Tuesday, November 26, 2013

Mites: Wildlife Bed Bugs

mitesThe arrival of weather with temperatures favorable for snowmaking, blustery northwest winds, and damp, unstable air that produces periodic bouts of flurries forces many forms of wildlife into a less active routine and causes them to spend more time in some type of shelter. As the length of their daily confinement to a nest or den increases, there is an expansion of the population of tiny organisms that make their home on the skin of many forms of wildlife.

While vast stretches of wilderness serve the ecological needs of numerous warm-blooded animals, the microenvironment that exists at the very base of a mammal’s dense coat of fur provides countless invertebrates with the space they need in which to carry out their life cycle.

With the approach of winter, all mammals develop a thicker coat of fur to better insulate them against the cold. As hair increases in density, more small air pockets are created directly against the creature’s skin to allow for better retention of body heat. This thicker coat of fur also forms an increased concentration of the nearly microscopic nooks that provide a refuge or habitat for ticks, lice, mites, fleas and other similar organisms.

In summer, when a mammal supports a relatively thin coat, it is more difficult for an organism that lives on the surface of another animal’s body to firmly anchor itself to its host’s hide. Since humans have relatively little body hair, except on their scalp, compared to any member of our wildlife community, most of these unseen skin inhabitants do not remain on a person should they accidentally come into contact with an arm, leg, or neck of a hiker, hunter or camper.

Not only is there a variety of types of skin organisms that occur on wildlife, there is also a diversity of species that impacts different animals and in some instances the same form of mammal. For instance, the hide of a beaver serves as home to 3 or 4 different types of mites. Each of these nearly microscopic arachnids has evolved to be most successful in a different place on the body of this rodent. While the exterior of a muskrat is also home to mites, these are not the same as the ones that impact the beaver. There are also various other skin organisms that can live in the fur of a beaver, including a tiny, worm-like beetle which has evolved a life cycle surrounding this flat-tailed mammal.
Since mites are best seen with the aid of a microscope, trappers that routinely handle their fur are oblivious to the presence of these organisms as they skin the carcass. While some mites may get transferred to the trapper during the fleshing process, these entities are unable to live on a human’s skin and die shortly thereafter.

While some of these surface organisms are considered to be parasitic, and can inflict harm and transfer disease to their host, the vast majority of them do not. During eons of evolution, some of these creatures have developed a style of feeding that actually benefits the host. For example, many types of mites derive their nourishment from dead skin cells that continually form on the surface of an animal. By consuming these particles of dandruff, these mites, in a small way, groom their host.

As a general rule in nature, the most successful parasites never seriously harm their host, as a sick or weak host is often unable to provide the same level of nourishment as one that is healthy. All effective parasites may become a nuisance to their host; however, their presence does not impact the overall ability of the host to survive. Bed bugs that have evolved to live in the bedding material used by humans do not carry any known disease, nor do they extract enough blood to produce any noticeable impact on a person’s daily routine. They simply take a few drops of blood while a person is unconscious in order to continue their life cycle. While this seems upsetting to many people, they are not considered to be a serious health threat.

As a squirrel, mouse, beaver, vole, raccoon, bear or other creature beds down for a day or more on a collection of dried leaves, needle, moss or grass, some adult fleas, mites, lice, or other nearly invisible organisms, or their nymphs or eggs become dislodged from the skin of their host and get embedded in the surface layer of the nest. Should another member of the host family, or visitor later lie down in that spot, these organisms can easily access the fur of the new host and enter a new ectoparasitic community. This allows for the propagation of genetic material and the continuation of a healthy population of skin organisms.

The Adirondacks is home to a wide diversity of wildlife, and the bodies of many of these creatures also serve as a functioning community of living entities, most of which have not been well researched and lie just out of our range of vision.


Tom Kalinowski

Tom Kalinowski is an avid outdoor enthusiast who taught field biology and ecology at Saranac Lake High School for 33 years. He has written numerous articles on natural history for Adirondack Life, The Conservationist, and Adirondack Explorer magazines and a weekly nature column for the Lake Placid News. In addition, Tom’s books, An Adirondack Almanac, and his most recent work entitled Adirondack Nature Notes, focuses on various events that occur among the region’s flora and fauna during very specific times of the calendar year. He also spends time photographing wildlife. Tom’s pictures have appeared in various publications across the New York State.




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