Distribution, morphology, and karyotype of San Joaquin pocket mice from the western Mojave Desert
The San Joaquin pocket mouse (Perognathus inornatus) is endemic to California and currently includes three subspecies (P. i. inornatus, neglectus, and psammophilus). P. inornatus from the western Mojave Desert have been assigned to the subspecies neglectus based on similar morphology. During the cou...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
California Department of Fish and Wildlife
2022-07-01
|
| Series: | California Fish and Wildlife Journal |
| Subjects: | |
| Online Access: | https://journal.wildlife.ca.gov/2022/06/30/distribution-morphology-and-karyotype-of-san-joaquin-pocket-mice-from-the-western-mojave-desert/ |
| _version_ | 1811162868386627584 |
|---|---|
| author | David M Laabs Mark L. Allaback Donald R. Mitchell |
| author_facet | David M Laabs Mark L. Allaback Donald R. Mitchell |
| author_sort | David M Laabs |
| collection | DOAJ |
| description | The San Joaquin pocket mouse (Perognathus inornatus) is endemic to California and currently includes three subspecies (P. i. inornatus, neglectus, and psammophilus). P. inornatus from the western Mojave Desert have been assigned to the subspecies neglectus based on similar morphology. During the course of live-trapping projects between 1990 and 2017, we captured P. inornatus at several locations in the Mojave Desert and gathered information on habitat associations, relative abundance, seasonal activity, and field identification. P. inornatus was found at elevations ranging from 668–1,109 m above mean sea level in creosote bush scrub, allscale scrub, Joshua tree woodland, rubber rabbitbrush scrub, spinescale scrub, and California juniper woodland. The capture locations and our review of museum specimens indicate that, at a minimum, the species’ range in the Mojave Desert encompasses approximately 7,000 km2 primarily in the Antelope Valley, extending at least as far north as the Rand Mountains, east to the vicinity of Hinkley, south to Palmdale, and west to near Gorman. P. inornatus capture rates were typically low relative to other nocturnal rodents, and it was not found consistently at localities at which it had been captured previously. Adults were sexually dimorphic, with males significantly larger than females. P. inornatus was significantly larger than the sympatric little pocket mouse (P. longimembris) for length of head-body, total length and body mass, and possessed a relatively shorter tail. We collected 15 specimens of P. inornatus from nine localities in the western Mojave Desert for cytogenetic analysis and each possessed the same karyotype, characterized by a diploid complement of 52 chromosomes, which has not been previously described for the genus. We argue that the 52-chromosome form should be considered distinct for conservation purposes, because it occupies a relatively small geographic area that is being subjected to increasing habitat loss and fragmentation due to residential, commercial, and renewable energy development. |
| first_indexed | 2024-04-10T06:36:13Z |
| format | Article |
| id | doaj.art-5928fa39f87d49ef8036a5bf965934b2 |
| institution | Directory Open Access Journal |
| issn | 2689-419X 2689-4203 |
| language | English |
| last_indexed | 2024-04-10T06:36:13Z |
| publishDate | 2022-07-01 |
| publisher | California Department of Fish and Wildlife |
| record_format | Article |
| series | California Fish and Wildlife Journal |
| spelling | doaj.art-5928fa39f87d49ef8036a5bf965934b22023-02-28T19:26:31ZengCalifornia Department of Fish and WildlifeCalifornia Fish and Wildlife Journal2689-419X2689-42032022-07-01108210.51492/cfwj.108.10Distribution, morphology, and karyotype of San Joaquin pocket mice from the western Mojave DesertDavid M Laabs0https://orcid.org/0000-0002-8604-9029Mark L. Allaback1Donald R. Mitchell2Biosearch Environmental ConsultingBiosearch Environmental ConsultingECORP Consulting, Inc.The San Joaquin pocket mouse (Perognathus inornatus) is endemic to California and currently includes three subspecies (P. i. inornatus, neglectus, and psammophilus). P. inornatus from the western Mojave Desert have been assigned to the subspecies neglectus based on similar morphology. During the course of live-trapping projects between 1990 and 2017, we captured P. inornatus at several locations in the Mojave Desert and gathered information on habitat associations, relative abundance, seasonal activity, and field identification. P. inornatus was found at elevations ranging from 668–1,109 m above mean sea level in creosote bush scrub, allscale scrub, Joshua tree woodland, rubber rabbitbrush scrub, spinescale scrub, and California juniper woodland. The capture locations and our review of museum specimens indicate that, at a minimum, the species’ range in the Mojave Desert encompasses approximately 7,000 km2 primarily in the Antelope Valley, extending at least as far north as the Rand Mountains, east to the vicinity of Hinkley, south to Palmdale, and west to near Gorman. P. inornatus capture rates were typically low relative to other nocturnal rodents, and it was not found consistently at localities at which it had been captured previously. Adults were sexually dimorphic, with males significantly larger than females. P. inornatus was significantly larger than the sympatric little pocket mouse (P. longimembris) for length of head-body, total length and body mass, and possessed a relatively shorter tail. We collected 15 specimens of P. inornatus from nine localities in the western Mojave Desert for cytogenetic analysis and each possessed the same karyotype, characterized by a diploid complement of 52 chromosomes, which has not been previously described for the genus. We argue that the 52-chromosome form should be considered distinct for conservation purposes, because it occupies a relatively small geographic area that is being subjected to increasing habitat loss and fragmentation due to residential, commercial, and renewable energy development.https://journal.wildlife.ca.gov/2022/06/30/distribution-morphology-and-karyotype-of-san-joaquin-pocket-mice-from-the-western-mojave-desert/distributionkaryotypelongimembris groupmojave desertnatural historyperognathus inornatussan joaquin pocket mouse |
| spellingShingle | David M Laabs Mark L. Allaback Donald R. Mitchell Distribution, morphology, and karyotype of San Joaquin pocket mice from the western Mojave Desert California Fish and Wildlife Journal distribution karyotype longimembris group mojave desert natural history perognathus inornatus san joaquin pocket mouse |
| title | Distribution, morphology, and karyotype of San Joaquin pocket mice from the western Mojave Desert |
| title_full | Distribution, morphology, and karyotype of San Joaquin pocket mice from the western Mojave Desert |
| title_fullStr | Distribution, morphology, and karyotype of San Joaquin pocket mice from the western Mojave Desert |
| title_full_unstemmed | Distribution, morphology, and karyotype of San Joaquin pocket mice from the western Mojave Desert |
| title_short | Distribution, morphology, and karyotype of San Joaquin pocket mice from the western Mojave Desert |
| title_sort | distribution morphology and karyotype of san joaquin pocket mice from the western mojave desert |
| topic | distribution karyotype longimembris group mojave desert natural history perognathus inornatus san joaquin pocket mouse |
| url | https://journal.wildlife.ca.gov/2022/06/30/distribution-morphology-and-karyotype-of-san-joaquin-pocket-mice-from-the-western-mojave-desert/ |
| work_keys_str_mv | AT davidmlaabs distributionmorphologyandkaryotypeofsanjoaquinpocketmicefromthewesternmojavedesert AT marklallaback distributionmorphologyandkaryotypeofsanjoaquinpocketmicefromthewesternmojavedesert AT donaldrmitchell distributionmorphologyandkaryotypeofsanjoaquinpocketmicefromthewesternmojavedesert |