|
Records Committee review for rare bird sighting of Mew Gull at Red Rock Reservoir Dam, 1994
|
Administrative records Clippings (information artifacts) Field notes
|
Bird watching Ornithology Ornithology--Societies, etc
|
1994-12-11
|
1996-04-25
|
Rare birds documentation form
|
Records Committee review of a Mew Gull at Red Rock Reservoir Dam in Marion County, IA on December 11, 1994. Includes a record review document with votes, an article in Iowa Bird Life, and four documentation forms submitted to the committee.
|
Dinsmore, Stephen J.
|
Mew Gull
|
Red Rock Dam
|
below Red Rock Reservoir dam, Marion Co., IA
|
spillway
|
The documentation form by Steve Dinsmore forms the basis of this record. Other documentation forms by Jim Sinclair, Ray Cummins, and Thomas H. Kent were submitted. Other observers include Tim Schantz, Jim Fuller, and many unidentified observers. | Elimination of similar species: The only species with which this bird could be confused is Ring-billed Gull. The tail and wing patterns, generally darker coloration, large eye, and smaller bill all eliminate first-winter Ring-billed Gull. Identification to subspecies was based on tail pattern and more extensive dark color on head and underparts. | The original documentation form event lasted from 07:20:00/08:30:00.
|
Iowa Ornithologists' Union | MS 166
|
10
|
23
|
|
Records Committee review for rare bird sighting of Mew Gull at Fairport Fish Hatchery, 1995
|
Administrative records Correspondence Field notes
|
Bird watching Ornithology Ornithology--Societies, etc
|
1995-09-08
|
2000-11-20
|
Rare birds documentation form
|
Records Committee review of a Mew Gull at Fairport Fish Hatchery in Muscatine County, IA on September 8, 1995. Includes a record review document with votes, correspondence from Peter Petersen to Thomas H. Kent, and a documentation form submitted to the committee.
|
Petersen, Peter C.
|
Mew Gull
|
Fairport State Fish Hatchery
|
Fairport Fish Hatchery, Muscatine Co. IA
|
Fish rearing ponds + adj. Miss. River
|
The documentation form by Peter C. Petersen is the only one submitted and forms the basis of this record. | Elimination of similar species: Ring-billed Gull- much more black on primary tips, black ring on yellow bill | The original documentation form event lasted from 08:05:00/08:10:00.
|
Iowa Ornithologists' Union | MS 166
|
10
|
23
|
|
Records Committee review for rare bird sighting of Mew Gull at Lake Rathbun, 1995
|
Administrative records Field notes
|
Bird watching Ornithology Ornithology--Societies, etc
|
1995-11-04
|
2000-11-20
|
Rare birds documentation form
|
Records Committee review of a Mew Gull at Lake Rathbun in Appanoose County, IA on November 4, 1995. Includes a record review document with votes and a documentation form submitted to the committee.
|
Cummins, Raymond L.
|
Mew Gull
|
Rathbun Lake
|
Lake Rathbun Appanoose Co.
|
Sandy beach with about 50 other gulls including Ring-billed, Franklin's, Bonaparte's and the 1st winter Mew Gull. After about 20 min the bird departed to the north with about a dozen other gulls. Did not see them take off.
|
The documentation form by Ray Cummins is the only one submitted and forms the basis of this record. | Elimination of similar species: See Ring-billed Gull comparicons [sic] above. [...] The size was slightly but noticeably smaller than all the Ring-billeds present. The head was more rounded in appearance than the ring-billeds. The bill was smaller in portion than the Ring-billeds, both shorter and thinner. [...] The tail was black, but not as black as side by side comparisons with the adult Ring-billeds. | The original documentation form event lasted from 07:45:00/08:05:00.
|
Iowa Ornithologists' Union | MS 166
|
10
|
23
|
|
Records Committee review for rare bird sighting of Mew Gull at Saylorville Reservoir, 1996
|
Administrative records Clippings (information artifacts) Field notes
|
Bird watching Ornithology Ornithology--Societies, etc
|
1996-11-29
|
2000-11-22
|
Rare birds documentation form
|
Records Committee review of a Mew Gull at Saylorville Reservoir in Polk County, IA on November 29, 1996. Includes a record review document with votes, an article in Iowa Bird Life, and a documentation form submitted to the committee.
|
Dinsmore, Stephen J.
