Sunday, May 3, 2009

The Mimids and the Thickets

A brown thrasher greeted us early this morning at the pond. He was perched atop a wild cherry tree, singing a series of mostly paired phrases, with brief pauses in between. His fellow "mimid," the catbird, was also singing from the thickets beyond; his being a more disjointed, cat-sounding series of phrases, without repeats. In late morning I heard the third member of this family of mimics, the mockingbird, carrying on from atop a red maple, repeating phrases as many as six times.

All three birds are nearly robin-sized, but much slimmer, with long, slender tails, that they often flip up. In addition to each having their own unique mimicking, song repertoire, the three mimids are quite distinct in their looks.

Gray catbird
(Dumatella carolinensis)
Uniformly slate-gray body,
black cap,
rufous vent,
noticeable since they raise their tail often

Brown thrasher
(Toxostoma rufum)
Rufous-brown above
long rufous tail
yellow eye
streaked breast, whitish wing bars

Northern mockingbird
(Mimus polyglottos)
pale gray body
white wing and tail patches,
that flash in flight and during foraging

The thasher and the catbird prefer thickets -- dense growth of shrubs, vines, and young trees. The mockingbird too, is a thicket bird, but seems to have adapted to suburban life, living among houses, yard trees, and lilac bushes.

The thickets along the streams and at the field edges
are a mix of woody species.

The native species are my favorites,

highbush blueberry
(Vaccinium corymbosum)

speckled alder
(Alnus incana)

silky dogwood
(Cornus amomum)

wild grape
(Vitis sp.)

We have an over abundance of invasive shrubs
in these thickets; they have
really gone wild on the farm.

The most common invasive shrubs or vines are
autumn olive, buckthorn,
bush honeysuckle, oriental bittersweet,
and most vicious of all - the mutilfora rose.
It's sturdy and very, very sharp thorns
are well hidden, but effective.

I do battle with these since they overtake the native shrubs, even though the birds may not notice, and the cardinal seems to thrive in the multiflora, but it too is a relative newcomer.

Among all the other farm chores, we periodically tackle a patch of invasive plants. The goal is to release and maintain the native shrub diversity, with the idea that this helps maintain the health of the soil and all the other plants and animals that live in these thickets.

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