Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The genus Leptodactylus has wide distribution and it can be found in many physiographic and climatic zones. This fact has raised questions about the taxonomy of this genus because many species that are considered of great geographic distribution has shown to be two or more closely related. The species Leptodactylus fuscus and Leptodactylus latrans, both widely spread, are found in the state of Sergipe in the Caatinga biome and little is known about the ecology, biology and diversity between and within populations that occupy this exclusively Brazilian biome. Therefore, the present study aimed to characterize the species L. fuscus and L. latrans, which occur in different fragments of Caatinga from the state of Sergipe, using cytogenetic and morphometric data. The karyotypes of populations from the municipalities of Carira, Poço Redondo and Tobias Barreto were analyzed by conventional staining techniques, C-band and Ag-RON. The species showed similar cytogenetic patterns, without evidence of species-specific markers; however some variations in morphology and bands were observed when compared to the karyotypes described in the literature. In morphometric analysis, 21 different characters were analyzed in the two species in each location, showing that populations of L. fuscus presented no significant differences between them; however variations were found in samples of L. latrans, mainly on the size of the specimens. The analyzed data showed that there were no cytogenetic and morphometric differences within the L. fuscus populations and that the morphometric variations observed in L. latrans may be due to environmental effects. / O gênero Leptodactylus tem ampla distribuição geográfica e está presente nas mais diversas zonas climáticas e fisiográficas. Esse fato tem levantado questionamentos de caráter taxonômico, pois muitas espécies consideradas de grande distribuição geográfica têm mostrado tratar-se de duas ou mais espécies estreitamente relacionadas. As espécies Leptodactylus fuscus e Leptodactylus latrans, ambas de ampla distribuição, são encontradas no Estado de Sergipe no bioma Caatinga e pouco se conhece sobre a ecologia, biologia e diversidade inter e intrapopulacional em populações que ocupam este bioma exclusivamente brasileiro. Nesse sentido, o presente estudo teve como objetivos caracterizar através de dados citogenéticos e morfométricos as espécies L. fuscus e L. latrans de ocorrência em diferentes fragmentos de Caatinga do Estado de Sergipe. Os cariótipos das populações dos municípios de Carira, Poço Redondo e Tobias Barreto foram analisados, por meio de técnicas de coloração convencional, Banda C e Ag-RON. Os exemplares estudados apresentaram padrões citogenéticos bastante similares, sem evidências de marcadores espécie-específicos; porém, algumas variações de morfologia e bandas foram observadas quando comparadas aos cariótipos já descritos na literatura. Nas análises morfométricas, 21 caracteres foram analisados nas duas espécies, em cada uma das localidades, mostrando que as populações de L. fuscus não apresentaram diferenças significativas entre elas; contudo variações foram encontradas nas amostras de L. latrans, principalmente quanto ao tamanho dos espécimes coletados. Os dados analisados conjuntamente mostram que populações de L. fuscus não diferem citogenética e morfometricamente entre si e as variações morfométricas observadas em L. latrans podem ser devidas aos efeitos ambientais.

Quantifying physiological stress may aid in a better understanding of how animals survive various environmental conditions. One noninvasive technique for assessing physiological stress in animals is to extract steroid hormones from fecal samples. This technique has the potential to aid in wildlife conservation by providing a better understanding of behavior and welfare for a variety of species. The objectives of the study were to (1) determine responses in plasma and fecal steroid hormone concentrations for coyotes (Canis latrans), (2) determine which steroid hormone (cortisol or corticosterone) was better for examining physiological stress responses for coyotes, and (3) determine the amount of time steroid hormone metabolites can be found in coyote scats during 2 different seasons. We first conducted an adrenocorticotropic hormone (ACTH) challenge in 16 coyotes and examined both plasma and fecal steroid hormone concentrations. An ACTH challenge is when there is an externally derived hormone (ACTH) injected into a subjects blood stream, which causes an increase in the subject’s circulating steroid hormones associated with physiological stress. We injected 16 treatment animals with ACTH and 16 control animals with a saline solution. We collected blood and fecal samples pre- and post-injection to measure steroid hormone concentrations. Radioimmunoassay, a laboratory method used to measure substances, was used to measure concentrations of steroid hormones in coyote blood and feces. To evaluate if steroid hormone concentrations remained in feces for an extended period of time we collected samples from 6 captive coyotes and left the samples in natural environmental conditions for 13 days. Each day a sub-sample was collected, and hormones were extracted and run through radioimmunoassay. We found increased steroid hormone concentrations after an ACTH challenge in both blood and feces, validating the use of fecal steroid hormone concentrations as a tool to measure physiological stress in coyotes. We also found there were no differences in levels of steroid hormone concentrations over 13 days. Our study provides validation for use of fecal steroid hormone concentrations in coyotes to quantify stress levels and confirms that steroid hormone metabolites are viable up to 13 days post deposition in coyote scat. This noninvasive tool can aid in the evaluation of the abilities of coyotes to adapt and exist in a variety of habitats.

