Crab-eating Fox Cerdocyon Thous Research Articles

Review of the diet for <i>Cerdocyon thous</i> (Carnivora: Canidae), and the first record of <i>Bothrops moojeni</i> (Serpentes: Viperidae) as prey

The crab-eating fox Cerdocyon thous has a diverse diet ranging from plants to vertebrates, but its diet has never been comprehensively reviewed. Here, we provide the first such review and report the first-ever record of C. thous feeding on the Brazilian lancehead Bothrops moojeni, although other Bothrops species have been documented in the diet of this fox species.

Breeding Biology of the Endangered Burrow-Nesting Lesser Crescent-Chested Puffbird Malacoptila minor

For many birds breeding success may be related to the availability of nesting sites, particularly in ecologically specialized cavity-nesting birds. For burrow-nesting species, the selection of an appropriate substrate may be fundamental to a successful breeding attempt. The Lesser Crescent-chested Puffbird Malacoptila minor is a bucconid with a restricted distribution, which is found in the states of Maranhão and Piauí, in northeastern Brazil. It is the only bucconid listed as threatened with extinction, and little is known about its natural history. A total of 49 nests were found over three breeding seasons (2017–2020). Nests consist of burrows dug in the ground that are used only once for breeding. Incubation lasted 21.2 ± 1.3 days and the nestlings fledged after 19.5 ± 2.9 days. The nests contained two or three eggs. The mean hatching rate was 0.46 ± 0.47 eggs per nest and the fecundity rate was 1.0 fledgling per female. The production was 0.53 fledglings per nest, apparent reproductive success was 22.4% (N = 49), and was 15.7% (N = 49) when based on Mayfield's protocol. The probability of breeding success per period was greater during the incubation phase than during the nestling phase. Predation was identified as the principal cause of nest failure (77.5%), mainly during the incubation phase. Three predators were identified: the Crab-eating Fox Cerdocyon thous, the fire ant Solenopsis saevissima, and a lizard, the Common Tegu Salvator merianae. Breeding season starts with the onset of rainy season and nest flooding did not appear to be a concern, which contrasts with the available data on other bucconids. The results of the present study are the first data on the breeding biology of the Lesser Crescent-chested Puffbird, and represent an important advance in the understanding of breeding patterns in the Bucconidae.

Variation in the prevalence and abundance of acanthocephalans in brown-nosed coatis Nasua nasua and crab-eating foxes Cerdocyon thous in the Brazilian Pantanal.

Host infection by parasites is influenced by an array of factors, including host and environmental features. We investigated the relationship between host sex, body size and age, as well as seasonality on infection patterns by acanthocephalan in coatis (Procyonidae: Nasua nasua) and in crab-eating foxes (Canidae: Cerdocyon thous ) from the Brazilian Pantanal wetlands. Between 2006 and 2009, we collected faecal samples from these hosts and analyzed for the presence of acanthocephalan eggs. Prevalence, abundance and intensity of eggs of acanthocephalans were calculated. Egg abundance was analyzed using generalized linear models (GLM) with a negative binomial distribution and models were compared by Akaike criteria to verify the effect of biotic and abiotic factors. Prevalence of acanthocephalans was higher in the wet season in both host species but did not differ between host sexes; however, adult crab-eating foxes showed higher prevalence of acanthocephalan eggs than juveniles. In contrast, prevalence of acanthocephalan eggs found in coatis was higher in coati juveniles than in adults. Host age, season and maximum temperature were the top predictors of abundance of acanthocephalan eggs in crab-eating foxes whereas season and host sex were predictors of egg abundance in coatis. The importance of seasonality for abundance of acanthocephalan was clear for both host species. The influence of host-related attributes, however, varied by host species, with host gender and host age being important factors associated with prevalence and parasite loads.

