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Friday, July 12, 2013

The Year of The Mosquito

The Year of The Mosquito
This year is shaping up as a bad one for people who are particularly annoyed by mosquitoes.
Michigan has about 60 species of mosquitoes.  Not all species of mosquitoes bite humans.  Not all human-biting mosquitoes carry disease? Some mosquitoes breed in wetlands.  Others breed in your sump pump, a bird bath, street catchment basins or any number of other locations. 
Although mosquitoes breed in wetlands,in healthy wetlands with stable water levels year after year, fish and other predators keep mosquito numbers low.
 Wetlands are definitely a glass-half-full/half-empty test of perception.  When you look at a wetland, you may see habitat for turtles, frogs, ducks, birds, spawning fish, deer and any number of other interesting species.  When a public health official looks at a wetland, he or she may see an incubator for life-threatening diseases.
It was only in the 1800’s that the link between malaria and mosquitoes was established. Previously, people believed that a miasma, or poisonous atmosphere rising off swamps, made people sick.  Real estate prices came to reflect that.  Wealthier people lived on higher ground; poorer people lived by the swamps.  Even the terminology has come to carry connotations:  wetland is more likely to be used by people who see the virtues of wet places; swamp is more likely to be used by someone who wants to drain them.  The first Europeans to arrive in Michigan found a land filled with wetlands and mosquitoes.  They didn’t find malaria, however.  That, they brought with them.  Later settlers found malarial swamps.  When the federal government made gifts of land for our state capitol and for the nation’s first land grant college, the Michigan Agricultural School (now Michigan State University), in the mid-1800’s, there were some strings attached.  Before the land could be comfortably used, it would first have to be drained.  Nonetheless, the school had to be closed several times because so many faculty and students were suffering from malaria.
Prior to the mid-1800’s, drainage was accomplished primarily by ditches.  Underground drainage tiles were first used in Michigan in a major way by Zachariah Chandler.  He owned a lot of land around Lansing and became a wealthy man by draining and selling it.  Portions of the march which bears his name still exist today, mere shadows of the great wetland which stretched from Bath, where the Bengel Wildlife Center stands today, to the Michigan State University Campus about 4 miles away.
To stand today on the eastern edge of one of the sod farms located in what was once the Chandler Marsh, and look into the sunset over miles of flat green grass, inspires the viewer to imagine the lush diversity of plant, animal and birdlife that must have once lived there.  To stand in the same place 150 years ago, and wonder if that mosquito at the back of your neck was carrying malaria must have been a very different experience—enough to inspire men to drain swamps.  And drain they did—Michigan today has only 50 percent of the wetlands it had when the Europeans arrived. 
It wasn’t the drainage that actually got rid of the malaria, however.  Malaria is transmitted to humans by Aedes aegypti mosquitoes.  To eliminate malaria from an area, you can, in theory, drain the swamps to eliminate mosquito habitat, or kill mosquitoes, or you can eliminate the malaria from the humans.  That’s ultimately how we got rid of malaria.  Window screens aren’t just a convenience they’re a public health measure.  Chloroquine and other drugs, along with window screens, eliminated malaria from the human population.  The mosquitoes keep breeding and biting, but they have no malaria to pass along.  If a traveler brought back malaria to Michigan today, the disease would not become established, because we have drugs to eliminate the parasite from humans.  That’s why malaria remains a disease of poverty and lack of education in some places in the world.  People cannot afford the drugs, or if they can, they may take them until they feel better and then share them with a sick family member.  Not completing the full course of antibiotics is what has led to the emergence of drug-resistant strains of malaria.
Malaria is in some ways simpler than other diseases, however.  West Nile virus, for example, survives in avian hosts.  Even if it were possible to treat or isolate every person who got the West Nile virus, it would be impossible to eliminate future cases of the disease.  That’s because some mosquitoes seek their blood meal from both birds and humans.  Killing all the birds seems an unlikely and unpopular solution.
As many as 43 other species of mosquitoes around the world have been found to harbor the West Nile virus and it is not known how many Michigan species carry the virus and bite humans.  Culex pipiens, a primary vector, represents a major problem however.  Standing water, whether in a cow’s hoof print, a clogged gutter, or under a potted plant, provides breeding habitat for Culex pipiens.  That makes control measures difficult to implement.
In the hierarchy of preferred ways to eliminate mosquitoes, eliminating habitat is near the top, in the view of some.  Depending upon the species of mosquito, this may or may not have an impact on other forms of wildlife.  Since culex pipiens breeds in many human artifacts, eliminating those habitats should be high priority.  You can reduce mosquito populations in your vicinity by eliminating standing water. 
 Most mosquitoes lay their eggs either singly or in a tiny “raft” on the surface of the water.  Larvae emerge from the eggs and go through further states of development in the water, eating organic matter and microorganisms.  BTI (Bacillus thuringiensis israelensis) is a bacterium that disrupts the digestion of the larva and kills it.  The bacteria don’t harm humans or pets, so among the control options, it has a smaller impact.  However, finding all the possible breeding locations is nearly impossible.  Chemical larvicide is also sometimes used, with more significant implications for other forms of wildlife.  Some species of mosquitoes lay their eggs in cattail roots, in which the larvae develop.  These survive larvicides. 
Insecticides are usually the option of last resort for mosquitoes.  Populations can be reduced, but not eliminated.  The pesticides are indiscriminate and land on mosquitoes, people and desirable forms of wildlife.  In Mosquito—Man’s Deadliest Foe, the authors report that truck spraying will…”kill at least some mosquitoes, and it does assure local residents that the outbreak is being taken seriously.”  In the period of public concern surrounding outbreak of a mosquito-borne disease, the public often initially supports spraying of pesticides.  Then the balance shifts and vociferous objections are heard.  It is not possible to make any ironclad scientific case for or against spraying, and decision-making is complicated by the fact that values must be accounted for as well. 

