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| Large Rufous Horseshoe Bat Rhinolophus rufus Eydoux & Gervais, 1863 |
| Common Names: Bayakan
Habitat/Distribution: Recorded from Bohol, Catanduanes, Laguna, Pampanga, Leyte, Mindanao, Rizal provinces. Description / Behavior: Head and body length is about 35-110 mm, tail length is 15-56 mm, and forearm length is 30-75 mm. Color varies greatly, ranging from reddish brown to deep black above and paler below. These bats have a peculiar, complex, nose-leaf expansion of the skin surrounding the nostrils. It consists of three parts. The lower part, which is horseshoe-shaped, covers the upper lip, surrounds the nostrils, and has a central notch in the lower edge. Above the nostrils, the appendage is a pointed, erect structure, the lancet, attached only by its base. Both the horseshoe and the lancet are flattened from front to back. The sella, located between the horseshoe and the lancet, is flattened from side to side; it is connected at its base by means of folds and ridges. The shape and arrangement of the nose leaf varies from species to species. These bats generally fly with their mouth closed and emit ultrasonic sounds through the nostrils. The sounds thus emitted may be oriented with the aid of the nose leaf. The ears are large and lack a tragus. Two teatlike processes not connected with a mammary gland, known as dummy teats, are found on the abdomens of females in addition to the two functional mammae on the chest. An infant horseshoe bat may grasp the dummy teats of its mother while she carries it during flight. 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: (i 1/2, c 1/1, pm 2/3, m 3/3) × 2 = 32. The nasal region of the skull is considerably expanded. All the toes have three bones, except the first, which has two; the Hipposideridae, in contrast, have only two bones in each toe. The eyes of horseshoe bats are quite small, and the field of vision seems to be partly obstructed by the large nose leaf, so sight is probably of little importance.
These bats, roosting where they can hang freely, do not close their wings
alongside their body as do most bats, but wrap them around the body. The
small bare patch on the back at the base of the tail is covered by the upturned
tail and membrane; the bat is thus completely enclosed in its flight membranes
and resembles the pod of a fruit or the cocoon of an enormous insect. When
the bat is at rest, the basal axis of the head makes a right angle with the
vertebral column, so that it looks in the direction of its ventral surfaces.
The wings are broad with rounded ends. Horseshoe bats generally have a
fluttering, butterflylike, or hovering flight. Their relatively short tails
and small tail membranes are not large enough to form a pouch for holding
insects. When a large insect is caught in flight, it may be tucked into the
wing membrane under the arm while the bat manipulates it with its mouth.
Horseshoe bats sometimes alight with large prey in order to eat more easily.
These bats begin feeding on insects and spiders later in the evening than
most bats and often return to the roost to eat their catch. They usually
hunt within six meters of the ground, and will also feed on the ground. Like
many bats, they generally have regular feeding territories or hunting
areas. Conservation Efforts/Measures: Photograph Information: Courtesy of the JHU. Not actual subspecies picture - just an example to show what the Rhinolopus GENUS looks like |
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