Niche Partitioning Among White-Lipped Peccaries (Tayassu pecari), Collared Peccaries (Pecari tajacu), and Feral Pigs (Sus Scrofa)

Spatial and Temporal Adaptations of Lowland Tapirs (Tapirus terrestris) to Environmental and Anthropogenic Impacts

The Pantanal is one of the most conserved wetland ecosystems in Brazil and a hotspot for biodiversity. Over the last decades intensification of human activities has become a major threat to the stability of the unique landscape. To establish effective conservation actions, it is essential to understand how species respond to anthropogenic and environmental regional factors. Here, data from two multiannual camera trap studies, one in the northern Pantanal and one in the southern Pantanal, were used to investigate the effects of habitat characteristics, seasons, and human interactions on the spatial and temporal patterns of lowland tapirs (Tapirus terrestris). Between 2010 and 2017, camera traps were repeatedly placed in consistent grids covering protected areas and areas with cattle-ranching and tourism. Data were analyzed using generalized linear mixed models and circular statistics. Activity patterns were similar and predominantly nocturnal in both areas, but tapirs indicated avoidance toward settlements and cattle and indicated habitat preferences only in the northern study area with less anthropogenic activities. The present study suggests that both environmental and anthropogenic factors can affect the species' spatial and temporal behavior, but tapirs show varying responses across regions and gradients of disturbance. The results indicate that adapting avoidance strategies might be more likely and effective in areas with low human pressure and sufficient protected areas as alternatives.

Disappearance of an ecosystem engineer, the white-lipped peccary (Tayassu pecari), leads to density compensation and ecological release

Given the rate of biodiversity loss, there is an urgent need to understand community-level responses to extirpation events, with two prevailing hypotheses. On one hand, the loss of an apex predator leads to an increase in primary prey species, triggering a trophic cascade of other changes within the community, while density compensation and ecological release can occur because of reduced competition for resources and absence of direct aggression. White-lipped peccary (Tayassu pecari—WLP), a species that typically co-occurs with collared peccary (Pecari tajacu), undergo major population crashes—often taking 20 to 30-years for populations to recover. Using a temporally replicated camera trapping dataset, in both a pre- and post- WLP crash, we explore how WLP disappearance alters the structure of a Neotropical vertebrate community with findings indicative of density compensation. White-lipped peccary were the most frequently detected terrestrial mammal in the 2006–2007 pre-population crash period but were undetected during the 2019 post-crash survey. Panthera onca (jaguar) camera trap encounter rates declined by 63% following the WLP crash, while collared peccary, puma (Puma concolor), red-brocket deer (Mazama americana) and short-eared dog (Atelocynus microtis) all displayed greater encounter rates (490%, 150%, 280%, and 500% respectively), and increased in rank-abundance. Absence of WLP was correlated with ecological release changes in habitat-use for six species, with the greatest increase in use in the preferred floodplain habitat of the WLP. Surprisingly, community-weighted mean trait distributions (body size, feeding guild and nocturnality) did not change, suggesting functional redundancy in diverse tropical mammal assemblages.

Beyond transcortical channels, a supra-parietal vascular plexus: A newly recognized anatomical feature

Survey of trans-cortical channels across mammalian phylogeny exposes a previously unrecognized phenomena, localized to the most caudal third of a Sus scrofa parietal. The current study is performed to assess the nature, ontogeny and phylogenetic distribution of this phenomenon. Dissection of a fresh Sus scrofa is performed to characterize the nature of these structures and assess the relationship of the phenomenon to overlying tissues. The external surface of the parietal region of the skulls of recent Artiodactyla, Perissodactyla, Lagomorpha and Rodentia and Pleistocene Platygonus compressus are systematically examined by surface microscopy. Dissection of the parietal region of a Sus scrofa head revealed a structure localized to the most caudal third of the parietal bone. It is composed of anastomosing blood vessels interposed between the dermis and bone. The phenomenon is present among Artiodactyla in all examined Suidae and Tayassuidae, but limited among Cervidae to Odocoileus and apparently limited among Perissodactyla to Tapiridae, both extant and extinct and independent of sex and age. A previously undescribed anatomic structure is observed during survey of trans-cortical parietal circulation. There is connection between the structure and parietal diploic vessels. Interpreted as a vascular plexus, the possibility of a countercurrent system for brain thermoregulation is considered.

