Mammalian carnivore occupancy is inversely related to presence of domestic dogs in the high Andes of Ecuador

Experience with Dog Sterilization Campaigns for Surveillance of Zoonotic Diseases in Ecuador: Building Bridges with Animal Organizations to Improve One Health Research

The extensive population of free-roaming dogs poses significant public health risks in low- and middle-income countries because of their potential role in spreading infectious and zoonotic diseases. This article discusses the successful collaboration between academia and nonprofit animal welfare organizations in Ecuador to enhance One Health surveillance despite limited research resources. This collaborative model could serve as a valuable example for other countries in the Americas and globally, where community-based strategies may improve One Health policies.

Availability of alternative prey rather than intraguild interactions determines the local abundance of two understudied and threatened small carnivore species

Intraguild interactions influence the structure and local dynamics of carnivore mammals' assemblages. The potential effects of these interactions are often determined by the body size of competing members and may result in negative relationships in their abundance and, ultimately, lead to species exclusion or coexistence. The relative importance of interspecific interactions along with landscape characteristics in determining population patterns of understudied and threatened sympatric small carnivores, such as skunks, remains poorly documented. Therefore, we assessed the spatiotemporal variation in the abundance of American hog-nosed skunks Conepatus leuconotus and pygmy spotted skunks Spilogale pygmaea and the effect of interspecific interactions, resource availability, and habitat complexity on their local abundance in areas with the deciduous tropical forest south of the Mexican Pacific slope. We used presence-absence data for skunk species from three camera-trapping surveys between 2018 and 2020 in combination with Royle-Nichols occupancy models fitted in a Bayesian framework to estimate abundance, incorporating the effects of covariates related to the factors evaluated. We analyzed the relationship between the abundances of skunks using Bayesian Generalized Linear Models. Both skunk species showed significant differences in their abundances between seasons and between study sites. Overall, pygmy skunks were more abundant than hog-nosed skunks. We found negative relationships among the relative abundances of skunks during the dry seasons, but no evidence that local abundance is governed by the competitive dominance of the larger species. Patterns of skunk abundance were better explained by prey availability and other predictors related to habitat complexity, rather than interspecific interactions, since these models showed the highest predictive accuracies and strong positive and negative relationships. Our study highlights the underlying factors that determine the local abundance of these understudied and threatened small carnivores, allowing us to better understand the mechanisms that govern their coexistence for effective management and conservation of species in seasonal environments.

A first insight into seropositivity of Neospora caninum and associated risk factors in free-roaming dogs from Ecuador

Neosporosis is a worldwide parasitic disease caused by the protozoan Neospora caninum. It can cause economic losses to farmers due to its relationship with abortions and neonatal mortality in cows. Dogs play a key role in its spread as they are considered definitive hosts. In this study, we determined for the first time the seropositivity of N. caninum infection in dogs from Ecuador and evaluated potential risk factors. A total number of 339 free-roaming dogs from the three main regions of Ecuador (Coastal, Andean, and Amazonian regions) were included in the study and classified either as urban or rural dogs. Serum samples were collected from November 2018 to May 2019, and analyzed with a commercial ELISA test. An overall seropositivity of 6.8 % (CI: 95 %, 2.8 % - 11.7 %) was found in N. caninum infection with no statistical differences among regions or urban/rural dogs. This is the first surveillance of N. caninum in Ecuador, confirming a country-wide distribution of this pathogen. Considering the large populations of free-roaming dogs in Ecuador, a One Health approach for surveillance and managing N. caninum in dogs is needed to protect either livestock or wildlife.

