Carly Vynne

Non-invasive measurement of thyroid hormone in feces of a diverse array of avian and mammalian species

We developed and validated a non-invasive thyroid hormone measure in feces of a diverse array of birds and mammals. An I(131) radiolabel ingestion study in domestic dogs coupled with High Pressure Liquid Chromatography (HPLC) analysis, showed that peak excretion in feces occurred at 24-48h post-ingestion, with I(131)-labelled thyroid hormone metabolites excreted primarily as triiodothyronine (T3) and relatively little thyroxine (T4), at all excretion times examined. The immunoreactive T3 profile across these same HPLC fractions closely corresponded with the I(131) radioactive profile. By contrast, the T4 immunoreactive profile was disproportionately high, suggesting that T4 excretion included a high percentage of T4 stores. We optimized and validated T3 and T4 extraction and assay methods in feces of wild northern spotted owls, African elephants, howler monkeys, caribou, moose, wolf, maned wolf, killer whales and Steller sea lions. We explained 99% of the variance in high and low T3 concentrations derived from species-specific sample pools, after controlling for species and the various extraction methods tested. Fecal T3 reflected nutritional deficits in two male and three female howler monkeys held in captivity for translocation from a highly degraded habitat. Results suggest that thyroid hormone can be accurately and reliably measured in feces, providing important indices for environmental physiology across a diverse array of birds and mammals.

Effectiveness of Scat-Detection Dogs in Determining Species Presence in a Tropical Savanna Landscape

Most protected areas are too small to sustain populations of wide-ranging mammals; thus, identification and conservation of high-quality habitat for those animals outside parks is often a high priority, particularly for regions where extensive land conversion is occurring. This is the case in the vicinity of Emas National Park, a small protected area in the Brazilian Cerrado. Over the last 40 years the native vegetation surrounding the park has been converted to agriculture, but the region still supports virtually all of the animals native to the area. We determined the effectiveness of scat-detection dogs in detecting presence of five species of mammals threatened with extinction by habitat loss: maned wolf (Chrysocyon brachyurus), puma (Puma concolor), jaguar (Panthera onca), giant anteater (Myrmecophaga tridactyla), and giant armadillo (Priodontes maximus). The probability of scat detection varied among the five species and among survey quadrats of different size, but was consistent across team, season, and year. The probability of occurrence, determined from the presence of scat, in a randomly selected site within the study area ranged from 0.14 for jaguars, which occur primarily in the forested areas of the park, to 0.91 for maned wolves, the most widely distributed species in our study area. Most occurrences of giant armadillos in the park were in open grasslands, but in the agricultural matrix they tended to occur in riparian woodlands. At least one target species occurred in every survey quadrat, and giant armadillos, jaguars, and maned wolves were more likely to be present in quadrats located inside than outside the park. The effort required for detection of scats was highest for the two felids. We were able to detect the presence for each of five wide-ranging species inside and outside the park and to assign occurrence probabilities to specific survey sites. Thus, scat dogs provide an effective survey tool for rare species even when accurate detection likelihoods are required. We believe the way we used scat-detection dogs to determine the presence of species can be applied to the detection of other mammalian species in other ecosystems.

Resource Selection and Its Implications for Wide-Ranging Mammals of the Brazilian Cerrado

Conserving animals beyond protected areas is critical because even the largest reserves may be too small to maintain viable populations for many wide-ranging species. Identification of landscape features that will promote persistence of a diverse array of species is a high priority, particularly, for protected areas that reside in regions of otherwise extensive habitat loss. This is the case for Emas National Park, a small but important protected area located in the Brazilian Cerrado, the worlds most biologically diverse savanna. Emas Park is a large-mammal global conservation priority area but is too small to protect wide-ranging mammals for the long-term and conserving these populations will depend on the landscape surrounding the park. We employed novel, noninvasive methods to determine the relative importance of resources found within the park, as well as identify landscape features that promote persistence of wide-ranging mammals outside reserve borders. We used scat detection dogs to survey for five large mammals of conservation concern: giant armadillo (Priodontes maximus), giant anteater (Myrmecophaga tridactyla), maned wolf (Chrysocyon brachyurus), jaguar (Panthera onca), and puma (Puma concolor). We estimated resource selection probability functions for each species from 1,572 scat locations and 434 giant armadillo burrow locations. Results indicate that giant armadillos and jaguars are highly selective of natural habitats, which makes both species sensitive to landscape change from agricultural development. Due to the high amount of such development outside of the Emas Park boundary, the park provides rare resource conditions that are particularly important for these two species. We also reveal that both woodland and forest vegetation remnants enable use of the agricultural landscape as a whole for maned wolves, pumas, and giant anteaters. We identify those features and their landscape compositions that should be prioritized for conservation, arguing that a multi-faceted approach is required to protect these species.

