Due to their fossorial lifestyle and solitary nature, Blarinomys breviceps sightings are rare. As a result, little is known of how they communicate with conspecifics and how they perceive their environment. It has reduced eyes, suggesting decreased reliance on sight. Thus, B. breviceps' haptic capabilities may be relatively advanced.
Perception Channels: visual ; tactile ; vibrations ; chemical
Silve et al. (2003) suggested that Blarinomys breviceps is extinct throughout much of its native range and is currently confined to mesic habitats in the Atlantic Forest. Although few specimens have been found at various locations throughout the Atlantic Forest, the IUCN Red List of Threatened Species lists B. breviceps as a species of "least concern". Due to its wide distribution and "presumed large population", there are not significant threats their their persistence. However, a potential threat to their survival is habitat destruction and fragmentation due to logging.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
There are no known adverse effects of Blarinomys breviceps on humans.
There are no known positive effects of Blarinomys breviceps on humans.
Blarinomys breviceps consumes insects and is an important prey item for a range of avian and possibly reptilian species. Also, its burrows provide shelter to other small, gallery-forest species.
Ecosystem Impact: creates habitat
Although limited information exists on the diet of wild Blarinomys breviceps, evidence suggests it is likely insectivorous (Abravaya and Matson, 1975; Abravaya and Matson, 1977). In captivity, B. breviceps consumes a variety of insects, including orthopterans (e.g., grasshoppers and crickets), lepidopterans (e.g., moths and butterflies), and cockroaches (Blattidae). With the exception of oranges, captive individuals tend to refuse fruits and seeds (Geise et al., 2008).
Animal Foods: insects
Plant Foods: fruit
Primary Diet: carnivore (Insectivore )
Blarinomys breviceps is rarely seen in the wild. As a result, during the 18th and 19th century it was widely assumed that they had become extinct. However, in 2003 and 2005, numerous specimens were captured near Rio De Janeiro, Brazil. Blarinomys breviceps is fossorial and occurs primarily in humid tropical and subtropical forests. Its geographic range includes forested areas in the Atlantic Forest, along the southeastern coast of Brazil, from Bahia State southwards to Misiones, Argentina. Although most sightings have been recorded in mountainous habitats, B. breviceps has also been found at sea level.
Biogeographic Regions: neotropical (Native )
Blarinomys breviceps can be found in semideciduous seasonal forests, evergreen forests, and mixed evergreen forests throughout the Atlantic Forest in southeastern Brazil (Geise et al., 2008). It is generally found at elevations between 750 and 1570 m (average 890 m), but has been sighted at sea level as well.
Range elevation: 750 to 1570 m.
Average elevation: 890 m.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: forest ; rainforest
Information regarding the lifespan of wild Brazilian shrew mice has not been documented. Captive specimens often refuse food and die within a few days. In general, Sigmondontine rodents live 5 to 12 months in the wild and up to 5 years in captivity.
Range lifespan
Status: captivity: 2 to 72 hours.
Brazilian shrew-mice have fusiform body morphology, suggesting a fossorial lifestyle. Their pelage is short and velvety, and has a slate-gray base color that becomes reddish-brown along the dorsal surface. They have reduced eyes, which are hidden beneath its fur (Geise et al. 2008; Abravaya and Matson 1977). Their hairless tail is short and usually less than 50% of total head and body length (Abravaya and Matson 1975). They have a conical skull with a flattened brain case and zygomatic breadth exceeds brain case breadth. They have high crowned teeth; however, tooth cusps often become worn flat. They have relatively long claws, which are most pronounced on the pollex. Brazilian shrew-mice exhibit minimal sexual dimorphism, as females have slightly longer tails.
Average mass: 12 g.
Range length: 129 to 161 mm.
Average length: 147 mm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: female larger
Blarinomys breviceps' fossorial lifestyle may help it avoid potential predators. However, a study performing dietary analysis on avian predators from South America suggests that B. breviceps has at least 3 main predators: burrowing owls (Athene cunicularia), white-tailed hawks (Buteo albicaudatus), and white-tailed kites (Elanus leucurus). Athene cunicularia is a nocturnal predator, while both B. albicaudatus and E. leucurus are diurnal predators. All three predator species tend to hunt in open environments such as fields and savannas.
Known Predators:
The mating system of Brazilian shrew mice has not been documented.
Although limited information exists for reproductive behavior in Brazilian shrew mice, scrotal males and lactating females have been found in January and February. In addition, pregnant females have been found from September to February (Davis, 1944; Matson, 1977). Based on this information, breeding season is thought to occur two times a year, from January to September,
Breeding interval: twice a year
Breeding season: January to September
Range number of offspring: 1 to 2.
Average number of offspring: 1.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Parental investment in Blarinomys breviceps has not been documented.
The Brazilian shrew mouse (Blarinomys breviceps),[2] also known as the blarinine akodont,[3] is a rodent in the tribe Akodontini from the Atlantic Forest of eastern and southeastern Brazil.[1] It is the only species in the genus Blarinomys.[3] Phylogenetic analysis suggest that there are two clear geographical clades, a northeastern and southeastern. [4]
The appearance of the Brazilian shrew mouse is often compared to that of small insectivorous shrews or moles with small, reduced eyes, short ears and tail, and short, soft fur.[5] Its mole-like appearance contributes to its ability to be differentiated from other rodents in its Neotropical habitat.[6] Overall, its specialized body structure lends itself to the animal's subterranean life, with broad forefeet and large claws for digging.[7] It has a long snout that is used to find insects in the ground and highly developed jaw muscles that help to close the mouth quickly, as to avoid swallowing dirt.[5] The species has demonstrated sexual dimorphism in that females are usually slightly larger than males.[6]
The average lifespan of the Brazilian shrew mouse is unknown, as they are difficult to find. Captive specimens tend to refuse food and die shortly after capture.[6] It is generally assumed that the species' lifespan is similar to other Sigmodontinae rodents, which is typically less than one year.[8]
Very little is known about the diet of B. breviceps, however it is assumed to be primarily insectivorous. When studied in captivity, many specimens refuse food and die within a few days. However, some captive organisms have been shown to eat a variety of insects including crickets, moths and butterflies, and roaches. Overall, they tend to refuse other food sources such as fruits or seeds.[6]
According to the International Union for Conservation of Nature's Red List of Endangered Species, the Brazilian shrew mouse is considered of least concern.[1] However, some experts suggest that since the species is so difficult to find, data is insufficient to confidently label their conservation status.[9]
The Brazilian shrew mouse (Blarinomys breviceps), also known as the blarinine akodont, is a rodent in the tribe Akodontini from the Atlantic Forest of eastern and southeastern Brazil. It is the only species in the genus Blarinomys. Phylogenetic analysis suggest that there are two clear geographical clades, a northeastern and southeastern.