Free-ranging dogs are seriously threatening Himalayan environment: delineating the high-risk areas for curbing free-ranging dog infestation in the Trans-Himalayan region

It is becoming more widely recognised that free-ranging dogs, which have a nearly global distribution, threatening native wildlife. Their increasing population and spread to new areas is of growing concern for the long-term viability of wildlife species. Hence, it is imperative to understand the factors responsible for their infestation and map areas where native species are most vulnerable. Using the random forests algorithm, we modelled the free-ranging dog infestation in the Trans-Himalayan region to pinpoint the high-risk areas where free-ranging dogs are threatening the native wildlife species. We found that the likelihood of free-ranging dog occurrence is most in valley regions and up to 4000 m, often in proximity to roads. Our results also indicated that free-ranging dog prefers areas with wildlife near to protected areas. The predictor variables, such as potential evapotranspiration of the coldest quarter, distance to protected areas, elevation, distance to roads, and potential evapotranspiration of the driest quarter, significantly influence the distribution of the free-ranging dogs. We found that within the Ladakh region of the Trans-Himalayan area, the high-risk zones for free-ranging dogs are located in and around Hemis National Park, Karakoram Wildlife Sanctuary, and Changthang Wildlife Sanctuary. While, in the Lahaul and Spiti region the high-risk areas encompass Pin Valley National Park, Inderkilla National Park, Khirganga National Park, Kugti Wildlife Sanctuary, and several other protected areas. We identified the potentially high-risk areas for implementing strategies to mitigate the possible impact of free-ranging dogs on native wildlife of the Himalayas. Hence, the identified high priority areas can be used for implementing actions for controlling the population growth and further preventing the infestation of the free-ranging dogs into the new areas.

Domestic dogs in indigenous Amazonian communities: key players in Leptospira cycling and transmission?

Background

Leptospirosis is the world's most common zoonotic disease. Mitigation and control rely on pathogen identification and understanding the roles of potential reservoirs in cycling and transmission. Underreporting and misdiagnosis obscure the magnitude of the problem and confound efforts to understand key epidemiological components. Difficulties in culturing hamper the use of serological diagnostics and delay the development of DNA detection methods. As a result, especially in complex ecosystems, we know very little about the importance of different mammalian host species in cycling and transmission to humans.

Methodology/Principal Findings

We sampled five indigenous Kichwa communities living in the Yasuní National Park in the Ecuadorian Amazon basin. Blood and urine samples from domestic dogs were collected to assess the exposure of these animals to Leptospira, and to identify the circulating species. Microscopic Agglutination Tests with a panel of 22 different serovars showed anti-leptospira antibodies in 36 sampled dogs (75%), and 10 serotypes were detected. Two DNA-based detection assays revealed pathogenic Leptospira DNA in 18 of 19 dog urine samples (94.7%). Amplicon sequencing and phylogenetic analysis of 16s rDNA and SecY genes from 15 urine samples revealed genetic diversity within two of three different Leptospira species: noguchii (n=7), santarosai (n=7), and interrogans (n=1).

Conclusions/Significance

The high prevalence of antibodies and Leptospira DNA provides strong evidence for high rates of past and current infections. Such high prevalence has not been previously reported for dogs. These dogs live in the peridomestic environment in close contact with humans, yet they are free-ranging animals that interact with wildlife. This complex web of interactions may explain the diverse types of pathogenic Leptospira observed in this study. Our results suggest that domestic dogs are likely to play an important role in the cycling and transmission of Leptospira. Future studies in areas with complex ecoepidemiology will enable better parsing of the significance of genotypic, environmental, and host characteristics.

Assessing microhabitat, landscape features and intraguild relationships in the occupancy of the enigmatic and threatened Andean tiger cat (Leopardus tigrinus pardinoides) in the cloud forests of northwestern Colombia

