Lemmus trimucronatus
Nearctic Brown Lemming
(Lemmus trimucronatus) | |
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Range | |
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Taxonomic classification | |
Order: | Rodentia |
Suborder: | Supramyomorpha |
Infraorder: | Myomorphi |
Superfamily: | Muroidea |
Family: | Cricetidae |
Subfamily: | Arvicolinae |
Tribe: | Lemmini |
Genus: | Lemmus |
Binomial details | |
Lemmus trimucronatus (J. Richardson, 1825) |
Lemmus nigripes was formerly considered a sister species of Lemuus trimucronatus restricted to St. George Island, Pribilof Islands (Davis, 1944). Genetic studies by Spitsyn et al. (2021) found the mean cytb p-distance between the eastern clade of Lemuus trimucronatus and the western clade, which includes northeastern Asia and northwestern North America, is as high as 7.2%, and they thus they were fully supported as separate species-level units. The western clade of Lemmus trimucronatus is now referred to as Lemmus nigripes.
Description
From Naughton (2012): "Like other lemmings, Nearctic Brown Lemmings have stocky, ovoid bodies, short legs, and a very short tail (< 20% of total length). Pelage colour and the extent of colour vary geographically. In general, adults have a grizzled, brownish head, a band of light orange or buff fur around the lower sides, an even lighter belly, and a rump of a rust colour that may be as small as a discrete patch or that may extend to suffuse the entire back and rump. Guard hairs on the back are grey-brown to black at their base. Tips of the same hairs over the head and shoulders are a mix of dark brown and light grey to buff, resulting in a grizzled look, while those over the back and rump are tipped with tan to reddish orange. The cheeks and flanks are orange and the chin, throat, and belly are pale orange to buffy orange to light grey. Belly hairs have a grey base. The tail is usually bicoloured, darker above and lighter below with a group of long, stiff, pale hairs at the tip. These lemmings do not become white in the winter. Their pelage colour does not change appreciably from summer to winter, but winter fur is longer, especially over the back and rump, and is somewhat greyer. Younger animals tend to be darker and duller than adults. Ears are short and do not extend beyond the fur. Feet are buffy to dirty grey and claws are tan or brown."
External measurements
Length measurements are in millimeters (mm) and weight measurements are in grams (g), unless stated otherwise. If available, the sample size (n=) is provided. If a range is not provided and n= is not given, then the listed measurement represents an average.
Part of range | Reference | Total length | Tail length | Hindfoot length | Ear length | Mass |
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Canada | Naughton (2012) | 122–170 | 8–29 | 13–26 | 9–16 | 24.6–98.4 |
Skull
References
Davis WB. 1944. Geographic variation in brown lemmings (Genus Lemmus). The Murrelet 25(2): 19-25.
Naughton D. 2012. The natural history of Canadian mammals. Toronto (ON, CA): University of Toronto Press.
Spitsyn VM, Bolotov IN, Kondakov AV, Klass AL, Mizin IA, Tomilova AA, Zubrii NA, Gofarov MY. 2021. A new Norwegian Lemming subspecies from Novaya Zemlya, Arctic Russia. Ecologica Montenegrina 40: 93-117.