Publications by authors named "Steve Torres"
Article Synopsis
- Peninsular bighorn sheep are endangered due to threats like introduced diseases, primarily found in Southern California and Baja Mexico.
- A study spanning from 1981 to 2017 examined 16 pathogens, revealing that disease prevalence varies by location and time, affecting lamb survival and overall population recovery.
- Findings suggest that lambs' lower survival rates are linked to higher levels of disease exposure, while adult survival is influenced by population size and past infectious disease rates.
Infestation with nonnative, "exotic" lice was first noted in Washington black-tailed deer (Odocoileus hemionus columbianus) in 1994 and has since then spread throughout the western United States. In California, infestation with the exotic louse Damalinia (Cervicola) sp. was first detected in black-tailed deer from northern California in 2004, and, in 2009, the exotic louse species Bovicola tibialis and Linognathus africanus were identified on mule deer (Odocoileus hemionus californicus) in central Sierra Nevada in association with a mortality event.
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- The study analyzed causes of death in golden eagles, turkey vultures, and common ravens, focusing on their exposure to contaminants found in carrion and prey.
- From 2007 to 2009, dead birds were tested, revealing that collision-related trauma (63%) was the leading cause of mortality, followed by lead poisoning (17%) and anticoagulant rodenticides (8%).
- The findings highlight the significant impact of human activities on these bird species, emphasizing the need for monitoring and regulation to reduce their mortality rates.
The primary challenge to mountain lion population viability in California is habitat loss and fragmentation. These habitat impacts could enhance disease risk by increasing contact with domestic animals and by altering patterns of exposure to other wild felids. We performed a serologic survey for feline pathogens in California mountain lions (Puma concolor) using 490 samples from 45 counties collected from 1990 to 2008.
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- * A ban on lead ammunition for most hunting in California's condor range was enacted in 2008 to combat this issue and aid species recovery.
- * Research showed that after the ban, blood lead levels in golden eagles and turkey vultures dropped significantly, indicating that the regulation effectively reduced lead exposure in these birds.