The extent to which predators regulate prey populations remains a subject of debate. Yet, when predator control is employed as a management strategy, it is often assumed that predators can and do regulate prey populations. From 2011 through 2015, I monitored the demography and space use of coyotes (Canis latrans) and cougars (Puma concolor) on Monroe Mountain in Fishlake National Forest, Utah as part of a larger collaboration investigating the impacts of coyote aerial control on mule deer (Odocoileus hemionus) neonate survival. My primary objective was to assess the impacts of anthropogenic regulation on the respective populations and identify any cascading effects relevant to mule deer management. To meet this objective, I established a monitoring program for both predators by deploying radio-telemetry collars (VHF and GPS) on each, documented predation events, established surveys for small mammals and lagomorphs to monitor primary prey populations during deer parturition (June – August), and collected data on the location and demographic composition of winter-removed coyotes. I analyzed these data primarily in a community-based, animal movement and resource selection framework permitting the integration of data from multiple sources. When evaluating coyote aerial removal as a management strategy, I identified a spatial dependency in the ability to match removals with indices of deer recruitment as Wildlife Services Operations personnel were primarily limited by terrain and tree cover. Thus, matching treatment with deer fawning was highly variable with only a small number of sites where removals were effective. In addition, I found that coyotes selected for sites with the highest densities of lagomorphs while avoiding areas with a high probability of encountering cougars. Coyotes did not select for mule deer fawning sites, although individual coyotes that occupied resource-poor home ranges were more likely to do so. Cougars strongly selected for mule deer high use areas throughout much of the year, only switching to elk (Cervus elaphus) during the cougar harvest season (i.e., winter). Data from cougar kill site investigations match the observed patterns in cougar space use. My results suggest that predator-prey processes are multi-dimensional and dynamic through time, which likely contribute to the lack of resolution regarding the efficacy of predator control and the regulatory potential of predators in general.

Coyote (Canis latrans) predation accounts for the majority of neonatal pronghorn (Antilocapra americana) mortality in many areas and may influence local population declines. Current techniques used to manage coyote predation on wildlife species generally focus on lethal control methods. However, these methods may be controversial to the general public. Coyote sterilization is an alternative predation control method which is more acceptable to the public and has been shown to be effective in reducing sheep predation. We hypothesized that surgical sterilization of coyotes may increase pronghorn fawn survival; in the same way it reduces coyote predation on domestic sheep. Sterilization reduces the energetic need to provision coyote pups, which may decrease the predation rate on fawns by sterile coyotes. We employed tubal ligation and vasectomy of captured coyotes to maintain pair bonds and territoriality. We monitored pronghorn fawns by radio telemetry for one year pre-treatment and coyotes and pronghorn fawns one year post-treatment. We also examined the effects of sterilization on coyote territorial maintenance and survival. Survival of fawns captured in sterile coyote home ranges was higher than survival of fawns captured in intact home ranges (P = 0.078). We also found that fawn survival was consistently higher in the northern part of the study site (P = 0.081). A severe winter followed by a wet spring in 2007 did not reduce fawn survival and may have increased fawn survival (P = 0.364); however, our sample sizes did not allow us to detect significance in this relationship. Our results also supported the hypothesis that sterilization, while keeping hormonal systems intact, did not change coyote territorial behaviors. Sterile coyote packs were the same size as intact packs (P = 0.554). Sterile and intact coyote packs maintained similar home range sizes in all seasons tested (P ¡Ý 0.556). We found differences between home range and core area overlap of sterile and intact packs in some seasons, but this trend appeared to exist before the coyotes were treated. Residency rates were similar for sterile and intact coyotes (P = 0.406). We recommend coyote sterilization as a tool to boost pronghorn fawn survival in areas where fawn survival is a critical factor in pronghorn population persistence. Because these techniques have been tested under few circumstances, we recommend careful monitoring in future coyote sterilization programs.

Increased snowmobile use in mountainous terrain has been highlighted as a conservation concern for some Canada lynx (Lynx canadensis) populations. Snow compaction resulting from winter recreation may potentially facilitate access by coyotes (Canis latrans) to habitats used by lynx during winter. Increased interactions could result in either exploitation or interference competition between the two species. Two recent, yet geographically distinct, studies showed contrasting findings regarding coyote movements and their use of snow-compacted trails during the winter. These findings suggest coyote association with snow-compacted trails may be regionally specific and dependent upon ecosystem dynamics and snow characteristics. The objectives of this study were to document diet, space use, and movements of coyotes occupying deep snow regions and explore whether a potential existed for increased interactions between coyotes and lynx due to snowmobile activity. We documented seasonal variation in coyote diets using scat collections to assess dietary overlap with lynx. Coyote resource use within and among habitats containing snowmobile activity was examined using coyote backtrack surveys during two consecutive field seasons in northwestern Wyoming. Although scat analysis findings suggest dietary overlap was not significant between coyotes and lynx during the winter or overall (all seasons combined), we lacked adequate sample size of lynx scats to determine if dietary overlap occurred during the fall, when coyote use of snowshoe hare peaked (24.1 % of all fall occurrences). Coyote backtrack surveys revealed that coyotes not only persisted in habitats used by lynx throughout the winter, but that snow compaction resulting from winter recreation use appeared to influence coyote movements during the winter months. Microhabitat analysis revealed that snow conditions influenced coyote behaviors and habitat use. This research provided insight into the impacts of winter recreation on coyote diet and habitat use during the winter months in northwestern Wyoming. In addition, these results have implications for local lynx populations in the southern periphery of their natural range. These results may assist land management agencies in planning and implementing management strategies to enhance lynx recovery, and may be used to guide decisions regarding areas designated for winter recreation and areas proposed for expansion of winter activities.

