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