|
Mew Gull
|
Saylorville Lake
|
Saylorville Reservoir, Polk Co., IA
|
large reservoir
|
The documentation form by Stephen J. Dinsmore is the only one submitted and forms the basis of this record. | Elimination of similar species: The wing pattern, size, and lack of black marks on the face eliminated any of the smaller gulls (i.e. Bonaparte's). The small size and smaller bill size eliminated California Gull. Ring-billed Gull was eliminated on the basis of the darker mantle and upperwings, large, dark eye, and bill color and shape. | The original documentation form event lasted from 16:03:00/16:41:00.
|
Iowa Ornithologists' Union | MS 166
|
10
|
23
|
|
Records Committee review for rare bird sighting of Mew Gull at Red Rock Reservoir Dam, 1997
|
Administrative records Field notes
|
Bird watching Ornithology Ornithology--Societies, etc
|
1997-12-20
|
2000-11-24
|
Rare birds documentation form
|
Records Committee review for a Mew Gull at Red Rock Reservoir Dam in Marion County, IA on December 20, 1997. Includes a record review document with votes and two documentation forms submitted to the committee.
|
Dinsmore, Stephen J.
|
Mew Gull
|
Red Rock Dam
|
Red Rock Reservoir, Marion Co., IA
|
large reservoir
|
The documentation form by Stephen J. Dinsmore forms the basis of this record. Another documentation form by Michael D. Overton was submitted. Other observers include Maridel Jackson, Ann Johnson, Aaron Brees, Gordon Brand, and many other unidentified observers. | Elimination of similar species: The wing pattern, size, and lack of black marks on the face eliminated any of the smaller gulls (i.e. Bonaparte's). The small size and smaller bill size eliminated California Gull. Ring-billed Gull was eliminated on the basis of the darker mantle and upperwings, large, dark eye, and bill color and shape. | The original documentation form event lasted from 15:30:00/16:40:00.
|
Iowa Ornithologists' Union | MS 166
|
10
|
23
|
|
Records Committee review for rare bird sighting of Mew Gull at Saylorville Reservoir, 1998
|
Administrative records Field notes
|
Bird watching Ornithology Ornithology--Societies, etc
|
1998-12-20
|
2000-11-24
|
Rare birds documentation form
|
Records Committee review for a Mew Gull at Saylorville Reservoir in Polk County, IA on December 20, 1998. Includes a record review document with votes and a documentation form submitted to the committee.
|
Dinsmore, Stephen J.
|
Mew Gull
|
Saylorville Lake
|
Saylorville Reservoir, Polk County, Iowa
|
feeding in spillway and resting on large reservoir
|
The documentation form by Stephen J. Dinsmore is the only one submitted and forms the basis of this record. Another observer was Kay Niyo. | Elimination of similar species: The only similar species (Ring-billed Gull) was eliminated by the combination of slightly smaller size, smaller bill, more extensive brown color on the underparts, and pattern of the rectrices. | The original documentation form event lasted from 13:46:00/14:08:00.
|
Iowa Ornithologists' Union | MS 166
|
10
|
23
|
|
Records Committee review for rare bird sighting of Mew Gull at Lock and Dam 19 at Keokuk, 1998
|
Administrative records Field notes
|
Bird watching Ornithology Ornithology--Societies, etc
|
1998-12-21
|
2000-11-24
|
Rare birds documentation form
|
Records Committee review for a Mew Gull at Lock and Dam 19 at Keokuk in Lee County, IA on December 21, 1998. Includes a record review document with votes and a documentation form submitted to the committee.
|
Dinsmore, Stephen J.
|
Mew Gull
|
Lock Number 19
|
Lock and Dam 19, Keokuk, Lee County, Iowa
|
feeding below dam of a large river
|
The documentation form by Stephen J. Dinsmore is the only one submitted and forms the basis of this record. Other observers were Aaron Brees and many unidentified other observers. | Elimination of similar species: The combination of a smaller bill, more extensive dark brown color on the underparts, darker gray mantle, and solidly dark rectrices eliminated the similar Ring-billed Gull. | The original documentation form event lasted from 12:25:00/13:00:00.
|
Iowa Ornithologists' Union | MS 166
|
10
|
23
|
|
Records Committee review for rare bird sighting of California Gull at Cherry Glen Recreation Area at Saylorville Reservoir, 1986
|
Administrative records Correspondence Field notes
|
Bird watching Ornithology Ornithology--Societies, etc
|
1986-12-07
|
1996-01-25
|
Rare birds documentation form
|
Records Committee review for a California Gull at Cherry Glen Recreation Area at Saylorville Reservoir in Polk County, IA on December 7, 1986. Includes a record review document with votes, correspondence about the bird sighting and a request for re-evaluation of sighting, summary of the review, and a documentation form submitted to the committee.
|
Dinsmore, Stephen J.
