Dollman's Tree Mouse
Encyclopedia
Dollman's Tree Mouse, Prionomys batesi, is a poorly understood climbing mouse
from Central Africa
. It is unique enough that it has been placed in a genus of its own, Prionomys, since its discovery in 1910.
in Cameroon
, La Maboké in Central African Republic
, and Odzala in Republic of the Congo
. In total only 23 specimens are known to be present in museum
s throughout the world (Denys et al., 2006).
Denys et al. (2006) indicate that Prionomys has a unique association with forest-savannah mosaics in central Africa. During interglacial
periods, this region has undergone varying degrees of wet and dry periods. Savannah
expands during dry periods and forest
expands during wet periods, but there are small scale shifts in which regions are dry or wet. Prionomys appears to be associated with forest habitat on the edge of savannah patches. In particular, the species occurs as forest is recolonizing areas that were once savannah. Thus it is thought to be associated with younger, earlier successional
forest but is no longer present in mature, late successional forest.
-like. Ears are small and round. The upper incisor
s are narrow, ungrooved, orange, and short. The lower incisors project forward (proodont) and are sharply pointed (Denys et al., 2006; Nowak, 1999).
Denys et al. (2006) note that the coronoid process
on the mandible
is reduced and that the animal appears to have the ability to push its lower jaw (and thereby its incisors) strongly forward. They suggest that Dollman's Tree Mouse uses this feature to dig its burrow with its lower incisors.
Prionomys appears to feed almost exclusively on certain species of ant
s, particularly Tetramorium aculeatum (Denys et al., 2006). Denys et al. (2006) suggest that this unusual diet may be part of the reason that so few individuals have been captured for study. Sherman live trap
s baited with vegetable-derived matter may not attract this species to the same degree that it does other small rodents. In many ways Prionomys is more shrew-like in its habits. Individuals have only been obtained in pitfall trap
s, captured by hand, or obtained from local hunters.
Dollman's Tree Mouse is nocturnal
and arboreal. Nowak (1999) suggests that the naked tip of its tail might be prehensile.
Deomys, but suggest this is due to convergence
due to similar diet and habits.
Dendromurinae
Dendromurinae is a subfamily of rodents in the family Nesomyidae and superfamily Muroidea. The dendromurines are currently restricted to Africa, as is the case for all extant members of the family Nesomyidae. The authorship of the subfamily has been contributed to both Alston, 1876, and to G. M...
from Central Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
. It is unique enough that it has been placed in a genus of its own, Prionomys, since its discovery in 1910.
Distribution and habitat
Dollman's Tree Mouse has only been recorded in four localities in three countries. These are Bitye and ObalaObala
Obala is a town in Cameroon's Centre Province, ca 45 km north of Yaoundé, the capital of Cameroon.-Overview:The town is the seat of a Roman Catholic diocese and hosts a military academy. Tourists in Obala may visit the somewhat derelict Luna Park whose main attraction is a swimming pool. Not far...
in Cameroon
Cameroon
Cameroon, officially the Republic of Cameroon , is a country in west Central Africa. It is bordered by Nigeria to the west; Chad to the northeast; the Central African Republic to the east; and Equatorial Guinea, Gabon, and the Republic of the Congo to the south. Cameroon's coastline lies on the...
, La Maboké in Central African Republic
Central African Republic
The Central African Republic , is a landlocked country in Central Africa. It borders Chad in the north, Sudan in the north east, South Sudan in the east, the Democratic Republic of the Congo and the Republic of the Congo in the south, and Cameroon in the west. The CAR covers a land area of about ,...
, and Odzala in Republic of the Congo
Republic of the Congo
The Republic of the Congo , sometimes known locally as Congo-Brazzaville, is a state in Central Africa. It is bordered by Gabon, Cameroon, the Central African Republic, the Democratic Republic of the Congo , the Angolan exclave province of Cabinda, and the Gulf of Guinea.The region was dominated by...
. In total only 23 specimens are known to be present in museum
Museum
A museum is an institution that cares for a collection of artifacts and other objects of scientific, artistic, cultural, or historical importance and makes them available for public viewing through exhibits that may be permanent or temporary. Most large museums are located in major cities...
s throughout the world (Denys et al., 2006).
