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Monday, January 21, 2013

A Wolf By Any Other Name

Less than a year after the U.S. Fish and Wildlife Service removed Michigan’s gray wolves from the federal endangered species list some perplexing management questions have arisen.  In particular, the DNR’s recent conclusions about wolf/coyote genetics in the Lower Peninsula have created confusion.

The federal government effectively turned over wolf management in our state to the DNR on January 27, 2012.  The state’s official wolf count then was 687 (made in 2010) and biologists said that Gogebic County in the western Upper Peninsula had “the highest density of wolves in the United States.”  The DNR claimed there were 131 wolf packs in the U.P. and a small number of wolves in the northeastern Lower Peninsula.
Many Michiganders welcomed the de-listing, because it might make it easier to get permission to kill wolves threatening cattle, dogs, and other domestic animals, and pave the way for wolves to be treated as a game animal. This past summer, House Bill 5834 was introduced to let the Natural Resources Commission establish Michigan’s first wolf hunting season.  This seems consistent with all the lines in a conservation success story – a species brought back from the brink of extirpation to be managed wisely under the North American Conservation Model.  But there’s a fly in this ointment. 

The federal delisting followed a period in which the DNR gradually recognized what citizens had been claiming for 25 years -- that wolves had crossed the Straits of Mackinac into the Lower Peninsula.  In a July 27, 2010 announcement about the trapping of a wolf pup in Cheboygan County, the DNR’s Wildlife Division Chief, Russ Mason, stated: “This is another example of how wolf recovery has been successful; however, it also underscores why Michigan needs full authority to manage these animals as they begin to expand across the state.”  But missing was any public statements about population goals, research objectives, or any other basic elements of a wolf management plan for the Lower Peninsula.  And coincidently, wolves in the Lower Peninsula seemed to go “poof” soon after with DNR statements this spring that wolf-like animals verified there are actually coyotes.  That conclusion, based on recently-published genetic tests, seemed likely, at least in the short-term, to relieve the DNR of figuring out how to manage wolves in the Lower Peninsula.

In June of this past year, the Michigan Wildlife Conservancy asked the DNR to clarify the agency’s position on wolves in the Lower Peninsula.  Dr. William Moritz, Natural Resources Deputy, replied on August 17:

“There have been four sightings of wolves in the Northern Lower Peninsula since 2004.  Three sightings were camera photos or video and one was a radio-collared animal caught in a trap.  Since the initial photo in 2004, we have conducted track surveys annually and have not confirmed the presence of wolves in the area.  We did discover one set of tracks found in 2011 in northeast Cheboygan County that were likely the tracks of a wolf.

In October of 2010, some canid pups were observed and subsequently marked that exhibited the physical appearance of wolves.  Those animals were genetically tested and found to be coyotes with some wolf ancestry on the maternal side, but back several generations.  Enclosed is an article published in the American Midland Naturalist that details these findings.  Since the radio-collaring of two of those animals, we have also determined that they act as coyotes with small home ranges and limited daily movements.

We continue to monitor the Northern Lower Peninsula for the presence of wolves.  While we have no recent confirmed sightings, it is plausible that a few animals are present.”

The article referred to by Dr. Moritz was authored by two staff members of the Ontario Ministry of Natural Resources and long-time DNR researcher Dean Beyer.  Titled “Coyotes in Wolves’ Clothing” it classified three pups the size of wolves as coyotes based on DNA analyses.  The authors acknowledged that a biologist with the U.S. Department of Agriculture’s Wildlife Services Branch had identified the first pup captured as a wolf based on dentition (teeth), size, and weight, had found adult-sized wolf tracks at the den where the trapping occurred, and saw three more “wolf” pups nearby.  A DNR biologist similarly identified two later-trapped pups as wolves.

However, the authors concluded all three trapped pups were coyotes based on “genetic assignments.”  They stated that a female wolf could have bred with a coyote in the Upper Peninsula and its descendants later crossed to the Lower Peninsula.  Alternatively, a female wolf could have crossed to the Lower Peninsula and bred with a coyote several generations back.  Such an event likely occurred 10 to 20 years ago, with certain genetic information passed on in coyote litters.