|
California Gull
|
Cherry Glen Recreation Area
|
Saylorville Reservoir, Polk Co. (Cherry Glen Recreation Area)
|
sitting on ice with other gulls
|
The documentation form by Steve Dinsmore is the only one submitted and forms the basis of this record. | Elimination of similar species: Herring Gull eliminated by larger size, lighter mantle color, lack of black and red spots on bill, and wrong leg color (pink, although a very few Herring Gull show yellowish legs). Ring-billed Gull eliminated by smaller size, lighter mantle color, lack of a black ring on bill, and by yellower leg color. | The original documentation form event lasted from 13:13:00/14:08:00.
|
Iowa Ornithologists' Union | MS 166
|
11
|
1
|
|
Records Committee review for rare bird sighting of California Gull at Credit Island, 1989
|
Administrative records Clippings (information artifacts) Correspondence Field notes
|
Bird watching Ornithology Ornithology--Societies, etc
|
1989-11-23
|
1993-07-21
|
Rare birds documentation form
|
Records Committee review for a California Gull at Credit Island in Scott County, IA on November 23, 1989. Includes a record review document with votes, an article in Iowa Bird Life, correspondence about the sighting from Louise Augustine to Carl Bendorf, and three documentation forms submitted to the committee.
|
Augustine, Louise
|
California Gull
|
Credit Island
|
Credit Island - Davenport, Iowa - Scott County
|
This is an unfamiliar Area for me - I have never birded there before - The Place Credit Island - Backwater of Mississippi River - There was some ICE and open water - Many Gulls were in this Backwater area - on ice and in water. Probably around 1,500 Gulls -
|
The documentation form by Louise Augustine forms the basis of this record. Other documentation forms by Peter C. Petersen and Jim Fuller were submitted. Other observers include Randy Pinkston, Mary Lou Petersen, Jerome Augustine, David Augustine, and Julie Augustine. | Elimination of similar species: Herring Gull - darker mantle - Dark eye - Leg Color - ashy-green gray not Pink - smaller size - slimmer build Ring-billed Gull - mantle too dark - dark eye - Bill had only a spot Leg Color not yellow - This bird larger than Ring-billed gulls - | The original documentation form event lasted from 12:00:00/13:00:00.
|
Iowa Ornithologists' Union | MS 166
|
11
|
1
|
|
Records Committee review for rare bird sighting of California Gull at Oak Grove Beach at Saylorville Reservoir, 1990
|
Administrative records Clippings (information artifacts) Field notes
|
Bird watching Ornithology Ornithology--Societies, etc
|
1990-09-08
|
1993-07-17
|
Rare birds documentation form
|
Records Committee review for a California Gull at Oak Grove Beach at Saylorville Reservoir in Polk County, IA on September 8, 1990. Includes a record review document with votes and the article California Gull at Saylorville Reservoir in Iowa Bird Life 61:20 by Stephen Dinsmore reviewed by the committee.
|
Dinsmore, Stephen J.
|
California Gull
|
Oak Grove Recreation Area
|
[...] Oak Grove Beach Recreation Area at Saylorville Reservoir, Polk County.
|
|
The article by Stephen J. Dinsmore forms the basis of this record. | Elimination of similar species: [...]The bird was similar in size to the largest Ring-billed Gulls, but slightly larger than others. I approached closer and noted that, when compared to a Ring-billed Gull, the bird had duller yellow legs, a stouter bill with black and red spots near the tip of the lower mandible, and a darker gray mantle. [...] The bird was slightly larger than most of the Ring-billed Gulls, although one or two of the biggest Ring-billed Gulls were as large as the bird I was studying. Proportionately, the bird was heavier and larger-headed than a Ring-billed Gull. [...] I estimated the mantle color to be about midway between those of Ring-billed Gull and a Lesser Black-backed Gull. [...] The bill was heavier than the bill of a Ring-billed Gull and had a distinct gonys. The legs were pale gray-green, unlike the bright yellow legs of a Ring-billed Gull. Leg length appeared similar to a Ring-billed Gull. | The original documentation form event lasted from 07:45:00/09:27:00.
|
Iowa Ornithologists' Union | MS 166
|
11
|
1
|
|
Records Committee review for rare bird sighting of California Gull at Babcock Access at Coralville Reservoir, 1990
|
Administrative records Clippings (information artifacts) Field notes
|
Bird watching Ornithology Ornithology--Societies, etc
|
1990-10-27
|
1993-07-17
|
Rare birds documentation form
|
Records Committee review for a California Gull at Babcock Access at Coralville Reservoir in Johnson County, IA on October 27, 1990. Includes a record review document with votes, two articles in Iowa Bird Life, and five documentation forms submitted to the committee.
