Article
Ecology
Danielle M. Glass, Paige R. Prentice, Ashley D. Evans, Oswald J. Schmitz
Summary: This study analyzes the surface water use and movement patterns of desert bighorn sheep populations in the Mojave Desert. The results suggest that temperature is the most significant factor influencing the sheep's visitation to water sources. Furthermore, individual animals exhibit changes in movement patterns when accessing surface water. The study also emphasizes the importance for managers to monitor water sources when the maximum daily temperature exceeds 35 degrees Celsius.
JOURNAL OF WILDLIFE MANAGEMENT
(2022)
Article
Multidisciplinary Sciences
Marie I. Tosa, Mark J. Biel, Tabitha A. Graves
Summary: Sociality has a direct impact on mating success, survival rates, and disease transmission in bighorn sheep. The study found that the rates of direct contact between individuals were influenced by intrinsic and extrinsic factors, as well as prior disease exposure. Same-sex dyads had more direct contacts than female-male dyads, and groups with overlapping summer home ranges had the highest direct contact rates.
Article
Ecology
Aidan Brushett, Jesse Whittington, Bryan Macbeth, John M. Fryxell
Summary: Understanding the behavioral changes induced by ungulate parturition is important for effective population management, but identifying birth sites and dates is challenging. This study used movement data from GPS collared bighorn sheep to identify lambing events and investigate resource selection and responses to human use. Results showed that postpartum ewes preferentially selected high-elevation, sunny, rugged, and remote sites. It is recommended that managers minimize human disturbance in lambing areas and ensure access to suitable habitat during the periparturient period.
Article
Ecology
Manuel Vargas-Felipe, Luis Pellegrin, Aldo A. Guevara-Carrizales, A. Pastor Lopez-Monroy, Hugo Jair Escalante, Jose A. Gonzalez-Fraga
Summary: Monitoring wildlife using camera traps is crucial for conservation efforts, but manual image classification remains expensive. This paper presents an automatic methodology for labeling images captured by camera traps, focusing on the analysis of the desert bighorn sheep. The method achieved high classification performances and the collected data set and models are publicly available to support further research on this species.
ECOLOGICAL INFORMATICS
(2021)
Article
Ecology
Elizabeth Flesch, Tabitha Graves, Jennifer Thomson, Kelly Proffitt, Robert Garrott
Summary: Understanding the influence of population attributes on genetic diversity is important for biological conservation. This study on bighorn sheep populations found that connectivity between populations, human-assisted gene flow, and minimum count were correlated with average pairwise kinship, while population origin was less important.
Article
Ecology
Marcus E. Blum, Frances E. Buderman, Joe R. Bennett, Kelley M. Stewart, Mike Cox, Perry J. Williams
Summary: Aerial surveys for large ungulates often underestimate the number of animals, which can lead to erroneous estimates of abundance. In this study, researchers developed a Bayesian integrated data model to estimate the abundance of bighorn sheep, taking into account availability and perception probability. They found that perception probability varied annually and that accounting for availability and imperfect perception resulted in greater estimates of abundance compared to traditional methods. The modeling framework developed in this study can be used to generate more accurate population estimates for bighorn sheep and other similar mammals surveyed in a similar manner.
JOURNAL OF WILDLIFE MANAGEMENT
(2023)
Article
Ecology
Adam M. Hering, Neil B. Chilton, Tasha Epp, Helen M. Schwantje, Frances Cassirer, Andrew Walker, Craig McLean, Prasobh Raveendran Thampy, Eryn Hanak, Peregrine Wolff, Mark Drew, Katherine D. Bardsley, Murray Woodbury
Summary: The study aimed to determine the source of Psoroptes outbreak in Canadian bighorn sheep, and found that the mites acquired from Canadian and outbreak-associated American bighorn sheep were more similar in morphology to those collected from rabbits than mites on historically infested bighorn sheep. This suggests that the Psoroptes outbreak in Canadian bighorn sheep was likely a result of disease spillover from rabbits rather than transmission from infested American bighorn sheep populations.
INTERNATIONAL JOURNAL FOR PARASITOLOGY-PARASITES AND WILDLIFE
(2021)
Article
Zoology
Ty J. Werdel, Jonathan A. Jenks, John T. Kanta, Chadwick P. Lehman, Teresa J. Frink
Summary: The study monitored the translocated bighorn sheep in the Black Hills region and found that they underwent an acclimation period after release, with their home range gradually shrinking and travel distances decreasing.
