Taxonomic and Biogeographic Relationships of Baja California Chickarees (Tamiasciurus)

Phylogeny, Divergence Time Estimates, and Phylogeography of the Diploid Species of the <I>Polypodium vulgare</I> Complex (Polypodiaceae)

“…The current geographic range of P. glycyrrhiza encompasses numerous Pleistocene coastal refugia, including Vancouver Island, the Queen Charlotte Islands, and the Columbia River Valley (Pielou 1991;Soltis et al 1997). The present range of P. californicum includes the Pacific coast of the Baja California peninsula and Guadalupe Island (Mickel and Smith 2004;Sigel et al 2014), areas also thought to harbor northern species during the Pleistocene glacial advances (Lindsay 1981;Arbogast et al 2001;Maldonado et al 2001;Oberbauer 2005). We hypothesize that prior to the Pleistocene, the common ancestor of P. glycyrrhiza and P. californicum spanned a coastal range from Alaska through the Pacific Northwest.…”

Nest-site characteristics of the montane endemic Mearns's squirrel (Tamiasciurus mearnsi): an obligate cavity-nester?

“…Large-scale surveys.-During 2005, we surveyed approximately 2,500 ha of forest in the margins of the Vallecitos Meadow, where the species was collected previously for museum specimens (Lindsay 1981;Yensen and Valdés-Alarcón 1999), to detect direct (animal sighting) and indirect (remnants of food with characteristic gnawing) occurrence of Mearns's squirrels and to establish potential capture sites. The area was explored systematically using a topographic map (Schad 1988).…”

“…Mearns's squirrels are separated from the nearest populations of Douglas's and red squirrels by approximately 600 km of mostly nonforested lowlands (Yensen and Valdés-Alarcón 1999). However, the exact distribution of Mearns's squirrels in SSPM is unknown, except for 3 locations , 10 km apart reported in the literature (Lindsay 1981;Yensen and Valdés-Alarcón 1999). The species is known from approximately 2,100 m to 2,750 m elevation in the coniferous forests of SSPM (Yensen and Valdés-Alarcón 1999).…”

“…Tamiasciurus mearnsi is an endemic species that occurs only in the coniferous forests of the Sierra de San Pedro Mártir (SSPM), Baja California, Mexico (Lindsay 1981). Mearns's squirrels are separated from the nearest populations of Douglas's and red squirrels by approximately 600 km of mostly nonforested lowlands (Yensen and Valdés-Alarcón 1999).…”

Spacing Behavior of a Non‐Larder‐Hoarding Tamiasciurus: A Study of Mearns's Squirrels in Xeric Coniferous Forests

“…In contrast, in xeric coniferous forests of Baja California, Mexico, Mearns's squirrels ( Tamiasciurus mearnsi ) do not store cones in middens (Lindsay ; Koprowski et al. ), and only one adult male was observed once in 2 yr of radiotelemetry monitoring feeding on a small cache of 20–30 lodgepole pine cones (Ramos‐Lara ); however, individuals occasionally scatter hoard single food items in branches of trees (Ramos‐Lara ).…”