Avalonia eTrails

By Beth Sullivan

Phenology…a word I have heard on multiple occasions in the last week. A word I pretty much knew the definition of, or the idea of, even more or less wrote about a few weeks back. But I decided to look it up to double check why it seemed to be a buzz word recently.

Phenology-noun: The science dealing with the influence of climate on the recurrence of such annual phenomena of animal and plant life such as budding and bird migrations.

We await the first Osprey in Mid-March.

Those of us who are nature watchers know the concept well, even let the word flow off our tongues frequently. We have kept journals and logs over years and decades, marking the cycle of seasons and annual “firsts” (Thoreau, Leopold and Teale did too). Over the last years of writing this blog, I have noted first occurrences of some of my favorites: “Return of the Osprey,” “The First Tree Swallow,” “First Purple Martins to return to Their Gourd Houses.” We wait for the Skunk cabbage to show itself from beneath the snow. We wait for the first warm rainy night when the salamanders and wood frogs leave their wintering spots and move to vernal ponds for egg laying. We eagerly listen for the first spring Peepers. I wait for the chipmunk in my stone wall.

Spring Peepers wait for the ice to melt and will call on warmer nights

It's not just the length of day

Many of these events are regulated by day length. Birds usually begin their Northward migration based on the length of the day, not necessarily the temperature. They do not know what the conditions are up North. Amphibians, deep in the ground, are stirred by temperature. Warming air temperatures translate to warming soil, and melting ice and stimulates them to move. The warming of the soil also dictates plant growth from seeds or dormant roots. Air temps as well as day light will determine tree budding and sap flow.

Populations of Canada Geese head north based on day length

This year we are all feeling a bit askew…whether or not we realize, it is phenology at work. The very cold, very late spring has everything off kilter. Ice is not off the waterways, and returning osprey need to fish. Overwintering water fowl are starving as the ice covers the shallow water, and they cannot graze on plants on the bottom. Sap flows are late, most insects are not emerging yet, and birds returning will not find food. We all know the Robins can’t find their March worms yet. If insects do emerge with the warmth, the blossoms are not yet present for them to feed on. Will the pollinators they need be out of sync when the flowers do open?

Persistent ice has starved many dabbling ducks

Those spring ephemeral wildflowers that should be well up by now are still dormant. Will their season be cut short? Will they be able to set seed in time? Will hibernating mammals respond to day length or warming before they emerge, and will there be plants readily available as food sources if the snow has not melted?

In warmer years, Blood Root could have been in bloom now

Think of how cold the water of Long Island Sound has been. We know it will affect our weather along the shore, but how will it affect the migration of fish and horseshoe crabs?

Temperature matters too

It is a delicately balanced web, and the seasonal cycles of temperature and light play a critical part of the balance.

It's a lot to think about. All we can do is continue to make our journal entries of our observations and wait and see what comes next. That is Phenology.

My Chipmunk made an appearance while snow was covering the walls

 Spotted Salamander 

Photographs by Beth Sullivan.
This post originally  appeared on March 30, 2015.