|
by Robert Colona What on earth are mustelids? Some sort of jarred edibles that must have their lids put on tightly to prevent spoilage? Wrong! Believe it or not, mustelids are the largest family of carnivores and Maryland’s leading family of furbearers. This group of mammals is more commonly known as the weasel family and contains nearly 70 species worldwide.
Virtually everyone is familiar with the striped
skunk (Mephitis mephitis). However, few people realize that the long-tailed
weasel (Mustela frenata), mink (Mustela vison), fisher (Martes pennanti) and
river otter (Lutra canadensis) are closely related to the skunk. The ferret,
stoat, polecat, marten and badger, as well as the ferocious wolverine, are also
members of the great mustelid family but are not found in Maryland. Mustelids are also elusive and rarely seen. In fact, they have a now-you-see-‘em-now-you-don’t quality about them. Found throughout Maryland, they fulfill extremely important roles in local ecosystems; with the exception of skunks, all are predators that feed predominantly on rodents and other small animals. Skunks are predators too, but they feed extensively on insects and some plant matter. Besides being ecologically valuable, mustelids
as furbearers are also a renewable economic resource. Furbearers can be loosely
defined as mammals that are legally harvested for their commercially desirable
pelts, which are fashioned into fur garments and other useful items. Of the
seven species of mustelid that live in Maryland, five are legally defined as
furbearers and are subject to regulated harvesting. Long-tailed weasels are generally brown with a yellowish-white underbelly and a distinct black tipped tail. In the northern United States, they molt in the fall and their pelage (furry coat) becomes totally white, remaining that color until they molt again in the spring, when it returns to brown. In the mid-Atlantic region (including Maryland) and farther south, they remain brown throughout the year. Weasels feed extensively on mice and other small mammals, but they also eat birds, small rabbits, reptiles and amphibians when available. Unevenly distributed across Maryland, they live in a broad variety of habitats including marshlands, woodlands, meadows, grasslands and rocky outcroppings. Mink Semi-aquatic, mink live near all types of water bodies, including fresh and brackish marshes, farm ponds, rivers and fast-moving streams. They prey on small mammals, fish, birds, amphibians and crustaceans, depending on what is seasonally available. Mink are common from Garrett County eastward to
the western shore of the Chesapeake and are found infrequently on some of the
Bay’s larger islands. For reasons unknown, mink are absent from the Eastern
Shore and many coastal regions of the eastern United States. Skunks feed extensively on insects but will eat plant matter, small mammals, birds and bird eggs when locally or seasonally abundant. Striped skunks are distributed statewide and are found in virtually all habitat types. The largest populations are normally found in mixed farmland and woodland areas, while lower densities are found in marshland and beach habitats. The characteristic odor produced by skunks comes from
butylmercaptan, a
sulfurous compound containing sulfuric acid. This compound is forcefully — and
famously — discharged from its two anal glands when the skunk is alarmed or
threatened. Animals sprayed by skunks often experience temporary blindness,
respiratory distress, nausea and burning skin. In fact, all mustelids have
glands that secrete a noxious substance, which they use as a territorial marker
or defensive weapon. Historically, fisher populations in eastern North America extended from Canada through the northeastern states and down through the Appalachian Mountains as far south as Tennessee. However, by the early 1900s, fisher were extirpated from Maryland and other central and southern Appalachian states. In 1969, the West Virginia Division of Wildlife Resources began a fisher reintroduction project. The agency obtained 23 animals from New Hampshire that were released at two sites: 15 on Canaan Mountain in Tucker County and 8 near Cranberry Glades in Pocahontas County. By 1972, just three years later, West Virginia’s fisher population had expanded sufficiently to support a legal harvest season. Fisher were first documented in Maryland in 1974. Since that time, population densities have risen, and occupied ranges have expanded to include suitable habitats throughout Garrett and western Allegany Counties. Fisher appear to be present at lower numbers in central and eastern Allegany County. The first modern recorded harvest of fisher in Maryland occurred during the winter of 1977-78, when two animals were incidentally trapped. Maryland established its first legal harvest season in the 1978-79 season, permitting both hunting and trapping. River Otter Until the last decade, otters were distributed throughout the state except for Garrett and Allegany Counties and western Washington County, where they had been extirpated in the 1800s. In the early 1990s, DNR began a project to reintroduce the species to the region when otters were taken from resident populations on the Eastern Shore and released in Garrett County. Initial efforts focused on the Youghiogheny River basin but later expanded to include the county’s smaller drainage systems. After populations became self-sustaining in Garrett County, otters were released in Allegany County. As a result of these successful reintroductions, river otters are now distributed statewide. The highest populations occur in the coastal plain adjacent to the Chesapeake Bay and decrease incrementally proceeding westward until reaching their lowest levels in Allegany County. In Garrett County, otter populations have increased dramatically and the animal is now considered common. Worth a Better
Understanding We humans can see a little of ourselves in mustelids, even putting them into our vocabulary. We speak of “ferreting” out the truth and “badgering” a witness. To lose a game badly is to be “skunked,” and to evade an obligation is to “weasel” out of it. Fascinating creatures, they are unfortunately seldom seen and therefore poorly understood by most of us. Mustelids have been around for roughly 35 million years — so now is probably as good a time as any to get to know more about them. Robert Colona
is furbearer Project Leader for the Maryland Department of Natural Resources.
|
Long-Tailed Weasel
to
be 50 percent larger than females. Their fur is short, soft, dense and lustrous,
and varies from light brown to almost black.
They have white chin and chest patches that vary in size.
The striped skunk is typically black with a white patch on its head and two
white stripes that extend down its back, which converge into a white stripe on
its tail. There is a great deal of natural variation in the pelage of striped
skunks, and individuals may infrequently appear almost entirely black or white.
The fisher diet includes squirrels, rabbits,
small mammals, birds and — surprisingly — porcupines. Fisher are arboreal; that
is, they spend a lot of time in trees. Consequently, their habitats always
include a large wooded component. They are found in or near mixed forests,
woodland glades and farm fields.
nearly
5 feet in total length (head to tail) and 12 to 35 pounds. Their short, dense,
and glossy fur runs in various shades of brown. River otters feed predominantly
on fish but will also eat crustaceans, mollusks, amphibians, reptiles and other
small animals when locally abundant. Like mink, they are semi-aquatic and are
found in most healthy bodies of water. In Maryland, they occupy rivers, streams
and tidal marshes.