Browsing by Author "Butler, Carson J."

Now showing 1 - 4 of 4

Assessing respiratory pathogen communities in bighorn sheep populations: Sampling realities, challenges, and improvements
(2017-07) Butler, Carson J.; Edwards, William H.; Jennings-Gaines, Jessica E.; Killion, Halcyon J.; Wood, Mary E.; McWhirter, Douglas E.; Paterson, J. Terrill; Proffitt, Kelly M.; Almberg, Emily S.; White, Patrick J.; Rotella, Jay J.; Garrott, Robert A.
Respiratory disease has been a persistent problem for the recovery of bighorn sheep (Ovis canadensis), but has uncertain etiology. The disease has been attributed to several bacterial pathogens including Mycoplasma ovipneumoniae and Pasteurellaceae pathogens belonging to the Mannheimia, Bibersteinia, and Pasteurella genera. We estimated detection probability for these pathogens using protocols with diagnostic tests offered by a fee-for-service laboratory and not offered by a fee-for-service laboratory. We conducted 2861 diagnostic tests on swab samples collected from 476 bighorn sheep captured across Montana and Wyoming to gain inferences regarding detection probability, pathogen prevalence, and the power of different sampling methodologies to detect pathogens in bighorn sheep populations. Estimated detection probability using fee-for-service protocols was less than 0.50 for all Pasteurellaceae and 0.73 for Mycoplasma ovipneumoniae. Non-fee-for-service Pasteurellaceae protocols had higher detection probabilities, but no single protocol increased detection probability of all Pasteurellaceae pathogens to greater than 0.50. At least one protocol resulted in an estimated detection probability of 0.80 for each pathogen except Mannheimia haemolytica, for which the highest detection probability was 0.45. In general, the power to detect Pasteurellaceae pathogens at low prevalence in populations was low unless many animals were sampled or replicate samples were collected per animal. Imperfect detection also resulted in low precision when estimating prevalence for any pathogen. Low and variable detection probabilities for respiratory pathogens using live-sampling protocols may lead to inaccurate conclusions regarding pathogen community dynamics and causes of bighorn sheep respiratory disease epizootics. We recommend that agencies collect multiples samples per animal for Pasteurellaceae detection, and one sample for Mycoplasma ovipneumoniae detection from at least 30 individuals to reliably detect both Pasteurellaceae and Mycoplasma ovipneumoniae at the population-level. Availability of PCR diagnostic tests to wildlife management agencies would improve the ability to reliably detect Pasteurellaceae in bighorn sheep populations.
Respiratory pathogens and their association with population performance in Montana and Wyoming bighorn sheep populations
(2018-11) Butler, Carson J.; Edwards, William H.; Paterson, J. Terrill; Proffitt, Kelly M.; Jennings-Gaines, Jessica E.; Killion, Halcyon J.; Wood, Mary E.; Ramsey, Jennifer M.; Almberg, Emily S.; Dewey, Sarah R.; McWhirter, Douglas E.; Courtemanch, Alyson B.; White, Patrick J.; Rotella, Jay J.; Garrott, Robert A.
At the request of National Park Service resource managers, we began a study in 2000 to evaluate causes for the decline of the bighorn sheep (Ovis canadensis) population inhabiting Bighorn Canyon National Recreation Area (BICA), the Pryor Mountain Wild Horse Range, and surrounding state and U.S. Forest Service lands in Montana and Wyoming. Our study consisted of radio-collaring adult rams and ewes with mortality sensors to monitor adult mortalities, tracking ewes to determine pregnancy and lambing rates, habitat assessments to determine why the population was not expanding into what had been modeled using GIS methodology as suitable bighorn sheep habitat, measuring ungulate herbaceous consumption rates and herbaceous production to determine plant responses, and aerial and boat surveys to determine bighorn sheep population range and population dynamics (Schoenecker and others, this report). Two habitat suitability models were created and conducted (Gudorf, this report; Wockner and others, this report) using different methodologies, and comparisons made between the two. Herd population dynamics were modeled using the POP-II and POP-III programs (Roelle, this report), and a reassessment of ungulate exclosures that were established 8–10 years ago was conducted (Gerhardt, this report). The bighorn sheep population of the greater Bighorn Canyon National Recreation Area (BICA) was extirpated in the 1800s, and then reintroduced in 1973. The herd increased to a peak population of about 211 animals (Kissell and others, 1996), but then declined sharply in 1995 and 1996. Causes for the decline were unknown. Numbers have remained around 100 ± 20 animals since 1998. Previous modeling efforts determined what areas were suitable bighorn sheep habitat (Gudorf and others, 1996). We tried to determine why sheep were not using areas that were modeled as suitable or acceptable habitat, and to evaluate population dynamics of the herd.
