniculus paca) and the Capybara (Hydrochoerus hydrochaeris). We argue that it may be acceptable to use non-sentient species that are typically not farmed as livestock. However, research should determine whether farming them offers human, environmental or sustainability benefits. In addition, we recommend that if invertebrate species are considered for farming, research should be conducted to determine the likelihood that they are sentient. Finally, given the ethical failings of current livestock farming practices, we argue that a high bar must be met if ‘new’ species that are sentient are to be farmed.

This work aims to study the major salivary gland morphology of peccaries during their growth. The glands were analyzed using macroscopic description, light microscopy, electron microscopy, histochemistry, and immunohistochemistry. Topographically, the salivary glands resemble other animals, including domestic animals and pigs. During growth, the parotid enlarges and mandibular gland loses weight. Histologically, the parotid has serous production, and sublingual has mucous production, resembles most species, however, mandibular gland produces mucous, unlike other animals, including pigs, which produce seromucous secretion. Histochemically, parotid produces more acidic mucins than pigs and it undergoes maturation during development; mandibular, and especially the sublingual gland, produce more acidic and basic mucopolysaccharides than pigs. The results found with transmission and scanning electron microscopy techniques corroborate the histological and histochemistry findings. The major salivary glands were positive to different lecithins (Com-A, BSA-I-B4, WGA and PNA), which were also more positive than in pigs and sheep. We conclude that collared peccaries have a salivary secretion that facilitates the digestion of carbohydrates, and biometric characteristics and positivity to lecithins that facilitate adaptation to foods with antinutritional factors.

A primary requirement of the mammalian skull is to exert forces on different foods and to resist the forces imposed on it during feeding. Skull shape patterns within and among mammals are generally well known, but the biomechanical relevance of this variation remains limited for some groups. By integrating geometric morphometric and biomechanical analyses, we test the hypothesis that skull shape in peccaries reflects biomechanical attributes to generate and dissipate powerful forces, presumably in response to tough foods. We obtained skull shape and size from 213 specimens of the three living peccary species and estimated bite force, bite stress at molars, bending and shear stress on the mandibular corpus, and condylar stress. We found larger estimated bite forces, greater resistance to bending loads, and lower stress emerging from the larger muscle attachment areas and shorter and deeper mandibular corpora for both Pecari tajacu and Tayassu pecari relative to Parachoerus wagneri. Peccaries (P. tajacu and T. pecari) with more powerful biomechanical attributes feed mainly on tougher foods (e.g., palm fruits). These results support the hypothesis that species eating tough foods tend to have a feeding morphology mechanically adapted to stronger bites and greater biting resistance, which must be closely reflected in their craniomandibular shape.

We scored pelage coloration of pigs and peccaries and matched them to socioecological variables to assess the relative strengths of protective coloration and signaling in driving coat coloration. Using phylogenetically controlled analyses, we found that faces, bellies, and perhaps flanks are lighter in larger species; ear coloration is lighter in less-shady environments and in more-social species; white facial spots are associated with less shade and with nighttime activity; and white body spots are associated with greater sociality. There is a marginal association between striped natal coats, a classically cryptic pelage, and litter size. These findings indicate that the body coloration of Suiformes has been selected to match overall background lighting conditions in both adults and neonates, but that specific areas and color patches on the body are associated with signaling. Our study suggests that small areas of contrasting pelage coloration are superimposed on classically cryptic body plans to allow both protective coloration and signaling to operate simultaneously.

Peccaries (collared peccary—CP—and white-lipped peccary—WLP) are an essential source of protein and income for rural communities in the Amazon region. Since 1980s, researchers in the Amazon have reported recurrent local disappearances of WLP populations. Although such disappearances impact the species conservation and the food security of rural societies, no studies have drawn consistent conclusions about the causes of these population collapses. However, it has recently been proposed that the overabundance of this species before its decline would be related to infectious disease outbreaks. In the current study, we aimed to determine the circulation (occurrence and exposure) of viruses relevant to swine health in CP and WLP populations, namely classical swine fever virus (CSFV), Aujeszky's disease virus (ADV), swine vesicular disease virus (SVDV), and porcine circoviruses (PCV). The study was conducted in two areas of the northeastern Peruvian Amazon: the Yavarí-Mirín River basin (2008 -2020), where WLPs experienced extreme population fluctuations, and the Pucacuro National Reserve (2012–2014), where no WLP disappearances have been reported. Since WLP is not easily found during population declines, we also sampled CP as an indicator of virus circulation in the area as they are likely to be susceptible to the same pathogens. CSFV and ADV antibodies were detected in both peccary species and both areas. Diseases caused by CSFV and ADV have the potential to act as ultimate causes of population collapse, especially in large WLP populations where overabundance could increase the rate of pathogen transmission. Our results were inconclusive in establishing whether or not these viruses drove the WLP population to collapse, but their potential role warrants deeper investigation, expanding the geographical coverage of studies on infectious diseases in peccaries.

