Nature’s clock: Studying the timing, life cycles of species

By Ted Watt Gazette Contributing Writer

Published in print: Saturday, January 17, 2015

Isn’t that a lyric cicada calling? How recently did he emerge from his underground nymph stage?

Here’s a patch of spring beauties; when did they start to bloom?

When did that scarlet tanager arrive from his wintering grounds in Venezuela?

Are the silver maples blooming earlier this year?

Biologists ask questions like these as they examine the phenology of species: the study of the timing of events in the life cycles of organisms.

As awareness of climate change has grown, phenology increasingly offers evidence of how shifts in temperature, precipitation, available sunlight and other factors are affecting a wide variety of species. These effects may influence how our crops will fare, what and how many pests we may have to contend with, what diseases we may have to be prepared for and what species we may expect to see or lose in our local ecosystems over the long term.

Phenological studies may also identify new problems in synchronicity between species — whether a plant’s pollinators will be present when it flowers, for example, or whether an animal’s required foods will be available when its young are born. Once the sole province of naturalists simply seeking to understand nature better, phenology has become an important tool in assessing the current and future impacts of climate change.

Last year, the Hitchcock Center organized a new series of nature walks for the community. This program, the brainchild of local naturalist Tamsin Flanders, carried out a variety of phenology investigations in our area and contributed data to national databases. We visited local natural areas once a month, each time with a different guest naturalist leader focusing on a different topic. We observed migratory spring birds, spring wildflowers, tree bark and buds, mushrooms, vernal pools, carnivorous plants in a bog, and more.

In April, led by local birding expert Scott Surner, we watched palm warblers actively feeding from the shrubs along the shore of the Fort River — dancing out over the water, snatching insects from the air, and flipping back into the bushes. There are so many fascinating questions about these tiny, 5½-inch-long, yellow and olive green birds with rusty brown caps and white patches flashing on their tail feathers.

Are they here on or about April 13 every year, or are they coming earlier? How do varied weather conditions influence their migration and feeding? How long do they stay here before they head farther north to breed?

Each year they fly between their wintering grounds in Florida, the Gulf Coast, the Caribbean and Central America, and their breeding grounds in northern spruce bogs. Daily observations from birders, entered into eBird, a data recording and analysis site run by the Cornell University Laboratory of Ornithology, accumulate quantities of information that can help us understand if and how palm warblers are sustaining and adjusting their migration.

In mid-August, Hitchcock Center staff member Jennifer Unkles led our search for monarch butterflies in local fields. The butterflies were on their southward migration, headed toward their wintering grounds in the mountains of central Mexico. Unkles knew just where to go to find the nectar sources that the butterflies rely on to refuel for their journey.

We visited the red clover fields along Moody Bridge Road in Hadley, planted by the Silvio O. Conte Fort River National Fish and Wildlife Refuge. Reports of reduced monarch numbers have been circulating the last several years so it was with excitement and hope that we discovered a good number of monarchs nectaring on the clover heads. We carefully netted, tagged and released them to continue their journey south.

The tags give the location and date of capture for each butterfly. We then forwarded our data for the day to MonarchWatch.org, another national database.

If any of our butterflies are recaptured — perhaps on their migration route or in Mexico — researchers will have more data for estimating populations and tracking migratory success.

These field walks are designed to get us out investigating our local habitats both throughout the year and from year to year. We focus on the natural history we see all around us. We’ve gained terrific insights into what is happening in the habitats we visited. As we continue developing our data gathering and recording, we expect to contribute even more useful information for long-range understanding of patterns and changes.

We’re excited that naturalists, aware of the details and changes in the natural world, are on the front lines of observing how the planet is responding to a changing climate. We’ve identified a number of informative citizen science phenology projects and websites that are appropriate for our region and skills. There are excellent resources on the web for data storage, tracking and analysis, and we’ve found numerous projects ready for our input. This year, we will be offering the phenology course again, and expect also to provide training for people who want to make observations and gather data on their own for submission to online databases. Phenological observation offers a great opportunity for any concerned citizen who would like to contribute to our understanding of climate change.

Ted Watt is a naturalist/educator at the Hitchcock Center for the Environment. The 2015 phenology study group meets once a month, beginning Jan. 25. For more information, visit the Hitchcock Center website or contact Ted Watt.

Earth Matters, written by staff and associates of the Hitchcock Center for the Environment at 525 South Pleasant St., Amherst, appears every other week. For more information, call 413-256-6006 or email us.