February 21 - 28 (29)

 

Racine has 11 hours and 11 minutes of daylight at the end of the period and Superior has 11 hours and 3 minutes of daylight - an increase of 23 minutes in the south and 27 minutes in the north from the previous period. The average high temperature is near or slight above 32 degrees for the much of the Northwoods.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Mammal zoogeography: Late February is a time of reduced activity in the forest and fields of Wisconsin. Mammal sightings or at least viewing of their tracks can highlight a naturalists outing, but can lead thinking about how these mammals got here. The mammals of the state are best understood in an historical perspective. Animal communities are ever dynamic. Changes over time occur in a repetitive fashion.

 

These changes are most dramatic when the environment changes at an equally dramatic pace. The best example is the post glacial Wisconsin. These historic mammal populations in what will eventually become Wisconsin have been long studied by paleontologists. We can learn much from these past studies regarding why our mammal fauna is so diverse.

 

After the Wisconsin ice sheet began to retreat, there were large numbers of mammals that are no longer found in our landscape. This was a time of rapid extinction for a huge group of mammals that roamed our state. Species such as mastodons, woolly mammoths, camels, ground slots, giant beaver, another species of bison, wetland musk-ox, and horses roamed this tundra and taiga landscape.

 

These species of course, are no longer with us. But the intervening time between then and now, has permitted additional species groups to come into the state. These species groups come from different biomes. Wisconsin is blessed with vegetation from the south and west – the prairie/Great plains component, deciduous forest from the east, and the boreal forest element from the north. Species whose primary habitat lies in these biomes come together to form the fauna of the state.

 

Our current mammal fauna consists of wide-ranging carnivores and ungulates, which comprise nearly 25% of the mammals for the state. Included in this group are:

• Little brown bat

• Silver-haired bat

• Big brown bat

• Hoary bat

• Beaver

• Deer mouse

• Muskrat

• Porcupine

• Coyote

• Timber Wolf

• Red fox

• Gray fox

• Black bear

• Raccoon

• Long-tailed weasel

• Mink

• Badger

• Striped skunk

• Otter

• Bobcat

• Elk

• White-tailed deer

The naturalist should note: this group of wide-ranging mammals is highly mobile. They consume at a higher trophic level than other species, and are thusly not directly limited by vegetation cover. In addition, bat species feed on insects and with their freedom of flight are not as limited to vegetation types.

 

Several species enter the state from the south and west. This group is called the Great Plains grassland faunal group. They live primarily in grassland habitat and comprise these species:

• Franklin’s ground squirrel

• 13-lined ground squirrel

• Plains pocket gopher

• Prairie vole

• Western harvest mouse

• Spotted skunk

 

The next group is species, which are found primarily in the eastern woodlands. Their center of core habitat is the eastern deciduous forest. Most of the species occur over much of the Midwest. This group includes:

• Least shrew

• Short-tailed shrew

• Eastern mole

• Star-nosed mole

• Eastern pipistrelle

• Northern long-eared bat

• Cottontail rabbit

• Eastern chipmunk

• Woodchuck

• Gray squirrel

• Fox squirrel

• Southern flying squirrel 

• White-footed mouse

• Woodland vole

• Southern bog lemming

• Woodland jumping mouse

 

The next group of species entered from the north and has boreal connections. These species are primarily found in Canada and Alaska. They reach their southern range limit in the state of Wisconsin. They prefer the coniferous boreal forest vegetation types. These species includes:

• Arctic shrew

• Water shrew

• Pygmy shrew

• Snowshoe hare

• Least chipmunk

• Red squirrel

• Northern flying squirrel

• Red-backed vole

• Meadow jumping mouse

• Martin

• Fisher

• Ermine

• Least weasel

• Lynx

• Moose

 

The final group has neotropical elements with species originating in the far south. This group only includes the opossum.

 

Bird song: Late February can produce migrants in the south during warmer years. Red-winged Blackbirds and Sandhill Cranes are a few of the species that may arrive in the far south during this time frame. Statewide, though, the longer day lengths stir the gonadal development in many male birds. Several species begin singing, even those not on territories like the Northern Cardinal. Pine Siskin, American Goldfinch, and Purple Finch can be heard especially on warm sunny days. Very special is listening for the song of the American Tree Sparrow. This species nest in the Canadian taiga, therefore its breeding rituals are unknown to most Wisconsinites.  Starting in late February and occasionally through late March when they have mostly departed the state. Listen for a clear, sweet – tsee tseea tsi tsi tsi. 

 

Snow fleas: On a warm late winter day, look closely at the snow or bases of trees and you may see what looks like soot on the snow. Stop and observe these little pepper flakes and you’ll notice they are moving. These little critters are snow fleas. They are little insects, which work their way to surface to feed on decaying plant material imbedded in the snow. They will also congregate in areas with an early flow of plant sap. These “fleas” are actually springtails that hop around. Their method for movement is a natural catapult.  Two tails on their back are tucked up underneath their bellies and held in place by hook-like structures. When released, the tails hit the snow and spring the critters into the air.

Mountain ash: A native of the upper Midwest, the mountain ash is very important for birds. Even the European mountain ash, which is grown as an ornamental in many backyards has the similar draw for birds. Many purists claim the American version is preferred and birds will consumed its berries before the European variety. Regardless the species, mountain ash is a preferred late winter food source. Species known to relish the fruits include: Ruffed Grouse, Sharp-tailed Grouse, Pine Grosbeak, Evening Grosbeak, Cedar Waxwing, Bohemian Waxwing, and American Robin.    

Signs of Spring: The gradual increase in birds song is one indicator. Mammal courting behavior is another. For the careful observer of nature changes, color patterns of bark on some common plant species is as solid an indicator of spring as can be found in the natural world. Naturalists should look for these features: aspen bark starts to photosynthesize and turns a yellowish-green, the outer branches on willow turn yellow, the reddish bark of red-osier dogwood becomes much more vibrant, apple branches turn from gray to more of a rose color, and alder branches become quite green.  

 

Other tidbits:

• Honey bees start to clean the hives.  

• This is peak time for mink and raccoon breeding.  

• If you have an opportunity to be in a horse or cow pasture, tip over the dung. Many times you can observe the lesser dung beetle, which remains active even in the winter.    

• This is a good time to erect bat houses.