While antipredator strategies have been a focus of behavioral research for decades, scientists generally study the responses of prey toward overt, explicit threat. However, risk can also be significant when a threat is covert, such as when an ambush predator may be nearby or a secondary threat remains after a predator's departure. Little is known about the mechanism that prey use to assess risk in a predator's absence. Tests were conducted to determine the manner in which coyotes respond to these ambiguous threats. Specifically, I tested whether coyotes respond to prior anthropogenic activity that has occurred near their only food source, whether they investigate human activity at both profitable (feeding) and unprofitable (non-feeding) locations, and what sort of information coyotes are capable of gaining through their investigation. I explored these questions in three experiments spanning 4 years at the USDA/APHIS/WS National Wildlife Research Center's Logan field station. Test subjects were eight pairs of captive coyotes. Results showed that coyotes delayed or avoided feeding in response to prior anthropogenic activity, and that often a delay was due to investigation of human scent trails. Investigation of non-feeding areas occurred but was relatively brief. When coyotes were prevented from investigating locations of prior anthropogenic activity, foraging ceased altogether. In addition, coyotes were able to differentiate among the activity of different humans based on their association with negative, neutral, or positive threat levels, even in the presence of confounding visual and olfactory cues. They remembered these associations even after one month. This study is the first that provides evidence suggesting that canids gather and interpret complex information for cognitive inference about threat level associated with access to food.

Historically, coyotes were associated with the western United States. During their expansion eastward, coyotes have become more tolerant of humans and have been able to live in varying degrees of urbanization. One main question ecologists around the country are asking is how coyotes are surviving in anthropogenic environments. To aid in answering this question, I have compared coyote land use preference generally and specifically during coyote breeding season, winter and summer, human tourist seasons, and day and night. I also compared coyote land cover preference for deciduous and evergreen cover types during natural seasons. I found that, in general, there was a high variation of preference between and within land use categories. More broadly however, they prefer natural areas over non-natural areas. They used natural and non-natural land use types equally in winter and summer, and during tourist and off-tourist seasons with increased variation in preference during seasons with higher human activity. They had a higher preference for non-natural land use types at night. There is no difference in coyote preference for deciduous or evergreen cover types during the seasons.

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Wild Canis species possess a unique suite of reproductive traits including social monogamy, copulatory lock/tie, and biparental care. Females are seasonally monestrous and experience an obligatory pseudopregnancy after spontaneous ovulation. While these characteristics have been ascribed to coyotes, an integrated profile of behavior and physiology has not yet been described. In this study, temporal correlations between steroid hormone levels and socio-sexual mating behaviors were documented, as were changes in vaginal epithelium. Pseudopregnancy was compared to pregnancy by contrasting hormone (progesterone, estradiol, prolactin and relaxin) profiles of unmated females to patterns obtained in alternate years when they bred. Meanwhile, social interactions between pseudopregnant females and their mates appeared similar to pregnant coyotes, suggesting a proximate role of pseudopregnancy in pair-bond enforcement. Finally, out-of-season stimulation of ovarian hormones and estrous behaviors suggested that reproductive seasonality of the coyote may possess some degree of plasticity, providing an adaptive response mechanism to environmental change.

Human-coyote conflict has intensified in Nova Scotia, following a fatal attack in Cape Breton Highlands National Park of Canada (CBHNPC) in October, 2009. This conflict has impacted people and coyotes across the province, and raised numerous questions about how humans and coyotes relate to one another and what steps we might take to avert future conflict. From 2011-2012, I used scat, remote camera, and snow tracking surveys to assess the degree of spatial overlap between human and coyote activity in CBHNPC. I found a negative correlation between hiker/biker and coyote activity in the summer and fall [r=-.830, n=14, p<.01]. In the winter, I found no correlation between human and coyote activity [r=.006, n=10], and a negative correlation between coyote and domestic dog activity [r=-.612, n=10, p<.05]. I discuss the implications of these research findings and the application of noninvasive survey methods in this, and potentially other, human-wildlife conflicts.