Monday, March 9, 2015

Everything's waiting for Spring

By Beth Sullivan
While winter continues to keep its icy grip, we are all altering our efforts, activities and energies to make the best of things.
To be positive, the sun really is getting warmer. As it rises higher in the sky, days are surely lengthening, and the Vernal Equinox looms. Day light and day length trigger so much of life in spring.
Under the snow, the woodland ephemeral wildflowers may be delayed because of snow cover, but they have been protected from the severe cold and the destructive cycles of freeze and thaw. As the snow cover diminishes, light can actually penetrate to the ground and begin to trigger changes. They will be ready when conditions are right!

Early crocus provide nectar for emerging insects.

On the other hand, it is temperature that will cue the sap flow in many trees, most famously the Sugar Maples. Syrup-makers are having a hard time this year because it takes several days of thawing temperatures to trigger the sap rise. We have not had that yet.
The higher temperatures also bring certain insects out of hibernation. These are specialists, not only adapted to somewhat colder weather, but also adapted to food sources that are available during a thaw: sap itself.
Sapsuckers drill rows of holes to allow seeping sap to attract insects.

Winter Firefly

Last week, on a day that was well below freezing we discovered a “Firefly” sitting on a sunny snow bank next to the base of a tree. To the touch, the tree bark was actually warm as it absorbed the sun's heat. I sent the photo to a friend of Avalonia who has conducted insect surveys on Perry Natural area. The beast in question actually was a Winter Firefly (Ellychnia corrusca), a “diurnal, non luminous” species. So we found a firefly, active by day, on a frigid snow bank! It did not have the ability to blink and shine as our summer favorites do. But what to eat? Sap!
Winter Firefly on the snow.

As the sap rises, other insects will find their way to the nutritive liquid. Mourning Cloak Butterflies will do so as well. Watch the trees where branches have broken over the winter and look for dripping liquid. It will attract insects, which will then attract birds. Sapsuckers drill holes in trees to get the sap to flow and attract insects that they can then eat.
Mourning Cloaks will look for sap drips on leaves.

The journey north

Many of our migratory species of birds will begin their northward journey based not on warmth, but on day length. Most of these are insect eaters. Tree Swallows and Phoebes are some of the first to head north. It will be a terrible situation if the snow pack continues so deeply, keeping everything so cold and plantless, and insects not emerging to provide the food they need. Trees that blossom based on warmth will be delayed as well, and the nectar they contain will not be available for insects or returning birds.
Orioles arrive early, and if there are few flowers with nectar, they will use humming bird feeders instead.

It is really amazing to pay attention to the seasonal cycles and to understand the interconnectedness of species -plants, insects, birds, animals - and how changes in climate, warmer or colder than usual in a particular area, can be really disruptive to the health of the entire cycle. Mother Nature will continue despite these bumps in the road. Species will adapt and survive or they will diminish…for a year, for a decade, or maybe for a lot longer.
Hummingbirds will not arrive until there is a greater certainty of abundant nectar. 


Photographs by Beth Sullivan.

1 comment:

  1. This was very interesting, thanks for the post :)

    ReplyDelete