Utilizing Remote Sensing and Geospatial Techniques to Determine Detection Probabilities of Large Mammals

Whether a species is rare and requires protection or is overabundant and needs control, an accurate estimate of population size is essential for the development of conservation plans and management goals. Wildlife censuses in remote locations or over extensive areas are logistically difficult, frequently biased, and time consuming. My dissertation examined various techniques to determine the probability of detecting animals using remotely sensed imagery. We investigated four procedures that integrated unsupervised classification, texture characteristics, spectral enhancements, and image differencing to identify and count animals in remotely sensed imagery. The semi-automated processes had relatively high errors of over-counting (i.e., greater than 60%) in contrast to low (i.e. less than 19%) under-counting errors. The single-day image differencing had over-counting errors of 53% while the manual interpretation had over-counting errors of 19%. The probability of detection indicates the ability of a process or analyst to detect animals in an image or during an aerial wildlife survey and can adjust total counts to estimate the size of a population. The probabilities of detecting an animal in remotely sensed imagery with semi-automated techniques, single-day image differencing, or manual interpretation were high (e.g. ≥ 80%). Single-day image differencing resulted in the highest probability of detection suggesting this method could provide a new technique for managers to estimate animal populations, especially in open, grassland habitats. Remotely sensed imagery can be successfully used to identify and count animals in isolated or remote areas and improve management decisions. Sightability models, used to estimate population abundances, are derived from count data and the probability of detecting an animal during a census. Global positioning systems (GPS) radio-collared bison in the Henry Mountains of south-central Utah provided a unique opportunity to examine remotely sensed physiographic and survey characteristics for known occurrences of double-counted and missed animals. Bison status (detected, missed, or double-counted) was determined by intersecting helicopter survey paths with bison travel paths during annual helicopter surveys. The probability of detecting GPS-collared bison during the survey ranged from 91% in 2011 to 88% in 2012

Gray Wolves

Wolf conflicts are primarily related to predation on livestock, pets and other domestic animals, as well as their direct and indirect impacts on native ungulates (i.e., big game). Economic losses vary widely with some livestock producers facing high levels of depredation in some areas. This publication focuses on wolf ecology, damage, and management, particularly as it relates to wolf depredation on livestock and other conflicts with people. Wolves and people share the same environments more than people realize. In the U.S., wolves are not confined to wilderness areas. Though curious, wolves generally fear people and rarely pose a threat to human safety. Wolf attacks on people are, and always have been, very rare compared to other wildlife species. However, there have been several cases of human injuries and a few deaths due to wolves in North America over the past 100 years. The main factors contributing to these incidents were habituation to people, rabies infections, conditioning to human foods, and the presence of domestic dogs. It is unusual for wild wolves to associate or interact with people, linger near buildings, livestock, or domestic dogs, but it does occur especially in areas of high wolf densities in and around rural communities. This type of behavior may be more prevalent in areas where wolves are not legally harvested. This “bold” behavior is more typical of a habituated or food- conditioned animal, a released captive wolf, or a released wolf-dog hybrid. The scale and scope of wolf depredation on livestock depends on local wolf density; numbers and kinds of livestock; livestock husbandry practices; availability and vulnerability of alternative prey; human density; road density; severity of winters; and local hunting pressure. In many instances, wolves live around livestock without causing damage or only occasional damage. Wolf pack size has been shown to increase the likelihood of depredations on domestic animals, with larger packs more likely to cause damage. Most losses occur between April and October when livestock are on summer pastures or grazing allotments. Cattle, especially calves, are the most common livestock killed by wolves. When wolves kill sheep or domestic poultry, often multiple individuals are killed or injured. As of 2019, stable wolf populations exist in many regions in the U.S., including Alaska, Minnesota, Wisconsin, Michigan, Wyoming, Montana, and Idaho, with growing populations in parts of Oregon and Washington (Figures 19, 20). Wolves have recently been documented in northern California and northwestern Colorado. A small population of introduced Mexican wolves exists in Arizona and New Mexico, and a small population of red wolves exists in eastern North Carolina. Both the Mexican and red wolf populations are considered more vulnerable to extinction than other North American wolf populations

