Marshall's Horseshoe Bat (Rhinolophus marshalli)


HB: 42; T: 20; FA; 45.5; E:27.

The pelage of the back is about 8mm long, dark brown with pale bases on the individual hairs above, smoky grey below. Some of the hairs on the back are tipped with Rufus. The ears are very large and funnel shaped with a large antitragus half the length of the ear. The anterior leaf is large, covering most of the upper lip and extending a few mm beyond the muzzle; it as a narrow, deep median anterior cleft. The internarial septum is cup shaped with the sides expanding into wing like structures enclosing the base of the  sella and behind the sella to merge with the base of the connecting process, which is low and poorly developed. The lancet is hidden behind the  sella when viewed from the front; the tip bluntly rounded . The skull is rather long, with the mastoid width greater than the zygomatic width. The nasal swelling are high and oblong, with a deep cavity behind them. The sagittal crest is low, the postorbital process obsolescent. The upper incisors are minute, widely separated and bifid, the lower incisors are trifid. The first upper and second lower premolars are small, but both are within the tooth row.

 Range Description:

 This species occurs in Myanmar, Thailand (Chantaburi, Amphoe Pong Nam Ron, foothills of Khao Soi Dao Thai),
Vietnam, Lao PDR, and Peninsular Malaysia.
Countries: Native:
Lao People's Democratic Republic; Malaysia; Myanmar; Thailand; Vietnam


It is always found as individuals, never in large numbers (P. Bates pers. comm.; S. Bumrungsri pers. comm.). It is not clear whether it has declined significantly historically (C. Francis pers. comm.).
Population Trend: Unknown

Habitat and Ecology:

 In Myanmar and Vietnam it is associated with limestone caves and is tolerant of very disturbed habitat (P. Bates pers. comm.). In Thailand it is also found in rock crevices (S. Bumrungsri pers. comm.).   No significant differences both in body mass and in forearm length between males and females at birth. On average, young bats were not agile fliers until 31 days of age. Body mass and forearm length of pups followed a linear pattern of growth until day 13, with mean growth rates of 0.17 g/day and 1.22 mm/day, respectively, and thereafter growth rates decreased. Length of the total epiphyseal gap of the fourth metacarpal-phalangeal joint showed a linear increase up to 10 days followed by a linear decrease until day 40 with a mean rate of 0.09 mm/day. Together, two equations permitted estimation of the age of R. marshalli pups between 1 and 40 days of age. Of the three nonlinear growth models (logistic, Gompertz, and von Bertalanffy), the logistic equation provided the best fit to the empirical curves for body mass and forearm length. The echolocation call is a long constant frequency signal, with a brief frequency-modulated start and tail. Frequencies with most energy recorded from hand-held bats ranged between 39.2-41.6 kHz
Systems: Terrestrial

Major Threat(s):

There are no major threats to this species.

 Conservation Actions:

This species occurs in a number of protected areas. All known populations are in protected areas in Thailand (S. Bumrungsri pers. comm.).