Mesocarnivores play a key role in ecosystem dynamics through the regulation of prey populations and are sensitive to environmental changes; thus, they are often considered good model organisms for conservation planning. However, data regarding the factors that influence the habitat use of threatened small wild felids such as the Andean tiger cat (Leopardus tigrinus pardinoides) are scarce. We conducted a two-year survey with 58 camera trap stations to evaluate the determinants of Andean tiger cat habitat use in three protected areas in the Middle Cauca, Colombia. We developed site occupancy models and found that Andean tiger cat habitat use increased with leaf litter depth at intermediate elevations and far from human settlements. Through conditional cooccurrence models, we found that Andean tiger cat habitat use was invariant to the presence of prey or potential intraguild competitors and killers/predators, but its detectability increased when they were present and detected. This suggests that Andean tiger cats may be more likely to be detected in sites with high prey availability. We found that Andean tiger cats preferred sites with deep leaf litter, which is a particular feature of cloud forests that provides suitable conditions for ambush hunting and hiding from intraguild enemies. Our results showed that Andean tiger cats avoided human settlements, which may minimize potential mortality risks in those areas. Moreover, the restricted use of middle elevations by Andean tiger cats suggested that they could be used as a sentinel species to track the effects of climate change since their suitable habitat is likely to be projected upward in elevation. Future conservation actions must be focused on identifying and mitigating human-related threats close to the Andean tiger cat habitat while preserving microhabitat conditions and the existing networks of protected areas.

First insights in terrestrial mammals monitoring in the Candelaria and Machay Reserves in the Ecuadorian Tropical Andes

Habitat disturbance leads to biodiversity decline and modifications in the landscape structure and composition, affecting both dispersal movements and ecological processes at different temporal and spatial scales. The Ecuadorian Tropical Andes harbour suitable habitats for the distribution of a wide variety of species; however, there is a lack of studies focused on mammal diversity and its association with the habitat attributes in the central-eastern slopes. Here, we reported the diversity of terrestrial mammals recorded between 2019 and 2021 in a camera-trap monitoring study in the Candelaria and Machay reserves in the upper basin of the Pastaza River, Ecuador. We performed site-occupancy probability analysis to assess the influence of spatial variables in the species' occurrence and also, based on natural marks, we reported preliminary findings in Andean bear individual identification. We detected 22 species of terrestrial mammals. Alpha diversity was similar between reserves with slightly higher species richness in Machay. Evenness indices showed unequal species distribution, with the Andean bear and domestic dogs exhibiting greater dominance. In addition, species composition was dissimilar between reserves, where the species turnover mostly explained the beta diversity. We observed that Andean bear and puma detections increased according to the natural vegetation cover. Conversely, domestic dogs were frequently detected in cells with an increasing proportion of pastures and crops. Additionally, we identified 26 Andean bears and six individuals recaptured during our study. Our results caution about the disturbance derived from human activities since we recorded unprecedented detections of domestic dogs in wild habitats. Nonetheless, it highlights the importance of private conservation areas (e.g. Candelaria, Machay and others) for supporting the occurrence and dispersal of terrestrial mammal species between larger areas in the upper basin of the Pastaza River.

First report of Sarcoptes scabiei parasitism (Sarcoptiformes: Sarcoptidae) in Lycalopes sechurae (Mammalia: Carnivora)

We present the first report of parasitism by Sarcoptes scabiei (Linnaeus, 1758), in a sechuran fox "Lycalopex sechurae". Sarcoptes scabiei is a mite that produces sarcoptic mange, which can lead to the death of the animal host and can cause epidemic episodes in wildlife communities. The sechuran fox was collected by the environmental police from a citizen who reported the animal. It was sent to a veterinarian specializing in wildlife, "Clinica Mansion Mascota", in Guayaquil, Ecuador. Immediate physical examination showed crusts on its skin, and samples of skin and blood were collected and analyzed. The skin samples were analyzed using a microscope at 40x magnification in the clinic. In addition, skin and blood samples were sent to a private laboratory for further analyses. Both analyses were positive for S. scabiei infection. It is the second report of S. scabiei in a new wildlife species in the Guayas province of Ecuador within less than a year. These events cause concern due the possibility of biological community transmission. Since domestic and feral animals are considered habitual spreaders of this disease, management through ethical procedures such as adoption, medical treatment and neutering campaigns, and awareness-raising projects with empathetic approach are recommended.

