Article
Ecology
Marcus E. E. Blum, Kelley M. M. Stewart, Mike Cox, Kevin T. T. Shoemaker, Joe R. R. Bennett, Benjamin W. W. Sullivan, Brian F. F. Wakeling, Vernon C. C. Bleich
Summary: Selection of forage and habitats in bighorn sheep is influenced by the nutritional needs of individuals, with some females sacrificing nutritional quality for the safety of their offspring. Our study examined diet quality and composition before and after parturition, revealing a tradeoff between diet quality and provisioning status. The results provide insight into habitat selection and evolutionary processes in these specialized artiodactyls.
FRONTIERS IN ECOLOGY AND EVOLUTION
(2023)
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
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
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
Christina M. Aiello, Nathan L. Galloway, Paige R. Prentice, Neal W. Darby, Debra Hughson, Clinton W. Epps
Summary: This study used simulation to assess the impact of human-made barriers on wildlife and proposed strategies to restore habitat connectivity. The results showed that removing highway barriers can increase habitat reachability and facilitate wildlife movement and conservation.
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
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
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
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
Soraia Barbosa, Kimberly R. Andrews, Richard B. Harris, Digpal S. Gour, Jennifer R. Adams, E. Frances Cassirer, Hollie M. Miyasaki, Helen M. Schwantje, Lisette P. Waits
Summary: The study described genetic variation in native and reintroduced herds of California and Rocky Mountain bighorn sheep, finding lower genetic diversity and higher relatedness in California herds, which may impact long-term fitness. Recommendations were made for future reintroductions to use appropriate source populations to avoid potential genetic diversity issues.
JOURNAL OF WILDLIFE MANAGEMENT
(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
Lawrence R. Walker, Steven S. Vrooman, Daniel B. Thompson
JOURNAL OF ARID ENVIRONMENTS
(2015)
Article
Ornithology
Joseph G. Barnes, Ross D. Haley, Daniel B. Thompson, Jef R. Jaeger
JOURNAL OF RAPTOR RESEARCH
(2015)
Article
Ecology
Jessica K. Cole, Joseph P. Peacock, Jeremy A. Dodsworth, Amanda J. Williams, Daniel B. Thompson, Hailiang Dong, Geng Wu, Brian P. Hedlund
Article
Ornithology
Joseph G. Barnes, Jef R. Jaeger, Daniel B. Thompson
JOURNAL OF RAPTOR RESEARCH
(2012)
Article
Biodiversity Conservation
David M. Choate, Kathleen M. Longshore, Daniel B. Thompson
WESTERN NORTH AMERICAN NATURALIST
(2018)
Article
Biodiversity Conservation
Kathleen Longshore, Chris Lowrey, Daniel B. Thompson
WILDLIFE SOCIETY BULLETIN
(2013)
Article
Ecology
Christopher Lowrey, Kathleen M. Longshore, David M. Choate, Jyoteshwar R. Nagol, Joseph Sexton, Daniel Thompson
ECOLOGY AND EVOLUTION
(2019)
Article
Zoology
Daniel B. Thompson
INTEGRATIVE AND COMPARATIVE BIOLOGY
(2019)
Article
Biodiversity Conservation
Daniel B. Thompson, Kevin McKelvey, Paul van Els, Gretchen Andrew, Paula Jacoby-Garrett, Matt Glenn, Corey Kallstrom, Kristine L. Pilgrim, Paul A. Opler
CONSERVATION GENETICS
(2020)
Article
Ecology
J. Mark Sappington, Kathleen M. Longshore, Daniel B. Thompson
JOURNAL OF WILDLIFE MANAGEMENT
(2007)
Article
Ecology
DB Thompson, LR Walker, FH Landau, LR Stark
JOURNAL OF ARID ENVIRONMENTS
(2005)
Article
Ornithology
EV Pearlstine, DB Thompson
JOURNAL OF RAPTOR RESEARCH
(2004)
Article
Plant Sciences
Aaron B. Shiels, Lawrence R. Walker, Daniel B. Thompson
Article
Plant Sciences
Z Xie, ZL Zhang, XL Zou, J Huang, P Ruas, D Thompson, QJ Shen
Article
Ecology
Narendra Nelli, Diana Francis, Ricardo Fonseca, Olivier Masson, Mamadou Sow, Emmanuel Bosc
Summary: This study investigates the changes in the atmospheric electric field (Ez) during foggy conditions in the hyperarid region of the United Arab Emirates. The results show that as fog persists, Ez becomes more variable due to the absorption and redistribution of charges by the fog, which alters the ion balance and affects electrical conductivity in the atmosphere.
JOURNAL OF ARID ENVIRONMENTS
(2024)
Article
Ecology
Ezra Hadad, Amir Balaban, Jakub Z. Kosicki, Reuven Yosef
Summary: This study investigated whether the prey of striped hyenas has adapted to the change in the natural environment caused by human activities, particularly artificial light at night (ALAN). The results showed that ALAN had no impact on the diet or den distribution of the hyenas in central Israel. The study also found that domestic animals were the most common prey, and there were also some vegetative species in their diet. Overall, the feeding behavior of striped hyenas is influenced by geographical region, habitat, and human activities.
JOURNAL OF ARID ENVIRONMENTS
(2024)
Article
Ecology
Rahim Najafi Tireh Shabankareh, Pardis Ziaee, Mohammad Javad Abedini
Summary: This study evaluated the IMERG satellite-based precipitation product in the Fars province of Iran using daily rain gauges as reference data. The results showed that the product tends to overestimate light rainfall and underestimate heavy rainfall, with the best performance in the 40-80 mm/day range. The accuracy of the product varies by month and is less biased in months with milder temperatures. Additionally, there was a higher correlation in mid-elevated areas, positive bias in low-elevated areas, and negative bias in high-elevated areas. Longer time scales showed considerable improvement in the IMERG estimates.
JOURNAL OF ARID ENVIRONMENTS
(2024)