Union Bay Natural Area May 19

Tine of day: 530-715pm
For a full description of the Union Bay Natural Area habitat see one of my previous posts from a trip to this area. This entry is focused on birds that I saw, and behavioral patterns of some of them.

The first interesting bird was the Red-winged blackbird. on three seperate occasions on the 1.5 hour visit I witnessed a red-winged blackbird chasing through the air, and making aggressive contact with the much larger American Crow. This was surprising because of the size differential, and the fact that there were several crows about, in closer knit groups than the red-winged blackbird. I also heard multiple distinctive calls coming from the red-winged black-bird. I have read that this species has up to 25 different calls due to its complex social interactions, but it was interesting to hear the bird cheap, as well as the usual flute and whistle like call.

Also interesting was the collective behavior of a flock of Barn Swallows and Violet-green Swallows. These birds acted almost identically to each other. They spent almost all their time in the air, such that I could never see one land even if I followed one perceptively. They would fly very close to the water of the pond which they were flocking around, and also they would steeply ascend upwards until they lost gliding speed, then fall back down. Additionally they flocked together every couple of minutes or so. This behavior describes both the barn swallows and the violet-green swallows i saw. Present around them was the pond, a carcass of a canadian goose on the shore, a gang of crows not too far away (30-50m) red-winged blackbirds here and there, ducks, geese, and the prairie wetland habitat in general.

I did see the invasive and very interesting Brown-headed cowbird, about 3 of them. Their call was a sharp, high pitched and rising in tone, human whistle like call. I didnt see them participating in any parasitizing behavior; two were in the branches of shrubs on the shore of the pond.

Bird species list:
White-crowned Sparrow (Zonotrichia leucophrys)
Brown-headed Cowbird(Molothrus ater)
American Goldfinch (Carduelis tristis)
American Robin (Turdus migratorius)
Barn Swallow (Hirundo rustica)
Violet-green Swallow (Tachycineta thalassina)
Red-winged Blackbird (Agelaius phoeniceus)
Song Sparrow (Melospiza melodica)
American Crow (Corvus brachyrhynchos)
Spotted Towhee (Pipilo maculatus)

Posted on May 21, 2012 12:32 AM by robertmarsh robertmarsh

Observations

Photos / Sounds

What

White-crowned Sparrow (Zonotrichia leucophrys)

Observer

robertmarsh

Date

May 19, 2012

Description

Whitish grey breast, yellow beak, brown woody camoflauged back and tail. Most distinguishable by white and black striped head, in which the very top of the head is white, and then there is a stripe of black underneath, then white, then black. long upright tail. Small bird, but not as small as a chickadee which was another distinguishable feature.
sparrow was cited foraging on the gravel path at the entrance to the union bay natural area. Wetland prairie habitat adjacent to lake washington, and riddled with shrubs, willows, invasive cottonwoods, and pools of water

Photos / Sounds

What

Song Sparrow (Melospiza melodia)

Observer

robertmarsh

Date

May 19, 2012

Description

A round shaped brown with white woody camoflauged bird, more white than brown on breast, with very short, stubby, and upright wings when sitting. Usually flitters tail when walking around. Dark beak, and prominent white eyebrows. Cited on branches of a shrub at the base of a cottonwood, just under 1.5 meters high up.
Wetland prairie habitat adjacent to lake washington, and riddled with shrubs, willows, invasive cottonwoods, and pools of water

Photos / Sounds

What

Brown-headed Cowbird (Molothrus ater)

Observer

robertmarsh

Date

May 19, 2012

Description

A blackbird that was smaller than a crow, and typically skinnier than the red-winged blackbirds in the area. Most distinguishable by its dark brown head when close enough to distinguish the dark brown head from its black body. Its call was one note of a long high and rising tone that sounded similar to a human whistling doing the same.
Wetland prairie habitat adjacent to lake washington, and riddled with shrubs, willows, invasive cottonwoods, and pools of water. Cowbird was cited is a shrub on the shore of one of the ponds.

Photos / Sounds

What

American Goldfinch (Spinus tristis)

Observer

robertmarsh

Date

May 19, 2012

Description

small and Bright pale yellow bird, distinguishible by black face mask, thick black tipped wings with fine white markings, and bright orange beak. Call was of very short cheaps when i approached.
Sited in the shrubbery on the bank of a pond in union bay natural area

Photos / Sounds

What

American Robin (Turdus migratorius)

Observer

robertmarsh

Date

May 19, 2012

Description

Recognizeable bird, dark back, red breasted thrush. Red breast splits in the shape of the breast yielding a white region at the base of the torso before the dark tail. Also has characteristic thin unconnected white markings around the eyes. Moderately long orange beak that slightly curves downward. Mating call is also very recognizeable as a two toned high and the low call, paired together or in threes, each lasting about 3/4 of a second, and sounding more throaty than other bird calls.
Wetland prairie habitat adjacent to lake washington, and riddled with shrubs, willows, invasive cottonwoods, and pools of water

Photos / Sounds

What

Barn Swallow (Hirundo rustica)

Observer

robertmarsh

Date

May 19, 2012

Description

Small bird, shiny dark blue back, and yellow breast. Distinguishable by the very forked tail when in flight(see second photo bottom left corner). Sited in abundance in union bay natural area between the shores of lake washington and the shore of one of the ponds, also in the group of birds were many violet green swallows. It was impossible to catch one of these birds not in flight, it seemed to be all they did, flying down very close to the water of the pond, steep ascents into the air followed by dives back down, occasional flocking, and generally flying all over the place.

Photos / Sounds

What

Violet-green Swallow (Tachycineta thalassina)

Observer

robertmarsh

Date

May 19, 2012

Description

Small bird with a white breast, green shiny upper back, and distinguishable white band across tail on top side when flying. It was impossible to catch one of these birds not in flight, it seemed to be all they did, flying down very close to the water of the pond, steep ascents into the air followed by dives back down, occasional flocking, and generally flying all over the place. Amongst the flock of birds at the time were some barn swallows.

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