Hatt's Vesper Rat
Encyclopedia
Hatt's vesper rat also known as the Yucatán vesper rat, is a species of rodent
in the family Cricetidae
. It is the only species in the genus
Otonyctomys. It is named for its discoverer, Robert T. Hatt.
-like appearance, and closely resembles the related Sumichrast's vesper rat
, from which it can most easily be distinguished by its much larger auditory bulla
e. It is relatively small for a rat, both sexes having a head body length of 9 to 12 cm (3.5 to 4.7 ), and a long, 6 to 13 cm (2.4 to 5.1 ), tail. Adults weigh from 23 to 36 g (0.811301128417575 to 1.3 ).
The rat is brightly coloured, with bright russet or yellowish fur over most of the body, and creamy or white underparts. The face has a short, rounded snout, and conspicuous black markings in front of the eyes, stretching as far as the whiskers. Younger individuals tend to be duller in colour, and have less glossy fur than the adults. The tail is thickly covered with brown fur along its entire length, although the ears are largely hairless. Females have four abdominal teats.
, in the Mexican states of Campeche
, Yucatán
, and Quintana Roo
, and in northern Guatemala
and Belize
. It inhabits broadleaf tropical forests close to water and below about 250 metres (820.2 ft) elevation. It has generally been recorded in trees or liana
s, on fallen wood, or even in the rafters of houses, and may be largely arboreal in its habits.
female. It is listed as a threatened species in Mexico, but is considered of least concern
by the IUCN because of its apparently wide distribution and adaptability. Fossil specimens have been discovered dating back to the Pleistocene
.
Rodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....
in the family Cricetidae
Cricetidae
The Cricetidae are a family of rodents in the large and complex superfamily Muroidea. It includes true hamsters, voles, lemmings, and New World rats and mice...
. It is the only species in the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Otonyctomys. It is named for its discoverer, Robert T. Hatt.
Description
Hatt's vesper rat has a typical ratRat
Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus...
-like appearance, and closely resembles the related Sumichrast's vesper rat
Sumichrast's vesper rat
Sumichrast's vesper rat is a rodent of the family Cricetidae found from southern Mexico to Panama. The adult length is 11–13 cm, with a tail length of 8.5-15.5 cm. It is one of the more brightly coloured rats, with a pinkish-brown back and white underparts. The first toe on each foot is...
, from which it can most easily be distinguished by its much larger auditory bulla
Auditory bulla
The auditory bulla is a hollow bony structure on the ventral, posterior portion of the skull of placental mammals that encloses parts of the middle and inner ear. In most species, it is formed by the tympanic part of the temporal bone.In extant primates, the structure is found in tarsiers,...
e. It is relatively small for a rat, both sexes having a head body length of 9 to 12 cm (3.5 to 4.7 ), and a long, 6 to 13 cm (2.4 to 5.1 ), tail. Adults weigh from 23 to 36 g (0.811301128417575 to 1.3 ).
The rat is brightly coloured, with bright russet or yellowish fur over most of the body, and creamy or white underparts. The face has a short, rounded snout, and conspicuous black markings in front of the eyes, stretching as far as the whiskers. Younger individuals tend to be duller in colour, and have less glossy fur than the adults. The tail is thickly covered with brown fur along its entire length, although the ears are largely hairless. Females have four abdominal teats.
Distribution and habitat
Hatt's vesper rat is found throughout the Yucatán PeninsulaYucatán Peninsula
The Yucatán Peninsula, in southeastern Mexico, separates the Caribbean Sea from the Gulf of Mexico, with the northern coastline on the Yucatán Channel...
, in the Mexican states of Campeche
Campeche
Campeche is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. Located in Southeast Mexico, it is bordered by the states of Yucatán to the north east, Quintana Roo to the east, and Tabasco to the south west...
, Yucatán
Yucatán
Yucatán officially Estado Libre y Soberano de Yucatán is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 106 municipalities and its capital city is Mérida....
, and Quintana Roo
Quintana Roo
Quintana Roo officially Estado Libre y Soberano de Quintana Roo is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 10 municipalities and its capital city is Chetumal....
, and in northern Guatemala
Guatemala
Guatemala is a country in Central America bordered by Mexico to the north and west, the Pacific Ocean to the southwest, Belize to the northeast, the Caribbean to the east, and Honduras and El Salvador to the southeast...
and Belize
Belize
Belize is a constitutional monarchy and the northernmost country in Central America. Belize has a diverse society, comprising many cultures and languages. Even though Kriol and Spanish are spoken among the population, Belize is the only country in Central America where English is the official...
. It inhabits broadleaf tropical forests close to water and below about 250 metres (820.2 ft) elevation. It has generally been recorded in trees or liana
Liana
A liana is any of various long-stemmed, woody vines that are rooted in the soil at ground level and use trees, as well as other means of vertical support, to climb up to the canopy to get access to well-lit areas of the forest. Lianas are especially characteristic of tropical moist deciduous...
s, on fallen wood, or even in the rafters of houses, and may be largely arboreal in its habits.
Biology
The rat is little studied, and, as of 2008, was known only from eighteen specimens. It appears to be nocturnal, and herbivorous, eating seeds and fruit, and to spend much of its time in the trees. The breeding season, if it has a specific one, is unknown, although one specimen caught in February was a lactatingLactation
Lactation describes the secretion of milk from the mammary glands and the period of time that a mother lactates to feed her young. The process occurs in all female mammals, however it predates mammals. In humans the process of feeding milk is called breastfeeding or nursing...
female. It is listed as a threatened species in Mexico, but is considered of least concern
Least Concern
Least Concern is an IUCN category assigned to extant taxon or lower taxa which have been evaluated but do not qualify for any other category. As such they do not qualify as threatened, Near Threatened, or Conservation Dependent...
by the IUCN because of its apparently wide distribution and adaptability. Fossil specimens have been discovered dating back to the Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
.