|
Kent, Thomas H. (Thomas Hugh), 1934-
|
California Gull
|
Babcock Access
|
Babcock Access, Coralville Reservoir, Johnson County, Iowa
|
shallow, open area of reservoir
|
The documentation form by Thomas H. Kent is the earliest and the one that forms the basis of this record. Other documentation forms by Jim Fuller, Randy Pinkston, Carol Thompson, and Carl J. Bendorf were submitted later. Other observers include Timothy Dwyer, John Cordell, James Huntington, Cal Knight, Bernie Knight, and Rick Hollis. | Elimination of similar species: First-year Ring-billed Gulls were all in first winter plumage with gray mantle and were much lighter overall. The only other species considered is juvenile Herring Gull. The size is small for Herring Gull. The elongated appearance and short legs fit California Gull. Most young Herrings that I see in early fall have mostly dark bills that are larger than that of this bird. The double inner wing bar and lighter tertial tips fit California Gull. The overall relatively uniform and relatively light brown color without windows in the inner primaries also made this bird look different from Herring Gull. | The original documentation form event lasted from 15:15:00/16:55:00 on October 27, 1990 and from 19:10:00/22:30:00 and 15:00:00/16:00:00 on October 28, 1990.
|
Iowa Ornithologists' Union | MS 166
|
11
|
1
|
|
Records Committee review for rare bird sighting of California Gull at Carter Lake, 1993
|
Administrative records Clippings (information artifacts) Field notes Photographs
|
Bird watching Ornithology Ornithology--Societies, etc
|
1993-11-21
|
1995-07-08
|
Rare birds documentation form
|
Records Committee review for a California Gull at Carter Lake in Pottawattamie County, IA on November 21, 1993. Includes a record review document with votes, a photograph, an article in Iowa Bird Life, and three documentation forms submitted to the committee.
|
Bray, Tanya
|
California Gull
|
Carter Lake
|
Carter Lake, Pottawattamie County
|
|
The documentation form by Tanya Bray forms the basis of this record. Other documentation forms by Loren and Babs Padelford, and Ross Silcock were submitted. Other observers include Jerry Toll and B.J. Rose. | Elimination of similar species: Both Ring-billed and Herring Gulls are eliminated by bill coloration, size, slightly darker mantle, and eye color. Western, Lesser-black backed would be darker mantled, different bill coloration. | The original documentation form event lasted from 10:30:00/10:58:00.
|
Iowa Ornithologists' Union | MS 166
|
11
|
1
|
|
Records Committee review for rare bird sighting of California Gull at Saylorville Dam, 1993
|
Administrative records Clippings (information artifacts) Field notes
|
Bird watching Ornithology Ornithology--Societies, etc
|
1993-12-06
|
1995-07-08
|
Rare birds documentation form
|
Records Committee review for a California Gull at Saylorville Dam in Polk County, IA on December 6, 1993. Includes a record review document with votes, an article in Iowa Bird Life, and two documentation forms submitted to the committee.
|
Pinkston, Randall, 1956-
|
California Gull
|
Saylorville Dam
|
Saylorville Reservoir dam, Polk County, Iowa
|
|
The documentation form by Randy Pinkston is the earliest and the one that forms the basis of this record. Another documentation form by Stephen J. Dinsmore was submitted later. Another observer includes Susan Grove. | Elimination of similar species: I am uncomfortable committing to California Gull given the brief and distant view I had, and my limited past experience with the species. My fear is that this was just a small Herring Gull. Herring can be quite variable in overall size, bill size, and in terms of color and shade of the first-winter plumage. Supposedly 10-15% of first-winter Herrings' can have a "dipped-in-ink" bill in the fall (Harrison 1983 or Grant 1986?). | The original documentation form event lasted from 12:30:00/15:30:00.
|
Iowa Ornithologists' Union | MS 166
|
11
|
1
|
|
Records Committee review for rare bird sighting of California Gull at Runnells Wildlife Area, 1995
|
Administrative records Clippings (information artifacts) Field notes Photographs
|
Bird watching Ornithology Ornithology--Societies, etc
|
1995-09-03
|
2000-11-20
|
Rare birds documentation form
|
Records Committee review for a California Gull at Runnells Wildlife Area in Marion County, IA on September 3, 1995. Includes a record review document with votes, two photographs, an article in Iowa Bird Life, and four documentation forms submitted to the committee.
|
Dinsmore, Stephen J.
|
California Gull
|
Red Rock Wildlife Area
|
1 mi e. of Swan, Marion Co. (Runnells W.A.)
