Mt. Pirri Isthmus Rat
Encyclopedia
The Mt. Pirri Isthmus Rat (Isthmomys pirrensis) is a species of rodent
in the family Cricetidae
.
Its natural habitat
is subtropical or tropical moist lowland forest
s. It is found only in Panama
. At the time of its discovery it was considered as the “most common rat of southeastern Panama” (Anthony 1916). Found only in the eastern region of Darien, I. pirrensis appears to be a relict
species confined to the Panamanian side of the Serrania del Darien (Hershkovitz 1966). Its occurrence on the Colombia
n side of the Serrania has been suggested without documentation of specimens (Alberico et al. 2000; Cuartas-Calle and Muñoz-Arango 2003; Hall and Kelson 1958; Hershkovitz 1966). Localities for I. pirrensis indicated by museum records are in the eastern Panama state of Darien throughout the areas surrounding Mt. Pirre (=Pirri, 7° 51' 8 N, 77° 46' 24 W), Mt. Tacarcuna and the Tacarcuna Village (8° 10' 58 N, 77° 17' 3.5 W); however, no specimens are recorded from the low lying areas (<800m) that bisect these two ranges.
Although neotomine-peromyscine rodents have historically been the subject of systematic research, studies involving Isthmomys have generally excluded I. flavidus due to its rarity in museum collections and the unavailability of tissue samples for molecular analysis (Bradley et al. 2007; Bradley et al. 2004; Carleton 1973; Engel et al. 1998; Hill 1975; Stangl and Baker 1984). In addition, morphological
and physiological
studies involving I. flavidus (Carleton 1973, 1980; Hill 1975; Hooper and Musser 1964; Linzey and Layne 1974; Linzey and Layne 1969; Voss and Linzey 1981) utilized specimens from the Cerro Hoya locality which was originally proposed as a geographic race of I. pirrensis (Handley 1966).
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...
.
Its natural habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
is subtropical or tropical moist lowland forest
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
s. It is found only in Panama
Panama
Panama , officially the Republic of Panama , is the southernmost country of Central America. Situated on the isthmus connecting North and South America, it is bordered by Costa Rica to the northwest, Colombia to the southeast, the Caribbean Sea to the north and the Pacific Ocean to the south. The...
. At the time of its discovery it was considered as the “most common rat of southeastern Panama” (Anthony 1916). Found only in the eastern region of Darien, I. pirrensis appears to be a relict
Relict
A relict is a surviving remnant of a natural phenomenon.* In biology a relict is an organism that at an earlier time was abundant in a large area but now occurs at only one or a few small areas....
species confined to the Panamanian side of the Serrania del Darien (Hershkovitz 1966). Its occurrence on the Colombia
Colombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
n side of the Serrania has been suggested without documentation of specimens (Alberico et al. 2000; Cuartas-Calle and Muñoz-Arango 2003; Hall and Kelson 1958; Hershkovitz 1966). Localities for I. pirrensis indicated by museum records are in the eastern Panama state of Darien throughout the areas surrounding Mt. Pirre (=Pirri, 7° 51' 8 N, 77° 46' 24 W), Mt. Tacarcuna and the Tacarcuna Village (8° 10' 58 N, 77° 17' 3.5 W); however, no specimens are recorded from the low lying areas (<800m) that bisect these two ranges.
Although neotomine-peromyscine rodents have historically been the subject of systematic research, studies involving Isthmomys have generally excluded I. flavidus due to its rarity in museum collections and the unavailability of tissue samples for molecular analysis (Bradley et al. 2007; Bradley et al. 2004; Carleton 1973; Engel et al. 1998; Hill 1975; Stangl and Baker 1984). In addition, morphological
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
and physiological
Physiology
Physiology is the science of the function of living systems. This includes how organisms, organ systems, organs, cells, and bio-molecules carry out the chemical or physical functions that exist in a living system. The highest honor awarded in physiology is the Nobel Prize in Physiology or...
studies involving I. flavidus (Carleton 1973, 1980; Hill 1975; Hooper and Musser 1964; Linzey and Layne 1974; Linzey and Layne 1969; Voss and Linzey 1981) utilized specimens from the Cerro Hoya locality which was originally proposed as a geographic race of I. pirrensis (Handley 1966).