White-lipped peccaries ( ) are key frugivores in Neotropical ecosystems and are classified as a vulnerable species, highlighting the need for safe, evidence-based anesthetic protocols for clinical management and conservation actions. To the best of our knowledge, this is the first study to investigate the effects of different dissociative anesthetic protocols on electrocardiographic and echocardiographic parameters in white-lipped peccaries, as well as to establish preliminary cardiovascular reference values for the species. Sixteen clinically healthy adult males, with a mean body weight of 30.7 kg, were evaluated and subjected to anesthesia with ketamine combined with midazolam administered intramuscularly (IM) or ketamine combined with dexmedetomidine administered either IM or intravenously (IV). Electrocardiographic (ECG) monitoring was performed for 30 min to assess mean heart rate (HR), waveform morphology, and the duration of waves and intervals. Echocardiography (ECHO) was used to measure ventricular dimensions, interventricular septal and myocardial wall thicknesses, as well as left atrial and aortic dimensions. The IM dexmedetomidine protocol resulted in a significant reduction in P wave amplitude compared to the midazolam protocol (  = 0.016), whereas IV administration was associated with a lower T wave amplitude compared to IM dexmedetomidine (  = 0.01) and a lower mean HR when compared to the midazolam group (  = 0.03), in addition to the occurrence of supraventricular and ventricular arrhythmias and second-degree atrioventricular block. No morphological cardiac abnormalities were detected on ECHO; however, a significant reduction in interventricular septal thickness during diastole was observed in the IM dexmedetomidine group (  = 0.01), without statistically significant changes in quantitative parameters. These findings provide the first integrated ECG and ECHO reference values for , supporting safer anesthetic decision-making, improved clinical management, and evidence-based conservation strategies.

Background Research on cancer in wild animals provides important insights into the mechanisms of carcinogenesis. Histiocytic sarcomas comprise a rare malignant macrophage-dendritic cell lineage neoplasm in wildlife. This study reports a case of histiocytic sarcoma in the small intestine of a collared peccary ( Pecari tajacu ), describing its clinical, anatomopathological, and immunohistochemical aspects. Case presentation A six-year-old male collared peccary maintained in captivity at a facility in Northeastern Brazil presented progressive weight loss, diarrhea, anorexia, dyspnea, lethargy, abdominal distension, bristled fur, and pale mucous membranes. A complete blood count indicated a mild degree of anemia and moderate leukocytosis. Treatment included anti-inflammatories and antibiotics; however, on the 18th day after initial presentation, the animal was found dead in its enclosure. An anatomopathological examination revealed that the animal exhibited poor body condition, scant body fat with a gelatinous appearance, hydrothorax, pulmonary edema, and ascites. Thickening of the duodenal wall was observed, along with the presence of a yellowish-white tumor. Histopathological examination of the affected intestinal segment revealed a neoplastic proliferation of round cells with large, hyperchromatic nuclei, prominent nucleoli, and a high mitotic index (20 mitoses per high-power field). Numerous multinucleated and binucleated giant cells were present. The neoplastic cells extensively infiltrated all layers of the intestinal wall, from the mucosa to the serosa. Immunohistochemical analysis showed strong positivity for macrophage/mononuclear phagocytic lineage markers (CD18, IBA-1, and lysozyme), while negative for T-cell (CD3), B-cell (CD79), and plasma cell (MUM1) markers. The proliferation index assessed by Ki-67 was approximately 60%. Conclusions The histopathological and immunohistochemical findings confirmed the diagnosis of intestinal histiocytic sarcoma in a collared peccary, representing the first documented case of this neoplasm in this species.