Medium and large-sized mammals of a private protected wetland in the Cerrado-Amazon biological corridor, Brazil

Brazil is the world's richest country in biodiversity, including mammal species. In the Brazilian Cerrado biome, mammalian diversity is vast, with about 251 species, 32 of them are endemic and 22 listed as threatened species. In this work, we investigated species diversity of medium- and large-sized mammals in the private protected area RPPN Pontal do Jaburu (RPPN-PJ) and its surroundings, which is a flooded area located in an important biological corridor in the Cerrado-Amazon ecotone zone, a priority area for biodiversity conservation in Brazil. We used camera-trapping, active search (night and day), and track survey during dry season (Apr - Aug 2016). We recorded 29 mammal species, being the Carnivora order the most representative with 11 species. Regarding threat status, 35.7% of the recorded species were listed as threatened in Brazil and 32.1% worldwide. We highlight the high relative frequency of threatened species records such as Tapirus terrestris, Panthera onca, Blastocerus dichotomus, Pteronura brasiliensis, Priodontes maximus, and other, as well as the presence of the newly described aquatic mammal species Inia araguaiaensis. We stress the importance of RPPN-PJ and its surroundings for mammal conservation, which include complex habitats (wetlands) located in an important ecotone zone.

The global impact of wild pigs (Sus scrofa) on terrestrial biodiversity

The International Union for the Conservation of Nature’s (IUCN) Red List of Threatened Species is a comprehensive database of over 120,000 species and is a powerful tool to evaluate the threat of invasive species to global biodiversity. Several problematic species have gained global recognition due to comprehensive threat assessments quantifying the threat these species pose to biodiversity using large datasets like the IUCN Red List of Threatened Species. However, the global threat of wild pigs (Sus scrofa) to biodiversity is still poorly understood despite well-documented ecosystem level impacts. In this study, we utilized the IUCN Red List to quantify the impacts of this globally distributed species throughout its native and non-native range. Here we show that wild pigs threaten 672 taxa in 54 different countries across the globe. Most of these taxa are listed as critically endangered or endangered and 14 species have been driven to extinction as a direct result of impacts from wild pigs. Our results show that threats from wild pigs are pervasive across taxonomic groups and that island endemics and taxa throughout the non-native range of wild pigs are particularly vulnerable.

Hepatitis E Virus (HEV) infection in captive white-collared peccaries (Pecari tajacu) from Uruguay

Hepatitis E virus (HEV) infection is a major cause of acute hepatitis worldwide. Clinical presentation of hepatitis E mainly occurs as an acute and self-limited disease, though chronic cases are now being commonly reported in immunocompromised individuals. In high-income developed areas and non-endemic regions, HEV is mainly transmitted by the zoonotic route through direct contact with infected animals or by consumption of contaminated meat products. Although pigs and wild boars are the main reservoirs of the disease, HEV can also infect deer, camels, and rats and seems to have an ever-expanding host range. Peccaries (Tayassuidae family, superfamily Suoidea), the 'new world pigs', share susceptibility to several pathogens with domestic pigs and wild boars. Herein, we performed a serological and molecular survey of two captive populations of white-collared peccaries (Pecari tajacu) from Uruguay, with the aim to assess the role of the species as an HEV reservoir. One-hundred and one serum samples were analysed for anti-HEV antibodies. Further evidences of active HEV infection were investigated in stool by RT-nested PCR. Animals from both wildlife reserves were exposed to HEV with an overall prevalence of 24.7%. Moreover, HEV RNA could be detected in peccaries' stool samples from one of the reserves. Phylogenetic analysis clustered the strains within HEV-3, closely related to both human and swine isolates. Our work provides the first evidences supporting the notion that white-collared peccaries are susceptible to HEV. However, these data should not be overinterpreted. Further research is needed concerning the role of peccaries in the transmission of HEV.