Because mosquito control decisions must be based on value judgments as well as scientific data, public participation is essential.  Find out what your community has planned to do to deal with mosquito outbreaks.

TREATING HEARTWORM IN YOUR DOG MAY PREVENT SUFFERING FROM MOSQUITO-BORNE DISEASE
IN AFRICA
In the 60’s and 70’s, the occurrence of heartworm, a mosquito-born disease of dogs, skyrocketed in Michigan.  What had been a disease of the American south became endemic here.  Dogs are not routinely treated to kill the tiny worms.  Similar microfilaria causes the mosquito-borne elephantiasis in parts of Africa.  Ivermectin, one of the drugs used to treat heartworm, is also used to treat people suffering from elephantiasis.  Andrew Spielman, coauthor of Mosquito:  Man’s Deadliest Foe, reports that U.S. sales of the drug for canine use may subsidize donations of Ivermectin by a U.S. Drug company to the World Health Organization for human use in Africa.



FOR MORE INFORMATION
The Michigan Mosquito Control Association provides good general background information at www.mimosq.org.  On the site, you can download a 109-page booklet to help communities plan for mosquito control, prepared in cooperation with the Michigan Department of Agriculture.
Official State of Michigan in on West Nile virus is at www.wnv.state.mi.us

Catching Great Air

Catching Great Air (1902)

A scientist documents the remarkable aerodynamic adaptations of northern flying squirrels.

Article and photograph by Alexander V. Badyaev
Alex Badyaev kicks off a series on Michigan squirrels and squirrel-like animals that will be featured in the next several issues of The Wildlife Volunteer.  Michigan is home to both flying squirrel species found in North America [the northern and southern flying squirrels.]  Although Badyaev researches the northern flying squirrel, the southern species is very similar in characteristics and ecological niche.

[Alex Badyaev, a professor of evolutionary biology at the University of Arizona, conducts long-term field research projects throughout Montana and Arizona. Also a professional photographer, Badyaev is a multiple winner of the BBC Wildlife Photographer of the Year, National Wildlife, and Nature Best Photography competitions. Most recently his photos are featured in a new book Mammals of Montana.  To view Alex Badyaev’s photography and order prints, please visit www.tenbestphotos.com.

