Leaf-nosed bat

Leaf-nosed bats
Artibeus sp.
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Chiroptera
Superfamily:	Noctilionoidea
Family:	Phyllostomidae Gray, 1825
Type genus
Phyllostomus Lacépède, 1799
Subfamilies
Brachyphyllinae Carolliinae Desmodontinae Glossophaginae Phyllostominae Stenodermatinae

The New World leaf-nosed bats (Phyllostomidae)^[1] are found from southern North America to South America, specifically from the Southwest United States to northern Argentina. They are ecologically the most varied and diverse family within the order Chiroptera. Most species are insectivorous, but the phyllostomid bats include within their number true predatory species and frugivores (subfamily Stenodermatinae and Carolliinae). For example, the spectral bat (Vampyrum spectrum), the largest bat in the Americas, eats vertebrate prey, including small, dove-sized birds. Members of this family have evolved to use food groups such as fruit, nectar, pollen, insects, frogs, other bats, and small vertebrates, and in the case of the vampire bats, even blood.

Both the scientific and common names derive from their often large, lance-shaped noses, greatly reduced in some of the nectar- and pollen-feeders. Because these bats echolocate nasally, this "nose-leaf" is thought to serve some role in modifying and directing the echolocation call. Similar nose leaves are found in some other groups of bats, most notably the Old World leaf-nosed bats.

New World leaf-nosed bats are usually brown, grey, or black, although five species are white. They range in size from 4.0 to 13.5 cm (1.6 to 5.3 in) in head-body length, and can weigh from 7 to 200 g (0.25 to 7.05 oz). Most roost in fairly small groups within caves, animal burrows, or hollow trees, although some species aggregate in colonies of several hundred individuals.^[2] They do not hibernate, although some species have been reported to aestivate.^[3][4]

Evolution[]

The Phyllostomidae, also known as New World leaf-nosed bats, are among the most ecologically diverse mammal families, displaying more morphological variation than any other mammalian family. This variation is measured by diversity in skull morphology and diet-related characteristics: Phyllostomidae consists of species that have evolved physical modifications for insectivory, frugivory, hematophagy, nectarivory, and omnivory.^[5][6] The nose-leaf—a distinctive characteristic of the family—is thought to have evolved to reflect dietary and foraging behavior of different species of Phyllostomidae.^[7] With an evolutionary history tracing back to the Oligocene, fossil and phylogenetic evidence suggests the family originated about 30 million years ago.^[8] Leaf nosed bats evolved from Yangochiroptera and Miniopteridae with sister groups also evolving from this group. The Phyllostomidae consist of 55 genera and about 180 species.^[6][9]

Description[]

New World leaf-nosed bats are bilaterally symmetrical and endothermic mammals^[10] characterized by an elaborate outgrowth of skin on their noses, called a nose-leaf, which is believed to aid in echolocation.^[11] The nose-leaf can be adorned with a vertical leaf, a concave upward leaf, or multiple accessory leaves; varying by species.^[12] Leaf-nosed bats lack a tail,^[11] have triangular-shaped ears that can have pointed or rounded tips,^[11] range in body size from 4 cm to 13.5 cm, and a wingspan up to 90 cm or more.^[9]

Biology and ecology[]

Like other bats, leaf-nosed bats are nocturnal foragers that use echolocation to locate food sources, though the food sources vary between species.^[13] Many bats in the family Phyllostomidae appear to have limited reliance on echolocation, likely because frugivorous bats do not need to quickly identify flying insects like many other bats.^[7] Instead, species of leaf-nosed fruit bats appear to use scent to identify their preferred food sources.^[14]

When they are not foraging, leaf-nosed bats roost in abandoned buildings, caves, and beneath folded leaves depending on the species. Nearly every roosting option present among bats is represented within this family, including species that prefer to roost alone, as well as species that roost with thousands of other individuals every day.^[15][16]

Diet[]

The Phyllostomidae demonstrate the most diverse dietary habits of any family of bats across the globe.^[17] Because of this, general dietary patterns are categorized for each species. Leaf-nosed bats generally specialize in a particular type of diet which leads to classification in one of these groups: frugivore, nectarivore, insectivore, omnivore, or haematophagous.^[15] However, categorizations are based only on primary consumption habits, therefore observing species that occasionally consume food items outside of their particular classifications is not uncommon.^[15] Usually, when leaf-nosed bats consume outside of their primary dietary categorization, it is to ensure sufficient intake of nutrients that their primary food source may not provide. For example, nectar and ripe fruits provide sufficient amounts of carbohydrates and water, but are lacking in protein and fat.^[18] To meet basic nutritional requirements, leaf-nosed bats that primarily feed on fruit and nectar must also ensure sufficient protein and fat intake by consuming insects or leaves.^[18]

Most leaf-nosed bats are classified as insectivores and feed on a variety of small insects. Certain species with this classification capture their prey either while in flight or from foliage in trees or on the ground. Carnivorous species feed on a variety of animals ranging from frogs to other bats. The Desmodontinae fall into this general carnivorous category, but are further distinguished by feeding exclusively on blood. In contrast, some species in this family feed on exclusively plants, gaining needed nutrients from fruits and leaves.^[17]

Life cycle[]

Leaf-nosed bats are gonochoric (separate sexes) that partake in sexual copulation.^[10] These bats can live for 20–30 years^[19] and females become sexually active at two years of age.^[20] Female ovulation occurs from October through September, after the female mates, the gestation period ranges from 8–9 months with an initial 3- to 5-month diapause period when the fetus growth is slowed; this diapause period is controlled by hormones.^[20] The female gives birth to a single pup, which has open ears, open eyes,^[19] and the first set of deciduous teeth,^[21] and is fully furred at birth.^[19]

Social systems[]

Among species that roost in groups, some evidence exists for a social hierarchy with higher-ranking individuals gaining access to preferred areas of the site.^[22] Solitary roosting bats, though, live alone and maintain a strict fidelity to a single roosting site.^[23] In some cases, males live alone or with harems, while females prefer to roost with other individuals and their pups.^[24] In nearly every species that has been studied, mothers and pups maintain a social bond that lasts beyond nursing.^[23] Apparently, young bats can learn food preferences from their mothers and when they are reluctant to leave the nest, mothers literally nudge the infants out of the roost.^[25][14]

Range[]

New World leaf-nosed bats range from the United States, in southern Arizona and the West Indies to northern Argentina.^[26][27] The family inhabits a diverse array of environments and habitats ranging from forests to deserts.^[9]

Human impact[]

Species of New World leaf-nosed bats that make their homes in forested areas are greatly affected by agricultural intensification.^[28] Specifically, it has been found that increased agricultural activity by humans causes negative conservation effects on these habitats and as a result reduces abundance and diversity of leaf-nosed bats that live there.^[28] California leaf-nosed bats in particular are susceptible to human disruption. This species is known to create large roosts in closed mine shafts due to their potential to provide warmth and isolation.^[29] When humans enter the shafts or rework old mines, this disrupts the roosts of the leaf-nosed bats and has the potential to be detrimental to the population as a whole.^{[citation needed]}

Classification[]

The 192 described species within 56 genera are:

References[]

Wikimedia Commons has media related to Phyllostomidae.

Wikispecies has information related to Phyllostomidae.