Physical characteristics

Horseshoe bats are characterized by a complex noseleaf expansion of the skin surrounding the nostrils and consisting of three parts. The horseshoe-shaped lower part covers the up per lip, surrounds the nostrils, and has a central notch in the lower edge. Above the nostrils is the lancet, a pointed, erect structure attached by its base. The horseshoe and the lancet are flattened from front to back. The sella is located between the horseshoe and the lancet, is flattened from side to side and is connected at its base by means of folds and ridges. The form of the noseleaf is often diagnostic in species identification. Horseshoe bats generally fly with the mouth closed and emit ultrasonic sounds through the nostrils. The sounds are channeled by the noseleaf structure to achieve a maximum intensity at a point of focus ahead of the bat, and the noseleaf also shields the ears from the direct reception of the impulses. In some species, such as Hildebrandt's horseshoe bat (R. hilde-brandti), the noseleaf has a distinctly arranged pattern of sensory hairs.

The large ears are widely separated, usually pointed, and lack a tragus, but the antitragal lobe is much enlarged and folds across the open base of the ear. The ears are capable of independent movement. The eyes are quite small, and the field of vision seems to be partly obstructed by the noseleaf, so sight is probably of little importance.

The fur of horseshoe bats is long, loose, and soft. The most common colors are gray-brown to rufous-brown, but the color varies from black or dark brown to bright orange-red

Blyth's horseshoe bat (Rhinolophus lepidus) roosting in Bhutan. (Photo by Harald Schutz. Reproduced by permission.)

or cream-yellow. The underparts are usually more pale than the upperparts. The woolly (R. luctus) and lesser woolly (R. beddomei) horseshoe bats have a very long, woolly pelage, unusual in the genus.

The wings are short, broad, and rounded, the second finger consisting of the metacarpal only, without phalanges. The third, fourth and fifth fingers each have two phalanges, which fold under the wing when the bat is at rest. The vertebrae of the tail end at the posterior fringe of the interfemoral membrane, which is supported on either side by curved calcanea arising from the ankles. The tail and interfemoral membrane fold upwards when the bat is resting. The hind limbs are poorly developed and these bats cannot walk quadrupedally. All the toes have three bones, except the first, which has two; the Hip-posideridae, in contrast, have only two bones in each toe.

Females have two mammary glands in the pectoral region and two "false nipples" on the lower abdomen, just anterior to the genital orifice, to which the young cling while they are carried around by their mother during flight. In two African species, the small Lander's horseshoe bat and the larger R. alcyone, the males have glandular hair tufts in the armpit area that are noticeable by their coloring. These males also have well-developed nipples, which do not produce milk, but perhaps secrete odor-producing substances.

Young horseshoe bats shed milk teeth before birth. The teeth of adults exhibit the normal cuspidate pattern found in insectivorous bats. The dental formula is: (I1/2, C1/1, PM2/3, M3/3) X 2 = 32. The upper incisors are mounted in a projection of the palatine bone, well forward of the canines. The lower incisors are trifid. The first upper and second lower premolars are small, usually displaced externally, and may be missing. The most characteristic feature of the skull is the dome just above the nasal aperture.

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