I spend the day in my research cabin north of Ovando in the Blackfoot River Valley poring through photographic equipment manuals to determine the lowest temperature of operation. Meanwhile, the radio is broadcasting severe winter weather warnings, with dangerously low overnight temperatures. Finally, I decide on a plan and head into the forest.
A few hours later, after snowshoeing six or seven miles into the backcountry, I stop and begin working in the diminishing February twilight. As quickly as possible in the freezing cold, I string a rope of strobe lights along the branches of several trees. The lights are connected to a high-speed camera set on the ground and aimed at a gap in the tree canopy framing a tiny half-acre forest pond on the southern boundary of the Bob Marshall Wilderness. From previous field research by me and my graduate students, I knew that local female northern flying squirrels regularly travel along the lakeshore. In winter, the squirrels emerge from roosting cavities shortly after midnight and range throughout the forest, traveling to their under-snow food caches by remarkably consistent routes.  My goal was to photograph squirrels in flight in a natural context, something that has rarely been done before.
Based on my observations from previous nights, I expected the female squirrel I’d targeted to fly over the lake sometime between 2:20 a.m. and 2:50 a.m. Unfortunately, the overnight temperature was predicted to plummet to -40 degrees F, greatly increasing the chances of camera failure. But the risks were worth it. In Montana, February is the middle of the northern flying squirrel’s mating season. During that time, even in severe cold, each female is typically escorted through the forest by a squabbling squadron of ardent males. I was hoping to also photograph those males and their dizzying aerial mating chases.
AN AIRBORNE KEYSTONE SPECIES
The northern flying squirrel is one of two flying squirrel species found in North America. The other is the smaller but almost identical southern flying squirrel. The species we see in Montana ranges across Canada, Alaska, and the northern, Great Lakes, and Appalachian states, often in cool mountain zones, as far south as North Carolina. The southern flying squirrel ranges across much of the eastern third of the United States, from Florida north to the Great Lakes.
Flying squirrels feed on plant material, including seeds, nuts, and flowers, and also eat insects, bird eggs, and, occasionally, meat scavenged from dead animals. Their passion for eating lichen, truffles, and other mushrooms helps spread the mycorrhizae, essential for plant root growth, through forest ecosystems. What’s more, when excavating fungi on the ground in the middle of the night, flying squirrels get so preoccupied with finding food they become highly vulnerable to great horned owls and great gray owls, their primary predators. The squirrel’s role as a central link in the forest food chain makes it a “keystone species,” one essential to maintaining the ecological integrity of its habitat.
The flying squirrel is well known for its amazing ability to glide among tree trunks on its outstretched patagium, the expandable furred flap of skin on either side of its body that spans uninterrupted from the animal’s neck to its ankles. For years, scientists assumed that flying squirrels were passive gliders that use their patagium simply to prolong jumps across canopy gaps and lessen the impact of landing.
These assumptions became suspect, however, when recent laboratory studies uncovered several exceptional features of squirrel aerodynamics that strongly hinted that the species might be capable of more than passive gliding. Time-lapse lab photos indicated that flying squirrels were capable of airborne feats that aerodynamic theory suggested should be impossible for a species that was simply gliding through the air. In particular, airborne squirrels have an unusually high “angle of attack”--the angle between the gliding membrane and the direction of oncoming airflow. While greater angles generate greater lift, valuable for gaining midair height and distance, the angles observed in flying squirrels far exceed those that could be sustained even by advanced military jets. In theory, the high angle should cause the soaring squirrel to stall midair and crash.
The laboratory studies also suggested that in order to sustain such high angles of attack, the squirrels need to eliminate the destabilizing forces of unequal air pressure above and below the patagium. These “mini-tornadoes” on either side of the jet wings are the cause of turbulence, and the forces increase as the plane angles upward. Such turbulence should greatly reduce the squirrels’ gliding distance and speed. But that doesn’t seem the case. How do they do it?
Scientists have also long been puzzled that flying squirrels don’t crash. Simple calculations show that a squirrel landing from a routine 40-foot glide would hit a tree with an impact of more than 30 times its body weight unless it actively stalls well in advance of the landing. Yet such a stall would further decrease flight stability and duration. Based on what what’s known about aerodynamics, flying squirrels should be confined to slow, short, and steady glides or risk constant crashes, stalls, and falls. Yet they have been documented soaring great distances. How was that possible? I hoped to learn the answers as I knelt in the snow that frigid February night.
EYEWITNESS
Shortly after 2:30 a.m., under a nearly full moon, I was treated to a remarkable air show. It began with a cloud of snow kicked up by two males chasing each other on the upper branches of a spruce tree high over my head. One lost his grip then dove into a long glide over the lake, followed immediately by the second male in a rapidly accelerating glide.
Both landed in the upper canopy across the lake--seemingly without much loss of elevation, despite a glide of at least 60 feet--and resumed their squabble. Then I spotted a female sitting quietly on a snow-covered branch against a tree trunk, inspecting a large fir cone probably left by a red squirrel during the day. A few seconds later, another male parachuted down from a nearby tree, somehow steering the end of his near vertical descent to land on the trunk right below the female.
The female crouched, and in an exceptionally powerful jump with a fully extended body and outstretched hind- and forelimbs, launched herself at a 40 degree angle high into the air. She kept her patagium completely folded until reaching a height of about 10 feet above her perch  She then spread the membranes wide open, and lighted by a series of high-speed strobes triggered by my camera, seemed to freeze in midair for a moment before gracefully gliding out of view across the snow-covered lake. After engaging in a few barely audible squabbles from across the frozen expanse, occasionally kicking up more snow dust, the squirrel group disappeared into the dark and the night’s silence was restored.
I was amazed. What I had witnessed and documented with my camera that night and subsequent ones were a series of astonishing aerial accomplishments:  150-foot-long flights across open fields; mid-air turns to evade attacking owls; vertical leaps so high the squirrels could then soar from midair to a nearby tree trunk. It was obvious this species is capable of much more than just simple static gliding.
I spent the rest of that night walking around to keep warm, watching an occasional owl for entertainment. At first light, I dismantled the by-then solidly frozen equipment with its long-dead batteries and started my way back to the cabin. I would spend many days afterward replaying and analyzing, frame-by-frame, the footage of these stunning performances, learning more about how the species elegantly solves major aerodynamic problems.
Foremost among these solutions is the squirrel’s “wing tip”—a short rod of cartilage outside the wrist that the animal moves at various angles to enable exceptional flight control and precision landings. This anatomical novelty, sort of like a large sixth digit though not attached to the others, is controlled by a powerful muscle. By adjusting the angle of the wing tip, the squirrel can generate a substantial lift modifying the speed, distance, and trajectory of its glides in mid-flight. This anatomical innovation precedes the static endplates (“winglets”) that NASA began installing on the wings of modern jets in the mid-1970s by at least 20 million years.
            A flying squirrel’s second novel physiological adaptation is the extensive musculature that crisscrosses the thin gliding membrane. These independently controlled muscles, combined with limb movements during flight, allow a squirrel to actively modify the billowing of its “wings” and the orientation of fur on their surface. This produces, in a typical aerial chase, wing shapes such as completely folded patagium during powerful takeoffs; thin, fully extended membranes in the middle of long-distance glides; and fully inflated furry parachutes for slowing nearly vertical descents.
Finally, unlike most other gliding mammals, flying squirrels have an additional fur-covered membrane between their neck and wrists they can curve down during flight. This “mini-patagium” guides air flow away from the larger membrane to lessen turbulence, while generating significant forward acceleration and lift.
In short, flying squirrels flawlessly combine, in a small furry package, features of heavy transport planes, agile military jets, and flexible-wing parachute gliders, making them one of the world’s most sophisticated mammalian gliders.
Scientists recently started to realize that flying squirrel’s seemed to be loaded with excess anatomical features. What purpose did they serve? Flying squirrels seemed overbuilt for simply gliding from one tree to another. My contribution from the nights spent in western Montana’s frigid woods was to document in the wild just how the squirrels use those remarkable features in flight. It indeed turned out that flying squirrels are more than just passive gliders. For instance, I saw them leap into the air from a tree trunk and then, as if forgetting something, turn 180 degrees in midair, independently adjusting wing tips on left and right membrane, and return to the same trunk.  And I documented the ways they accomplish both rapid acceleration at the onset of prolonged glide and remarkably effective deceleration before landing so they don’t smash into the destination tree.
Over millions of years, flying squirrels have come up with elegant solutions to the same aerodynamic problems that face modern aircraft engineers. Undoubtedly we have much to learn from these small, furry mammals. I have to wonder: What other marvels in these and Montana’s many other mammal species are still out there waiting to be discovered? 
(reprinted with permission of Montana Outdoors)


