February 11 – 20
Racine has 10 hours and 48 minutes of daylight at the end of the period and Superior has 10 hours and 37 minutes of daylight - an increase of 27 minutes in the south and 31 minutes in the north from the previous period. The average high temperature climbs above 32 degrees for the first time since early December in the south.
Common Raven: Mid-February could easily be referenced as the time of the Raven, especially for the Northwoods. While many species are struggling to survive winter’s challenge, the Common Raven displays an exuberance that seems to defy the season. They are in a preparation mode for courtship and anything goes. Observers in the north should spend time just watching these high intelligent and creative birds. They have been seen swooping in the winds, making quick turns, barrel rolls, dropping stones, and foot grabs while in flight. On the ground or in trees, they conduct tug-of-war games with leaves and twigs, hang by one foot or their bill, roll onto their backs, steal food, plus many other fun games.
Gypsy Moth Egg Masses: This time frame is great to search for and manage gypsy moth egg masses. Even though they are in place from August to May, February is a good time to do something, because human management can add to natural winter stressors to become more effective. Egg masses are typically tear-drop shaped, 1 to 2 inches long, and can be found in any protected location. Search for them on trees, logs, rock piles, on houses and even lawn furniture. Each egg mass destroyed represents several hundred caterpillars that won’t eat your trees leaves. Carefully inspect your trees, buildings, wood piles, year furniture, etc., for the presence of egg masses. If they are found, you will need to scrap or spray before mid-April. Contact your local nursery or garden center for spray products.
Redpolls: Obviously, there must be a correlation between harsh winters with heavy snowfall and redpoll movements. The answer to the postulation is a resounding no. If it is not weather, then it must be a paucity of food. The answer for redpolls is not as obvious as it may seem. Several studies indicate high densities of redpolls are more important than current year seed crop failure. A combination of high seed crops combined with excellent redpoll productivity, then followed by a poor seed crop is needed for the largest interruptions.
Both redpoll species appear to react differently than other boreal interruptive species – Red and White-winged Crossbill, Pine Grosbeak, Pine Siskin, Evening Grosbeak, and Red-breasted Nuthatch. These species are more attuned to conifer seed crops. They feed more selectively on different species of conifers, thus they have different patterns of interruption. Conversely, redpolls feed on deciduous tree and weed seeds almost exclusively.
During fall, winter and spring, redpolls are almost entirely vegetarian. Primary food sources are birch, alder, willow, and weed seeds, especially during interruptive years. Decades ago, such weeds as ragweed, goosefoot, smartweed, and pigweed (3) formed a majority of the winter diet. In more recent decades, the primary winter food may be Niger seed.
The biology of redpolls favored foods may be telling. Birch, mostly white [paper] birch, but occasionally yellow and bog birch, flowers in spring with catkins providing a possible food source during the time of little food. The seeds ripen in August and disperse before the end of October, thus providing an abundant food source for a short period of time in fall. Birch seed production is not constant and peaks every other year. Alder seed develops in late summer and hangs unto the branches throughout the winter. The little cones house the seed that in a normal winter provide the primary winter food for redpolls. Alder tends to have a bumper crop of seed every fourth year. Willow blooms early and sets its short-lived seeds in May and June, which provides a brief and important food source before the bugs come out.
The predominant food in summer is animal providing a rich protein filled diet for growing youngsters. Of course, during all parts of the year other weed seeds are gleaned from openings and edges for added sustenance. The combined facets of the food and its somewhat predictable nature, a pattern of predictability should be in the offing.
To make predictions months in advance requires productivity information for at least two years. In addition, information on alder seed production would be needed to make more accurate predictions. To date, the birding community and foresters are doing a poor job of collecting both types of data.
When an invasion gets closer, we do have better methods for determining the prospects of seeing redpolls. Ebird data from the past five years can help give a first glimpse of insight. Early trend data indicates if big flocks of redpolls are reported from the north in late October to mid-November, the southern part of the state can reasonably expect redpolls by winters end.
A lag effect takes place with the south not seeing any real frequent numbers until mid-January. Peak numbers usually occur in the middle part of February and some individuals stick around to late March.
If the initial numbers in fall are small, the prospects for Hoary Redpoll are equally small to non-existent. Big numbers of Common Redpoll should alert birders and purveyors of feeders to keep an eye out for Hoary Redpoll, although not at the same time. Curiously and cautiously looking at the data indicates southern Wisconsin should anticipate some Hoary Redpolls during the mid-January push. However, and confounding, the north really does not have any Hoary Redpolls until mid-February.
Winter moths: Unknown to virtually everyone, except ardent lepidopterists and traditional maple sap gathers are active flying moths in winter. Several species in the subfamily Cucullinae can appear in winter. They overwinter as adults with most of them mating and laying their eggs just as the trees start to bud in spring. As temperatures start to rise and sap begins to flow (see the next section) these moths emerge. They have the capacity to raise their body temperature enough to fly by shivering. Many times they can be seen floating in maple sap buckets, as they were attracted to this primary food source.
Holes in the Snow: Mid-February is a great time to observe an effect plants can have on the environment. In many deciduous forests, the crusty snow pack has a Swiss cheese-like effect of having holes in the snow around nearly every tree. This effect is a combination of mechanical forces (less snow accumulation due to branch interception and wind blowing the snow away from the base) and heat. Tree trunks can absorb more heat at this time of year and reradiate it assisting with snow melt. Much of the warmth though is absorbed, which starts the process of breaking senescence and starting the flow sap back to the branches. This process also generates heat that helps melt these rings around the trees.
Water Striders: These insects are predators and feed on anything that falls onto the water’s surface. Light weight and waterproof hairs near the tips of the legs allows these bugs to “walk on water”. Water striders are one of the most recognizable aquatic insects. They overwinter as adults and when the first warm days come along in mid-February they can be seen skimming along the water surface. Look for them in calm open waters on warm days.
Sumac Berries: Of the four species of sumac in the state, the staghorn sumac is the most recognizable. The brilliant red fall colors are a favorite of many Wisconsin travelers. Equally observable are the red cone-shaped berries. They ripen in autumn and persist throughout the winter. The berries are excellent food sources for many bird species with over 300 species known to utilize the fruit including American Robin, Eastern Bluebird, American Crow. Black-capped Chickadees readily probed the clusters for hidden invertebrates and egg masses. Squirrels and cottontail rabbits consume the berries and also eat the bark.
Horned Larks are our first migrants. Driving roads in open landscapes can produce pairs of Horned Larks every few hundred feet.
Short-eared Owls can occasionally be seen on their day time roosts. Consistent locations for observation have been the Bong Recreation Area, Harrington Beach State Park and the southern unit of the Kettle Moraine State Forest.
The Buena Vista and Crex Meadows Wildlife Areas are good locations to observe Greater Prairie-Chickens and Sharp-tailed Grouse. At this time of year, these species can be seen in the tree tops foraging on buds that a beginning to pop.
The best chance for observation of the highly irregular and interruptive Hoary Redpoll is now.