Successful carnivore identification with faecal DNA across a fragmented Amazonian landscape

The use of scat surveys to obtain DNA has been well documented in temperate areas, where DNA preservation may be more effective than in tropical forests. Samples obtained in the tropics are often exposed to high humidity, warm temperatures, frequent rain and intense sunlight, all of which can rapidly degrade DNA. Despite these potential problems, we demonstrate successful mtDNA amplification and sequencing for faeces of carnivores collected in tropical conditions and quantify how sample condition and environmental variables influence the success of PCR amplification and species identification. Additionally, the feasibility of genotyping nuclear microsatellites from jaguar (Panthera onca) faeces was investigated. From October 2007 to December 2008, 93 faecal samples were collected in the southern Brazilian Amazon. A total of eight carnivore species was successfully identified from 71% of all samples obtained. Information theoretic analysis revealed that the number of PCR attempts before a successful sequence was an important negative predictor across all three responses (success of species identification, success of species identification from the first sequence and PCR amplification success), whereas the relative importance of the other three predictors (sample condition, season and distance from forest edge) varied between the three responses. Nuclear microsatellite amplification from jaguar faeces had lower success rates (15–44%) compared with those of the mtDNA marker. Our results show that DNA obtained from faecal samples works efficiently for carnivore species identification in the Amazon forest and also shows potential for nuclear DNA analysis, thus providing a valuable tool for genetic, ecological and conservation studies.

Scent-Matching Dogs Determine Number of Unique Individuals From Scat

Abstract Noninvasive scat sampling methods can generate large samples sizes, collected over vast landscapes, ideal for addressing wildlife conservation and management questions. However, the cost of genotyping scat samples limits the accessibility of these techniques. We describe detection-dog methods for matching large numbers of scat samples to the individual, reducing or eliminating the need for sample genotyping. Three dogs correctly matched 25 out of 28 samples from 6 captive maned wolves (Chrysocyon brachyurus) of known identity. Sample scent-matching can increase overall accessibility and breadth of applications of noninvasive scat-collection methods to important landscape scale problems in wildlife sciences.

Physiological implications of landscape use by free-ranging maned wolves (Chrysocyon brachyurus) in Brazil