|
pool of shallow water
|
The documentation form by Steve Dinsmore is the earliest and the one that forms the basis of this record. Other documentation forms by Jim Sinclair, Thomas H. Kent, and Jim Fuller were submitted later. | Elimination of similar species: Ring-billed and Herring gulls are the two most likely species of confusion. Ring-billed Gull never shows this much brown in any plumage, has a dark tail band in immature plumages, has a different wing pattern, and is structurally different from California Gull. Herring Gull is more similar in first-basic plumage, but always shows a pale window on the inner primaries, lacks the double dark bar effect in the innerwing, is larger, and very rarely shows a strongly bicolored bill. | The original documentation form event lasted from 10:55:00/12:24:00.
|
Iowa Ornithologists' Union | MS 166
|
11
|
1
|
|
Records Committee review for rare bird sighting of California Gull at Mini-Wakan State Park, 1996
|
Administrative records Clippings (information artifacts) Field notes
|
Bird watching Ornithology Ornithology--Societies, etc
|
1996-09-06
|
2000-11-22
|
Rare birds documentation form
|
Records Committee review for a California Gull at Mini-Wakan State Park in Dickinson County, IA on September 6, 1996. Includes a record review document with votes, an article in Iowa Bird Life, and a documentation form submitted to the committee.
|
Bangma, Jim Johnson, Ann
|
California Gull
|
Mini Wakan State Park
|
Spirit Lake, north end, Dickinson Co., IA
|
Lakeshore
|
The documentation form by Jim Bangma and Ann Johnson is the only one submitted and forms the basis of this record. | Elimination of similar species: Ring-billed is ruled out by the solid gray mantle combined with the extensive molt of the flight feathers. Ring-bills and similar 3 year gulls obtain the gray mantle during a post-juvenal molt. Flight feathers are not molted at this time. Flight feathers are molted after one year, at which time the body of a Ring-bill would be much whiter. Also, the mantle was a much darker shade of gray than any Ring-bill present. Additionally, Ring-billed Gull's bill is proportionally smaller and thinner, with more curve. Herring Gull would be larger. The mantle of a Herring Gull would be paler gray, nearly the same shade as that of the Ring-bills. The bill would be proportionally heavier with a more marked gonydeal angle. Herring Gulls may show a black tipped bill, but the black normally blends into the pink of the base or runs in along the cutting edges of the bill. The bill and legs would be brighter pink. Other similarly sized extralimitals can be ruled out by the mantle color as well as bill pattern and shape. A striking feature of this bird was its leg length. In an effort to better understand this, Bangma paid a visit to the American Museum of Natural History and examined specimens of Herring, Ring-billed and California Gulls. Measurements were made of a representative selection of specimens. The following chart shows the results. [Chart] While there is some overlap between these species, it is interesting to note that the breaking point between California Gull and the other two is very near the ratio of 1.5. While not diagnostic by itself, the length of this bird's tarsus relative to the culmen as estimated by us in the field is indicative of California Gull. | The original documentation form event lasted from 11:00:00/11:40:00.
|
Iowa Ornithologists' Union | MS 166
|
11
|
1
|
|
Records Committee review for rare bird sighting of California Gull at Lost Island Lake, 1996
|
Administrative records Field notes
|
Bird watching Ornithology Ornithology--Societies, etc
|
1996-11-03
|
2000-11-22
|
Rare birds documentation form
|
Records Committee review for a California Gull at Lost Island Lake in Palo Alto County, IA on November 3, 1996. Includes a record review document with votes and a documentation form submitted to the committee.
|
Schoenewe, Lee A.
|
California Gull
|
Lost Island Lake
|
N. Shore of Lost Island Lake, Palo Alto, Co.
|
Shoreline
|
The documentation form by Lee A. Schoenewe is the only one submitted and forms the basis of this record. | Elimination of similar species: Herring Gull - bill, eye and leg color Ring-billed Gull - Bill size, tail + wingtips in flight | The original documentation form event lasted from 10:35:00/10:55:00.
|
Iowa Ornithologists' Union | MS 166
|
11
|
1
|
|
Records Committee review for rare bird sighting of California Gull at Gull Point at West Okoboji Lake, 1997
|
Administrative records Correspondence Field notes
|
Bird watching Ornithology Ornithology--Societies, etc
|
1997-09-07
|
2000-11-24
|
Rare birds documentation form
|
Records Committee review of a California Gull at Gull Point at West Okoboji Lake in Dickinson County, IA on September 7, 1997. Includes a record review document with votes, correspondence from Ken Brock to Thomas Kent, and two copies of a documentation form submitted to the committee.
|
Schoenewe, Lee A.