Monarchs On The Wind

Monarchs On The Wind
 

Mid-August last year I returned to a familiar late summer haunt, a picnic table on a dune overlooking the northern tip of Lake Michigan.  I go there each August to do my table-top survey of one of the world’s most beautiful insects—the Monarch butterfly.  Monarchs have always been special to me, even as a little boy I would chase them through fields to get a closer look.  Now as most time lies behind me my attention has returned to the butterfly of my youth.  Who doesn’t want this miraculous flapper to draw future generations of kids to the same fields.

So I count Monarch butterflies as they fly over or past me, heading westward down the beach toward their destiny—Mexico.  My survey is rather crude, a time-count that I made up.  All I need is my notebook, pencil, watch and a beer to survey the fall flight.  I measure the interval, in seconds, between animals to get a long time average.  In the mid-2000’s the flies would pass my position every 10-15 seconds if I hit the peak of migration at a spot six miles east of Manistique.  Peak numbers were  late in 2012, September 1-2.  I counted butterflies on both days, with the same disappointing results-a fly every 45 seconds.  Could the butterfly numbers have fallen by 70% in just 5 years?

My answer came from an internet search of the website –Monarch Watch.  This group of butterfly conservationists is performing wonderful educational and research work in an attempt to help the Monarch.  They are involved with the World Wildlife Fund and the science people from Mexico to document the wintering population of Monarchs in the mountains of North Central Mexico.  The animals wintering roosts were first discovered in 1975 in the states of Michoacan and Mexico.

Good population estimates were first attempted in 1993 when an index was devised to gauge their relative abundance by measuring the roosting area occupied by butterflies during the winter.  This was made possible by the communal behavior of the Monarch to “pack” together in roost trees.  Because of this “packing” behavior we can compare butterfly numbers on the wintering grounds from year to year by simply measuring the area occupied.

In the winter of 93-94 that area measured 6.23 hectares (15.39 acres).  Butterfly numbers rose the next three years to an all time recorded high of 20.97 hectares (51.8 acres) in 96-97.  But from that highpoint numbers have been in a decline until last winter the Monarchs occupied only 1.19 hectares (2.94 acres).  That probably represents less than 100 million individual animals, a decline of almost 59% from the area occupied just one year ago.

Dr. Chip Taylor, Director of Monarch Watch, and a prominent Midwest butterfly researcher, cites several important factors to explain the Monarch butterflies precipitous decline:

1) The loss of milkweeds in row crops (corn and soybeans) due to the adoption of seed varieties genetically modified to tolerate treatment with herbicides. The utilization of these herbicide tolerant crops has all but eliminated milkweeds from these fields.
2) The push for the production of biofuels, which has resulted in the planting of 25.5 million more acres of corn and soybeans than were planted as recently as 2006. This increase has been at the expense of milkweed-containing Conservation Reserve Program land, grassland, and rangeland (as well as other crops).
3) Development, which consumes 6000 acres a day or 2.2 million acres a year.
4) Intensive farming that reduces the area from the edge of the road to the field, and management of our roadsides with the use of herbicides (and excessive mowing) which also eliminates milkweeds.
5) Deforestation of the oyamel fir forests – although this has declined over the last few years, the condition of these forests is less than optimal for the survival of overwintering Monarchs.
6) Unusual weather – and we had plenty of that during the 2012 Monarch breeding season. March was the warmest recorded since nationwide record keeping began in 1895. Warm weather tends allow returning Monarchs to spread north rapidly and arrivals of Monarchs in areas north of Oklahoma in April are often followed by low temperatures that delay development of the population. In 2012, first generation Monarchs moving north-northeast out of Texas arrived much earlier in the northern breeding areas than previously recorded. Historically, low overwintering numbers have followed the early arrival of Monarchs. These early establishments were followed by one of the hottest and driest summers in recent decades. Hot and dry conditions probably have the effect of reducing adult lifespan and therefore the number of eggs laid per female over its lifetime.
            Some of these ominous trends are not likely to be reversed.  One can only conclude that the survival of this beautiful animal is in peril.