Denys et al. (2006) indicate that Prionomys has a unique association with forest-savannah mosaics in central Africa. During interglacial
Interglacial
An Interglacial period is a geological interval of warmer global average temperature lasting thousands of years that separates consecutive glacial periods within an ice age...
periods, this region has undergone varying degrees of wet and dry periods. Savannah
Savannah
Savannah or savanna is a type of grassland.It can also mean:-People:* Savannah King, a Canadian freestyle swimmer* Savannah Outen, a singer who gained popularity on You Tube...
expands during dry periods and 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...
expands during wet periods, but there are small scale shifts in which regions are dry or wet. Prionomys appears to be associated with forest habitat on the edge of savannah patches. In particular, the species occurs as forest is recolonizing areas that were once savannah. Thus it is thought to be associated with younger, earlier successional
Ecological succession
Ecological succession, is the phenomenon or process by which a community progressively transforms itself until a stable community is formed. It is a fundamental concept in ecology, and refers to more or less predictable and orderly changes in the composition or structure of an ecological community...
forest but is no longer present in mature, late successional forest.
Description and natural history
This is a rather small (head and body = 60 mm) mouse with a fairly long (~100 mm) tail. The hair is short, soft, brown, and generally shrewShrew
A shrew or shrew mouse is a small molelike mammal classified in the order Soricomorpha. True shrews are also not to be confused with West Indies shrews, treeshrews, otter shrews, or elephant shrews, which belong to different families or orders.Although its external appearance is generally that of...
-like. Ears are small and round. The upper incisor
Incisor
Incisors are the first kind of tooth in heterodont mammals. They are located in the premaxilla above and mandible below.-Function:...
s are narrow, ungrooved, orange, and short. The lower incisors project forward (proodont) and are sharply pointed (Denys et al., 2006; Nowak, 1999).
Denys et al. (2006) note that the coronoid process
Coronoid process
The Coronoid process can refer to:* The coronoid process of the mandible, part of the ramus mandibulae of the mandible...
on the mandible
Mandible
The mandible pronunciation or inferior maxillary bone forms the lower jaw and holds the lower teeth in place...
is reduced and that the animal appears to have the ability to push its lower jaw (and thereby its incisors) strongly forward. They suggest that Dollman's Tree Mouse uses this feature to dig its burrow with its lower incisors.
Prionomys appears to feed almost exclusively on certain species of ant
Ant
Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...
s, particularly Tetramorium aculeatum (Denys et al., 2006). Denys et al. (2006) suggest that this unusual diet may be part of the reason that so few individuals have been captured for study. Sherman live trap
Sherman Trap
The Sherman trap is a box-style animal trap designed for the live capture of small mammals. It was invented by Dr. H.B. Sherman in the 1920s and became commercially available in 1955. Since that time, the Sherman trap has been used extensively by researchers in the biological sciences for...
s baited with vegetable-derived matter may not attract this species to the same degree that it does other small rodents. In many ways Prionomys is more shrew-like in its habits. Individuals have only been obtained in pitfall trap
Pitfall trap
A pitfall trap is a trapping pit for small animals, such as insects, amphibians and reptiles. Pitfall traps are mainly used for ecology studies and ecologic pest control. Animals that enter a pitfall trap are unable to escape, and may either be killed by the trap or remain unharmed...
s, captured by hand, or obtained from local hunters.
Dollman's Tree Mouse is nocturnal
Nocturnal animal
Nocturnality is an animal behavior characterized by activity during the night and sleeping during the day. The common adjective is "nocturnal"....
and arboreal. Nowak (1999) suggests that the naked tip of its tail might be prehensile.
Relationships
As with many other mice historically referred to as the "dendromurines", the phylogenetic position of Prionomys is somewhat uncertain. Denys et al. (1995) demonstrated a close association between Prionomys and Dendroprionomys on the basis of molar structure. This association has been widely noted elsewhere. Musser and Carleton (2005) suggest that the two are related may warrant a distinct tribe within the Dendromurinae. They also noted the retention of these two genera in the Dendromurinae seems reasonable but requires further testing. Denys et al. (2006) note the similarities between Prionomys and the deomyineDeomyinae
The subfamily Deomyinae consists of four genera of mouse-like rodents that were placed in the subfamilies Murinae and Dendromurinae until very recently. They are sometimes called Acomyinae, particularly in references that predate the discovery that the link rat, Deomys ferugineus, is part of the...
Deomys, but suggest this is due to convergence
Convergent evolution
Convergent evolution describes the acquisition of the same biological trait in unrelated lineages.The wing is a classic example of convergent evolution in action. Although their last common ancestor did not have wings, both birds and bats do, and are capable of powered flight. The wings are...
due to similar diet and habits.