There is nothing in this published research to suggest errors in those genetic assignments.  So, assuming their analyses are valid, this should be troubling news.  Does this effectively stifle protection of any wolf-like animals in the Lower Peninsula because anyone who shoots or traps such an animal can easily get off the hook?  The DNR reportedly told a trapper who later caught the three pups in question that it was up to him whether he killed the animals because they had been classified as coyotes.  The trapper released them, but the incident suggests that the DNR will not protect wolf-like animals, refusing to invoke the so-called “look alike” clause of endangered species protection law, unless their genetic information matches “pure wolf.”  And could there be a bunch of “coyotes in wolves’ clothing” in the Upper Peninsula?

Despite some “behind the scenes” criticism by biologists over the classification of Lower Peninsula wolves as coyotes, officials don’t seem to care much.  The DNR hasn’t even said whether having wolves in the Lower Peninsula is a goal.  DNR biologist, Adam Bump, recently acknowledged there are likely some “real” (but unverified) wolves in the Lower Peninsula, but offered no indication of where management might be headed.

In January of 2012, Russ Mason, chief of the wildlife division for the DNR had said giving the DNR the right to manage gray wolves was “a big win for the state.”  He added, “the best thing about this decision (federal de-listing) is that it turns management of wolves back over to Michigan, and (other) state wildlife agencies that have brought back 90% of the wildlife in this country, whether it’s deer or turkey or elk.”
Of course, with management rights comes responsibility.  It seems reasonable to expect animals that weigh 90 or so pounds and leave four to five-inch foot prints will be properly classified – in a legal and ecological sense – not just according to a DNA analytical model.  “Super coyotes” like the three pups are likely equivalent of wolves to most Michiganders.

When wolves were extirpated, or at least reduced in numbers, in the Midwest and East a century ago, coyotes showed up and thrived.  The natural range expansion of coyotes came from multiple strongholds in the West.  It was rapid and complete.  There are now few areas east of the Mississippi River where coyotes are absent.

In parts of southeastern Canada interbreeding between timber wolves and coyotes has been fairly-well documented.  And in North Carolina, re-establishment of red wolves has been hindered by such mixing of red wolves and coyotes.

Still, there are northern wolf populations in parts of Quebec as well as the Northwest where there are no coyotes.  The recent restoration of wolf packs in Yellowstone National Park involved importing “pure” gray wolves.  The idea is that while Yellowstone has coyotes as well, the wolves won’t mate with them if there are enough wolves.  Research suggests wolves mate with coyotes only where wolves are scarce and coyotes abundant.

The genetics of the wild dog family in North America have only recently been explored in any detail.  Some scientists now think eastern coyotes should be classified as a separate species from coyotes from the west.  That’s because eastern coyotes have some DNA typical of eastern wolves as well as DNA characteristic of “western coyotes”.   A study in Maine in 2004 found that about one-fifth of eastern coyotes sampled there had some DNA characteristic of wolves and about five percent had some DNA typical of dogs.

The nature of Michigan’s Upper Peninsula wolves is also unclear.  Some may be gray wolves, others resulted from matings (long ago) among gray wolves and Eastern timber wolves, which many geneticists believe is a separate species.

The finding of “coyotes in wolves’ clothing” in the Lower Peninsula is yet another potential blurring of genetic lines.  The size of what the DNR is presently calling “coyote pups” is well beyond the ancestral hybridization affect seen in Maine where adult coyotes may reach 60 pounds.  It’s also interesting that the DNR says the Lower Peninsula animals in question have coyote-like tendencies while the coyotes in the East are said to have wolf-like tendencies such as pack hunting.

At any rate, there seem to be more questions than answers.  And that’s getting the new era of wolf management off on the wrong foot.  More genetic testing of wolves (and coyotes) in both Peninsulas seems warranted, and the DNR should address a number of management scenarios for the Lower Peninsula “wolves.”

Monday, January 14, 2013

Alive Under the Microscope

Exploring BWC Wetlands with Dr. James Atkinson

Few people take a closer look at our waters than Dr. James Atkinson, a biologist and educator retired from Michigan State University.  In this first article of a two-part series, he describes the fascinating animals from the Bengel Wildlife Center that escape the naked eye.

Advocates of the conservation of lakes, ponds and wetlands usually focus on the large, charismatic organisms found in these ecosystems. Cranes, ducks, mink, moose and fish serve as symbols of the animals needing protection. However, these ecosystems also teem with tiny creatures whose diverse roles in complex food webs make them essential for the survival of the larger animals. Many of these creatures are visible only as tiny specs with the unaided eye.  The microscope can reveal their complex structures and fascinating behaviors and give us clues to the critical roles these animals play in the aquatic food web.