Dennis Fijalkowski

A New Look At Skunks

A New Look At Skunks


Few mammals are more easily recognized than the striped skunk (Mephites mephitis).  The species is prominent in children’s books, cartoons and movies and many are seen dead along highways.  But much of what we’ve been told about the odiferous, cat-sized animal with the ultra-familiar white stripe on a black body is myth, or at least, not quite correct. 

Authors of books on mammals have long-considered all four North American skunks – the striped skunk, spotted skunk (Spilogale putorius), hooded skunk (Mephites macroura), and hognose skunk (Conepatus leuconotus) – as members of the weasel family (Mustelidae).  But genetic research by evolutionary biologist, Jerry Drague, and others has revealed that skunks have much different chromosomes and proteins than weasels and should be classed in their own family (Mephidae).  Although weasels use odor to mark territories and some, like mink, even use scent to repel other species, skunks take it to a whole other level.  Skunks have also evolved some behaviors not shared by any of the weasels.

Only the striped skunk is found in Michigan.  Its range includes almost all of the U.S., except Alaska, and extends north to the boreal forest of Canada and south well into Mexico.  The spotted skunk also has a wide range, but is not found as far north or east.  The spotted skunk does well in prairie habitat, even in the cold climates of Wyoming, the Dakotas, Minnesota and Wisconsin.    And unlike the other skunks, it can climb and feed in trees on birds’ eggs and smaller mammals.  The hooded and hognose skunks are confined to the southwestern U.S. and Mexico.

The striped skunk is nocturnal, but occasionally moves about in daylight.  It feeds on almost anything from small animals to eggs to dead carcasses and garbage.  It is a highly-skilled predator of mice and voles, on a par with foxes and cats in catching small rodents in grassy areas.  The striped skunk uses a set of burrows and dens, often returning to several spread out along a route that may be 15 miles long.  A skunk typically travels about three miles a night during feeding, but that varies greatly depending on the terrain and food availability.

The males tend to be solitary, but female skunks sometimes den together, especially in the winter in cold climates to share body warmth.  Striped skunks don’t hibernate, but may stay underground for several days during harsh winter weather.  Mating typically occurs in February or March with young born temporarily blind in May.  Litter size varies widely – usually four to six – but with as many as 10 occasionally recorded.  This prolific reproductive rate can lead to populations of up to 60 skunks per square mile in some areas.  Some of the highest skunk populations occur in urban/suburban areas where skunks take cat food off of porches and garbage from dumpsters by night and hole up under abandoned buildings by day.

One study found that skunks and cats can be surprisingly tolerant of each other, often sharing resting and feeding areas.  The normal reaction of skunks to larger animals, however, is to threaten chemical warfare.  The striped skunk employs a series of tactics and warning gestures before it gets down to the business of spraying a would-be predator.  First, it tries to walk or run away; this is followed by a backwards shuffle if forced to face the threat.  Next, the skunk often stomps its front feet up and down.  When a quick escape seems unlikely, the skunk elevates its tail to show as much of its white stripe as possible.  (The spotted skunk will actually do a very impressive hand-stand with its rear and tail high in the air.  Yes, it can spray from that position!)  A predator with previous (and bad) skunk experience may remember the white warning signal.  If not, the skunk then releases as much as four tablespoons of a greenish liquid emitted from a nozzle-like structure.  It comes out as a mist that looks yellowish as it travels through the air.  It was evolved to irritate the odor-sensing system of many of the skunk’s potential predators.  It works on most (see accompanying story on the next page), but one important predator of skunks not effected much by the spray is the great horned owl.  It has a very poorly developed sense of smell and its eyes aren’t irritated by the chemical.

Researchers have also discovered that some people are much less susceptible to skunk spray than others.  There are individuals who can be sprayed at close range with very limited reaction.  Researchers comparing sprays in laboratories have found that spotted skunk spray tends to smell “sweeter” than that of striped skunk, at least to most people.

After a skunk sprays, it takes several days for it to replenish its supply.  The skunk apparently can’t tell when it carries enough chemical for an effective defense.  So, the evolution of the series of warning gestures is very important for survival of skunks that are temporarily “unloaded.”  The skunk carries out the same gestures regardless if the chemical is present.  If there is none, and the predator does not fall for the “bluff,” the skunk gets eaten. 

Skunks take a toll on both eggs and newly-hatched young of ground-nesting song birds, pheasants and quail, but also reduce numbers of small rodents, snakes, and harmful insects.  They raid poultry houses, but take fewer eggs and chickens than other common predators.  They do sometimes carry rabies – ranking second to raccoons among mammal carriers of the dreaded disease.

Many people have de-scented or ranch-raised skunks as pets.  The latter are often all-white or blonde.  Some skunk owners find them delightful, but most people aren’t willing to provide the care skunks require.  It is illegal and otherwise highly inadvisable to capture and keep a skunk found in the wild.