Identification of kill sites from GPS clusters for jaguars (\u3ci\u3ePanthera onca\u3c/i\u3e) in the southern Pantanal, Brazil

Context. Understanding predator–prey relationships is important for making informed management decisions. Knowledge of jaguar (Panthera onca) predation on livestock and native prey is imperative for future conservation of jaguars in Central and South America. Aim. As part of an investigation to determine predation patterns of jaguars in the southern Pantanal, Brazil, we examined spatial, temporal and habitat variables, which are useful in categorising location clusters as kill sites and non-kill sites. Methods. Using GPS-collars on 10 jaguars we obtained a total of 11 784 locations, from which 877 clusters were identified, visited and examined for prey remains. Ofthe 877 clusters, 421 were associated with a kill and 456 clusters were not associated with a kill. We used univariate and multivariate models to examine the influence of spatial (distance to nearest: water, dense cover, road; dispersion of points), temporal (season, time, number of nights, duration) and habitat (percentage of seven habitat classes, dominant habitat class) variables on categorising clusters as kill or non-kill sites. Key results.Wefound the time a jaguar spent at a cluster (duration), the dispersion of points around the centre of the cluster (dispersion) and the number of nights spent at the cluster were all reliable predictors of whether a cluster was a kill or non-kill site. The best model predicting the likelihood a cluster was a jaguar kill site was a combination of duration and dispersion. Habitat variables were not important in discriminating kills from non-kill sites. Conclusion.Weidentified factors useful for discriminating between kills and non-kill sites for jaguars.Wefound that as a jaguar spent more time at a cluster and as the dispersion of points around the centre of the cluster increased, the higher likelihood the cluster was a jaguar kill. Similarly, as the number of nights spent at the cluster increased, the greater the probability the cluster was a kill. Implications. Our results will increase the efficiency of field investigations of location clusters in determining predation patterns of jaguars in Central and South America. Being able to prioritise which location clusters should be investigated will assist researchers with limited time and resources

Influence of Behavioral State, Sex, and Season on Resource Selection by Jaguars (Panthera onca): Always on the Prowl?

How a predator uses its landscape to move through its territory and acquire prey is a fundamental question for scientific research. The influence of abiotic and biotic factors on space use of large carnivores has profound implications for their future management and conservation. In the Pantanal, Brazil, jaguars (Panthera onca) are the apex predator, but conflicts with cattle depredations pose a risk to their future conservation. We examined whether behavioral state, sex, and season influenced how jaguars used the landscape in the Pantanal. To accomplish this, we radio‐collared four females and six males; radio‐collared jaguars were monitored for 76 radio‐months with 11,787 GPS locations acquired. We developed resource selection functions (RSFs) examining how female and male jaguars used their landscape during three behavioral states (moving, killing native prey, killing cattle) during two seasons (dry, wet). From the RSF models, we found similar variables and relationships of landscape characteristics that jaguars selected for when moving and when depredating native prey and cattle. While moving, jaguars selected for locations that were either in dense cover or very near dense cover, with higher plant diversity and closer to water than available across the landscape. While null models suggested jaguars opportunistically depredated native prey in the dry season and cattle in the wet season, there was some indication they selected for specific landscape characteristics, mainly dense cover when killing cattle in the dry season and native prey in the wet season. Both sexes killed native prey and cattle within dense cover or close to dense cover as expected of an ambush predator. Particular habitat types were not important as long as there was dense cover for concealment. Additionally, jaguars killed prey closer to water than was available on the landscape. The similar variables across the models showed the importance of dense cover and distance to dense cover during all three behavioral states indicating jaguars in the Pantanal were “always on the prowl.” Understanding the spatial requirements for jaguars during the acquisition of native prey and cattle may lead to improved management strategies to allow for continued coexistence of jaguars in an area of traditional cattle production