Are pioneering coyotes, foxes and jackals alien species? Canid colonists in the changing conservation landscape of the Anthropocene

AbstractThe pervasive influence of human agency on biodiversity in the Anthropocene gives rise to several new challenges for national and international wildlife law, including questions regarding what is natural and what is alien. Ultimately, a new vision and new rules are called for but in the meantime wildlife lawyers and other conservation professionals must work with conventional legal frameworks. Striking instances where vexing issues arise are the recent range expansions of certain canids. Coyotes Canis latrans and crab-eating foxes Cerdocyon thous in the Americas and golden jackals Canis aureus in Europe are progressively colonizing areas and countries where they did not previously occur. A key question is whether to consider this as acceptable extensions of natural range or whether the pioneering carnivores should be viewed as alien species, potentially triggering legal obligations of prevention, control and eradication. In addressing this question we draw on guidance provided under the Convention on Biological Diversity and other international legal frameworks, in which governments are forced to grapple with the application of long-standing concepts to new phenomena in an era of profound global change. Our analysis suggests that coyotes in Costa Rica, crab-eating foxes in Panama, and golden jackals in the Netherlands are not to be considered alien species, whether invasive or not. Thus, even if action to address adverse impacts by these canids on native biodiversity may sometimes be desirable, these species are not subject to legal requirements to combat invasive alien species.

Diet and habitat use by two sympatric canids in the Pampas of South America

The crab-eating fox (Cerdocyon thous) and the Pampas fox (Lycalopex gymnocercus) are two canids with very similar food and habitat requirements, which live in sympatry across parts of their distributions. Here we describe the diet and habitat use of both canids in the Pampas biome. The study took place in southern Brazil from December 2012 to December 2013. Diet and habitat use analyses were based on fecal samples, footprints and direct visualizations. Diet overlap was measured using Pianka’s index, while habitat use was measured using presence records from three different environments; forests, edges and open areas. Both canids feed on invertebrates and vertebrates but have preferences for fruits, especially Syagrus romanzoffiana. Pianka’s index showed a high overlap of their diets throughout the year, with the exception of autumn. Regarding habitat use, C. thous preferred to inhabit forested areas while L. gymnocercus was more active in open areas. Our results showed that fruits were the most consumed food item in the Pampas biome. Our findings suggest that habitat use by these two canids is affected by seasonal variation in fruit abundance, but other factors, such as parental care, should be taken into account when explaining how they behave throughout the year.

Human perceptions of and interactions with wild canids on cattle ranches in central Brazil

AbstractLocal attitudes towards carnivores often reflect the degree of damage they are perceived to cause. Consequently, understanding the interactions between people and these species is essential to conservation efforts. This study investigated local perceptions of three Cerrado canid species and current chicken management practices, to identify the potential damage they cause and how this relates to peoples’ attitudes towards these species. Results from structured interviews at 50 ranches in Goiás, Brazil, highlighted that general knowledge about Cerrado canids differed significantly by species, with interviewees unable to correctly answer questions about the hoary fox Lycalopex vetulus and crab-eating fox Cerdocyon thous in comparison to the maned wolf Chrysocyon brachyurus. Chicken coops were identified as the most effective method for preventing predation, yet only 44% of respondents employed this method. Using a perceived predation measure, interviewees reported chicken predation by all three Cerrado canids even though most of these events were stated to occur during the day, outside the species’ active periods. Reported predation events were a strong predictor of attitude. Participants who experienced predation events reported they did not like having a Cerrado canid on their property. However, 86% of the respondents agreed that Cerrado canids should nevertheless be protected. Our findings support the need to incorporate the human dimension in canid and broader carnivore conservation issues.

ATLANTIC-CAMTRAPS: a dataset of medium and large terrestrial mammal communities in the Atlantic Forest of South America.

Our understanding of mammal ecology has always been hindered by the difficulties of observing species in closed tropical forests. Camera trapping has become a major advance for monitoring terrestrial mammals in biodiversity rich ecosystems. Here we compiled one of the largest datasets of inventories of terrestrial mammal communities for the Neotropical region based on camera trapping studies. The dataset comprises 170 surveys of medium to large terrestrial mammals using camera traps conducted in 144 areas by 74 studies, covering six vegetation types of tropical and subtropical Atlantic Forest of South America (Brazil and Argentina), and present data on species composition and richness. The complete dataset comprises 53,438 independent records of 83 species of mammals, includes 10 species of marsupials, 15 rodents, 20 carnivores, eight ungulates and six armadillos. Species richness averaged 13 species (±6.07 SD) per site. Only six species occurred in more than 50% of the sites: the domestic dog Canis familiaris, crab-eating fox Cerdocyon thous, tayra Eira barbara, south American coati Nasua nasua, crab-eating raccoon Procyon cancrivorus and the nine-banded armadillo Dasypus novemcinctus. The information contained in this dataset can be used to understand macroecological patterns of biodiversity, community, and population structure, but also to evaluate the ecological consequences of fragmentation, defaunation, and trophic interactions.