Who's afraid of the big bad boar? Assessing the effect of wild boar presence on the occurrence and activity patterns of other mammals

Wild boar are considered one the world’s worst invasive species and linked to biodiversity loss, competition for resources, predation of native species, and habitat modifications. In this study, we use camera traps to evaluate whether the invasive wild boar had an effect on the medium-sized mammal community of a protected area in southern Brazil. Based on photographic records, we evaluated whether the presence and relative abundance of wild boar was associated with a decrease in diversity or change in activity of medium-sized mammals. All comparisons were made between samples where wild boar were present or absent. The records of each camera during a season were considered a sample. The wild boar was the fourth most common species in the study area being present in 7.8% of the photographic records. The species richness of mammals was not negatively affected by the occurrence of wild boar and most common species did not exhibit changes in the daily activity pattern. However, we recorded an increase in the time elapsed between an observation of wild boar and the record of the next species relative to the average latency period observed among other mammalian species. This average latency period was similar to that observed in the case of large predators such as Puma, and its increase could be reflective partly of the avoidance of native species to wild boar. Nevertheless, our results show that the effect of invasive wild boar on the mammal community is not large as expected.

Dominance hierarchy on palm resource partitioning among Neotropical frugivorous mammals

In tropical forests, the diets of many frugivorous mammals overlap, yet how hyper-diverse assemblages of consumers exploit resources and coexist remains poorly understood. We evaluated competitive interactions among three species of terrestrial frugivorous mammals, the ungulate Tayassu pecari (white-lipped peccary), its close relative Pecari tajacu (collared peccary), and a large rodent (Dasyprocta azarae, agouti), in their exploitation strategies of palm resources of different quality. We conducted the study in a large isolated fragment at the tropical Atlantic Forest of Brazil, where these mammal species show high spatial and temporal overlap. We evaluated if body mass and foraging group size define a hierarchy in exploitation of preferentially richer palm resources. We used camera traps and two-species occupancy models to examine patterns of co-occurrence and variable interaction strength between these consumers and three species of palms. Our analyses supported the hypothesis of partial resource overlap but no competition among frugivores, and a body mass dominance hierarchical exploitation of resources. The larger frugivore (white-lipped peccary) dominated patches of the lipid-rich palm Euterpe edulis, where the smallest frugivore (agouti) was absent. Instead, the smallest frugivore concentrated its foraging in areas with the poorest palm resource, Syagrus oleracea. Collared peccaries preferred areas of high abundance of Syagrus romanzoffiana when the other two mammal species were rarely detected or absent, strongly avoided patches of E. edulis, and showed higher average detection probabilities when agoutis were present. Our study highlights the important role of behavioral plasticity in promoting coexistence and indicates that through context-dependent interactions and hierarchical partitioning of resources, consumers can avoid strong competition, even under conditions of high spatial and temporal overlap and high levels of habitat fragmentation and isolation.

87Sr/86Sr and 14C evidence for peccary (Tayassuidae) introduction challenges accepted historical interpretation of the 1657 Ligon map of Barbados

Contemporary West Indian biodiversity has been shaped by two millennia of non-native species introductions. Understanding the dynamics of this process and its legacy across extended temporal and spatial scales requires accurate knowledge of introduction timing and the species involved. Richard Ligon’s 17^th century account and celebrated map of early colonial Barbados records the translocation of several Old World species to the island in the post-contact era, including pigs (Sus scrofa) believed to have been released by passing sailors the century prior. Here we challenge this long-accepted historical narrative, presenting evidence that Ligon’s “pigs” were in fact peccaries, a New World continental mammal often confused with wild boars. We document the first recorded instance of non-native peccary (Tayassuidae) on Barbados based on a securely identified mandibular specimen from a historic archaeological context. Results of specimen ⁸⁷Sr/⁸⁶Sr and AMS radiocarbon assays, along with newly reported data from Sr isotope environmental analyses, indicate a local origin dating to AD 1645–1670/1780–1800. These data support the presence of living peccary on Barbados some time during the first 175 years of English settlement, which, based on review of historical and archaeological data, most likely arises from 16^th century peccary introduction from the Guianas/Trinidad by the Spanish or Portuguese. We argue dimorphic representations of “pigs” on Ligon’s map reflect the co-occurrence of peccary and European domestic swine on historic Barbados. Our findings overturn conventional history and provide greater taxonomic and chronological resolution for Caribbean bioinvasion studies, helping to refine our understanding of potential ecological impacts. In addition, the new bioavailable ⁸⁷Sr/⁸⁶Sr data for Barbados reported here advance current efforts toward mapping the Caribbean Sr isoscape.