Abstract Wide-ranging species with large spatial requirements can rarely be supported in protected areas alone, yet most species face greater threats outside reserves. The need to consider conservation of large mammals in landscape mosaics is very relevant to the Brazilian Cerrado, which is the worlds most biologically diverse and threatened savanna. The maned wolf (Chrysocyon brachyurus), South Americas largest canid, has been proposed as a flagship species for the Cerrado. The majority of the maned wolfs distribution overlaps croplands, whereas < 4% of its range overlaps with a protected area. To understand how landscape use influences maned wolf physiological health and likelihood of persistence, we collected scat samples (n = 974) from a 4,000-km2 area encompassing national park, cropland, cattle pasture, and remnant vegetation. From these samples, we measured fecal hormone metabolites of glucocorticoids (indicative of stress), thyroid hormone (indicative of nutritional status), and progesterone (indicative of reproductive health). Glucocorticoid metabolite concentrations increased with distance from natural habitat patches and during times of peak harvest activity. Thyroid hormone metabolite levels were higher in areas with more cropland, indicating good nutritional status. Progesterone metabolite levels in females were higher inside than outside the park, suggesting females residing in the park have higher reproductive success. Results indicate that maned wolves make extensive use of the landscape matrix and are able to tolerate modified agricultural fields despite being sensitive to disturbance. Ensuring their conservation for the long-term will require increased monitoring and incentivizing conservation on private lands that compose much of the Cerrado. Resumo Espécies com grandes requerimentos de área raramente podem ser protegidas unicamente em unidades de conservação, pois muitas delas enfrentam significativas ameaças fora de tais espaços. A necessidade de se considerar a conservação de mamíferos de grande porte em mosaicos na paisagem é bastante relevante no Cerrado brasileiro, que é considerado a mais rica e ameaçada savana do planeta. O lobo-guará (Chrysocyon brachyurus), maior canídeo da América do Sul, tem sido considerado como uma bandeira de conservação para o Cerrado. A maior parte da distribuição do lobo-guará é sobreposta com áreas de cultivo, sendo menos de 4% efetivamente protegida. Com o intuito de investigar como o uso da paisagem influencia a saúde fisiológica do lobo-guará e sua probabilidade de persistência, coletamos amostras de fezes em uma área de 4.000 km2, que abrangeu um parque nacional, áreas de cultivo, pastagens e remanescentes de vegetação natural. A partir dessas amostras, mensuramos os níveis de glucocorticóides (indicadores de estress), hormônio tireoidiano (indicador do estado nutricional) e progesterona (indicadora da saúde reprodutiva). A concentração de glucocorticóide foi maior com o aumento da distância de áreas nativas e também com os picos de atividade de colheita da safra regional. Os níveis de hormônio tireoidiano foram maiores em áreas com cultivos, aspecto que indica uma melhor condição alimentar. O nível de progesterona das fêmeas foi mais elevado dentro do parque do que em seu entorno, sugerindo que as fêmeas dentro da unidade podem ter maior sucesso de reprodução. Os resultados indicam que o lobo-guará faz uso extensivo da matriz de paisagem e é capaz de tolerar áreas modificadas por cultivos, embora seja sensível aos eventos de perturbação. Assegurar que a espécie seja mantida a longo prazo requer um aumento no monitoramento e no estímulo à sua proteção em propriedades privadas, que compreendem a maior parte do Cerrado.

Scat-Detection Dogs Seek Out New Locations of Priodontes maximus and Myrmecophaga tridactyla in Central Brazil

The use of scat-detection dogs is increasingly recognized as a valuable wildlife assessment and monitoring tool (Long et al., 2007a). Chosen for their drive for play-reward with a tennis ball, these dogs enable researchers to seek out scat samples of rare and otherwise difficult-to-study species. The dogs are able to cover large areas, are unbiased in their sampling of gender, and have demonstrated accuracy in their ability to home in on their targets while ignoring nontarget species (Smith et al., 2003). Studies comparing detection dogs with camera-traps and hairsnag surveys have demonstrated that detection dogs are superior both at locating the presence of target species as well as number of individuals (Wasser et al., 2004; Harrison, 2006; Long et al., 2007b). Once located, the scat samples may be used to understand wildlife movements, for diet and disease studies, and for DNA and hormone analyses (Wasser et al., 2004).

First Record of Entodiniomorph Ciliates in a Carnivore, the Maned Wolf (Chrysocyon brachyurus), from Brazil

Abstract The entodiniomorph ciliates (Ciliophora: Entodiniomorphida) are endosymbiotes widely found in the intestines of herbivorous mammals. These commensals commonly occur in the Artiodactyla and Perissodactyla and have also been described in the Proboscidea, Primates, Rodentia, and Diprotodontia. This study reports the first finding of a ciliate in a member of order Carnivora, the maned wolf (Chrysocyon brachyurus). Fecal samples from wild and captive maned wolves were screened using ethyl acetate sedimentation. Prevalence in fecal samples collected from free-ranging maned wolves in Brazil was 40% (6 of 15). Fecal samples from two of four captive individuals from the St. Louis Zoo also had the same species of ciliate. The largely frugivorous diet of the maned wolf likely explains the occurrence of these normally herbivore-associated endosymbiotes in a carnivore.