Townsend’s Bat Solution by Special Contributor Jack Nisbet

05 Jul


John Kirk Townsend was a young Philadelphia ornithologist who traveled overland to the Columbia country with an American trading party in 1833.Armed with a sensible Quaker background and a self deprecating sense of humor, Townsend spent the better part of the next three years documenting the fauna of our region.

    Specializing in bird and rodent specimens, Townsend managed to procure one of the last California condor collections from the lower California, but he also took a special interest in smaller fare. During his time here he described no fewer than five new wood warblers, including the beautiful one that still bears his name today.

      Along the way, he learned the Chinook jargon so he could communicate with the locals, and took the teasing of tribal people in stride.Occasionally harassed by their dogs while hunting for specimens, Townsend threatened to shoot the unruly animals if they were not tied up.From there on,” whenever i approached the lodges, there was a universal stir among the people and the words ‘iskam kahmooks kalaklalah tie chahko’ (take up your dogs, the bird chief is coming)’ echoed through the little village.”

    The Bird Chief was equally keen on small rodents, documenting the common pocket gopher of the area around Fort Vancouver and noticing a distinctive bat roosting in the buildings around the post.Today this animal is called Townsend’s big-eared bat, Plecotus townsendii, aptly named for ears that stretch to about half of the bat’s entire body length.A welter of strange lumps above its nose provide an alternate, unseemly name- the lump-nosed-bat- but its story is more intriguing than those unsightly bulges.

   Townsend’s big-eared bats are found at low-to-middle elevations throughout the Northwest.In breeding surveys made in the past few decades, it became clear that these bats were not common in the caves, mines, and crevices where biologists usually look, but frequented old buildings, especially in the warmer, more humid coastal areas.Females of the species roost in groups that range from a dozen to several hundred individuals, clumping together in tight clusters to preserve body heat and speed up the growth of the young.Males roost alone during summertime, usually in completely separate situations. Even though they have adapted to human buildings, both sexes are easily disturbed by the presence of people, and will quickly abandon the roost.

 In late summer, the nursery colonies disperse as the bats head for established hibernaculums, usually caves or mine adits that keep a steady cool temperature.Individual Townsend’s have been found alive in caves, where the air temperature is below freezing, with each gigantic ear curled down like a ram’s horn while the tragus- a thin cartilaginous structure attached to the base of the ear that is unique to bats and may serve as a temperature sensor- stands erect.

  For years the general theory of this bat’s out-sized ears was that they must amplify its rather quiet echolocation calls. More recently, some engineering-minded scientists have proposed that the extra surface area might serve as an airfoil during flight.In fact the Townsend’s is very agile in the air, capable of slow movements and quick turns. The ears might also help to regulate temperature, throwing off heat during sultry summer nights. The odd glandular lumps on the noses of these bats continue to perplex the zoologist as well. A favoured theory is that they could be sexual scent glands.

The documented food list of these nifty fliers lean toward small moths, with plenty of lace wings, dung beetles, flies, and sawflies on the menu. But this list does not include a singular interaction noticed by John Kirk Townsend when he was living at Fort Vancouver in the 1830s. There Townsend noted that the big-eared bats were “protected by the gentlemen of the Hudson’s Bay Company, for their services in destroying the dermestes beetles which abound in their fur establishments.”

Now we have arrived at a story. Dermestes makes up the group known as carrion beetles, but when fur men mentioned “dermestes” they meant Dermestes maculatus, known to company voyageurs as the hide, leather, or skin beetle. Hide beetles are long and oval in profile, dun-coloured, and lack the beautifuls patterns and colors that made beetle collecting a popular hobby during Townsend’s time. They have hairy fore wings and well-developed hind wings that allow them to fly in droning, straight-line trajectories that make them perfect for bat food.

Dermestes maculatus has a worldwide distribution and a long association with humanity. They are the species of carrion beetle typically used by universities, museums, and forensic labs to remove the flesh from bones in skeleton preparation. These flesh-gnawing habits created all kinds of havoc during the fur trade era, because they worked directly on industry’s stored hides. If a few hide beetle larvae made it into a ship’s stores at Fort Vancouver, they might infest the entire cargo by the time the vessel arrived at Hudson’s Bay Company headquarters in London. There were cases where the pelts of an entire season were condemned out of hand.

 That is why London merchants once considered offering a cash prize of E20,000 for a practical method that would control hide beetles in their furs. It was the same amount offered for the famous Longitude Prize of the 18th century, based on developing a dependable chronometer that could be used to determine accurate coordinates for vessels at sea. Yet it sounds as if, based on the keen observations of Mr. Townsend, that the fur men at Fort Vancouver had figured out a way to atleast put a dent in the Dermestes population by catering to a shy, lumpy-nosed bat with disturbingly large ears.

 Bats of British Columbia, by David Nagorsen and Mark Brigham, is a great place to find out about our local bats.


Treasured Northwest writer Jack Nisbet is a teacher, naturalist, and writer who lives in Spokane, Washington with his wife and two children.

Originally posted in


See our beautiful maps of the Great American Northwest! 



No comments yet.

Leave a Reply