Population ecology and survivorship of San Joaquin antelope squirrels in grazed and control plots in the San Joaquin Desert of California
The San Joaquin antelope squirrel (Ammospermophilus nelsoni) is endemic to the San Joaquin Desert of California. It has been listed as Threatened by the state of California since 1980 due to profound habitat loss, but a paucity of information could limit conservation efforts for this species. We exa...
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| Format: | Article |
| Language: | English |
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California Department of Fish and Wildlife
2021-07-01
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| Series: | California Fish and Wildlife Journal |
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| _version_ | 1819146653255335936 |
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| author | David J. Germano Galen B. Rathbun Lawrence R. Saslaw Brian L. Cypher |
| author_facet | David J. Germano Galen B. Rathbun Lawrence R. Saslaw Brian L. Cypher |
| author_sort | David J. Germano |
| collection | DOAJ |
| description | The San Joaquin antelope squirrel (Ammospermophilus nelsoni) is endemic to the San Joaquin Desert of California. It has been listed as Threatened by the state of California since 1980 due to profound habitat loss, but a paucity of information could limit conservation efforts for this species. We examined data collected each August during 1997–2006 to determine whether A. nelsoni population attributes differed between grazed and ungrazed study plots. We found that sex ratios, mean weights, percentage of reproductive males, number of young, yearly survival, longevity, overall survivorship, and population growth trajectories all were similar between grazed and ungrazed plots. In general, sex ratios were even, males were heavier than females, some males were reproductive in August (although most females were not), and the number of young was inversely related to residual dry matter. We also found that we captured most individuals only once, but we captured a few squirrels for up to for 5 years, and the populations on both grazed and ungrazed plots were growing during the 10-year study. Our study was only the second long-term investigation of this species and the information is needed for further conservation and recovery efforts. |
| first_indexed | 2024-12-22T13:17:17Z |
| format | Article |
| id | doaj.art-ad5bdd2fa2cf4ceb88cd305203841837 |
| institution | Directory Open Access Journal |
| issn | 2689-419X 2689-4203 |
| language | English |
| last_indexed | 2024-12-22T13:17:17Z |
| publishDate | 2021-07-01 |
| publisher | California Department of Fish and Wildlife |
| record_format | Article |
| series | California Fish and Wildlife Journal |
| spelling | doaj.art-ad5bdd2fa2cf4ceb88cd3052038418372022-12-21T18:24:34ZengCalifornia Department of Fish and WildlifeCalifornia Fish and Wildlife Journal2689-419X2689-42032021-07-01107CESA Special Issue32934410.51492/cfwj.cesasi.20Population ecology and survivorship of San Joaquin antelope squirrels in grazed and control plots in the San Joaquin Desert of CaliforniaDavid J. Germano0https://orcid.org/0000-0003-2146-0332Galen B. Rathbun1https://orcid.org/0000-0001-7349-6172Lawrence R. Saslaw2Brian L. Cypher3https://orcid.org/0000-0002-7349-545XCalifornia State University, BakersfieldCalifornia Academy of SciencesCalifornia State University, StanislausCalifornia State University, StanislausThe San Joaquin antelope squirrel (Ammospermophilus nelsoni) is endemic to the San Joaquin Desert of California. It has been listed as Threatened by the state of California since 1980 due to profound habitat loss, but a paucity of information could limit conservation efforts for this species. We examined data collected each August during 1997–2006 to determine whether A. nelsoni population attributes differed between grazed and ungrazed study plots. We found that sex ratios, mean weights, percentage of reproductive males, number of young, yearly survival, longevity, overall survivorship, and population growth trajectories all were similar between grazed and ungrazed plots. In general, sex ratios were even, males were heavier than females, some males were reproductive in August (although most females were not), and the number of young was inversely related to residual dry matter. We also found that we captured most individuals only once, but we captured a few squirrels for up to for 5 years, and the populations on both grazed and ungrazed plots were growing during the 10-year study. Our study was only the second long-term investigation of this species and the information is needed for further conservation and recovery efforts.ammospermophilus nelsoniconservationreproductionsex ratiossurvival |
| spellingShingle | David J. Germano Galen B. Rathbun Lawrence R. Saslaw Brian L. Cypher Population ecology and survivorship of San Joaquin antelope squirrels in grazed and control plots in the San Joaquin Desert of California California Fish and Wildlife Journal ammospermophilus nelsoni conservation reproduction sex ratios survival |
| title | Population ecology and survivorship of San Joaquin antelope squirrels in grazed and control plots in the San Joaquin Desert of California |
| title_full | Population ecology and survivorship of San Joaquin antelope squirrels in grazed and control plots in the San Joaquin Desert of California |
| title_fullStr | Population ecology and survivorship of San Joaquin antelope squirrels in grazed and control plots in the San Joaquin Desert of California |
| title_full_unstemmed | Population ecology and survivorship of San Joaquin antelope squirrels in grazed and control plots in the San Joaquin Desert of California |
| title_short | Population ecology and survivorship of San Joaquin antelope squirrels in grazed and control plots in the San Joaquin Desert of California |
| title_sort | population ecology and survivorship of san joaquin antelope squirrels in grazed and control plots in the san joaquin desert of california |
| topic | ammospermophilus nelsoni conservation reproduction sex ratios survival |
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