Molecular detection of Mycoplasma suis in captive white-lipped peccaries (Tayassu pecari) and wild boars (Sus scrofa) in Brazil

Mycoplasma suis, the etiological agent of swine hemoplasmosis, is an epicellular bacterium that adheres to the surface of pig erythrocytes leading to deformations of the target cells. Little is known about the occurrence of M. suis in wild swine populations around the world, its economic impact on swine herds, and the risk of human infection. The aim of this study was to investigate, by quantitative real-time PCR (qPCR) based on the 16S rRNA gene, the occurrence of M. suis in a captive population of white-lipped peccaries (100 Tayassu pecari) and in free-living wild boars (14 Sus scrofa) in Brazil. None of the white-lipped peccaries were positive for M. suis, whereas seven (50%) wild boars were positive in qPCR assays. The quantification of M. suis-16S rRNA copies/μL ranged from 1.42 × 10° to 3.906 × 10¹ in positive animals, indicating a low bacteremia and a chronic carrier status in free-living wild boars. In conclusion, M. suis might be a non-frequent pathogen in wild suids maintained in captivity. Despite the low bacteremia, the prevalence of M. suis in wild boar population in Brazil seems to be high.

Collared peccary (Pecari tajacu) are susceptible to porcine reproductive and respiratory syndrome virus (PRRSV)

Collared peccary (Pecari tajacu) and pigs (Sus scrofa) are two members of superfamily Suoidea that coexist in the Americas and share some of the same viral infections. Although porcine reproductive and respiratory syndrome virus (PRRSV) is among the most impactful pathogens of swine on a worldwide basis, the susceptibility of peccaries to PRRSV has not been investigated. In this study, three peccaries were intramuscularly inoculated with a PRRSV-2 field virus. One PRRSV-inoculated pig served as a positive control and two pigs and one peccary as negative controls. Serum samples were collected at regular intervals over a 23-day observation period and tested by PRRSV rtRT-PCR and isotype-specific (IgM, IgA, IgG) PRRSV ELISAs. The detection of viremia (DPI 3-23) and a PRRSV-specific humoural immune response (≥DPI 10) supported the conclusion that collared peccary are susceptible to PRRSV. The results raise questions regarding the natural history of PRRSV in non-Sus members of superfamily Suoidea and, more broadly, their role in the evolution and ecology of PRRSV.

A globally-distributed alien invasive species poses risks to United States imperiled species

In the midst of Earth’s sixth mass extinction event, non-native species are a driving factor in many imperiled species’ declines. One of the most widespread and destructive alien invasive species in the world, wild pigs (Sus scrofa) threaten native species through predation, habitat destruction, competition, and disease transmission. We show that wild pigs co-occur with up to 87.2% of imperiled species in the contiguous U.S. identified as susceptible to their direct impacts, and we project increases in both the number of species at risk and the geographic extent of risks by 2025. Wild pigs may therefore present a severe threat to U.S. imperiled species, with serious implications for management of at-risk species throughout wild pigs’ global distribution. We offer guidance for efficient allocation of research effort and conservation resources across species and regions using a simple approach that can be applied to wild pigs and other alien invasive species globally.

