Tamiasciurus fremonti, Audubon & Bachman, 1853
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publication ID |
https://doi.org/ 10.5281/zenodo.6840226 |
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DOI |
https://doi.org/10.5281/zenodo.6835660 |
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persistent identifier |
https://treatment.plazi.org/id/064D0660-FFED-ED10-FF60-F512F83EFD69 |
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treatment provided by |
Diego |
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scientific name |
Tamiasciurus fremonti |
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Fremont’s Squirrel
French: Ecureuil de Frémont / German: Stidwestliches Rothérnchen / Spanish: Ardilla de Frémont
Other nommon names: Southwestern Red Squirrel; Mount Graham Red Squirrel (grahamensis)
Taxonomy. Tamiasciurus fremonti Audubon & Bachman, 1853 ,
“Rocky Mountains.”
Genetic evidence suggests that subspecies of Fremont’s Squirrel are supported. Four subspecies recognized.
Subspecies and Distribution.
TI.f.lychnuchusStone&Rehn,1903—C& SENewMexicoandWTexas,USA.
T. f. mogollonensis Mearns, 1890 — N & C Arizona and W New Mexico, USA.
Populations in SC Wyoming are of uncertain subspecific affinity.
Descriptive notes. Head-body 194-219 mm, tail 104-146 mm; weight mean 231 g (males) and 223 g (females). Fremont’s Squirrel has reddish to ferruginous brown to olivaceous gray dorsal pelage, with bright to faint reddish medial band that is especially apparent on grayish forms. Ventral pelage is white to grayish and is separated from dorsum by charcoal-to-black longitudinal stripe. White-to-buff eye ring is usually prominent, with white to buff at snout and chin. In winter, ears can have black tuft, and white-to-buff postauricular patches are often present. Tail is similar in color to dorsum, with ventral side often most reddish; tail is often frosted with white to cream. Nominate Jremonti and subspecies lychnuchus are reddish; mogollensis and grahamensis are grayish. Chromosome number of 2n = 46.
Habitat. Mixed and coniferous forests dominated by pine (Pinus), fir (Pseudotsuga and Abies), and spruce (Picea), all Pinaceae, with closed canopies most favored. Fremont’s Squirrel will use open parkland forests in some areas. It can be found in urban and suburban areas, with mature seed-producing trees, and can use secondary growth forests.
Food and Feeding. Fremont’s Squirrel is primarily granivorous but also an opportunistic omnivore. Primary foods include seeds of pine,fir, and spruce. Epigeous and hypogeous mycorrhizal fungi are also commonly used. Supplementary plant tissues are used including tree buds and flowers, fruits, and phloem from branch tips. Fremont’s Squirrel will also feed on insects, bones, eggs, avian nestlings, and other animal material. Fremont’s Squirrel hoards conifer cones in a larder (midden) located near large trees, dense understory, and fallen logs near the center of the home range. Fremont’s Squirrel also scatterhoard cones and seeds just below the surface. Middens are crucial for overwinter survival because they permit storage of conifer cones in cool moist environments to maintain conifer seeds. Individuals pilfer cones from caches of neighbors, and other species are attracted to middens for potential food and cover. Fungi are common summer foods and are often cached in tree canopies or hoarded in tree cavities.
Breeding. Fremont’s Squirrel nests in leaf and twig dreys,cavities in trees or occasionally in burrows into which young are sometimes born. It is in estrus for only one day during the breeding season when several males chase a female that copulates with multiple males. Litter sizes are 2-9-3-4 young. Fremont’s Squirrel typically produces only one litter per year and rarely two litters. Young leave nests by 7-8 weeks of age, are weaned at c.14 weeks of age, and begin to disperse a few weeks after weaning.
Activity patterns. Fremont’s Squirrel is diurnal, with midday peak in activity during winter and bimodal activity pattern in spring and summer. It remains active throughout the year but may enter torpor for short periods during extreme weather events.
Movements, Home range and Social organization. Fremont’s Squirrel is generally asocial; it is often fiercely territorial, maintaining exclusive-use areas usually less than 1 ha. Territories of subspecies grahamensis are relaxed and average 12-1 ha. Although most young disperse from natal areas, territories of adult females are sometimes given to their young upon weaning. Densities are 0-5—1-3 ind/ha in most habitats. Minimal sex differences in space use have been reported. Most interactions are agonistic and consist of vocalizations and foot stomping, followed by chasing and rarely combat. Adults, especially females, occasionally nest together in winter. Alarm calls are highpitched whines that follow series of chatters or chucks. The loud rattle call reverberates through the forest, especially in autumn when food resources are stockpiled and territories are vigorously defended. Roads and forest openings impede movement; vehicle noise decreases occupancy in vicinity or roads.
Status and Conservation. Not yet assessed on The [UCN Red List due recent classification as a unique species. Fremont’s Squirrel is found in montane environments and appears common in the northern parts of the distribution but persists in small isolates in the south. It responds negatively to forest fragmentation and clear cutting. Insect damage and wildfires are significant threats in arid forests. Fremont’s Squirrel can damage trees by bark stripping and girdling trees to consume phloem and cambium. Subspecies grahamensis is isolated on a single high-elevation mountaintop and numbers less than 300 individuals, resulting in endangered species status in the USA.
Bibliography. Chen Hsiangling & Koprowski (2015, 2016), Gurnell (1984), Hoffmeister (1986), Hope et al. (2016), Koprowski (2005b), Koprowski, Alanen & Lynch (2005), Koprowski, Leonard et al. (2006), Minor & Koprowski (2015), Posthumus et al. (2015), Steele (1998).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