|
California Gull
|
Gull Point
|
Gull Point, West Lake Okoboji, Dickinson Co.
|
Rocky point on natural lake
|
|
Iowa Ornithologists' Union | MS 166
|
11
|
1
|
|
Records Committee review for rare bird sighting of California Gull at Cherry Glen Recreation Area at Saylorville Reservoir, 1997
|
Administrative records Field notes
|
Bird watching Ornithology Ornithology--Societies, etc
|
1997-12-09
|
2000-11-24
|
Rare birds documentation form
|
Records Committee review for a California Gull at Cherry Glen Recreation Area at Saylorville Reservoir in Polk County, IA on December 9, 1997. Includes a record review document with votes and a documentation form submitted to the committee.
|
Overton, Michael D.
|
California Gull
|
Cherry Glen Recreation Area
|
Polk co., Saylorville Reservoir, Cherry Glen Recreation Area
|
On ice along lakeshore of large manmade lake in mixed hardwood forest agricultural cropland.
|
The documentation form by Michael D. Overton is the only one submitted and forms the basis of this record. Other observers include Eugene Armstrong and Eloise Armstrong. | Elimination of similar species: Ring-billed Gull, Herring Gull: Immatures of both species were present so direct comparisons were possible. Bill color, shape, and size reletive [sic] to head. Tail and rump color. Wing color and pattern especially mantle, greater coverts, and secondaries. | The original documentation form event lasted from 10:20:00/10:55:00.
|
Iowa Ornithologists' Union | MS 166
|
11
|
1
|
|
Records Committee review for rare bird sighting of Thayer's Gull at Lake Manawa, 1981
|
Administrative records Clippings (information artifacts) Correspondence Field notes
|
Bird watching Ornithology Ornithology--Societies, etc
|
1981-03-19
|
1993-08-26
|
Rare birds documentation form
|
Records Committee review for two Thayer's Gulls at Lake Manawa in Pottawattamie County, IA on March 19, 1981. Includes a record review document with votes, correspondence and comments about the sighting, an article in Iowa Bird Life, and four documentation forms submitted to the committee.
|
Silcock, W. Ross
|
Thayer's Gull
|
Lake Manawa
|
Lake Manawa, Pottawattamie County, Iowa.
|
|
The documentation form by Ross Silcock is the earliest and the one that forms the basis of this record. Other documentation forms by Thomas H. Kent, Peter C. Petersen, and Robert K. Myers were submitted later. Other observers include Tom Shires, James Kovanda, Sandra Kovanda, Tanya Bray, Babs Padelford, Loren Padelford, B.J. Rose, and four unidentified other observers. | Elimination of similar species: The above description separates by direct comparison first-year Thayer's and Herring Gulls, the most similar species present. Thayer's may be confused in first year plumage with Kumlien's form of Iceland Gull, but the Thayer's had primaries slightly darker than the mantle (from above), whereas the opposite occurs in Iceland Gull (Lehman). Lehman also notes that some first-year Western Gulls may show translucent primaries from below in certain light, but these observations took place in excellent light at fairly close range. | The original documentation form event lasted from approximately 09:30:00/11:00:00.
|
Iowa Ornithologists' Union | MS 166
|
11
|
3
|
|
Records Committee review for rare bird sighting of Thayer's Gull at Coralville Dam, 1981
|
Administrative records Correspondence Field notes
|
Bird watching Ornithology Ornithology--Societies, etc
|
1981-11-07
|
1993-08-26
|
Rare birds documentation form
|
Records Committee review for two Thayer's Gulls at Coralville Dam in Johnson County, IA on November 7, 1981. Includes a record review document with votes, correspondence and commentary about the sighting, and a documentation form submitted to the committee.
|
Kent, Thomas H. (Thomas Hugh), 1934-
|
Thayer's Gull
|
Coralville Dam
|
Coralville Res. Dam, west overlook, Johnson Co. Iowa
|
Reservoir, just above dam, in water and on swimming beach
|
The documentation form by Thomas H. Kent is the only one submitted and forms the basis of this record. Other observers include Carl Bendorf, Mike Newlon, and many unidentified other observers. | Elimination of similar species: Photographs taken at the first encounter with a Celestron 750 mm lens demonstrate the size difference, the bill and head shape difference, the lighter overall color, and the window in the wing. An adult Herring was in the photo with the Thayer's on 7 Nov and imm Herring were photographed on 10 Nov for comparison. | The original documentation form event lasted from 09:25:00/09:50:00 and 11:00:00/11:20:00 on November 7, 1981 and 07:30:00/08:30:00 on November 8, 1981.
|
Iowa Ornithologists' Union | MS 166
|
11
|
3
|
|
Records Committee review for rare bird sighting of Thayer's Gull at Coralville Dam, 1981
|
Administrative records Correspondence Field notes
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Bird watching Ornithology Ornithology--Societies, etc
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1981-11-08
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1993-08-26
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Rare birds documentation form
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Records Committee review for three Thayer's Gulls at Coralville Dam in Johnson County, IA on November 8, 1981. Includes a record review document with votes, correspondence and commentary about the sighting, summary of the review, and a documentation form submitted to the committee.