Achilles heel of a powerful invader: restrictions on distribution and disappearance of feral pigs from a protected area in Northern Pantanal, Western Brazil

This paper focuses on a rare case of natural disappearance of feral pigs (Sus scrofa) in an extensive area without using traditional methods of eradication programs. The study was conducted both in the Private Reserve of Natural Heritage (PRNH) Sesc Pantanal and in an adjacent traditional private cattle ranch. In 1998, feral pigs were abundant and widely distributed in the PRNH. However, the feral pigs gradually disappeared from the area and currently, the absence of pigs in the PRNH contrasts with the adjacent cattle ranch where the species is abundant. To understand the current distribution of the species in the region we partitioned the effects of variation of feral pigs' presence considering the habitat structure (local), landscape composition and the occurrence of potential predators. Additionally, we modeled the distributions of the species in Northern Pantanal, projecting into the past using the classes of vegetation cover before the PRNH implementation (year 1988). Our results show areas with more suitability for feral pigs in regions where the landscape is dominated by pastures and permeated by patches of Seasonal Dry Forest. The species tends to avoid predominantly forested areas. Additionally, we recorded that the environmental suitability decreases exponentially as the distance from water bodies increases. The disappearance of feral pigs in the PRNH area seems to be associated with changes in the landscape and vegetation structure after the removal of the cattle. In the Brazilian Pantanal, the feral pigs' occurrence seems strongly conditioned to environmental changes associated to livestock activity.

Caracterização histomorfológica do sistema tegumentar auricular de cateto - Pecari tajacu Linnaeus, 1758)

RESUMO A criopreservação de tecido somático derivado da pele de catetos consiste numa alternativa para a conservação da biodiversidade por meio da associação com a transferência nuclear. Nesse contexto, a manipulação de tecidos da pele é uma etapa crucial para o sucesso dessa biotécnica. Portanto, o objetivo do presente estudo, foi caracterizar o sistema tegumentar auricular periférico de catetos, visando aprimorar a conservação tecidual. Para tanto, fragmentos auriculares de oito animais foram avaliados quanto às camadas teciduais, aos componentes, à atividade proliferativa e à viabilidade metabólica, usando-se as colorações hematoxilina-eosina e tricrômico de Gomori, quantificação de AgNORs e microscopia eletrônica de transmissão. Assim, tamanhos de 104,2µm e 222,6µm foram observados para epiderme e derme, com uma proporção volumétrica de 36,6% e 58,7%, respectivamente. Além disso, na epiderme, foram evidenciadas as camadas basal (22,5µm), intermediárias (53,5µm) e córnea (28,2µm), com valores médios de 65,3 células epidermais, 43,4 melanócitos e 14,8 halos perinucleares. Já a derme apresentou 127 fibroblastos, com 2,5 AgNORs/nucléolo. Adicionalmente, a atividade metabólica foi de 0,243. Em conclusão, o sistema tegumentar auricular periférico de catetos possui algumas marcantes variações em relação a outros mamíferos, quanto ao número de camadas e espessura da epiderme, quantidade de células epidermais, melanócitos e parâmetros proliferativos.

The partitioning of food resources between two rodents in the subtropical region of southern Brazil

The capybara (Hydrochoerus hydrochaeris) and nutria (Myocastor coypus) are herbivorous semi-aquatic rodents. Although these rodents occur in sympatry in southern South America, little is known about how the two species interact in relationship to food resources. In this context, the aim of this study was to analyze the food resource overlap, the feeding strategy and the diversity of the diet of capybaras and nutria. A micro-histological analysis of feces was used to study the diets. A total of 48 plant species belonging to 10 families were identified in the diet of H. hydrochaeris, and a total of 49 species belonging to 14 families were identified in the diet of M. coypus. According to the Amundsen graphical method, both rodents adopted a specialized strategy for feeding on Poaceae and a generalized strategy for other families. The results of a multivariate analysis of the dietary data showed significant differences between the two rodent species and among the seasons. These differences between diets may be related to the different proportions of each food item eaten. However, the dietary overlap between the two rodents in the Taim wetland was high, suggesting that partitioning of other resources ensured the coexistence of the species.

