Sorex fumeus G. S. Miller 1895

51. Smoky Shrew Sorex fumeus French: Musaraigne fuligineuse / German: Rauchfarbene Spitzmaus / Spanish: Musarafia ahumada Taxonomy. Sorex fumeus G. S. Miller, 1895, “ Peterboro [Madison Co.], N. Y. [= New York],” USA. Sorexfumeus is in the S. oreopolus group and subgenus Ofisorex along with S. tenellus, S. nanus, S. oreopolus, S. orizabae, and S. ventralis. Two subspecies recognized. Subspecies and Distribution. S.f.fumeusG.S.Miller,1895—SECanada(SOntarioandSQuebec)andEUSA(NEMinnesota,NewEngland,exceptmostofMaine,NVermont,andNNewHamnsire,SIndiana,Ohio,Pennsylvania,WestVirginia,Maryland,WNewJersey,Kentucky,N&WVirginia,ETennessee,WNorthCarolina,NEGeorgia,andNWSouthCarolina). S. f. umbrosus H. H. T. Jackson, 1917 — SE Canada (SE Quebec, New Brunswick, and Nova Scotia) and NE USA (NE New York, N Vermont, N New Hampshire, and most of Maine). Descriptive notes. Head—body 59-75 mm, tail 43-53 mm, hindfoot 12-15 mm; weight 5-9 g. The Smoky Shrew is medium-sized. In summer, dorsum is grayish brown, and venter is pale brown. In winter, dorsum is dark gray to nearly blackish, and venteris pale gray. In southern part of the distribution, Smoky Shrews can have dark dorsal stripe that extends onto forelimbs and lightersides. Feet are whitish; ears are small and rounded but relatively conspicuous. Tail is ¢.75% of head-body length, well furred, and bicolored, being grayish brown above and lighter below. Teeth are pigmented dark red. There are five unicuspids,first and second are largest and nearly equal in size, third is slightly larger than fourth, and both are smaller than first and second, and fifth is minute. Chromosomal complement has 2n = 66 and FN = 98. Habitat. Mostly damp areas in various conifer and hardwood forest habitats, being most common in deciduous forests. Smoky Shrews are often associated with mosscovered logs and rocks, deep leaf litter, thick vegetation, and stream edge habitats. In Canada, they have been reported from swamps and bogs, rocky slopes, and grassy areas surrounded by forest. Food and Feeding. Diets of Smoky Shrews consist of various small invertebrates and small amounts of vegetation. In North Carolina, diets contained centipedes (36:5%), earthworms (19%), adult lepidopterans (19-5%), adult scarabaeids (10%), and various other insect larvae and sowbugs. Individually, centipedes seem to make up the largest proportion oftheir diet, along with various larval and adult insects. Earthworms also make up a large part of diets, indicating that they will often dig to find food and forage hypogeally. Fungus (Endogone) and snails have also been reported in diets on occasion. In captivity, individuals were maintained on small snails, beetles, small earthworms, mouse meat, centipedes, spiders, and sowbugs. Overall, Smoky Shrews are generalists and might also feed on carrion (as indicated by feeding on mouse meat in captivity). They do not seem to be able to kill other small mammals such as mice; however, when a Smoky Shrew was placed in the same enclosure as a deermouse (Peromyscus sp.), it attempted to kill it but gave up after several attempts. Breeding. Reproduction of the Smoky Shrew occurs from late March until early October (generally from spring until late summer/early autumn); breeding begins later in northern regions, such as Maine where it starts in late April or early May. Female reproductive organs mature later in the season than males. Like all temperate shrews, Smoky Shrews overwinter as immatures and loose significant weight beforehand, quickly gaining it back in spring before reproducing. Litters have 2-8 young (average c.5-5). Pregnant females are generally found in April-September, and lactating females have been found as late as early October. Gestation lasts c.3 weeks, and as many as three litters can be produced in a season. Smoky Shrews only live c.14-17 months. Activity patterns. Although Smoky Shrews are active day and night, but they are more active throughout the night. They seem to forage epigeally on the surface and hypogeally under the surface, which might allow them to coexist with competing Rock Shrews (S. dispar) in certain regions. Nests of Smoky Shrews are spherical (¢.23 cm in diameter); located in hollow logs, within tunnels, or under debris on forest floors (10.2-22.9 cm underground); and lined with animal fur and plant material. Movements, Home range and Social organization. To forage and move around, Smoky Shrews use pre-existing tunnels underground and runways aboveground. They rarely create their own tunnels and runways, generally using those created by other small mammals. They are solitary except when breeding and rearing young; males abandon their home ranges, while females expand theirs during the breeding season; and males promiscuously breed with many females and competing with other males. Densities vary throughout the year and among populations. Densities up to 143 ind/ha have been reported, but ¢.2 ind/ha is more common. In good habitat in New York, densities were 62-124 ind/ha, which is exceptionally high because densities are 12-15 ind/ha in other regions. Densities are highest just after the breeding season and decrease as older individuals die during autumn and winter. Status and Conservation. Classified as Least Concern on The IUCN Red List. The Smoky Shrew has a wide distribution and no major threats. It seems to benefit from habitat modification because it expanded westward after coniferous forests were deforested and replaced by deciduous regrowth. Bibliography. Blair (1940), Bole (1939), Bole & Moulthrop (1942), Brannon (2000), Buckner (1957), Burt (1940), Caldwell et al. (1981), Cassola (2016m), Hamilton (1940), Jannett & Oehlenschlager (1994), Meylan (1968a), Owen (1984), Sipe & Browne (2004), Whitaker & Cudmore (1986), Whitaker & French (1984), Whitaker et al. (1975).

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