In recent years, the term “food web” has replaced “food chain” because we’ve come to realize that the interaction of organisms is much more varied than originally thought. The bottom level of the aquatic food web consists of two types of resources upon which succeeding levels are based. The first resource is the producers: green plants, algae, and some protists (protists are single-celled plants and animals) that convert the energy of sunlight into organic compounds through photosynthesis. The second resource involves the organic waste (animal waste, the parts of dead plants and animals) that accumulates at the bottom of wetlands. Collectively referred to as “detritus,” this material serves as the medium for a wide variety of bacteria (the so-called “bacteria of decay”) which grow by breaking down the complex organic material into simpler components.  Thus begins a process of recycling critical to a healthy aquatic ecosystem.

Subsequent levels of the food web are: consumer level I that is occupied by the herbivores that feed on the producers, and detritivores that feed on the detritus and the bacteria within it; consumer level II that includes animals that feed on occupants of level I as well as other members of level II; and consumer level III consisting of the ‘top ‘carnivores among the invertebrates such as insect larvae and crayfish and the smaller vertebrates such as fish fry, frogs and salamanders. Above this last group are the larger fish, birds such as ducks, herons and eagles, and mammals such as ourselves which feed on the insects, fish and frogs.

Consumer Level I

The herbivores: There are many types of single-celled organisms, protists, that feed on algae and the photosynthesizing protists. The microscopic animal herbivores that can be found in aquatic systems include the eight-legged water bears (tardigrades) and the round worms (nematodes) that have complex mouth parts allowing them to penetrate plant cell walls and suck out the contents. Newly hatched aquatic snails feed on algae and some plants by rasping with their ribbons of ‘teeth.’ The adults of such snails are not microscopic, but nevertheless function as level I consumers. 

The detritivores: The most diverse group of microscopic creatures of consumer level I feed on the bacteria within the detritus or their products (simple organic compounds). Most of the familiar protists we learned about in high school biology such as Paramecium and Amoeba are detritivores. Among the many groups of animals that occupy level I is one of the smallest but perhaps most important, the gastrotrichs. These tiny animals (smaller than some protists) feed directly upon the bacteria. There are about 800 species of gastrotriches world wide, but under certain environmental conditions a single species may be found with a million individuals per cubic meter of water. This is because gastrotrichs are among the few animals that can survive at extremely low levels of oxygen.  So, in wetlands that are heavily polluted with organic wastes and thus have extremely large numbers of bacteria, the gastrotrichs thrive. Since they serve as food for level II consumers, gastrotrichs help restore such polluted wetlands to good health.  

Perhaps the most diverse group of the microscopic detritivores is the rotifers. Called “wheeled animacules” by Leewenhoek, the 16th century founder of microscopy, they appear to have spinning wheels at their anterior end. This appearance is produced by the rapid beating of hair-like cilia which function to either propel the animal through the water or propel the water through the animal. In the latter case, the animal consumes the bacteria and detritus in the water, digesting the nutrients and expelling the waste. Some rotifers stop swimming in order to feed and others are able to feed while they swim.  

The largest of the microscopic detritivores are representatives of two groups of worms. The flatworms are free-living relatives of important parasites (tapeworms and flukes). They have a single opening into their digestive tract that serves as both a mouth and an anus. Some of the larger flatworms such as the planaria act as scavengers, feeding on the bodies of dead animals and thus acting like vultures in the process of recycling. Many small flatworms feed directly on the detritus, apparently digesting the bacteria. Many of these worms reproduce by producing small buds that remain attached to the parent as they grow.  This gives the worm a chain-like appearance.  These chains should not be confused with the segmented worms, microscopic relatives of the earthworm. Unlike the flatworms, the segmented worms have separate mouth and anus, and are often so transparent that the gut contents as well as their movement reveal their presence. The active feeding of segmented worms helps to stir up the detritus, releasing some of the smaller organic molecules into the water column and making them available to swimming animals and protists.

Another group of detritivores that stirs up the detritus while feeding is the microscopic crustaceans. The water fleas (cladocerans) and copepods are relatives of crayfish and crabs with jointed legs. Some species of water fleas and copepods swim within the detritus, pulling pieces of organic material into their mouths with their many jointed legs and digesting the bacteria within. 