Biotic and abiotic factors predicting the global distribution and population density of an invasive large mammal

Biotic and abiotic factors are increasingly acknowledged to synergistically shape broad-scale species distributions. However, the relative importance of biotic and abiotic factors in predicting species distributions is unclear. In particular, biotic factors, such as predation and vegetation, including those resulting from anthropogenic land-use change, are underrepresented in species distribution modeling, but could improve model predictions. Using generalized linear models and model selection techniques, we used 129 estimates of population density of wild pigs (Sus scrofa) from 5 continents to evaluate the relative importance, magnitude, and direction of biotic and abiotic factors in predicting population density of an invasive large mammal with a global distribution. Incorporating diverse biotic factors, including agriculture, vegetation cover, and large carnivore richness, into species distribution modeling substantially improved model fit and predictions. Abiotic factors, including precipitation and potential evapotranspiration, were also important predictors. The predictive map of population density revealed wide-ranging potential for an invasive large mammal to expand its distribution globally. This information can be used to proactively create conservation/management plans to control future invasions. Our study demonstrates that the ongoing paradigm shift, which recognizes that both biotic and abiotic factors shape species distributions across broad scales, can be advanced by incorporating diverse biotic factors.

Incorporating animal spatial memory in step selection functions

Memory is among the most important and neglected forces that shapes animal movement patterns. Research on the movement-memory interface is crucial to understand how animals use spatial learning to navigate across space because memory-based navigation is directly linked to animals' space use and home range behaviour; however, because memory cannot be measured directly, it is difficult to account for. Here, we incorporated spatial memory into step selection functions (SSF) to understand how resource selection and spatial memory affect space use of feral hogs (Sus scrofa). We used Biased Random Bridge kernel estimates linked to residence time as a surrogate for memory and tested four conceptually different dynamic maps of spatial memory. We applied this memory-based SSF to a data set of hog relocations to evaluate the importance of land cover type, time of day and spatial memory on the animals' space use. Our approach has shown how the incorporation of spatial memory into animal movement models can improve estimates of habitat selection. Memory-based SSF provided a feasible way to gain insight into how animals use spatial learning to guide their movement decisions. We found that while hogs selected forested areas and water bodies and avoided grasslands during the day (primarily at noon), they had a strong tendency to select previously visited areas, mainly those held in recent memory. Beyond actively updating their memory with recent experiences, hogs were able to discriminate among spatial memories encoded at different circadian phases of their activity. Even though hogs are thought to have long memory retention, they likely relied on recent experiences because the local food resources are quickly depleted and slowly renewed, yielding an uncertain spatial distribution of resources.

Diet Overlap and Foraging Activity between Feral Pigs and Native Peccaries in the Pantanal

Inter-specific competition is considered one of the main selective pressures affecting species distribution and coexistence. Different species vary in the way they forage in order to minimize encounters with their competitors and with their predators. However, it is still poorly known whether and how native species change their foraging behavior in the presence of exotic species, particularly in South America. Here we compare diet overlap of fruits and foraging activity period of two sympatric native ungulates (the white-lipped peccary, Tayassu pecari, and the collared peccary, Pecari tajacu) with the invasive feral pig (Sus scrofa) in the Brazilian Pantanal. We found high diet overlap between white-lipped peccaries and feral pigs, but low overlap between collared peccaries and feral pigs. Furthermore, we found that feral pigs may influence the foraging period of both native peccaries, but in different ways. In the absence of feral pigs, collared peccary activity peaks in the early evening, possibly allowing them to avoid white-lipped peccary activity peaks, which occur in the morning. In the presence of feral pigs, collared peccaries forage mostly in early morning, while white-lipped peccaries forage throughout the day. Our results indicate that collared peccaries may avoid foraging at the same time as white-lipped peccaries. However, they forage during the same periods as feral pigs, with whom they have lower diet overlap. Our study highlights how an exotic species may alter interactions between native species by interfering in their foraging periods.

Serological and molecular investigation of the prevalence of Aujeszky's disease in feral swine (Sus scrofa) in the subregions of the Pantanal wetland, Brazil

