Macrophyllum macrophyllum
long-legged bat

M. macrophyllum is found throughout eastern Central America and South America (Emmons, 1997). First discovered in Brazil, at Rio Mucuri, M. macrophyllum is also found in localities in Peru, Ecuador, Bolivia, British Guiana, Venezuela, and Colombia. The species ranges down to San Ignacio, Argentina and as far north as central Mexico (Harrison, 1975).

M. macrophyllum is found in a variety of habitats including tropical deciduous forest, rain forests and rain forest clearings (Harrison, 1975). These bats are usually found near water pools. They roost singly or in small groups in wet tunnels, culverts, under bridges and in caves and abandoned buildings. The species is often found living in irrigation tunnels in Central and South America (Emmons, 1997). Specimens have been caught on tree trunks over water, hanging in sea caves, and in a vaulted cellar in Old Panamas ruins (French, 1999). One colony of M. macrophyllum, described by Harrison and Pendleton in 1975, lived in a water culvert under a road in Guatemala (Harrison,1975).

M. macrophyllum can be distinguished by its long tail enclosed within the broad interfemoral membrane, which is studded on the ventral side with a distinctive row of about seven vertical lines of dots, each ending with a bump on the straight rear edge of the tail membrane (Reid,1997). The wing membrane extends from the distal end of the tibia. The dorsum is dark brown and the ventral side is paler, and the wings and tail membrane are brown. Hair becomes paler toward the base and the wings and interfemoral membrane are naked (Harrison, 1975).

M. macrophyllum has long legs, hence its common name. Its feet are enlarged. Extremely large and powerful claws, which are as long as the animals' tibia, protrude from the hind feet of the bat. The ears are large, pointed, and slightly hairy on upper rim with a large tragus extending up into the ear, typical in this family of bats. The noseleaf, used in echolocation, is large with a vertical central ridge, as is also typical in the family. The rostrum is short, shorter than the width of the skull. The tympanic bulae are small and basioccipital pits are absent (Harrison, 1975).

The dentition is similar to Micronycteris, but the upper anterior premolar is reduced, slightly larger than the outer upper incisor, and the first and third lower premolar almost touch because they crowd the middle premolar (McCarthy, 1989). The gap between the canines is almost completely filled by the upper incisors, and the middle incisors are much larger than the outer incisors. The overall body form is slender.

M. macrophyllum can be distinguished from all other small (forearm less than 40mm) leaf nosed bats because they have much longer tails (Emmons, 1997; Harrison, 1975).

Females were pregnant at two different localities at two different times in Guatemala (Seymour and Dickerman, 1982). At El Recuerdo, the females were pregnant in the rainy season and at San Jose, they were pregnant in the dry season. Another study showed the testes of males obtained on October 16 to range between 4.6 and 5.1mm and a male collected on June 16 had testes measuring 5.7mm. Three of the males collected by Felton in 1956 in December were considered to be sexually active (Harrison, 1975).

In the 2 births described, the single embryo was 18mm and 17.5mm length in length. Even though at birth the embryos were quite small, the claws and feet were well developed and large, the feet and claws of both individuals measured 8mm. This was equal to the length of the specimens' forearms and nearly half the animals' length. The distinguishing nodules were already present at birth (Harrison, 1975).

Seymour and Dickerman (1982) reported that of an original cohort of 90 bats, 41 were recaptured on later dates. Seven were recaptured for the last time after 232-239 days, eight after 334-341 days, 10 after 593-605 days, and 9 at the end of the study after 960-966 days(Eisenberg, 1989; Seymour and Dickerson, 1982).

Echolocation is used to find prey. The noseleaf is thought to be used to help focus the waves produced in echolocation (Baud, 1989). These bats fly with a fluttering, butterfly-like flight and may use their long toes and tail membrane to skim insects from or near the water surface (Emmons, 1997)

M. macrophyllum feed on insects, including water striders.

The anatomy of the posterior extremities is in some ways similar to that of fish-eating bats Noctilio and Pizonyx, and some researchers thought that M. macrophyllum had a similar diet as the fish eating bats. But further research reveals no evidence of aquatic hunting. Examination of the bats' stomachs found finely chewed insect remains, and wing fragments (probably lepidopterous and dipterous), confirming that most of the animals diet consists of flying insects although aquatic insects and blood from animals were found on occasion as well (Reid, 1997).

When found in large colonies, M. macrophyllum, like all other insectivorous bats, can have a dramatic effect on the insect populations in the area. M. macrophyllum has more of an effect on the aquatic insect life than most bats just specializing in the predation of flying insects. (Harrison, 1975).

M. macrophyllum, like many bat species, controls insect problems through predation. Also, when bats congregate in caves and other habitats to roost, they produce guano in massive quantities. This guano can be mined for use as fertilizer for crops or just mined for its phosphorous content (Seymour and Dickerman, 1982).

M. macrophyllum is an uncommon bat scattered throughout Central and South America. It normally lives in the rainforest, and destruction to the rainforest limits habitats for M. macrophyllum (Nowak, 1999). In contrast, construction of roads with access and irrigation tunnels may be beneficial for M. macrophyllum (Harrison, 1975).