384.

Cinnamon Myotis

Myotis fortidens

French: Murin a dents fortes / German: Zimtbraunes Mausohr / Spanish: Ratonero dentudo

Taxonomy. Myotis lucifugus fortidens G. S. Miller & G. M. Allen, 1928,

“Teapa, Tabasco, Mexico.”

Subgenus Pyzonix; lucifugus species group. Myotis fortidens was originally described as a subspecies of M. lucifugus and later raised to a distinct species based on morphology. Two subspecies recognized.

Subspecies and Distribution.

M. f. fortidens G. S. Miller & G. M. Allen, 1928 — Mexico, from N Sinaloa S along narrow strip on Pacific coast and from Veracruz S to Chiapas, and Guatemala.

M. f. sonoriensis Findley & C. Jones, 1967 — at least Sonora and N Sinaloa in NW Mexico.

Distributional limits of subspecies are obscure.

Descriptive notes. Head—body 46-54 mm, tail 31-40 mm, ear 10-14 mm, hindfoot 7-11 mm, forearm 35-5-38- 8 mm; weight 5-8 g. Specimens from northernmost part of distribution (e.g. Sonora, Mexico) are considerably larger than those from southernmost part, supporting recognition of two subspecies. The Cinnamon Myotis is morphologically similar to the Little Brown Myotis ( M. lucifugus). Dorsal hairs are bicolored, with dark brown bases and cinnamon-brown to reddish golden or yellowish tips. Ventral hairs are bicolored and lighter than dorsum, with dark brown bases and medium brown to pale yellow tips. Ears are medium-sized, extending forward halfway from eye to nostril. Tragus is long and slender, with broad base and narrower terminal one-half. Membranes, ears, and skin are mummy brown;tail is long; and uropatagium is highly developed and lacks dorsal and ventral hairs. Wings attach to outer toes. Skull is medium-sized and delicate (greatest skull lengths 14-8-15- 5 mm); frontals are subtly sloping; sagittal and lambdoidalcrests are well-developed; and occipital region is rounded and projects behind posterior surfaces of occipital condyles. Upper and lower molars are well developed, so that distance between C! and P! is reduced, and noticeable crowding of small P? and P* takes place.

Habitat. Tropical rainforests, deciduous forest, dry forests, forest edge, and agricultural areas adjacentto secondary vegetation from sea level up to elevations of ¢. 870 m.

Food and Feeding. The Cinnamon Myotis flies slowly and erratically at heights of c. 2-4 m. It catches insects in flight in forests, open habitats, and near water bodies. Diet composition consists of small insects, preferably dipterans, Formosan termites, and isopterans.

Breeding. Cinnamon Myotis breed once a year, coinciding with rainy season. Males with scrotal testicles have been found in August-September. Pregnant females have been reported in April-May, and births probably occurin late May. Females have one young per pregnancy.

Activity patterns. The Cinnamon Myotis is active during the early hours of the night and at dawn. It roosts in caves, crevices, tunnels, abandoned buildings, thatched roofs, hollow trees, holes in thistle stems, and coiled Heliconia (Heliconiaceae) leaves and under tree bark.

Movements, Home range and Social organization. Small groups of Cinnamon Myotis commonly share roosts, with individuals hanging separately rather than clustered together.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Cinnamon Myotis is widespread, presumably has a large population, occurs in protected areas, tolerates some degree of habitat modification, and is unlikely to be declining at nearly the rate to qualify for listing in a threatened category.

Bibliography. Chavez-Tovar & Ceballos (2014), Hall (1981), Hall & Dalquest (1950), Miller & Allen (1928), Perez et al. (2017), Reid (2009), Simmons (2005).