The feral swine (FS) originated from the domestic pig and is present throughout the Brazilian wetland plain (the Pantanal). Aujeszky's disease (AD) was first serologically confirmed in the state of Mato Grosso do Sul (MS) in 2001; however, there was no viral confirmation. The aim of this study was to investigate antibodies against-SuHV-1 in the sera of feral swine in the studied areas, detect SuHV-1 through PCR and classify the viral genome. Among the 218 animals sampled, 186 were analyzed by ELISA, resulting in 88 (47.3%) reactive samples. In the serum neutralization test (SN), 57/179 (31.8%) samples presented antibodies against the AD virus (SuHV-1). By nested PCR, 104 DNA samples were extracted for analysis and confirmed with amplification of a fragment of glycoprotein B (gB) in five samples. The SuHV-1 was detected in 12 samples by using primers for glycoprotein E (gE) and viral genome was classified as Type I by ul44 partial sequencing. The amplification of SuHV-1 glycoprotein fragments in the fetuses of seropositive sows indicate that the vertical transmission contribute to maintain SuHV-1 in a free-living feral swine population. The origin of AD in the feral swine populations of the Pantanal is unknown, however, the determination of viral latency, the vertical transmission of the antigen by the amplification of SuHV-1 glycoprotein fragments in the fetuses of seropositive sows and genome typing contribute to the elucidation of the epidemiology of this disease in the wetlands of MS, Brazil.

Range-wide declines of a key Neotropical ecosystem architect, the Near Threatened white-lipped peccary Tayassu pecari

We report a range-wide status assessment of a key Neotropical ecosystem architect, the white-lipped peccary Tayassu pecari, categorized as Near Threatened on the IUCN Red List, using published information and unpublished data from 41 scientists in 15 range countries. We estimate that the white-lipped peccary has been extirpated in 21% of its historical range over the last 100 years, with reduced abundance and a low to medium probability of long-term survival in another 48% of its current range. We found major range declines in Argentina, Paraguay, southern Brazil, Colombia, Venezuela, north-east Brazil, Mexico and Costa Rica. This species is particularly at risk in more xeric ecosystems, especially the caatinga, cerrado and pampas. Hunting and habitat destruction are the most severe threats, although there are also unexplained sudden die-offs suggestive of disease. We evaluate our results in light of this species’ important interspecific interactions and its role as an ecosystem architect. One of our recommendations is that conservation efforts should focus on landscape conservation of large, continuous and ecologically intact areas containing a mosaic of different habitat types.

No evidence of interference competition among the invasive feral pig and two native peccary species in a Neotropical wetland

In South America, the invasive feral pig (Sus scrofa Linnaeus) has become established in Argentina, Uruguay, Paraguay and in a wide range within Brazil, along the southern half of the Atlantic Forest, in the cerrado (savanna) and in the Pantanal wetland. The geographical ranges of the two most common South American native peccary (Tayassu pecari Link and Pecari tajacu Linnaeus) overlap almost entirely, and the feral pig now co-occurs with them in several areas. Because feral pig, white-lipped and collared peccary are considered ecological equivalents, there has been much speculation about possible competitive interactions among them (Desbiez et al. 2009, Sicuro & Oliveira 2002).

Introduced species in the Pantanal: implications for conservation

Land use and human occupation within the natural habitats of the Pantanal have facilitated introduction of invasive species of plants and animals, including domestic species. Exotic species threaten regional biodiversity because they modify ecological community structure, alter natural habitats and affect local biodiversity. An international organisation, the International Union for Conservation of Nature (IUCN), and the Brazilian government, identify invasive species as the third most important threat to biodiversity, following habitat loss and direct effect on species. In addition, exotic species carry pathogens or may function as vectors or reservoirs for diseases that affect regional biota.

Invasive species and bushmeat hunting contributing to wildlife conservation: the case of feral pigs in a Neotropical wetland

An unusual combination of two major conservation threats, invasive species and bushmeat hunting, has had a positive outcome for wildlife conservation in the Brazilian Pantanal. The Pantanal is a wetland and one of the few non-protected areas in the Neotropics where people live but rarely hunt native wildlife. To understand why wildlife hunting is not a major conservation issue in the Pantanal an exploratory survey, semi-structured interviews, skull collection and tooth wear analysis of feral pig Sus scrofa, white-lipped peccary Tayassu pecari and collared peccary Pecari tajacu were conducted, and hunting registers distributed, in the central region of the Pantanal. The results showed that feral pigs are the main hunting target. Feral pigs are effectively acting as a replacement species for hunting of native wildlife because the pigs provide a constant, culturally acceptable, readily available and free source of meat and oil to remote ranches. We cannot evaluate, however, if the buffer from hunting that feral pigs provide to native wildlife outweigh this species’ potential negative ecological impacts.