386.

Northern Hairy-legged Myotis

Myotis pilosatibialis

French: Murin a pattes velues / German: Nordliches HaarfiRiges Mausohr / Spanish: Ratonero de patas peludas

Taxonomy. Myotis keaysi pilosatibialis LaVal, 1973,

“ 1 km W Talanga, Francisco Morazan [= Morazrin], Honduras, elevation 750 m.”

Subgenus Pyzonix; ruber species group (7 species). Myotis pilosatibialis became a distinct species after analysis of morphological data in 2014. Monotypic.

Distribution. From EC Mexico S through Central America into Colombia and N Venezuela; also on Trinidad I.

Descriptive notes. Head-body c. 45-51 mm, tail 34-39 mm, ear 12-14 mm, hindfoot 7-9 mm; forearm 32- 2-39 mm; weight 4-7 g. The Northern Hairy-legged Myotis is morphologically similar to its Neotropical congeners. Fur is short to medium long (dorsal fur 3-5- 6 mm; ventral fur 3-5 mm) and woolly. Dorsal fur is unicolored and dark brown to cinnamon-brown, but a few individuals can have slightly darker bases. Ventral hairs are strongly bicolored, with dark brown bases and reddish or yellowish brown tips. Hair color can vary seasonally. Ears are comparatively short, extending forward halfway from eye to nostril. Antitragal notch is barely evident. Membranes are mummy brown; plagiopatagium is broadly attached to foot at bases of toes. Fringe of hairs along trailing edge of uropatagium is absent; dorsal surface of uropatagium is covered with dense hair, extending to middle of tail and exceeding to foot, including fur across tibia onto plagiopatagium. Skull is moderate in size (greatest skull lengths 12:5-14- 1 mm, generally less than 14 mm); frontal bone is vertically sloped laterally; palatal angle is acute (angle formed between palatal plane and plane of basicranium is greater than 30°); acute nasal angle is noticeable laterally (angle formed between nasals and plane of frontals is less than 45); parietalis inclined forward; occipital region is comparatively flattened posteriorly; and sagittal and lambdoidal crests are present, ranging from low to high. P? is displaced to lingualside with respect to tooth row. Chromosomal complement has 2n = 44 and FN = 50, with large submetacentric X-chromosome and small acrocentric Y-chromosome.

Habitat. Various habitats, including scrub-steppe, upland semideciduous forest, oakconifer forest, and upland and lowland rainforests from sea level up to elevations of c. 2500 m.

Food and Feeding. The Northern Hairy-legged Myotis forages in forested areas and over water, where captures mostly lepidopterans, coleopterans, and dipterans in flight.

Breeding. In Costa Rica, the Northern Hairy-legged Myotis is seasonal polyestrous, without bimodal birth peaks. Births occur mostly in May-June, but breeding can extend through the wet season. In Mexico, one pregnant female captured had a 15-mm long embryo in April.

Activity patterns. Activity of the Northern Hairy-legged Myotis begins at sunset and ends c.1 hour before sunrise. It seems to be cave roosting. In Mexico, calls had steep down sweeps that end in narrowband tail, with most energy at 59-63 kHz; initial frequency was ¢.110 kHz but could be lower (c.80 kHz).

Movements, Home range and Social organization. In Costa Rica, a few recaptures at the same site and long-distance recaptures (200-1450 m) suggested that Northern Hairy-legged Myotis have large home ranges. In Mexico, colonies of more than 500 individuals in caves are common. In Costa Rica, a colony of 200 individuals was recorded roosting under a bridge. Colonies also can have less than ten individuals.

Status and Conservation. Not assessed on The IUCN Red List. The Northern Hairylegged Myotis is widespread and ecological flexible and probably does not face any major threats.

Bibliography. Allen (1914), Arita & Vargas (1995), Barquez & Diaz (2016g), Bickham et al. (1986), Hernandez-Meza et al. (2005), LaVal (1973b), LaVal & Fitch (1977), Mantilla-Meluk & Munoz-Garay (2014), Moratelli et al. (2013), Rydell et al. (2002), Timm et al. (1989), Wilson (2008b).