Dr. Patrick Rusz
Director of Wildlife Programs


Monday, March 11, 2013

Mourning Cloak - The Beautiful Early Butterfly

The Mourning Cloak butterfly is one of Michigan’s most beautiful harbingers of spring, and our first sightings usually occur in March.   
 
This hardy butterfly is slightly smaller than the Monarch and can be recognized by the deep maroon-brown color of its upper wing surfaces and contrasting wing borders with ragged edges.  The wing borders vary from yellow to white across the species’ range, and are usually cream-colored in my Southern Michigan area.  The wings also include rows of iridescent blue spots just inside these borders that remove any doubt about the butterfly’s identity.
                                                                             
Mourning Cloaks emerge earlier in the spring than other butterflies because they overwinter as adults instead of as caterpillars or chrysalises.  They do this by hiding in a hollow tree or other shelter after secreting chemical compounds into their bodies that prevent ice from forming in the tissues.  The Mourning Cloak is one of a small number of native butterflies that overwinter this way, and the process is technically known as cryo-preservation rather than hibernation.
 
 They typically mate here in late April or May, and the females lay clusters of eggs on the twigs of a willow, aspen, cottonwood, birch, or elm tree.  Both sexes die soon afterwards, but the nine to eleven months that they live is one of the longest life spans of any North American butterfly.  And the eggs that they leave behind hatch into caterpillars that change into butterflies in mid-summer and perpetuate the species.             
                                                                                   
Mourning Cloaks obtain most of their nourishment from tree sap, and this is normally readily available when they awaken and need quick food in the early spring.  They also consume flower nectar and feed on mushy fruit when they can find it.  Some butterfly enthusiasts take advantage of this sweet tooth and attract them to their yards with ripe bananas, rotting apples, or a variety of special recipes.            
 
Mourning Cloaks also have to bask regularly to function in cool weather, and their dark colored wings make natural solar collectors.  My sunny yard attracts a couple of them every year, and they look like pretty yard ornaments absorbing solar heat with their wings spread wide open.  However, they can fold their wings together and look like a dead leaf or piece of tree bark in an instant if someone gets too close.    
       
Many readers are probably wondering how the Mourning Cloak received its haunting name, and this story is as unusual as the butterfly.  While the species inhabits all of the northern continents the association with the garments known as cloaks practically guarantees that its name originated in Europe during the Middle Ages.  And linguistic evidence indicates that this probably happened in present-day Germany or Scandinavia.  In fact, the German, Swedish, and Norwegian names for the species all translate into Mourning Cloak.
 
Many aspects of medieval life in this region are still mysterious, and the butterfly helps fill out the picture.  It tells us that some Germanic or Norse people wore special cloaks to mourn the death of loved ones, and that these cloaks were probably dark brown with light trim.  They began calling the butterfly Mourning Cloak because of its resemblance to these cloaks, and the name caught on throughout the region.  Then German and Scandinavian immigrants found the same butterfly in North America, and almost certainly introduced the name here.      
            
While the Mourning Cloak is frequently described as a woodland butterfly, it also thrives in city neighborhoods that provide the necessary food and shelter.  It was the most common large butterfly in the Lansing neighborhood where I grew up, and we saw some in our yard every year.  In other words, our rural, suburban, and urban readers could all see this beautiful butterfly some warm day this spring.
 
 

Monday, March 4, 2013

The King of Weasels

The Wolverine is More to Michigan Than Football

This is the sixth and last in a series of articles on the weasels of Michigan. 

In February of 2004, many newspapers and magazines ran a story and photo of what they called the first live wolverine (Gulo gulo) documented in Michigan, “the wolverine state.”  Hunters with hounds had chased the animal near Ubly, along the border of Huron and Sanilac Counties.  The hunters eventually called in a DNR biologist, Arnie Karr, who was taken by snowmobile to a field where he photographed the wolverine in a tree.

There was much speculation regarding the wolverine’s origin.  Some thought it must be an escaped or released pet.  Others said it likely came from the James Bay Region of Canada, having crossed Lake Huron on ice.  The DNR Endangered Species Specialist at the time even suggested that it rode in from Canada on a garbage truck.  (Michigan landfills accept trash from Canada.)  Wildlife officials assumed the wolverine was a wanderer, just passing through rather than living in an established range.  The implication was that one sighting of this big member of the weasel family should not change the conventional wisdom that Michigan has no wolverines—and maybe never did.

An Ubly-area resident and high school science teacher, Jeff Ford, conducted research that proved the animal was a resident, not a transient.  Ford, working with fellow sportsman Jason Rosser, and later with Steve Noble, released photographs taken with a trail camera in the same area one year after the photo was snapped by the DNR employee.  Mr. Ford also found tracks of the wolverine periodically. 

For the next six years, the three men spent a lot of time and effort monitoring the wolverine, which spent most of its days in dense swamps in the Minden City State Game Area and periodically visited the Verona State Game Area.  They gradually obtained more information, and shared it with wolverine researchers in the northwestern U.S. and Canada.  The trio sent the experts hair samples from barbed wire wrapped around a tree where baits were hung.  Genetic analyses revealed that the animal’s DNA was consistent with that of wolverines in Ontario and Quebec.

