Sunday, March 8, 2009

March Trails - the Wetlands


March Trails – the Wetlands
© 2009 Dave Spier

The change from winter to spring, as much as we'd like it to be a one-way continuum, is never that simple. It would be great if one day it was winter -- and the next day it was spring -- and there was no going back. Instead it's a push and pull seesaw of alternating warm and cold air. A warm front one day is followed by a cold front the next, and then it reverses itself again. Temperatures go up and down, but on the average we drift toward spring.

Since meteorologists keep records on a monthly basis, spring for them begins on March 1. Meteorological winter was December, January and February, the three coldest months of the year. At the opposite end, meteorological summer is June through August, the warmest months. When we speak of spring beginning on March 20, the vernal equinox, we are speaking of astronomical spring when day and night are equal lengths.

Physical weather changes in March trigger biological changes, so we might say that biological spring also begins March 1. The two are closely tied. Even though thousands of Canada Geese wintered on the Finger Lakes, tens of thousands more return from the Chesapeake Bay at the end of February every year. For them, it's spring. Similarly large numbers of Snow Geese are now returning, too.
When the ice melts, walk down to the local pond and watch for the resident Mallards to return. To save time, they formed pair bonds last fall and now they're ready to go. They'll also be checking out grassy puddles in the corners of fields. Unless she's swimming with the drake, you may not notice the drab-colored hen. Her brown-mottled plumage is camouflage to blend with the dead vegetation as she picks a nest site.

Mallards have to share their wetland and field habitats with the Ring-billed Gull, named for the dark band near the tip of the adult's bill. (For once ornithologists made the name accurate and simple.) Gulls are primarily scavengers and their main food is dead fish, but in the spring they move inland and feed on worms, insects and other bits of food gleaned from fields. When not feeding they rest on the meltwater puddles that collect in low depressions. These are only temporary and when they dry out the gulls will return to the lakes. By then the baitfish should have returned to the shallows.

Many ponds are bordered by cattail marshes, still beige from the winter. The exposed edges were matted by snow and wind, but the denser interior is more self-supporting and provides perches for the male Red-winged Blackbirds returning from the south. They flare their red shoulder patches as they sing "kong-ka-reeee," a warning to other males that "this is my turf." In another week or two, the females, which look more like large, brown-streaked sparrows, but with pointier bills, will join the males and begin pairing and preparing for nest building.

Cattail marshes are important storage pools for spring flood waters and they deserve protection for this reason alone. By slowing the runoff, they allow underground aquifers to be recharged. The third benefit is serving as wildlife habitat for waterfowl and muskrats plus secretive animals that we seldom see but sometimes hear.

On slightly higher ground, where it dries out during the summer, willows and Red-osier Dogwood take over. For a sure sign of spring, look in these swampy borders for Pussy Willows, a shrub that seldom exceeds 15 feet in height. The soft, gray-fuzzy buds are really male flowers that later turn yellow with pollen. Since the buds were originally formed at the end of last summer, their only protection through the winter was a single, brown bud scale which gets pushed back as the bud opens. Red-winged Blackbirds looking for a higher singing perch might choose the Pussy Willow.
Another wetland shrub related to willows is the Speckled Alder. More common in the Adirondacks than western New York, it's in the same family as birches, musclewood and hazelnut. Look for the transverse, whitish lenticels on smooth, dark bark. It's a favorite food of the Beaver.

Now look down at your feet and search for the Skunk-cabbage that often grows in this same habitat. A long, starchy tap root fuels their spring growth as they chemically generate heat to melt through any remaining snow and to woft their odors to the first flies emerging from dormancy.

In spite of temperatures in the teens this morning, there are two Red-winged Blackbirds singing from the top of the Silver Maple in the backyard. Normally a tree of the bottomland swamps, this one was probably planted. In about two weeks, the red flower buds will open and release their wind-blown pollen. The timing is risky because that is often when we get ice storms. Warm, moist air trying to return from the south over-runs cold air on the ground and falling rain freezes when it contacts anything below 32° F. (0° C.) The upper trunk and branches -- smooth, gray and brittle -- are easily broken by the weight of glaze ice.

Another maple species that grows on wet bottomlands and creek banks is the Boxelder, or Ash-leaved Maple. The opposite pairs of buds are still closed. If it's a mild day, look in the bark for adult Boxelder Bugs coming out of dormancy. You'll also find them on Sycamores and other flood plain trees. Only adult females overwinter so any you see in March will be looking for a crevice to hide her eggs.

This copyrighted article and photo are adapted from one of my slide shows. They first appeared in the March 9, 2009 issue of the Times of Wayne County.

On March 28 at 10:30 am, I will be leading a hike at the Montezuma Audubon Center (MAC) to look for signs of spring. In the event of bad weather, I will present an indoor slide program. Contact me at northeastnaturalist@yahoo.com to request a copy of the MAC newsletter or go to http://groups.yahoo.com/group/MontezumaAudubon/ and look in “Files.” My photo websites are http://picasaweb.google.com/northeastnaturalist and http://www.flickr.com/photos/dave_spier .