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Moore, Francis L.
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Thayer's Gull
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Coralville Dam
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Coralville Reservoir
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Open wate [sic] near small sandy beach near the Dam area, Johnson County
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The documentation form by Francis L. Moore is the only one submitted and forms the basis of this record. Other observers include Russell Hays, Tom Kent, Tom Shires, Tom Staudt, and many unidentified other observers. | Elimination of similar species: Ring-billed Gull and Herring Gull, see above. The Ring-billed Gulls were seen in direct contrast to these three birds and were definitely much smaller birds. The Herring Gulls (first year birds) that I have seen have more of a contrast between the rump and back and upper wing surfaces and none that I remember showed the whitish trailing edge on the tail. [...] The three birds seen were about the size of Herring Gulls in typical first year plumage. They were obviously large gulls of the genus Larus with a noticeably larger size than the Ring-billed Gulls and one Bonaparte's Gull that were next to the three larger birds. [...] There were no Herring Gulls nearby with which to make a comparison of size and coloration. The bills of all three gulls were black did not seem as heavy or bulky as the bill of a Herring Gull. | The original documentation form event lasted from 08:10:00/09:30:00.
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Iowa Ornithologists' Union | MS 166
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11
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3
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Records Committee review for rare bird sighting of Thayer's Gull at Lake Manawa, 1981
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Administrative records Correspondence Field notes
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Bird watching Ornithology Ornithology--Societies, etc
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1981-12-05
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1993-08-26
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Rare birds documentation form
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Records Committee review for a Thayer's Gull at Lake Manawa in Pottawattamie County, IA on December 5, 1981. Includes a record review document with votes, correspondence and commentary about the sighting, and a documentation form submitted to the committee.
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Silcock, W. Ross
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Thayer's Gull
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Lake Manawa
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Lake Manawa
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The documentation form by W. Ross Silcock is the only one submitted and forms the basis of this record. | Elimination of similar species: [...] Smaller than adult Herring Gull (winter plumage, red spot end of lower mandible) beside it, legs a little pinker. Larger than Ring-billed Gulls- flock of 14 adjacent. [...] Headmuch [sic] smaller relative to body than in the Herring Gull- also flatter-appearing. [...] 1. Bill was black (or very dark); this , combined with the rather pale underparts relative to the rest of the (also rather pale) plumage tends to rule out a first year Herring Gull. 2. Bill and head size and shape were not as heavy-appearing as in Herring Gull. Direct comparison with adjacent adult Herring Gull was very useful in deciding this. [...] 5. Size and pinker legs than Herring Gull are not sure characters, but lend support to identification as Thayer's Gull.
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Iowa Ornithologists' Union | MS 166
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11
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3
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Records Committee review for rare bird sighting of Thayer's Gull at Coralville Dam, 1981
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Administrative records Correspondence Field notes
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Bird watching Ornithology Ornithology--Societies, etc
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1981-12-06
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1993-08-26
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Rare birds documentation form
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Records Committee review for a Thayer's Gull at Coralville Dam in Johnson County, IA on December 6, 1981. Includes a record review document with votes, correspondence and commentary about the sighting, field notes, and a documentation form submitted to the committee.
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Kent, Thomas H. (Thomas Hugh), 1934-
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Thayer's Gull
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Coralville Dam
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Coralville Res. Dam, Johnson Co., Iowa
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Reservoir just above dam on ice
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The documentation form by Thomas H. Kent as dictated to Carl Bendorf is the only one submitted and forms the basis of this record. Another observer was Carl Bendorf. | Elimination of similar species: imm. Herring Gull. The second year Herring has a light bill with black tip and more contrasting black and white pattern to wings and tail. The first year Herring is much darker, has a more bulbous, hooked bill, and lacks the definitewhite [sic] window in flight. | The original documentation form event lasted from 08:15:00/08:30:00.
