Saturday, April 11, 2015

Nest Box Archaeology and the Last of the Winter Tracks

A Flamboyantly decorated Tree Swallow nest removed from the box
As the snow finally recedes, it's time to clean out the bluebird boxes at the nature preserve. It probably sounds like a chore, especially when you consider that we have over 100 of them. Actually it's quite interesting, since we finally  get to get a  look at the construction techniques employed by our cavity nesting birds. Some Tree Swallows are particularly talented; they finish off their nest by lavishly decorating them with bird feathers. Feathers from grouse, turkeys and waterfowl are brought together and carefully positioned around the nest rim. Most nests aren't quite that flamboyant, but the designs are still worth checking out. Often multiple nests will be inside the same box - built one on-top of the other. This indicates a succession of house owners. Most often a Tree Swallow or Bluebird nest will be the original construction. On top of that will be the nest of a House Wren or a House Sparrow. The very top layer is often created by a White-footed Mouse, which claims the box for the winter season. Sometimes the mouse will borrow material from the lower nests, but more often they bring in a variety of new materials - mostly soft plant fibers or animal hair.
This is a nest of a House Wren, which still contains an unhatched egg from last season
A Tree Swallow nest with a mouse nest on top - the mouse brought in leaves and milkweed  silk
Tree Swallow nest below with a well insulated mouse nest on top
An apparent never-used House Wren nest with a mouse nest capping it off
Mouse nest made partly of animal hair on top a probable Bluebird nest
Material removed from a mouse nest - all finely cut milkweed silk
Tree Swallow nest with feather decorations
Two levels of Bluebird nests in this box
A male Bluebird waits patiently for the boxes to be cleaned
One thing that I will miss about winter is the ability to easily see what land dwelling wildlife is up to. Their tracks in the snow tell so much about their behavior and now minus that written intelligence, their lives become covert again. Last Monday the forest was covered with fresh tracks - very likely for the last time this spring.

Raccoon prints going one way and then the other
Wild Turkey tracks are unmistakable
The lone Turkey traverses the deep woods
Coyote tracks are subsequently crossed by the prints of a Gray Squirrel
Fisher tracks criss-cross over 50 acres of woods

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