Right in Our Backyard

Nature’s Timetable May Be a Changin’

By Bill Lawyer

For the past few months, I have written about the fact that many natural history events seem to have started later than usual this year, if at all.

When the daffodils bloom, when the American and Asian dogwoods flower, when the red-wing blackbirds arrive, when the chipmunks come out from their semi-hibernation, and the like.

Some of the most recent examples of delayed events include when horseshoe crabs start “making out” on our beaches, and when cicadas begin their buzzing song of summer.

It’s not as though the length of days and nights has been changing. Stonehenge is still working, after all. And, when you look at the actual average temperatures and amounts of rainfall, they’re close to normal.

Since we know that the earth is still turning on its axis, causing daytime and nighttime to strictly follow their normal pattern, it must be something else causing these aspects of “Nature’s Time Table.”

Just recently The New York Times published an article about changes in summer night temperatures. Because most people sleep with air conditioning on hot summer nights, they may not realize that nighttime low temperatures are getting hotter. Summer nights have warmed at nearly twice the rate of daytime temperatures.

Studies of temperature and health have found that “heat waves kill more Americans than any other natural disaster, including floods, tornadoes, and hurricanes.”

Looking for changing temperatures in our backyards as an indication of changes in heat patterns, we see things in both directions.

Take daffodils, for example. This past spring was a fairly normal month in terms of average temperature, but in March, when bulbs were looking for sunlight, they got three nor’easters in a row, and never recovered.

Over the years I’ve been informally keeping a record of when we start to see lightning bugs make their entrance on the backyard “stage.” They normally arrive in mid-June, and by the end of the month the yard is so crowded with their flashing lights that they truly brighten the treetops.

As I write this on July 14, their population is still going strong, with one caveat, however. I live on a fairly dark street, but as soon as I get out onto a city street with new LED light posts the fireflies seem to vanish.

Scientists have made the point that fireflies use their bioluminescence to stand out from the darkness of natural “lightscapes”. And the dark protects them from predators. When people turn on floodlights all around their property it’s like putting up a No Trespassing sign, except for moths.

Fireflies are part of an elaborate web of plants and animals, darkness and light, cold and warmth, silence and sounds, and camouflage and boldness.

There is so much we don’t know about the subtle changes that are occurring in our climate that we need to look before we leap.

As the nights become increasingly warm, plants that need a lengthy cold and warm season, such as sugar maples, are not reproducing in our northeastern forests.

And then there are the cicadas. By my calculations, they should have started to come up from the ground, shed their skins, and started their distinctive buzzing sounds. And waiting in the wings are the large cicada killer wasps.

But so far there’s been nothing.

Hopefully, by the time you read this they will have “made the scene” right in our backyard.

Adult cicada

Cicada killer wasp