Sunday, May 4, 2014

Undercover Expert

Brown Thrasher by Margo Goetschkes

The Brown Thrasher is an actor, robed in reddish hue, not in the distinguished gray like 
the catbird or the mockingbird.  As noted in Chris Leahy's information packed and 
engaging resource,  The Birdwatchers' Companion, the Brown Thrasher doesn't beat 
or thrash with its long tail and doesn't thresh with its long, curved blade of a bill.  The bill 
allows it to forage deep in thickets and last season's leaf litter by sweeping the detritus and 
soil away and then pecking, probing and seeking insects, snails, toads, frogs, seed,
beetles, fruits and nuts.

I watch them intently as they pass in jerky flight along the vegetated edges 
roadside and take cover.  The ruddy hue makes them difficult to see undercover.

I smile when I hear their smack call which I liken to a loud kiss ~ that 
"tcheh" call note of this mimic.  I regularly focus on Brown Thrashers 
as they cross low over the road at Parker River National Wildlife Refuge.  My 
concern for them heightens when the beach-goers stream to the Refuge's and 
Sandy Point's beaches.  I've studied them for hours as they fly in and out of the 
shadbush, serviceberry, shadblow, viburnam and beach plum thickets at this 
important and renowned birding area. They appear unsettled and uncomfortable 
in the open; they're in their element when undercover.

The Brown Thrasher has several monikers: Brown Thrush, Eastern Roadrunner, Sandy 
Mocker, Ferruginous Mockingbird, Planting Bird and Red Mavis. 

The Brown Thrasher has a slender bill, and the lower mandible has yellow at the 
base.  Its face is gray; its eyes are yellow.  Those white wing bars and yellow 
legs are easy to discern and focus on. Its tail is long, rounded and keel-like.  It's 
known as a large, boldly patterned, long-tailed skulker that loves the thickets.  Both 
sexes are rich, bright rufous with buff to white underparts with black streaking.  The 
Brown Thrashers are conspicuous due to their large size  [9-12 inches].  With a 
wingspan of 11-13 inches, they are seen well as they dart low, barely undulating, 
in front of my car.  I've invested the time watching them dust bathe roadside 
when I'm heading to Sandy Point.

The male Brown Thrasher's rich, musical and varied song is one of duplicity,  
a series of long phrases separated by pauses. This mimic has a large song repertoire
and is the only thrasher routinely seen in the northeast. 

By the second or third week in April, the males arrive.  Once on territory, the 
vain male will perch high vertically and announce the breeding season.  The male is on 
territory ahead of the female, and often his song is delayed for a few days. 
When the female arrives, the male's song of doubleness begins.  Once a mate is secured, 
the pair limit their movements and begin nest building.   The mated male sings a softer 
song.  The female shapes the nest, and both male and female bring in the nest 
construction supplies - twigs, grapevine, rootlets, grass and dry leaves.  The nest is a 
hefty, dense parfait with many tiers - often four -  first twigs, then dry leaves, grapevine and 
paper compose the second tier; the third tier is stems, twig roots with soil, and the fourth 
tier is rootlets without any dirt attached.  I've watched them beat the roots on the hot, black 
pavement and shake them to remove the dirt.  The nest's outside diameter measures 12 
inches; the inside diameter is 3 - 4 inches; the inside depth is 1 inch.

Often the nests are in thorny shrubs below 12 feet; but most often they are at  
2 - 7 feet.  I found an active nest on the ground once.  2 - 6 eggs are laid
that are white to pale blue with faint to heavy speckles and muddy brown 
markings. The Brown Thrasher is aggressive around the nest like a highly-skilled 
defenseman on the "Atlanta Thrashers"...

The nestlings are helpless with downy tufts; they fledge between 10 to 14 days, 
earlier than Gray Catbirds and Northern Mockingbirds.  The male has charge of 
the fledglings, affording the female the opportunity to produce 2 - 3 clutches.  
If there isn't a second or third brood, the pair divide the care of the fledglings, 
sometimes moving the young to separate areas.

Good birding,
Sue

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