The Florida bonneted bat or Florida mastiff bat (Eumops floridanus) is a species of bat in the genus Eumops, the bonneted bats or mastiff bats. Until recently, it was classified as a subspecies of Wagner's bonneted bat (Eumops glaucinus). It is endemic to southern Florida in the United States. This species has one of the smallest geographical distributions of any New World bat. It has been called "one of the most critically endangered mammal species in North America". It is protected under the Endangered Species Act.
Taxonomy
The earliest bonneted bat fossil was discovered in 1922 in Melbourne, Florida. The fossil consisted of a preserved jawbone that dated back to the Pleistocene; its similarity to genera Eumops and Molossus was noted, but it was initially placed into a new genus, Molossides, due to what appeared to be a unique dental formula. The fossil was reclassified into the genus Eumops in 1963 on the belief that the original fossil did not show a bat with a single lower incisor, but rather the fossil jaw was missing an incisor and the species actually had two lower incisors.
A live bonneted bat was first recorded in Florida in 1936, from an individual collected from a high school in North Miami. At the time, it was identified as a Eumops glaucinus specimen, and it was hypothesized that it had been introduced accidentally by a fruit steamer from Cuba. In the following years, there was evidence of a breeding population in Florida, which refuted ideas that they were only occasionally transported in from Cuba. In 1971, the bonneted bat was reclassified as a well-marked subspecies of Eumops glaucinus, identified as Eumops glaucinus floridanus. This classification was maintained until 2004, when morphological analyses showed that the bonneted bat was distinct from other subpopulations of Eumops glaucinus in its skull, body mass, and forearm length. The new classification elevated the bonneted bat to its own species, Eumops floridanus.
Description
This is the largest bat in Florida. Adults weigh . Males and females are non-dimorphic in body mass. Forearm length is between . Individual wing length is , with male wings slightly longer and wider than female wings.
As a molossid, particularly from the genus Eumops, the bonneted bat has exceptionally high wing loading and aspect ratios. The tail extends far beyond the short uropatagium. The short, glossy fur is brownish-gray to cinnamon-brown in color. The hairs are bicolored, with the base of the hair lighter than the tip. Some individuals have been observed with a white band across their abdomens that is variable in size.
The ears of bonneted bats are large and forward-facing, their position giving the head a bonnetlike appearance. Their skulls have short, deep basisphenoid pits which aid in vocalization. Male bonneted bats sometimes have a gular-thoracic gland that may be used to mark females or a roosting site. Bonneted bats are non-migratory, and unlike other temperate bat species, they do not have periods of hibernation.
Distribution
The bonneted bat is endemic to southern Florida. It occurs in several counties, including Charlotte, Collier, Lee, Miami-Dade, Monroe, Okeechobee, and Polk. Florida bonneted bats are more likely to be detected in agricultural areas, as well as areas that have a high mean annual rainfall.
Biology
Reproduction
The female bears a single pup. Pregnant females have been observed in April, June, July, August, and September. Juveniles have been observed in January, April, May, June, July, August, September, October, November, and December. Females are believed to be aseasonally polyestrous, meaning that they could breed and become pregnant at multiple times throughout the year. However, a population of bonneted bats in Babcock-Webb Wildlife Management Area has the highest rate of pregnancy in April, when 95% of adult females are pregnant, compared to 10% in August and 0% in December.
Social structure
It roosts singly or colonially and may form harems. Many observed roosts have a strong female bias, with one harem containing twenty adult females and only one adult male. Roosts usually have one dominant male, that can be identified from an open gular gland, the largest body mass, and the greatest testes length. Harems are maintained throughout the year, which is in contrast to other bats of the eastern US where social groupings are seasonally variable.
Diet
The diet of the bat includes beetles, flies, and true bugs.