Phenology

The American Heritage Dictionary defines phenology as “the study of periodic biological phenomena, such as flowering, breeding and migration, especially as related to climate.”

As winter bids adieu and spring weather tiptoes toward us, we are highlighting phenological occurrences that many of us might easily miss or take for granted as we go about our busy lives.

Early May brings a variety of warblers to the Madison area. Local bird watchers look forward to this time each year. Warblers, which are colorful insect-eaters with thin, pointed bills, arrive just as trees and shrubs are leafing out. They stop for a short while before making the journey to northern Wisconsin and Canada for the summer.

During the fall migration, warblers aren’t as easy to identify as in spring. Many of them are also listed in field guides as “confusing fall warblers.”

The majority of warblers have at least some yellow coloring, along with gray, brown or olive. But if you use a field guide and binoculars, you should be able to figure out what they are. In addition to noting the bird’s color, look closely at its markings — tail pattern, rump patch, eye stripes and wing bars.

Their names often provide a clue: yellow-throated, bay-breasted or yellow-rumped, for example. The black-and-white warbler is just that — with bold stripes. The stripes and the bird’s nuthatch-like behavior make it one of the easiest warblers to identify. The yellow warbler is predominantly yellow, but the male has rust-colored streaks on his breast that set him apart.

The woods and shrubby areas of the Arboretum and Picnic Point are great locations to look for warblers during the next few weeks. You might even spot them flitting around the trees and shrubs in your own yard. Give it a try.

The forest floor is greening up fast, and spring ephemerals such as Dutchman’s breeches, wild geranium and Virginia bluebells are or will soon be flowering. These plants blossom for just a short time before the leaves on the trees can block their sunlight. Trillium, jack-in-the-pulpit and violets also will be putting on a show soon.

The Arboretum’s Longenecker Gardens is a showcase for early blooming trees and shrubs such as serviceberry, forsythia and magnolia. As mid-May approaches, the crabapples should be in full bloom.

More bats are moving around. There are eight species in Wisconsin. The three most common in our area are the little brown, big brown and red. These flying mammals are voracious insect eaters. A single little brown bat can catch up to 600 mosquitoes per night.