Article
Ecology
Alynn M. Martin, E. Frances Cassirer, Lisette P. Waits, Raina K. Plowright, Paul C. Cross, Kimberly R. Andrews
Summary: The study suggests that genetic composition may influence the persistent carriage of Mycoplasma ovipneumoniae in bighorn sheep, with SNP panel explaining around 55% of the phenotypic variance in carriage. However, there is considerable uncertainty in these estimates, and further research incorporating larger sample sizes and different herds is needed to explore the genomic basis of chronic carriage.
ECOLOGY AND EVOLUTION
(2021)
Article
Veterinary Sciences
Amelie Mathieu, Caeley Thacker, Irene Teske, Emily Jenkins, Brent Wagner, Bryan Macbeth, Stephen Raverty, Margo Pybus
Summary: This study identified cases of mortality in the Radium-Stoddart bighorn sheep population in southeastern British Columbia, Canada, caused by infection with the giant liver fluke, Fascioloides magna. The affected animals exhibited typical clinical signs and pathology consistent with previous reports on other hosts. The change in migratory behavior among some rams may have contributed to their exposure to F. magna. This research highlights the pathogenic nature of the giant liver fluke and its threat to the conservation of bighorn sheep herds in endemic regions.
JOURNAL OF WILDLIFE DISEASES
(2022)
Article
Ecology
Andrew S. Jones, Esther S. Rubin, Matthew J. Clement, Larisa E. Harding, Jacob I. Mesler
Summary: This study investigated how mountain lions impact habitat selection and mortality risk of bighorn sheep. The findings suggest that bighorn sheep select habitats based on ruggedness and slope, reducing the risk of mountain lion predation. Additionally, increasing group size decreases the risk of mortality.
JOURNAL OF WILDLIFE MANAGEMENT
(2022)
Article
Ecology
J. Terrill Paterson, Kelly Proffitt, Jay Rotella, Douglas McWhirter, Robert Garrott
Summary: Research on bighorn sheep populations reveals significant variation in vital rates, with evidence of overall decline in 9 out of 17 populations and various combinations of vital rates leading to positive population trajectories. The contribution of lamb survival to population growth rates is significant, and environmental factors play a key role in influencing lamb survival.
Article
Engineering, Biomedical
Luca H. Fuller, Kourosh F. Karimy, Paige L. Ruschke, Meredith M. Taghon, Alfred J. Crosby, Seth W. Donahue
Summary: This study reveals that the velar bone tissue in bighorn sheep rams' horncore has energy absorption capabilities, which helps reduce brain cavity accelerations during high-energy head impacts. The study also found that the velar bone tissue has lower flexibility and toughness compared to other mammalian cortical bone tissues. The presence of osteons in the velar bone, which are rarely found in trabecular struts, was also discovered. These findings can contribute to a better understanding of how bighorn sheep avoid brain injuries during head-to-head impacts.
ACTA BIOMATERIALIA
(2023)
Article
Veterinary Sciences
Elis A. Fisk, E. Frances Cassirer, Katey S. Huggler, Allan P. Pessier, Laura A. White, Joshua D. Ramsay, Elizabeth W. Goldsmith, Holly R. Drankhan, Rebecca M. Wolking, Kezia R. Manlove, Todd Nordeen, John T. Hogg, Kyle R. Taylor
Summary: Low lamb recruitment is a hindrance to bighorn sheep conservation and restoration. The causes of abortion and neonatal death in bighorn sheep, which affect recruitment, are not well understood. This study identified toxoplasmosis as a major cause of reproductive loss in bighorn sheep through postmortem examination and histologic testing. The findings highlight the need for further investigation into abortions and neonatal deaths, particularly in herds with low reproductive rates.
JOURNAL OF WILDLIFE DISEASES
(2023)
Article
Ecology
Patrick J. Terry, Aaron C. Alvidrez, Christian W. Black
Summary: The study showed that desert bighorn sheep primarily visit artificial water sources during summer for hydration and thermoregulatory relief. The presence of interspecific species increases the visitation frequency of bighorn sheep at water developments. Bighorn sheep adjust their temporal activity to avoid predators and competitors, showing a behavioral adaptation to reduce potential threats during all seasons.
JOURNAL OF WILDLIFE MANAGEMENT
(2022)