Asellia tridens
trident leaf-nosed bat

Trident nose-leaf bats are found in Northern Africa and the Middle east. Asellia tridens lives in some of the hottest areas in the world, spanning the region from Morocco to northern India.

There are two sub-species, A.t. tridens and A.t. murriana. Asellia t. murriana is commonly found only from Egypt to Saudi Arabia and into Israel and Jordan, , while A.t. tridens is found on either side of the range of A. t. muriana. (Qumsiyeh, 1996; Qumsiyeh, Amr, and Al-Oran, 1991; Weber, 1955; Yom-Tov and Kadmon, 1998)

Although successful in all habitats within its range, from from the desert to the Mediterranean coast, the sub-species A. t. murriana is found in some of the hottest areas of the desert where no other bats can seem to survive. (Qumsiyeh, Amr, and Al-Oran, 1991; Weber, 1955)

Although mainly a desert species, Asellia tridens has made some headway into coastal and mountainous regions. It roosts in a variety of sheltered areas, from caves to sheds and temples. (Qumsiyeh, 1996)

Asellia tridens is a member of the family Rhinolophidae, which is known for its nose-leaves. The nose-leaf is distinct, with three cusps (trident) on the leaf; the outer two are blunted, whereas the central one is pointed. (Fergusun, 2002; Pint and Pint, 2005; Weber, 1955)

There are two distinct color phases in this species, with one other variant sometimes appearing. The first phase is pale grayish-brown, and the second is pale orange-brown or silty-yellow with a whitish underside. The additional variant is described as having a reddish hue. (Fergusun, 2002; Qumsiyeh, 1996; Weber, 1955)

Some other important characteristics for identifying these bats in the field are its lack of a tragus, and its projecting tail, which can extend up to 5 mm beyond the flight membrane. Specimens are generally 66-90 mm in total length. (Hoath, 2003)

No information regarding the lifespan of these bats could be found.

Asellia tridens is a highly mobile, highly colonial species. These bats tend to roost in the hundreds to thousands in whatever shelter they can find, usually in caves, cliff crevices, and older or abandoned buildings.

They leave their roosts in the late evening when their prey items (especially moths) are abundant and easier to catch. Their flight pattern is described as low, with rapid swerving and twisting, much like a butterfly. They become torpid during daily roosting.

There is no evidence to suggest any social hierarchies or systems, though in most bats social grooming is common. (Qumsiyeh, Amr, and Al-Oran, 1991; Roberts, 2006)

Home Range

No information is available.

It is not known to what extent members of this species communicate with one another; however, it is likely that there is some scent communication, like pheromones, because they are mammals. In fact there is extensive use of scent marking within another Chiropteran order, Emballonuridae.

The most intriguing thing about bats must be their use of echolocation. Within the sub-order Microchiroptera all species use this as one of their primary sources of perception.

Because this species is nocturnal and insectivorous, individuals rely mainly on echolocation to locate and hunt down prey. In fact, this species' ability to negotiate through complex environments has been extensively researched, Asellia tridens can detect and avoid wires with a diameter of only .65 mm. ("Echolocation and obstacle avoidance in the hipposiderid bat Asellia tridens", 1979)

An in-depth study of Asellia tridens gives us a good estimate of its diet. The following is a list of the main prey found in guano in Israel:

Beetles (Coleoptera): this is the main prey item in the diet of A. tridens. The diet of the other bats in the area also consisted mainly of this prey item, in fact compared to the competition; Asellia was the least successful with this particular prey item.

Butterflies and moths (Lepidoptera): Asellia tridens was much better at catching this prey compared to the competition. This isn't too surprising, as many people have described their flight to be very quick and agile.

Crickets and grasshoppers (Orthoptera): Asellia tridens was also much more successful at catching these prey items than were their competitors.

Flies (Diptera): Asellia tridens was also quite successful at catching these prey items.

True bugs (Heteroptera): Asellia tridens was the worst amongst other bats in the area at catching these prey items, however, this group did not make up a significant portion of any of their diets.

Caddisflies (Trichoptera) and wasps and bees (Hymenoptera) were also found within the guano of A. tridens in the study.

Comparatively, A. tridens had the most diverse diet of all sympatric bat species, and excelled above all in their ability to catch moths and butterflies. (Whitaker Jr., 2002)

There are no known natural predators of this species. Young in roosts may be taken by predators such as snakes or other small, agile carnivores.

Asellia tridens plays a large role in controlling insect populations in its habitat. Nothing is known about its parasites, except that it is host to a tick (Argas fischeri). (Weber, 1955)

There are no recorded negative economic impacts due to Asellia tridens, although it could be considered a nuisance since it at times roosts within man-made structures. (Weber, 1955)

Colonies of A. tridens can consume vast numbers of insects, which may be crop pests or disease vectors.

Trident leaf-nosed bats are not currently protected by any legislation, populations seem stable and the species is widespread. Like all bats, populations may be threatened by roost disturbance, pesticides, and human persecution.