Scapanus orarius True 1896

10. Coast Mole Scapanus orarius French: Taupe du Pacifique / German: Pazifischer Maulwurf / Spanish: Topo costero del Pacifico Other common names: Coastal Mole, Pacific Mole, Red-footed Mole Taxonomy. Scapanus orarius True, 1896, “Shoalwater Bay,” Pacific County, Wash- ington, USA. Scapanus orarius is genetically closer to S. townsendii than to S. latimanus. Two subspecies recognized. Subspecies and Distribution. S.o.orariusTrue,1896—PacificcoastofUSA(WWashington,includingVashon-MauryI,W&COregon,andNWCalifornia). S. o. schefferi H. H. T. Jackson, 1915 — extreme SW Canada (SW British Columbia) and NW USA (C & E Washington, NE Oregon, and very marginally WC Idaho in Adams and Washington counties). Descriptive notes. Head-body c.106-145 mm (males) and c.133-168 mm (females), tail 30-45 mm (males) and 21-46 mm (females), hindfoot 16-24 mm (males) and 15-22 mm (females); weight 64-91 g (males) and 61-79 g (females). Male Coast Moles are larger than females, and the largest individuals occur in the easternmost part of the distribution. Externally, the Costal Mole differs from the very similar Broad-footed Mole (S. latimanus) by its naked tip of snout. Tail of the Coast Mole is fleshy, only slightly constricted at base, and tappers toward tip. Females have eight nipples: two pairs of pectoral and one pair each of abdominal and inguinal. Nipples are positioned more laterally than in other species of Scapanus. Skull has broad braincase and relatively narrow and pointed rostrum. Braincase is moderately deep, and mandible has relatively large ramus. Dental formula is 1 3/3, C 1/1, P 4/4, M 3/3 (x2) = 44. I' is large and broad but smaller than in the Broad-footed Mole. Unicuspid teeth are rather evenly spaced, and the first two molars in the upper and lower jaws are subequal. Karyotype is 2n = 34. Habitat. Not restricted to any particular vegetation type or successional stage. In British Columbia, Coast Moles occupy almost all types of soils: glacial till, alluvial clay, sands, gravel, and river deposits. They are found in agricultural land, grassy meadows, coastal dunes, coniferous and deciduous forests, and woodlands. Numbers of molehills are positively correlated with biomass of earthworms and soil moisture. The Coast Mole only rarely occurs above elevations of 350 m in British Columbia. Wherever the Coast Mole is sympatric with the much larger Townsend's Mole (S. townsendiz), the two species occupy different microhabitats. Under such circumstances, the Coast Mole lives along streams and in forests where soil is lighter and better drained. Food and Feeding. Earthworms are by far the most important prey of Coast Moles and usually are 70-98% oftheir diets. Other prey includes slugs, centipedes (Chilopoda), vegetable matter, and various adult and larval insects including flies (Diptera), butterflies (Lepidoptera), beetles (Coleoptera), grasshoppers and crickets (Orthoptera), and hymenopterans (Hymenoptera). Captive Coast Moles readily eat earthworms, slugs, snails, insect larvae, and centipedes and millipedes (Diplopoda), but they rejected sawfly (Symphyta) larvae, hairy caterpillars, injured earthworms, and meat leftovers. Adults eat 100-150 g of earthworms/day, equaling nearly twice their body weight. Captive Coast Moles refused water. Breeding. The Coast Mole is probably polygynous. Mating occurs between early January and early March. During this time, males dig tunnels to reach females’ territories. There is single litter each year, with births in late March or early April. Length of gestation is unknown; 2—4 young are born in nests of coarse grass. Young stay in the nest for c.3 weeks, hunt in their mother’s home range for several more weeks and are sexually mature at 9-10 months old. Life expectancy is 3—4 years. Activity patterns. The Coast Mole is primarily fossorial. Tunnels with diameters of c.5 cm expand to small chambers (diameter 10 cm) of unknown function that are spaced c.1 m apart. These expansions are common at junctions of two or more tunnels. Tunnels are of three types. Surface tunnels are just belowground and are frequently used only once during dispersal or mating. When an individual moves just 2.5-5 cm beneath the ground’s surface, soil is not truly excavated but merely pushed up to form a ridge. Up to 275 m of these shallow tunnels can be excavated in a single night. Hunting tunnels are 15-20 cm deep, are used on a daily basis, and act as pitfalls for soil invertebrates. Deep tunnels descend 1-2 m belowground and are constructed during dry periods. Nests are c¢.15 cm deep undertree roots or old buildings and frequently in rough land and never marked by excessively large molehills. Nests usually have several entrances from which numerous runways radiate in all directions. Under deep snow, surface runways are lined with soil. Coast Moles are active year-round but dig most in autumn and winter when soils are moist. Excavated soil is transported to the ground’s surface and piled up in molehills, which average 30 cm in diameter and 15 cm high and contain 2-6 liters of soil. A single Coast Mole can make 200-400 molehills from October to March. Dispersingjuveniles move aboveground during summer. Adults swim readily and promptly recolonize areas after floods. Periods of activity last c.b hours and are not confined to any particular time of the day. Movements, Home range and Social organization. The Coast Mole is most active near its nest and visits peripheries of its home range less frequently. One individual was active in an area of 39 x 39 m. Home range averages 0-12 ha. Densities are 9-9-14-2 ind/ ha. Coast Molesliving in cultivated fields move to turf grasslands in autumn. They are territorial and solitary for most of the year. Status and Conservation. Classified as Least Concern on The IUCN Red Last. Bibliography. Glendenning (1959), Hartman & Yates (1985), Maser et al. (1981), Schaefer (1979, 1982), Schaefer & Sadleir (1981), Verts & Carraway (1988).

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