Increasing potential risk for American visceral leishmaniasis in Amapá, Brazil.

The present note discusses some evidence on the increasing potential risk for American visceral leishmaniasis (AVL) transmission in the Northern Brazilian State of Amapá, the Guianan-Amazon biome. Early and present data about AVL were collected, including our recent entomological findings. The spread of the sand fly vector Lutzomyia longipalpis, and a sylvatic reservoir host, the crab-eating fox Cerdocyon thous in that region represents important findings related to the epidemiology of AVL in the Guianan-Amazon biome. These observations suggest that Brazilian authorities need to develop surveillance strategies in these risk areas.

Niche Partitioning among Mesocarnivores in a Brazilian Wetland.

We investigated the home range size, habitat selection, as well as the spatial and activity overlap, of four mid-sized carnivore species in the Central Pantanal, Mato Grosso do Sul, Brazil. From December 2005 to September 2008, seven crab-eating foxes Cerdocyon thous, seven brown-nosed coatis Nasua nasua, and six ocelots Leopardus pardalis were radio-collared and monitored. Camera trap data on these species were also collected for the crab-eating raccoon Procyon cancrivorus. We hypothesized that there would be large niche differentiation in preferred habitat-type or active period between generalist species with similar diet, and higher similarity in habitat-type or activity time between the generalist species (crab-eating foxes and coatis) and the more specialized ocelot. Individual home ranges were estimated using the utilization distribution index (UD– 95% fixed Kernel). With data obtained from radio-collared individuals, we evaluated habitat selection using compositional analysis. Median home range size of ocelots was 8 km2. The proportion of habitats within the home ranges of ocelots did not differ from the overall habitat proportion in the study area, but ocelots preferentially used forest within their home range. The median home range size of crab-eating foxes was 1.4 km2. Foxes showed second-order habitat selection and selected savanna over shrub-savanna vegetation. The median home range size for coati was 1.5 km2. Coati home ranges were located randomly in the study area. However, within their home range, coatis occurred more frequently in savanna than in other vegetation types. Among the four species, the overlap in activity period was the highest (87%) between ocelots and raccoons, with the least overlap occurring between the ocelot and coati (25%). We suggest that temporal segregation of carnivores was more important than spatial segregation, notably between the generalist coati, crab-eating fox and crab-eating raccoon.

Dissimilar responses of the Gray brocket deer (Mazama gouazoubira), Crab-eating fox (Cerdocyon thous) and Pampas fox (Lycalopex gymnocercus) to livestock frequency in subtropical forests of NW Argentina

This study represents the first analysis of livestock influence over individual mammal species in NW Argentina forests. Through camera-trapping, I found a negative correlation between frequencies of occurrence of livestock (sheep, goats and cattle) and Gray brocket deer Mazama gouazoubira, and a modification of the daily activities patterns of the latter according to changes in density of the former. However, no evident associations between Crab-eating fox Cerdocyon thous and Pampas fox Lycalopex gymnocercus frequencies and livestock were found. This study provides insights on the effects of extensive ranching over mammal species in NW forests of Argentina, where this activity is of major importance among forests inhabitants.

