Blarina
Blarina is a genus of venomous shrews found in North America. These small mammals belong to the family Soricidae and are characterized by their short tails, dense fur, and notably, the presence of venom in their saliva.
Taxonomy:
- Kingdom: Animalia
- Phylum: Chordata
- Class: Mammalia
- Order: Eulipotyphla
- Family: Soricidae
- Genus: Blarina
Species:
The genus Blarina contains several recognized species, including:
- Blarina brevicauda (Northern Short-tailed Shrew) - the most widespread and well-studied species.
- Blarina carolinensis (Southern Short-tailed Shrew)
- Blarina hylophaga (Elliot's Short-tailed Shrew)
- Blarina peninsulae (Florida Short-tailed Shrew)
Description:
Blarina shrews are relatively small, typically measuring between 75 and 105 mm in body length, with a short tail of around 20-30 mm. Their fur is dense and velvety, usually dark gray or blackish in color, though variations can occur. They possess small eyes and ears, which are partially concealed by their fur. The rostrum (snout) is elongated and sensitive, enabling them to locate prey underground.
Venom:
The most distinctive feature of Blarina shrews is their venomous saliva. The venom, produced by submaxillary glands, contains kallikrein-like proteases. While not lethal to humans, a bite from a Blarina shrew can cause localized pain, swelling, and prolonged bleeding. The venom aids in subduing prey, such as insects, earthworms, and small vertebrates, and may also play a role in food storage.
Habitat and Distribution:
Blarina shrews inhabit a variety of habitats, including forests, grasslands, and wetlands. They are found throughout eastern and central North America, with ranges varying among the different species. They typically construct intricate burrow systems in the soil and leaf litter.
Behavior and Ecology:
These shrews are primarily nocturnal and crepuscular, meaning they are most active during the night and twilight hours. They are voracious predators with a high metabolic rate, requiring them to consume a large amount of food each day. They use their keen sense of smell and touch to locate prey. They are generally solitary animals, except during the breeding season.
Conservation Status:
The conservation status of Blarina species varies. Some species, such as Blarina brevicauda, are relatively common and widespread, while others may be more localized and vulnerable. Habitat loss and degradation are potential threats to some populations.
Interaction with Humans:
While Blarina shrews are not typically considered pests, they may occasionally enter human dwellings in search of food or shelter. Their venomous bite can be a concern, although serious complications are rare. Their role in controlling insect populations is often beneficial.