| UID |
|
| Digital Object Type |
Rare birds documentation form |
| Content DM Link |
https://n2t.net/ark:/87292/w9hm52n5t |
| Type |
Text |
| Description |
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. |
| Related Genres |
Administrative records Clippings (information artifacts) Field notes |
| Sort Date |
1996-09-06 - 2000-11-22 |
| People / Organizations |
|
| Time |
11:00 AM |
| Rights |
This complex item has mixed rights protection. Portions in which Iowa State University is the copyright holder are made available for non-commercial use, including sharing and adapting the work. No permission is required for non-commercial use to these portions so long as attribution is provided. All other uses of these portions, including commercial, require permission from the Iowa State University Library Special Collections and University Archives (archives@iastate.edu). (CC BY-NC 4.0 International). Portions in which Iowa State University is not the copyright holder are believed to be under copyright, but either (a) no rights-holder(s) have been identified or (b) one or more rights-holder(s) have been identified but none have been located. If you have any information that can contribute to identifying or locating the rights-holder(s) please notify the Iowa State University Library Digital Initiatives Program (digital@iastate.edu). (Rightsstatements.org InC-RUU 1.0). The original object is available at the Iowa State University Library Special Collections and University Archives (archives@iastate.edu). |
| Data Access Rights |
http://vertnet.org/resources/norms.html |
| Data License |
http://creativecommons.org/publicdomain/zero/1.0 |
| Collection |
Iowa Ornithologists' Union | MS 166 |
| Box |
11 |
| Folder |
1 |
| Contributing Institution |
Iowa State University Library Special Collections and University Archives |
| Creator / Author |
Bangma, Jim Johnson, Ann |
| Contributors |
Iowa Ornithologists' Union Records Committee |
| Topics |
Bird watching Ornithology Ornithology--Societies, etc |
| Birds |
California Gull |
| Locations |
Mini Wakan State Park |
| Map |
|
| Verbatim Locality |
Spirit Lake, north end, Dickinson Co., IA |
| Location Remarks |
The documentation forms do not include georeferences |
| Habitat |
Lakeshore |
| Extent |
6 pages |
| Language(s) |
eng |
| Bibliographic Citation |
|
| Information Withheld |
|
| Individual Count |
1 |
| Occurrence Remarks |
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. |
| Occurrence Status |
present |
| Field Number |
1996-59 |
| Event Remarks |
Viewing Conditions: Good light, approx off left shoulder, distance approx 100 yards, optics included Zeiss 7x42 and Spacemaster Jr with 20x eyepiece |
| Supporting Documentation |
National Geographic. Field guide to the birds of North America. 2nd Edition. Washington, DC: National Geographic Society; 1987. | Farrand J. The Audubon society master guide to birding, vol. 2, gulls to dippers. New York: Alfred A. Knopf, Inc; 1983. | Grant, PJ. Gulls: a guide to identification. Staffordshire, UK: T & A D Pyser, Ltd; 1983. | Harrison P. Seabirds: an identification guide. Boston: Houghton Mifflin Harcourt; 1985. | Harrison P. A field guide to seabirds of the world. Lexington, MA: The Stephen Greene Press; 1987. |
| Date Digital |
30 May 2017 |
| File Type |
image/jpeg |
| Hardware / Software |
Epson - sheet feed/flatbed |