These Level I consumers are fed on by a host of animals that many first-time pond explorers as well as scientists find fascinating.  We’ll look as these incredibly adapted predators in the next issue of The Wildlife Volunteer.

Monday, January 7, 2013

Mother Nature’s Digging Machine

The badger has sacrificed so much sleekness to become a powerful digger that many people are surprised to learn that it is a member of the weasel family.   However, it does belong to that family, and has all of the normal weasel toughness and tenacity.  
It also has a variety of special adaptations that include massive shoulders and short, powerful legs.  The front feet contain long curved claws that can pulverize virtually any soil, and the hind feet are specially adapted to throw this loosened soil back up the hole.  These features help make the American badger and some cousins on other continents the best digging carnivores in the world. 
The American badger’s upper body is covered by a grizzled mixture of white, black, and gray fur that blends in well with grass and brush.  It also has vivid white cheeks and a striking white line that runs across the top of its nose and head to the shoulders.  A large badger can reach 30 inches long and weigh 25 pounds, and would be an extremely handsome animal if its height was proportional to its length.     
Badgers maintain individual territories up to two miles across, and move from one old  burrow to another or dig new ones as they travel around it.  They obtain most of their food by digging woodchucks, ground squirrels, and other burrowing rodents out of their dens, but are also known to eat birds, snakes, insects, and plant material. 
While badgers are usually associated with the prairie and plains states, Michigan does have populations in both peninsulas.  However, many Michiganders have never seen one because our populations are small and the species is largely nocturnal.  I have a venerable old Montana badger skin in my house that encourages sighting reports, but I seldom hear about more than one or two Michigan sightings a year.     
This skin also provides me with occasional badger stories, including a classic chicken coop story from one of my Calhoun County neighbors.  He was awakened by a  ruckus in his chicken coop one night many years ago, and brought his ten year old daughter along to investigate the situation.  When they pushed the coop door open they found several dead chickens and a ferocious, snarling animal that my neighbor did not immediately recognize.  However, he knew that it was not compatible with chickens, and shot it by the light of the flashlight that his young daughter was holding.
This incident illustrates why badgers were viewed as pests in the days when most farms had chickens.  However, those days are gone, and our rural residents have a much better relationship with this interesting and intelligent animal now. 
No article about badgers would be complete without mentioning the lost boy who may have lived with badgers for several days.  While this old Manitoba story was not investigated as closely as it would be now, it does include specific names, dates, and locations.  In addition, the renowned naturalist Ernest Thompson Seton explored the story when it was relatively fresh and accepted its basic truth.     
The story began when five-year old Billy Service wandered away from home and became lost while picking strawberries near Springfield, Manitoba in the summer of 1873.  Billy eventually came to a badger den that had a large side entrance because it had originally been excavated by wolves, and crawled inside when it began to rain. 
Alas, part of the den was being used by a mother badger and two young ones, and the  mother initially tried to drive Billy away.  However, Billy refused to leave, and the mother gradually mellowed as Billy and her own babies became happy playmates out in front of the den.  Remarkably, the legend even credits her with bringing Billy an occasional dead rodent or grasshopper while she was feeding her own babies.  Billy ate enough grasshoppers and strawberries to be reasonably healthy when a neighbor found him at the den ten days later.
This is the story that became a Manitoba legend and inspired a whole genre of novels about children and badgers.  It will always be problematic because of Billy’s age and the sparsely settled nature of the area in 1873.  However, Billy was found in a large badger den and had the sort of scratches and torn clothing that a mother badger might inflict trying to drive him away.   And his descriptions of the playful babies and the way that their mother brought them food are consistent with known badger behavior.  While Billy’s story still needs to be treated with caution, it is too intriguing to leave out of an article on the digging weasel.
Additional Information
More Facts About Badgers
Badgers do best in grasslands but can also live in other environments with dry, diggable soil and large amounts of open land.                  
While badgers have lived more than 20 years in captivity, five years is a more realistic life expectancy for wild ones.  
The American badger is not a true hibernator, but does become lethargic and spends a large amount of time sleeping in its den in cold weather.
The badger’s continual digging can create serious hazards in fields and pastures.  However, it also provides ready-made dens for rabbits, skunks, snakes, and a variety of other animals. 
Female badgers typically give birth to two or three young in a grass-lined section of their den in the early spring.  The pups begin eating solid food and playing outside the den  in late Ssring, and are usually ready to strike out on their own by late summer or early fall. 
Badgers will fight fiercely when provoked.