Summer range occupancy modeling of non-native mountain goats in the greater Yellowstone area
(2015-11) DeVoe, Jesse D.; Garrott, Robert A.; Rotella, Jay J.; Challender, Stuart; White, Patrick J.; O'Reilly, Megan; Butler, Carson J.
Non-native species can have adverse impacts on native species. Predicting the potential extent of distributional expansion and abundance of an invading non-native species can inform appropriate conservation and management actions. Non-native mountain goats (Oreamnos americanus) in the greater Yellowstone area (GYA) have substantial potential to occupy similar habitats to native Rocky Mountain bighorn sheep (Ovis canadensis canadensis). To understand the potential for expansion of mountain goats in the GYA, this study evaluated detection-nondetection data derived from ground-based occupancy surveys of viewsheds partitioned into a grid of 100 × 100 m sampling units. Surveys were conducted over three summer seasons (2011–2013) in two study areas with well-established mountain goat populations. Relationships between scale-specific habitat covariates and mountain goat selection were evaluated to model occupancy and detection probabilities based on mountain goat detections in 505 of the 53,098 sampling units surveyed. Habitat selection was most strongly associated with terrain covariates, including mean slope and slope variance, at a spatial scale of 500 × 500 m, and canopy cover, heat load, and normalized difference vegetation index at a spatial scale of 100 × 100 m. These results provide new insight into multi-scale patterns of mountain goat habitat selection, as well as evidence that mean slope and slope variance are more informative terrain covariates than distance to escape terrain, which has been commonly used in published mountain goat habitat models. The model predicted 9,035 km2 of suitable habitat within the GYA, of which 57% is currently un-colonized. Seventy-five percent of all bighorn observations recorded in the GYA fall within predicted suitable mountain goat habitat. We also estimated that the GYA might have the potential to support 5,331–8,854 mountain goats when all predicted habitat is occupied, or approximately 2.5–4.2 times the most recent abundance estimate of 2,354.
A Survey of Bacterial Respiratory Pathogens in Native and Introduced Mountain Goats ( Oreamnos americanus)
(2018-06) Lowrey, Blake; Butler, Carson J.; Edwards, William H.; Wood, Mary E.; Dewey, Sarah R.; Fralick, Gary L.; Jennings-Gaines, Jessica E.; Killion, Halcyon J.; McWhirter, Douglas E.; Miyasaki, Hollie M.; Stewart, Shawn T.; White, Kevin S.; White, Patrick J.; Garrott, Robert A.
In contrast to broad range expansion through translocations, many mountain goat ( Oreamnos americanus) populations have shown signs of decline. Recent documentation of pneumonia in mountain goats highlights their susceptibility to bacterial pathogens typically associated with bighorn sheep ( Ovis canadensis) epizootics. Respiratory pathogen communities of mountain goats are poorly characterized yet have important implications for management and conservation of both species. We characterized resident pathogen communities across a range of mountain goat populations as an initial step to inform management efforts. Between 2010 and 2017, we sampled 98 individuals within three regions of the Greater Yellowstone Area (GYA), with a smaller sampling effort in southeast Alaska, USA. Within the GYA, we detected Mycoplasma ovipneumoniae in two regions and we found at least two Pasteurellaceae species in animals from all regions. Mannheimia haemolytica was the only pathogen that we detected in southeast Alaska. Given the difficult sampling conditions, limited sample size, and imperfect detection, our failure to detect specific pathogens should be interpreted with caution. Nonetheless, respiratory pathogens within the GYA may be an important, yet underappreciated, cause of mountain goat mortality. Moreover, because of the strong niche overlap of bighorn sheep and mountain goats, interspecific transmission is an important concern for managers restoring or introducing mountain ungulates within sympatric ranges.