Part of the story ended in mid-March of 2010 when hikers found the animal’s carcass, which was fairly fresh, in the water along a trail by a beaver dam in the Minden City State Game Area.  The wolverine was then likely about nine years old, “grandma” aged, according to Ford.

No research on the wolverine was conducted by the DNR in the six years it was confirmed in Michigan, even though the animal stayed mostly on state-managed land.  All wildlife officials continued to agree that the wolverine, although interesting, was of no real importance--coming from who knows where and why.  Ford, thought the wolverine came from Canada, but acknowledged some things just don’t add up.  “We know wolverines aren’t supposed to set up territories where there is no potential mate,” he said.

A book has since been written about the wolverine and the citizen science conducted by Ford, Rosser, and Noble.  The now mounted wolverine is being displayed around Michigan.  But the status of the wolverine in Michigan is not being reconsidered.  The DNR still classifies the wolverine as “extirpated” (gone), contends there has been no other evidence of a wolverine in Michigan, and states that the closest ones are at least 400 miles to the northeast near James Bay.  However, a wolverine was photographed in 2010 in the Manitoulin Islands just a few dozen miles from the border of Michigan’s Upper Peninsula, and over the past 100 years many Michigan citizens have reported seeing wolverines.  The sightings have traditionally been treated like those of cougars – wildlife officials have scoffed, claiming the citizens must have seen bear cubs, raccoons, or badgers.  Yet, a wolverine was killed, near Portland in the Lansing area in 1932.  The incident was documented in a 1936 article by A.M. Stebler in “Michigan Conservation,” the official publication of the Michigan Department of Conservation (later to become the DNR).

Stebler reported that biologist Harry Ruhl (later to become chief of the Wildlife Division of the Department) investigated the shooting and took the skull and one foot.  He subsequently gave the skull to the Zoology Department at Michigan State University for use in teaching.  The significance of the wolverine itself was blown off by the Department of Conservation which concluded “the animal likely escaped from a Detroit zoo five months previously.”

The Department of Zoology at MSU cannot find the skull.  The Detroit Zoo (established in 1928) did have wolverines at that time.  However, according to the Registrar at the Detroit Zoological Institute, the Zoo kept very detailed records that indicate no wolverine ever escaped from the facility.  “The escaped animal story used to explain the wolverine shot in Portland was likely just made up by the Conservation Department,” says Larry Massie, one of Michigan’s foremost historians who has written about the incident.  “They no doubt felt they needed an explanation that would get rid of the matter.”

History aside, the six-year occupation of the Ubly area by the wolverine Ford, Rosser, and Noble had been studying shows that wolverines can live in Michigan and that the species does not necessarily require “huge expanses of wilderness” as many biologists have assumed.  The DNR actually explored the idea of a reintroduction 25 years ago (although it’s unclear how seriously).  That’s unlikely to ever occur.  “The DNR is adamant that it will not allow any wolverines to be brought into Michigan,” said Ford during a presentation in Saginaw.  “We asked the DNR about a project to bring in a mate for the wolverine in the Thumb, but they said ‘no way.’”

The DNR’s view of the Ubly area wolverine contrasts sharply with the response of state and federal officials to the discovery of a wolverine in February of 2008 in California’s Tahoe National Forest.  An unexpected photo of a wolverine was taken by Katie Moriarty, a graduate student at Oregon State University, who was hoping to document pine martens and certain bird species. 

Within a week of the initial photograph, researchers, biologists and volunteers intensified the search for more wolverine evidence in the same general area.  A large grid (approximately 150 square miles) with remote cameras and hair snares was established and monitored.  Ground searches were made looking for wolverine tracks.  Flights were conducted to detect possible radio telemetry signals from wolverines previously fitted with radio transmitters in studies in Montana.  Approximately 50 scat and hair samples were found and sent to the U.S. Forest Service’s Rocky Mountain Research Station’s Genetic Laboratory for analysis. 

An interagency wolverine team was initiated to include the U.S. Forest Service and the California Department of Fish and Game (DFG) in consultation with wolverine experts from Idaho, Montana, and Washington.  Through regular conference calls and meetings, this group developed a coordinated strategy to search for additional wolverine evidence.  Funding was obtained for monitoring and data gathering by the Forest Service and DFG.  Groundwork was laid for a long term wolverine survey by DFG.

Then the animal started showing up on trail camera photos taken by Sierra Pacific Industries on the company’s timber lands.  Sierra Pacific was conducting carnivore studies and documented the wolverine “by accident” in three consecutive years.  Like the wolverine in Michigan, it clearly took up residency.  “A wolverine with no potential mate should keep on going,” says Ed Murphy, an inventory forester with Sierra Pacific.  “But this animal has a home range.  Either our surveys are missing other wolverines, or there are obstacles to movement, such as highways, we don’t understand.”

