Timing of reproduction in antelope ground squirrels, Ammospermophilus
leucurus, near La Paz, Baja California Sur.
Some synapomorphic or possible synapomorphic species did not allow proper identification of areas of endemism: Ammospermophilus harrisii, Corynorhinus mexicanus, Dermanura watsoni, Dasyprocta mexicana, Geomys tropicalis, Megadontomys thomasi, Phyllostomus stenops, Sorex macrodon, Tapirus bairdii, and Zygogeomys trichopus.
Baja California Baja California Ammospermophilus leucurus Peninsula Peninsula, BCP1 and Neotoma lepida 2a.
This life-form is represented in Asia by susliks (Spermophilus and Spermophilopsis, both members of the squirrel family Sciuridae); in North America by ground squirrels (Spermophilus and Ammospermophilus
, both Sciuridae); and in South America by guinea-pigs and similar genera (Cavia, Galea, and Microcavia, all of the guinea-pig family Caviidae).
b) Sciurid species including Spermophilus beecheyi, Ammospermophilus
leucurus, and Xerospermophilus tereticaudus.
The non-heteromyid species included Ammospermophilus
leucurus, Onychomys torridus and Peromyscus maniculatus.
In a Sonoran Desert community of four granivorous species (Arizona pocket mouse, Perognathus amplus; Merriam's kangaroo rat, Dipodomys merriami; round-tailed ground squirrel, Spermophilus tereticaudus; and Harris's antelope squirrel, Ammospermophilus
harrisii), we concluded that two mechanisms were jointly responsible for community organization.
Records for Ammospermophilus
interpres, Geomys texensis and Vulpes vulpes represent range extensions.
Energy assimilation, nitrogen requirement, and diet in free-living antelope ground squirrels, Ammospermophilus
Prey item Lepus californicus Black-tailed jackrabbit Sylvilagus audubonii Desert cottontail Ammospermophilus
interpres Texas antelope squirrel Spermophilus variegatus Rock squirrel Thomomys bottae Botta's pocket gopher Chaetodipus Pocket mouse Dipodomys spectabilis Banner-tailed kangaroo rat Dipodomys Ord's or Merriam's kangaroo rat Neotoma albigula White-throated woodrat Neotoma mexicana Mexican woodrat Peromyscus boylei Brush deermouse Peromyscus eremicus Cactus deermouse Peromyscus truei Pinyon deermouse Sigmodon fulviventer Tawny-bellied cotton rat Sigmodon hispidus Hispid cotton rat Callipepla gambelli Gambel's quail Zenaida Dove Unidentified Aves Lizard Reptilian egg Invertebrate Total Percentage of Percent Prey item occurrences frequency Lepus californicus 8.
Noteworthy records include an unusually high population of Ammospermophilus
interpres, and an apparently isolated group of Chaetodipus nelsoni, which provides the northernmost record for the species in the Trans-Pecos, and evidence of the continuing northern expansion in western Texas of the javelina (Tayassu tajacu).