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 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.

For example, in mid-March:

• Male red-winged blackbirds are returning in flocks to stake out prime nesting territories in marshes, brushy swamps and grasslands. The females arrive a couple of weeks later. Described as gregarious, redwings are one of the most abundant and familiar birds. One place to look for them on campus is the area around the Class of 1918 Marsh behind the Nielsen Tennis Stadium. The males are jet black with bright red epaulets. A narrow yellow wing stripe is also visible. The females are brownish in color.
• Some American robins stay around the Madison area all winter, especially when natural food and water are available, but they’ll be migrating back to the state in large numbers now. They usually start showing up around the second week of March.
• Northern cardinals are singing again as their mating season arrives. They are relatively silent during the winter. Listen for their familiar song early in the morning. The Wisconsin Department of Natural Resources advises that the best time to observe territorial bird activity is between dawn and 10 a.m. and from 4 p.m. to dusk.
• In the plant community, skunk cabbage is a definite harbinger of spring and the first plant to pop up in the Arboretum. It is a member of the same family as the titan arum, the stinky plant that attracted tens of thousands of people to the Botany Greenhouse in 2001. Like the titan, it gives off a strong odor as it begins to flower. The heat generated by its rapid growth can melt the snow around it.
• As for the furry critters, chipmunks should be emerging from their winter hibernation sometime this week. According to early phenological records at the Arboretum, the average date of their first appearance is March 16.

Of course, Mother Nature is unpredictable when it comes to these matters and so the dates vary from year to year. That’s what makes it all so interesting. One thing is for sure — spring will arrive on its own schedule.