Human disturbance and shifts in vertebrate community composition in a biodiversity hotspot

Understanding how human modification of the landscape shapes vertebrate community composition is vital to understanding the current status and future trajectory of wildlife. Using a participatory approach, we deployed the largest camera-trap network in Mesoamerica to date to investigate how anthropogenic disturbance shapes the occupancy and co-occurrence of terrestrial vertebrate species in a tropical biodiversity hotspot: the Osa Peninsula, Costa Rica. We estimated species richness in different categories of land protection with rarefaction analysis and estimated the expected occupancy with a joint species distribution model that included covariates for anthropogenic disturbance, land protection, habitat quality, and habitat availability. Areas with the most stringent land-use protections (e.g., Corcovado National Park, 24 species [95% CI 23-25]) harbored significantly more species than unprotected areas (20 species [19.7-20.3]), mainly due to a reduced presence of large-bodied species of conservation concern in unprotected areas (e.g., jaguar Panthera onca and white-lipped peccary Tayassu pecari). Small-bodied generalist species, such as opossums (Didelphidae) and armadillos (Dasypus novemcinctus), in contrast, were more common at disturbed sites, resulting in a significant difference in vertebrate community composition between sites with low and high disturbance. Co-occurrence of species was also mainly associated with response to disturbance. Similar responses to disturbance create two groups of species, those whose site-level occupancy usually increased as anthropogenic disturbance increased and those whose estimated occupancy decreased. The absence of large-bodied species entails an important loss of ecological function in disturbed areas and can hinder forest development and maintenance. Efforts to protect and restore forested landscapes are likely having a positive effect on the abundance of some threatened species. These efforts, however, must be sustained and expanded to increase connectivity and ensure the long-term viability of the wildlife community.

Dystocia and cesarean section in a free-ranging ocelot (Leopardus pardalis) after traumatic spinal cord injury resulting from dog (Canis familiaris) attack

Background:

Ex situ breeding programs are essential to establish genetic resource banks and produce offspring to strengthen the in situ conservation of endangered species. However, many programs fail to maintain viable ex situ populations due to reproductive problems, including dystocia in pregnant females. Dystocia encompasses different emergency obstetric situations for the lives of dams and fetuses that require urgent intervention. This condition has been studied in domesticated species but published records in wildlife, specifically in felines species, are scarce.

Case Description:

An adult female ocelot (Leopardus pardalis) was referred to the wildlife hospital of the Universidad San Francisco de Quito after being attacked by dogs (Canis familiaris). Neurological tests revealed traumatic spinal cord injury at a thoracolumbar level. Complementary tests (laboratory exams, radiographs, and ultrasound) revealed a full-term pregnancy, failure in the labor progress, and critical fetal stress. A cesarean section was performed, and the newborns received resuscitation care after assessing their viability using the Apgar score system. The neonate with the lowest Apgar score died within the first hour after birth, while the second one showed an increase in Apgar score after resuscitation care and survived the procedure.

Conclusion:

We provide new obstetric data that could be relevant to save the lives of dams and newborns in related cases for ocelots and other species of wild felids. Furthermore, this study confirms the adverse effects that domestic dogs have on wildlife species.

Free-ranging dogs as a potential threat to Iranian mammals

Free-ranging domestic dogs Canis familiaris threaten wildlife species through predation, hybridization, competition for resources, and by contributing to the transmission of pathogens. The impacts of predation may be problematic, but in many regions the interactions of free-ranging dogs and wildlife are poorly studied. To determine the extent of the impacts of attacks by free-ranging dogs on Iranian mammals, we reviewed nearly 2 decades of social and traditional media reports and the scientific literature to gather data from across the country. We identified 160 free-ranging dog attacks (79 from academic articles, 14 from social media, and 67 from a variety of news websites) from 22 of the country's 31 provinces. Attacks by dogs were reported on 17 species, including nine Carnivora, six Artiodactyla, one Rodentia, and one Lagomorpha species. Most of the reported attacks on carnivores were on felids, including the Asiatic cheetah Acinonyx jubatus (n = 19), Eurasian lynx Lynx lynx (n = 18), caracal Caracal caracal (n = 10) and Pallas's cat Otocolobus manul (n = 8). Attacks on Artiodactyla were primarily reported for goitered gazelle Gazella subgutturosa (n = 47). Most of these attacks occurred within or adjacent to protected areas (n = 116, 73%), suggesting that free-ranging dogs are one of the most important human-associated threats to wildlife species even in protected landscapes. The impact of free-ranging dogs may be hampering conservation, and therefore we suggest some practical policy guidance for managing the impacts of free-ranging dogs on threatened species.