In a 2009 paper published in Northwest Science, Moriarty and nine co-authors stated: “This current observation provides hope that the dispersal to, and even recolonization of, long-vacant portions of a species’ range is possible.”  Their implication that habitation of part of California by wolverines would be a good thing is in stark contrast to the attitude of Michigan’s DNR which clearly wants nothing to do with wolverines.  The Ubly wolverine was ignored, or treated by the DNR as a public relations problem.  Now it seems to be just a curiosity.  There is no hope expressed for the future. 

Perhaps our state government’s peculiar attitude about wolverines stems from a long and strange controversy over whether the species ever existed in Michigan.  Historian Massie notes the view that Michigan was never part of the wolverine’s range was expressed in Michigan History For Kids in spring of 2001.  This seems puzzling as a host of writings by naturalists and historians have provided evidence of wolverines in at least 16 counties in both the Upper and Lower Peninsulas until the 1800s. Massie suggests the notion of no wolverines started with “hedging” by early mammalogists because no preserved Michigan wolverine specimens were in museums.  Then in 1943, according to Massie, “Fielding Yost was named head football coach at the University of Michigan and soon launched the golden era of the gridiron for Ann Arbor… but he was no naturalist or historian.  Nevertheless, he collaborated with R. Ray Baker, a juvenile fiction author, to write an article published in Michigan History Magazine in 1943, “The Wolverine.”  For twenty years Yost had been searching for a live Michigan Wolverine to serve as mascot for his teams.  Based on his lack of success in finding one he concluded in his article, “there ain’t no such animal” and “the animal which gave the state its nick-name never made the region its home.”

In 1980, one of the state’s leading historians, George May, undertook a revision of Willis Dunbar’s classic Michigan: A History of the Wolverine State.  For some reason May found the coach’s article compelling and he cited it as the source for his statement, “none of the latter (wolverine pelts), strangely enough, came from the future Wolverine State because the natural habitat of this contentious animal was much farther north in Canada.”

In 2003, the U.S. Forest Service launched a study to “shed light on whether wolverines lived in the Great Lakes region.”  Before the project could be completed, DNR biologist, Karr, snapped his picture near Ubly.

Dr. Patrick Rusz
Director of Wildlife Programs

Wolverine Fast Facts
  • The wolverine is also called “glutton,” “skunk bear,” or “carcajou.”  The latter name was spread by French trappers.

  • Its current range is Canada south into the northern part of the Rocky Mountains and (perhaps) the Great Lakes Region.

  • Wolverines are typically 30-40 inches long and weigh 18-42 pounds.  Males are larger than females.

  • The wolverine does not hibernate and can cover great distances in all seasons.  Wolverines are great climbers.

  • Wolverines are versatile predators eating about anything.  They can kill prey much larger than themselves, and are notorious scavengers capable of driving all other animals – including bears, wolves, or mountain lions – from a carcass. 

  • Wolverines mark their territories and food catches with a foul-smelling musk. 

  • Like other weasels, wolverines tend to be solitary and can delay true pregnancy until long after mating.  Litters of 2-5 are typically born in spring in protected dens. 

Monday, February 25, 2013

“Vats Dat?”

Larch Balls 

The January-February issue of the Wildlife Volunteer included a photograph of two unusual natural objects that washed up on a Lake Superior beach last October.  We invited our readers to guess what they were, and several people submitted answers that were in the “ballpark” but not as specific as the “larch ball” one we were seeking.    
 

These objects are called larch balls because they basically consist of needles from Michigan’s native eastern larch or tamarack tree.  Larch are one of the few conifers that shed their needles in the fall, and the needles float when they end up in water.  Then they get compressed into larch balls when waves wash large numbers of needles back and forth against a sloping beach in a certain way.  

The compacted needles of the western larch are also called larch balls.  In fact, most of the internet references to larch balls come from Montana because tall western larch grow on slopes above several Montana lakes and drop huge numbers of needles into them.  One of these internet items mentions an old Flathead Indian legend that goes like this:           

“In the past, before the white man came to claim the land, the Flathead Indians crossed the Seeley-Swan Valley to reach their hunting grounds in the South Fork of the Flathead River Valley located in today’s Bob Marshal Wilderness.  If an Indian found one of these rare larch balls, the lucky finder could have the ability to place all of his wrong-doings, or “sins”, into the ball – cleansing him and allowing a new start in life.  Still it was a risk to pick up a “sin ball” which had already had sins placed in it. 

The Indian brave that picked it up would be given all the sins held within.”     

Picking up a larch ball can be risky.     

The closest answer to the mystery question came from Janet Dorin Roe, of Lansing, daughter of a long-time Conservancy member and volunteer, Larry Dorin.  Janet called the objects “whale burps” or “surf balls”.  Janet, you get a gold star.

Thursday, February 14, 2013

Lake Superior Mystery Objects



We thought that the strange ball-like objects that Olivet residents Wayne and Janet Gay found on the Lake Superior shoreline last October would make an interesting outdoor quiz for our readers.  The two balls in the photograph are representative of several that they found at the water’s edge near a roadside park west of Munising.  The balls are vegetative in nature but are not seed pods or fruiting bodies. 

 

We will provide our answer in the next newsletter.  In the meantime, readers who believe that they know what these unusual natural objects are or wish to make a guess should contact us on (517) 641-7677 or wildlife@miwildlife.org.                               

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.”