HOW LANDSCAPE PATTERNS INFLUENCE ROAD-KILL OF THREE SPECIES OF MAMMALS IN THE BRAZILIAN SAVANNA

Roads are one of the main threats to mammal species conservation. Identifying relationships between landscape and road-kill patterns is necessary to build predictive models and to propose mitigation measures, particularly in heterogeneous landscapes. We choose three species of medium-sized mammals with high dispersal capacity and opportunistic habitat use as representatives to understand which landscape features affect road-kills: the crab-eating fox Cerdocyon thous , the maned-wolf Chrysocyon brachyurus , and the hare Lepus europaeus. The study was done over two consecutive years on the SP-225 highway in the State of Sao Paulo, southeastern Brazil. Road-kill data were collected on a daily basis, every three hours, by car travelling at 50-60 km/h. We used a logistic regression considering, as dependent variable, the occurrence of road-kills for each species, and as independent variables, the following landscape features: sugarcane fields cover, pasture cover, native vegetation cover, forestry cover, orange groves cover, urban area, and distance to the nearest river. Three buffer sizes were created around each road-kill occurrence to evaluate the effect of spatial scale. Model selection using Akaike Information Criterion with correction for small samples (AICc) showed that the road-kill incidence of Chrysocyon brachyurus was positive associated to urban area at larger scale, and for Cerdocyon thous and Lepus europaeus was found a positive association to forestry cover at different scales. For C. thous and L. europaeus , some models worth interpreting included water bodies area, distance to the nearest river and sugarcane fields cover. Matrix permeability and river proximity could be used to indicate sites to apply mitigation measures to road-kill for these mammal species in the Brazilian Savanna.

Heavy Metals in Hair of Wild Canids from the Brazilian Cerrado

In this study, we aimed to assess whether free-ranging wild canids are exposed to heavy metals in one of the most developed and populated regions of Brazil. Hair of 26 wild canids (maned wolves Chrysocyon brachyurus, crab-eating foxes Cerdocyon thous, and hoary foxes Lycalopex vetulus) from the Cerrado biome in Southeast Brazil were analyzed by spectrophotometry to detect cadmium, chromium, and lead, and also the essential copper, iron, manganese, and zinc traces. All samples showed traces of copper, iron, manganese, and zinc. Non-essential lead was detected in 57% (2.35 ± 0.99 mg/kg), and chromium in 88% (2.98 ± 1.56 mg/kg) of samples. Cadmium traces (detection limit 0.8 mg/kg) were not found. Crab-eating foxes had more copper, iron, and manganese in hair than maned wolves. Correlations among element levels differed between maned wolves and crab-eating foxes. Concentrations of chromium and lead were outstandingly higher than in wild canids from other areas. Addressing the causes of such levels and the impacts of the heavy metal pollution in Neotropical ecosystems is urgent for animal health and conservation purposes. We argue that heavy metal pollution should be considered as dangerous threats to wildlife health in Brazil and recommend hair sampling as a biomonitoring tool for heavy metals in Neotropical terrestrial mammals.

Diet of brown-nosed coatis and crab-eating raccoons from a mosaic landscape with exotic plantations in southern Brazil

We described the diets of two procyonids, the brown-nosed coati Nasua nasua and the crab-eating raccoon Procyon cancrivorus, through analysis of stomach contents of road-killed specimens in southern Brazil. We compared them with previously published dietary information for another syntopic mesopredator, the crab-eating fox Cerdocyon thous. The landscape of the study area includes native grasslands, forests, exotic tree plantations, and other crops. Food items were represented by frequency of occurrence (FO) and relative volume (RV). Stomach contents of 23 coatis were analyzed. Animal and plant items were equally frequent, although the volume of plants was greater. Exotic plant species were consumed more than native plants. Among prey items, invertebrates were more important than vertebrates, mainly because of the frequency of coleopterans and annelids and the volume of necrophagous dipteran larvae. Five specimens of raccoons were analyzed, in which animal items had the highest FO and plant items had the highest RV. Both invertebrate and vertebrate prey had the same FO, although vertebrates had a higher RV. Our data suggest that these procyonids are opportunistic hypocarnivores, utilizing anthropic sources, with diet overlap. The coatis also overlapped their diet substantially with the foxes. The stomach-contents analysis revealed the importance of fruit pulp biomass, soft-bodied animals such as larvae, and also soil, which might indicate feeding habits such as scavenging and geophagy.