Anthropogenic and Environmental Factors Determining Local Favourable Conditions for Wolves during the Cold Season

Simple Summary

Wolves normally howl in response to unfamiliar vocalisations, to defend their territory and the important resources within it (e.g., pups and prey). During the non-rendezvous period (late autumn and winter), the protectiveness of adults towards pups decreases, as well as reactions to unfamiliar vocal stimuli. In the late fall of 2010, we performed a saturation wolf howling design in the Cicolano area (Central Apennines, Italy), aiming to identify environmental and human-related characteristics of locations where wolves are prone to respond to unfamiliar howling and to assess their eventual ability to provide insights into the distribution of valuable resources (aside from pups) during the cold season. We found that winter response sites (WRS) were characterized by diverging conditions, with respect to all available sites, suggesting that they are non-randomly located but, instead, had been selected by wolves for some reason. We recorded a positive role of thermal refuges and the occurrence of wild boar drive hunts, as well as the negative roles of other forms of human presence and activities, including the occurrence of free-ranging dogs. These results could be of interest both for conservation purposes and for assessing interactions with human activities.

Abstract

Winter resources are crucial for wildlife, and, at a local scale, some anthropogenic and environmental factors could affect their availability. In the case of wolves, it is known that vocalisations in response to unfamiliar howls are issued to defend their territory and the important resources within it. Then, we studied the characteristics of winter response sites (WRS) during the cold season, aiming to assess their eventual ability to provide insights into the distribution of valuable resources within their territories. Within this scope, we planned a wolf-howling survey following a standardised approach. The study covered an Apennine (Central Italy) area of 500 km². A hexagonal mesh was imposed on the area, in order to determine the values of different variables at the local scale. A logistic LASSO regression was performed. WRS were positively related to the presence of thermal refuges (odds = 114.485), to patch richness (odds = 1.153), wild boar drive hunting areas (odds = 1.015), and time elapsed since the last hunt (odds = 1.019). Among negative factors, stray dogs reply considerably affects wolves’ responsiveness (odds = 0.207), where odds are the exponentiated coefficients estimated by the logistic lasso regression. These results suggest that WRS are related to anthropogenic and environmental factors favouring the predation process.

The relationship between landscape features and domestic species on the occupancy of native mammals in urban forests

Landscape features such as roads, hiking trails, and forest edge are prevalent features of urban forests. These features can negatively influence biodiversity through fragmentation and facilitate the penetration of invasive species, particularly predators such as domestic dogs and cats. This study examined how these landscape features affect the distribution of native and domestic mammals and how domestic species affect the occupancy and activity patterns of native mammals. To this end, we conducted camera trap surveys in forested urban and suburban parks in Indiana and Kentucky, USA, to record the presence of native species (deer, raccoons, coyote, and opossums) and non-native predators (domesticated cats and dogs) in relation to distance to nearest roads, hiking trails, and forest edge. We found negative correlations between proximity to roads, hiking trails, and forest edge and the occupancy of the native species with this effect extending up to 300 m. We also found evidence that the presence of dog and cat was negatively correlated with the occupancy for all native species. We recommend park management consider the impact of roads, hiking trails, and forest edge when designing parks and the enforcement of dog leash regulations for the conservation of large mammals in urban parks.