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Iowa Ornithologists' Union | MS 166
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11
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3
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Records Committee review for rare bird sighting of Thayer's Gull at Saylorville Dam, 1981
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Administrative records Correspondence Field notes
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Bird watching Ornithology Ornithology--Societies, etc
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1981-12-10
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1993-08-26
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Rare birds documentation form
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Records Committee review for a Thayer's Gull at Saylorville Dam in Polk County, IA on December 10, 1981 recorded incorrectly as 1982 on the documentation form. Includes a record review document with votes, correspondence and commentary about the sighting, and a documentation form submitted to the committee.
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Schaufenbuel, Joseph P.
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Thayer's Gull
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Saylorville Dam
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Above and below Saylorville Dam
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Open water, rocky shore and ice covered pond.
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The documentation form by Joe Schaufenbuel is the only one submitted and forms the basis of this record. | Elimination of similar species: [...] Nearly the same size as an immature Herring Gull, but neck seemed thinner, head smaller. Bill was same length as a Herring Gull's but was blunter, not as strongly hooked. [...] The primaries were not nearly as dark as immature (1st year) or 2nd year Herring Gulls and was of a much different color than the black color of that species. Primaries and tail were nearly the same color. [...] In flight this bird could be easily picked out from the immature Herring Gulls at considerable distances. Using 7x35 binoculars the beige color of the upper surface of wings and translucent underwing could be detected as far as three-quarters of a mile. There were also three other birds that resembled this particular bird though they appeared darker on the upperparts. However I was unable to get close observations of these birds. The bird I observed closely and documented had one primary feather missing and aided in tracking the bird from day to day.
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Iowa Ornithologists' Union | MS 166
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11
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3
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Records Committee review for rare bird sighting of a Thayer's Gull at Red Rock Reservoir Dam, 1985
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Administrative records Clippings (information artifacts) Field notes
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Bird watching Ornithology Ornithology--Societies, etc
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1985-12-10
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1993-09-03
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Rare birds documentation form
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Records Committee review for a Thayer's Gull at Red Rock Reservoir Dam in Marion County, IA on December 10, 1985. Includes a record review document with votes, an article in Iowa Bird Life, and six documentation forms submitted to the committee.
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Bendorf, Carl J.
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Thayer's Gull
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Red Rock Dam
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Red Rock Res. Tailwater
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The documentation form by Carl J. Bendorf forms the basis of this record. Other documentation forms by Thomas H. Kent, Francis L. Moore, Bob Myers, Beth Proescholdt and Mark Proescholdt, and Dennis Thompson were submitted. Other observers include Joe Schaufenbuel, Darwin Koenig, Steve Dinsmore, Eugene Armstrong, Eloise Armstrong, and many unidentified observers. | Elimination of similar species: Thayer's Gull is a difficult bird to identify. In researching this problem, I have found several helpful sources in addition to the standard field guides and I have tried to understand what it takes to know a Thayer's Gull when you see one. Nearly every reference makes it clear that Thayer's cannot be identified on the basis of one or two positive field marks. It takes a combination of characters to come to a conclusion of any certainty. In discussing this particular observation, I will examine each of the fieldmarks and compare and contrast to similar species with liberal reference to the literature, especially Lehman (1980). The most likely similar gulls in this case are 1st winter Herring and 1st winter Iceland (Kumlien's). The Kumlien's form is the darker form of the Iceland Gull and is the form that breeds in the Baffin Island area and winters mainly on the Atlantic coast. Lehman's article deals mainly with Kumlien's. Several similarly sized and possible but unlikely candidates can be eliminated rather quickly. A 1st winter California should not have an all dark bill and would show much darkening in the primaries in flight. Lesser Black-backed Gull could be about the right size, but in flight a 1st winter bird should show darker primary and secondary coverts, more extensively dark primaries, even compared to Herring Gull. A 1st summer Slaty-backed Gull is also light uniform brown with an all dark bill, but it should exhibit extensive darkening in the primaries on the upper wing. A 1st winter Glaucous-winged Gull would be very similar to Thayer's but should be larger, with a larger bill, and less mottling to the body color. Except for the first two, one would probably not consider the likelihood of their occurrence in Iowa to be very great. One hybrid, Glaucous-winged X Western, might be similar but should have a quite heavy bill. [...] Summary: Of the most likely similar species, 1st winter Herring Gull and 1st winter Kumlien's Iceland Gull, each is eliminated by one or more of the features discussed above. The wing pattern is especially damaging to the possibility of Herring, along with the bill shape and size. Iceland is ruled out by the presence of the noticeable tail band and by the darker secondaries on the upper wing. To identify a Thayer's Gull, one must see a combination of field marks. I feel that the bird I saw at Red Rock is consistent on every point.| The original documentation form event lasted from 14:15:00/14:45:00.
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Iowa Ornithologists' Union | MS 166
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11
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3
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