Verification of Unusual
Rec. # 2006-19
|Scientific name:||Podiceps grisegena|
|Date:||May 20, 2006|
|Length of time observed:||30-45 minutes|
|Location:||Willard Reservoir along the north dike|
|Latilong:||2 (N 41*25.240' W112*03.656')|
|Distance to bird:||50-100 feet|
|Optical equipment:||8x42 binoculars; 85 mm spotting scope w/ 20-60x eyepiece|
|Weather:||Mostly sunny, clear, 80+ degrees|
|Light Conditions:||Bright evening just before sunset. Long rays of sun from west|
|Description: Size of bird:||16-18"|
|(Description:) Basic Shape:||Long neck, body low to water and low sloping back|
|(Description:) Overall Pattern:||Black, white, dark rust, dusky gray|
|(Description:) Bill Type:||Sharp, sturdy spear-like|
Field Marks and
Shape/appearance similar to Western Grebes present,
although bird was smaller/chunkier with different coloration. Plumage
was wet and slicked down during the entire observation period.
Beak: About 3-3.5 inches long. Upper mandible: Culmen straight; mostly dark dusky with about 25% of sides of base yellow.
Lower mandible: Bottom edge just slightly curved upward toward the tip.
Mostly dusky, basal third bright yellow, distal tip somewhat pale.
Head: Black crown beginning at base of upper bill, running across top one-third of head. Smooth curve of crown (always wet and slicked down) except once when the bird shook and roused all feathers; then a faint point appeared directly over eye. Distinct point at back of head/top of
nape. Eye contained within black of crown. Irides dark, possibly brown. Narrow circle of orbital skin yellow. Extensive white cheeks and throat. White projected well back onto nape and was visible when the bird was turned completely away from observer. White cheeks appeared to have a dusky gray or silvery sheen on them depending on how the bird turned.
Neck: Front and sides were dark rust becoming washed out rust or buff at upper breast. Back of neck: Thin black stripe running from rear point of crown down to back.
Belly: Pale or white.
Body: Dusky gray. Shape of back was two longitudinal low humps with a faint dip (the spine area) between them.
Feet: Appeared dark below the surface of the water and seemed positioned well behind the tail as the bird paddled.
At one point the bird reared up out of the water and did a brief wing flap. Underbody and underwings appeared white or pale; flight feathers pale gray or silvery. Also got a flash of white where folded wings met the tail area.
|Song or call & method of delivery:||None heard|
|Behavior:||Bird swam close to rocky edge of dike within 5 to 20 feet. Most of the time the bird picked items off the surface of the water like a Bonaparte's Gull does, but less rhythmically. Not wary of people fishing. Bird only dove 5 to 6 times in 30-45 minutes.|
|Habitat:||Large freshwater reservoir, 5-20 feet from rocky dike|
were they eliminated:
Red-throated Loon: Review bird had a black
crown with a rear point, extensive white cheeks, and dusky/yellow bill.
RTLO has none of these features.
Pied-billed Grebe: Review bird had a dark rusty neck, black crown, and white cheeks. Pied-billed Grebe is mostly brown at this time of year and has a vertical black stripe running through its bill.
Horned Grebe: Review bird was lacking bright gold head plumage of Horned Grebe, more petite body, and red eye.
Eared Grebe: Review bird was lacking wispy gold head plumage, petite body with fluffy undertail coverts, and red eye.
Aechmorphorus Grebes: Review bird was smaller and chunkier than Western or Clark's Grebes (Western were present for comparison). In addition, the big grebes have a longer, slimmer neck lacking the dark rust color.
this & similar species:
|One RNGR; a juvenile at Pineview Reservoir in Nov 2004. Have seen all other comparison species many times except just one RTLO in non-breeding plumage.|
|Description from:||Notes made later|
|Observer:||Kristin M. Purdy|
|Observer's address:||1961 Arapaho Circle|
|Observer's e-mail address:||email@example.com|
|Other observers who independently identified this bird:||Bob Huntington|
|Date prepared:||May 20, 2006|
|Additional material:||Photo by Brian Currie|