Clinical and pathological findings in a Dwarf Red Brocket Mazama rufina (Mammalia: Cetartiodactyla: Cervidae) attacked by dogs

Capture myopathy is a common fatal syndrome in wild ungulates resulting from anthropogenic stressful events such as the capture or transport of specimens.  There are, however, few published data on this issue due to predator attacks.  The present report describes for the first time the capture myopathy syndrome in a Dwarf Red Brocket Mazama rufina following dog Canis familiaris attack.  Clinical signs included pale mucous with increase capillary refill time, tachycardia, tachypnea, hypertension, hypothermia, hypoglycemia, and red brown urine.  Muscle tremors, ataxia, prostration, paralysis, and opisthotonus were progressively observed.  Laboratory tests showed increased levels of cortisol, creatinine, creatine kinase, lactate dehydrogenase, and potassium; decreased blood urea nitrogen-creatinine ratio; and myoglobinuria.  The animal died 72 hours after hospital admission.  At necropsy, findings included injuries on both hindlimbs with edema, emphysema, and soft-friable texture in affected muscles, dark kidneys and brown urine in bladder.  Histopathological exams were indicative of skeletal-cardiac muscle degenerative lesions and myoglobinuric nephrosis.  Immuno-histochemistry revealed myoglobin depletion in degenerate muscles and myoglobin accumulation in renal tissues.  We strongly recommend that treatment for capture myopathy be initiated when a wild ungulate is admitted with history of predator attack, since the syndrome may have already established.  This report adds to the instances of negative impacts caused by domestic dogs on threatened wildlife species.   

New records of Leopardus tigrinus (Carnivora: Felidae) in the Department of Santander, Colombia

Leopardus tigrinus is the smallest native cat species of America. In Colombia, the species has been rarely registered in agricultural landscapes and mostly registered in highlands of natural habitats like mountain forests, cloud forests, and paramos. However, recent trail-camera and roadkills records have increased the reports of this species into the country, showing that it is also living close to cities. Here, we report the trail camera observations of two individuals of L. tigrinus in the vicinity of Bucaramanga, Santander. This is the third and northern-most record of the Northern Tiger Cat in the department of Santander. Additionally, we made comments on key local challenges for the conservation of this threatened species.

Current and future suitable habitat areas for Nasuella olivacea (Gray, 1865) in Colombia and Ecuador and analysis of its distribution across different land uses

Nasuella olivacea is an endemic mammal from the Andes of Ecuador and Colombia. Due to its rarity, aspects about its natural history, ecology and distribution patterns are not well known, therefore, research is needed to generate knowledge about this carnivore and a first step is studying suitable habitat areas. We performed Ecological Niche Models and applied future climate change scenarios (2.6 and 8.5 RCP) to determine the potential distribution of this mammal in Colombia and Ecuador, with current and future climate change conditions; furthermore, we analysed its distribution along several land covers. We found that N. olivacea is likely to be found in areas where no records have been reported previously; likewise, climate change conditions would increase suitable distribution areas. Concerning land cover, 73.4% of N. olivacea potential distribution was located outside Protected Areas (PA), 46.1% in Forests and 40.3% in Agricultural Lands. These findings highlight the need to further research understudied species, furthering our understanding about distribution trends and responses to changing climatic conditions, as well as informig future PA designing. These are essential tools for supporting wildlife conservation plans, being applicable for rare species whose biology and ecology remain unknown.

Humans, but not their dogs, displace pumas from their kills: An experimental approach

Domestic dogs are the most abundant large carnivore on the planet, and their ubiquity has led to concern regarding the impacts of dogs as predators of and competitors with native wildlife. If native large carnivores perceive dogs as threatening, impacts could extend to the community level by altering interactions between large carnivores and their prey. Dog impacts may be further exacerbated if these human-associated predators are also perceived as indicators of risk from humans. However, observational approaches used to date have led to ambiguity regarding the effects of dog presence on wildlife. We experimentally quantified dog impacts on the behavior of a native large carnivore, presenting playbacks of dog vocalizations to pumas in central California. We show that the perceived presence of dogs has minimal impacts on puma behavior at their kill sites, and is no more likely to affect total feeding time at kills than non-threatening controls. We previously demonstrated that pumas exhibit strong responses to human cues, and here show that perceived risk from human presence far exceeds that from dogs. Our results suggest that protected areas management policies that restrict dogs but permit human access may in some cases be of limited value for large carnivores.