Callospermophilus lateralis “Golden Mantled Ground Squirrel” Sciuridae

Blackfoot River Recreation Corridor (BLM), MT
June 8, 2016
Robert Niese

Look at this adorable little fatling! Golden Mantled Ground Squirrels are a common, endearingly pudgy species found throughout western North America east of the cascades and Sierras. They, along with dozens of other ground squirrel species (41, to be precise), were part of the Great Ground Squirrel Generic Revision of 2009. In this taxonomic revision, mammalogists at the Smithsonian National Museum of Natural History determined that the mega-genus Spermophilus was likely a paraphyletic clade of 8 separate genera. Callospermophilus was one of those genera that rose from the ashes of the Spermophilus mega-genus. Today it remains a distinct genus with only three species, all of which are restricted to western North America. Here in the PNW, one of these species, C. saturatus, is endemic to the Cascade range where it likely became isolated by the Columbia River, allowing it to differentiate from its eastern sister species, C. lateralis.


Tamiasciurus hudsonicus “Red Squirrel” Sciuridae

Missoula, MT
October 24, 2015
Robert Niese

Red Squirrels are rarely found in town here in Missoula. They require an ample supply of pine cones unlike their more adaptive relatives, the Eastern Fox Squirrel and the Eastern Gray Squirrel. But in neighborhoods adjacent to our nearby open spaces, these critters can adapt to live alongside people. This little guy was busy munching on an overripe plum when I interrupted him for a photo.

Tamiasciurus hudsonicus “Red Squirrel” Sciuridae

Drinking Horse Mountain, Bozeman, MT
June 3, 2015
Robert Niese

Red Squirrels are found throughout Nearctic coniferous forests where they defend territories year-round (they don’t hibernate). In the summer, squirrels will collect cones, seeds, and mushrooms in large caches which they feed from throughout the winter. As they eat these cones, they discard the scales in massive piles, called middens, which can grow to be over a meter tall. Winters here in Montana tend to be devoid of active fauna, however, these squirrels will angrily chirp at snowshoers and cross-country-skiers that wander through their territories.

Tamias amoenus “Yellow-pine Chipmunk” Rodentia

National Bison Range, MT
September 21, 2013
Robert Niese

Chipmunks can be hard to identify from afar, so knowing what habitat types certain species prefer can really narrow-down your options. Here in western Montana, three species regularly co-occur (Red-tailed, Yellow-pine, and Least). Red-tailed Chipmunks tend to prefer moist coniferous forests like those in Glacier National Park, while Yellow-pine Chipmunks tend to prefer drier, Ponderosa/Doug-Fir forest edges. Least Chipmunks are found everywhere in between including alpine, sagebrush, coniferous forests, and meadows.