Terrestrial and aquatic mammals of the Pantanal

Different works have registered the number of mammal species within the natural habitats of the Pantanal based on currently known records, with species richness ranging from 89 to 152 of annotated occurrences. Our present list sums 174 species. However, at least three factors have to be emphasised to deal with recorded numbers: 1) to establish the ecotone limit between the floodplain (which is the Pantanal) and its neighbouring domain like the Cerrado, besides the existence of maps recently produced; 2) the lack of intensive surveys, especially on small mammals, rodents and marsupials; and 3) the constant taxonomic revision on bats, rodents and marsupials. Some species are very abundant--for example the capybara Hydrochoerus hydrochaeris and the crab-eating fox Cerdocyon thous, and some are rare, and others are still intrinsically rare--for example, the bush dog Speothos venaticus. Abundance of species is assumed to reflect ecological resources of the habitat. Local diversity and number of individuals of wild rodents and marsupials also rely on the offering of ecological resources and behavioural specialisation to microhabitat components. A large number of species interact with the type of the vegetation of the habitat, by means of habitat selection through active patterns of ecological behaviour, resulting on dependency on arboreal and forested habitats of the Pantanal. In addition, mammals respond to seasonal shrinking-and-expansion of habitats due to flooding regime of the Pantanal. The highest number of species is observed during the dry season, when there is a considerable expansion of terrestrial habitats, mainly seasonally flooded grassland. Major threats to mammal species are the loss and alteration of habitats due to human intervention, mainly deforestation, unsustainable agricultural and cattle-ranching practices, which convert the natural vegetation into pastures. The Pantanal still harbours about a dozen of species officially listened as in danger.

Transmission, reservoir hosts and control of zoonotic visceral leishmaniasis

Zoonotic visceral leishmaniasis (ZVL) caused by Leishmania infantum is an important disease of humans and dogs. Here we review aspects of the transmission and control of ZVL. Whilst there is clear evidence that ZVL is maintained by sandfly transmission, transmission may also occur by non-sandfly routes, such as congenital and sexual transmission. Dogs are the only confirmed primary reservoir of infection. Meta-analysis of dog studies confirms that infectiousness is higher in symptomatic infection; infectiousness is also higher in European than South American studies. A high prevalence of infection has been reported from an increasing number of domestic and wild mammals; updated host ranges are provided. The crab-eating fox Cerdocyon thous, opossums Didelphis spp., domestic cat Felis cattus, black rat Rattus rattus and humans can infect sandflies, but confirmation of these hosts as primary or secondary reservoirs requires further xenodiagnosis studies at the population level. Thus the putative sylvatic reservoir(s) of ZVL remains unknown. Review of intervention studies examining the effectiveness of current control methods highlights the lack of randomized controlled trials of both dog culling and residual insecticide spraying. Topical insecticides (deltamethrin-impregnated collars and pour-ons) have been shown to provide a high level of individual protection to treated dogs, but further community-level studies are needed.

Atropelamentos de vertebrados na Floresta Nacional de Carajás, Pará, Brasil

Vários pesquisadores têm avaliado impactos de estradas. Estes podem envolver aspectos paisagísticos, degradação do solo, poluição do ar e impactos sobre a fauna, como atropelamentos. Na estrada Raimundo Mascarenhas, que atravessa a Floresta Nacional de Carajás (ca. 400 mil hectares), há intenso tráfego de veículos automotores. O objetivo deste trabalho foi testar se há diferenças entre trechos da estrada, em três escalas espaciais; se há alteração ao longo dos anos; se alguns táxons são mais freqüentemente atropelados, e se a freqüência de atropelamentos aumenta com a precipitação mensal. Analisamos a freqüência de atropelamentos de vertebrados de abril/2003 até outubro/2006 ao longo dos 25 km iniciais da estrada. Registramos 155 atropelamentos. O número de atropelamentos diminui ao longo dos anos (P=0,01), e com a distância do início da estrada (P=0,0002). Serpentes (Ophidia) e gambás Didelphis marsupialis foram mais atropelados (7,5/ano), seguidos de aves, raposas Cerdocyon thous, quatis Nasua nasua, roedores (Rodentia), e não identificados (4,9/ano); cuíca Marmosops sp., tapeti Sylvilagus brasiliensis, guariba Alouatta sp., irara Eira barbara, jabuti Geochelone sp., lagartos (Lacertilia) e macaco prego Cebus apella (1/ano). Não houve relação significativa entre o número mensal de atropelamentos e a precipitação mensal.