Changes in Fecal Glucocorticoid Metabolites in Captive Coyotes (\u3ci\u3eCanis latrans\u3c/i\u3e): Influence of Gender, Time, and Reproductive Status

Reproduction is considered an energetically and physiologically demanding time in the life of an animal. Changes in physiological stress are partly reflected in changes in glucocorticoid metabolites and can be measured from fecal samples. We examined levels of fecal glucocorticoid metabolites (fGCMs) in 24 captive coyotes (Canis latrans) to investigate responses to the demands of reproduction. Using 12 pairs of coyotes (five pairs produced pups, seven pairs did not), we analyzed 633 fecal samples covering 11 biological periods (e.g., breeding, gestation, and lactation). Levels of fGCMs showed high individual variability, with females having higher fGCM levels than males. The production of pups showed no statistical effect on fGCM levels among females or males. Among females, fGCM levels were highest during 4–6 weeks of gestation compared to other periods but were not significantly different between pregnant and nonpregnant females. Among males, the highest fGCM levels were during 1–3 weeks of gestation compared to other periods, but were not significantly different between males with a pregnant mate versus nonpregnant mate. Of females producing pups, litter size did not influence fGCM levels. Given that they were fed ample food throughout the year, we found that the demands of producing pups did not appear to statistically influence measures of fGCM concentrations in captive coyotes

Influence of behavioral state, sex, and season on resource selection by jaguars (\u3ci\u3ePanthera onca\u3c/i\u3e): Always on the prowl?

How a predator uses its landscape to move through its territory and acquire prey is a fundamental question for scientific research. The influence of abiotic and biotic factors on space use of large carnivores has profound implications for their future management and conservation. In the Pantanal, Brazil, jaguars (Panthera onca) are the apex predator, but conflicts with cattle depredations pose a risk to their future conservation. We examined whether behavioral state, sex, and season influenced how jaguars used the landscape in the Pantanal. To accomplish this, we radio-collared four females and six males; radiocollared jaguars were monitored for 76 radio-months with 11,787 GPS locations acquired. We developed resource selection functions (RSFs) examining how female and male jaguars used their landscape during three behavioral states (moving, killing native prey, killing cattle) during two seasons (dry, wet). From the RSF models, we found similar variables and relationships of landscape characteristics that jaguars selected for when moving and when depredating native prey and cattle. While moving, jaguars selected for locations that were either in dense cover or very near dense cover, with higher plant diversity and closer to water than available across the landscape. While null models suggested jaguars opportunistically depredated native prey in the dry season and cattle in the wet season, there was some indication they selected for specific landscape characteristics, mainly dense cover when killing cattle in the dry season and native prey in the wet season. Both sexes killed native prey and cattle within dense cover or close to dense cover as expected of an ambush predator. Particular habitat types were not important as long as there was dense cover for concealment. Additionally, jaguars killed prey closer to water than was available on the landscape.The similar variables across the models showed the importance of dense cover and distance to dense cover during all three behavioral states indicating jaguars in the Pantanal were “always on the prowl.” Understanding the spatial requirements for jaguars during the acquisition of native prey and cattle may lead to improved management strategies to allow for continued coexistence of jaguars in an area of traditional cattle production

Demographic and temporal variations in immunity and condition of polar bears (\u3ci\u3eUrsus maritimus\u3c/i\u3e) from the southern Beaufort Sea

Assessing the health and condition of animals in their natural environment can be problematic. Many physiological metrics, including immunity, are highly influenced by specific context and recent events to which researchers may be unaware. Thus, using a multifaceted physiological approach and a context-specific analysis encompassing multiple time scales can be highly informative. Ecoimmunological tools in particular can provide important indications to the health of animals in the wild.We collected blood and hair samples from free-ranging polar bears (Ursus maritimus) in the southern Beaufort Sea and examined the influence of sex, age, and reproductive status on metrics of immunity, stress, and body condition during 2013–2015.We examined metrics of innate immunity (bactericidal ability and lysis) and stress (hair cortisol, reactive oxygen species, and oxidative barrier), in relation to indices of body condition considered to be short term (urea to creatinine ratio; UC ratio) and long term (storage energy and body mass index). We found the factors of sex, age, and reproductive status of the bear were critical for interpreting different physiological metrics. Additionally, the metrics of body condition were important predictors for stress indicators. Finally,many of these metrics differed between years, illustrating the need to examine populations on a longer time scale. Taken together, this study demonstrates the complex relationship between multiple facets of physiology and how interpretation requires us to examine individuals within a specific context

Landscape of stress: Tree mortality influences physiological stress and survival in a native mesocarnivore

Climate change and anthropogenic modifications to the landscape can have both positive and negative effects on an animal. Linking landscape change to physiological stress and fitness of an animal is a fundamental tenet to be examined in applied ecology. Cortisol is a glucocorticoid hormone that can be used to indicate an animal’s physiological stress response. In the Sierra Nevada Mountains of California, fishers (Pekania pennanti) are a threatened mesocarnivore that have been subjected to rapid landscape changes due to anthropogenic modifications and tree mortality related to a 4-year drought. We measured cortisol concentrations in the hair of 64 fishers (41 females, 23 males) captured and radio-collared in the Sierra National Forest, California. We addressed two main questions: (1) Is the physiological stress response of fishers influenced by anthropogenic factors, habitat type, canopy cover, and tree mortality due to drought in their home range? (2) Does the physiological stress response influence survival, reproduction, or body condition? We examined these factors within a fisher home range at 3 scales (30, 60, 95% isopleths). Using model selection, we found that tree mortality was the principle driver influencing stress levels among individual fishers with female and male fishers having increasing cortisol levels in home ranges with increasing tree mortality. Most importantly, we also found a link between physiological stress and demography where female fishers with low cortisol levels had the highest annual survival rate (0.94), whereas females with medium and high cortisol had lower annual survival rates, 0.78 and 0.81, respectively. We found no significant relationships between cortisol levels and body condition, male survival, or litter size. We concluded that tree mortality related to a 4-year drought has created a “landscape of stress” for this small, isolated fisher population

Injury Scores and Spatial Responses of Wolves Following Capture: Cable Restraints Versus Foothold Traps

Wolves (Canis lupus) have been captured with foothold traps for several decades to equip them with radiocollars for population monitoring. However, trapping in most areas is limited to spring, summer, and autumn as cold winter temperatures can lead to frozen appendages in trapped animals. In addition, conflicts arise when domestic dogs encounter these traps in nonwinter seasons. An alternative capture method is the use of cable restraint devices (modified neck snares) in the winter. We evaluated injury scores, movement patterns, and space use of wolves captured in cable restraint devices and foothold traps in north‐central Minnesota, USA, during 2012–2016. Injury scores did not differ between capture techniques; however, movement patterns and space use were different. We found that the movement away from the capture site appeared to plateau by approximately 8–10 days for wolves captured by either foothold traps or cable restraints, but wolves captured in traps travelled farther away. Daily movement rates reached an asymptote approximately 14 days earlier for wolves captured with cable restraints as compared with wolves caught with foothold traps. We found the space use among wolves caught with cable restraint devices plateaued in a shorter time frame than wolves caught with foothold traps whether using days since capture (38 days earlier) or number of locations (149 locations earlier). When we controlled for seasonal effects and the presence of a capture using locational data collected 6 months later, there was no difference in space use. We concluded that wolves captured in cable restraints recovered more quickly from the capture and resumed space use and activity patterns more rapidly than wolves captured with foothold traps. Published 2019. This article is a U.S. Government work and is in the public domain in the USA