| UID |
|
| Digital Object Type |
Rare birds documentation form |
| Content DM Link |
https://n2t.net/ark:/87292/w9dj58j1d |
| Type |
Text |
| Description |
Rare bird documentation form for two Red-throated Loons at Saylorville Reservoir in Polk County, IA on November 7, 1999. |
| Related Genres |
Field notes |
| Sort Date |
1999-11-07 |
| People / Organizations |
|
| Time |
7:45 AM |
| Rights |
This Item is protected by copyright and/or related rights. However, for this Item, 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 |
32 |
| Folder |
8 |
| Contributing Institution |
Iowa State University Library Special Collections and University Archives |
| Creator / Author |
Dinsmore, James J. |
| Contributors |
|
| Topics |
Birds--Identification Ornithology Rare birds |
| Birds |
Red-throated Loon |
| Locations |
Saylorville Dam |
| Map |
|
| Verbatim Locality |
Saylorville Reservoir, off of west end of dam |
| Location Remarks |
The documentation forms do not include georeferences |
| Habitat |
freshwater lake |
| Extent |
2 pages |
| Language(s) |
eng |
| Bibliographic Citation |
|
| Information Withheld |
|
| Individual Count |
2 |
| Occurrence Remarks |
The documentation form by Jim Dinsmore is the only one submitted and forms the basis of this record. Other observers include Bery Engebretsen and Dennis Thompson. | Elimination of similar species: I spent a long time puzzling over these birds, both in the field and later when I had several references to consult. None of the guides I looked at showed a bird that looked like these. Common (a small one): removed on the basis of size (birds too small for Common Loon), the thinner and bicolored bill, and the color pattern on the neck. At this time of year, all of the Common Loons I have seen (and saw on Saylorville that day) were distinctly white on the front of the neck with some partial bands of brown extending back in to the white. Pacific Loon: Eliminated on behavior (head posture), lack of a distinct dark/white line along the side of the neck, lack of chin straps across neck, and presence of brown on front of neck. Also the gray/brown contrast between neck and back would point away from Pacific but not eliminate it. Red-throated Loon: This is what I first thought the birds were but as I viewed them, I convinced myself several times that they were Pacific Loons. However, the combination of characters listed above seem to eliminate the other two possible species and also are positive characters for the Red-throated Loon. One character that puzzled me was the size of the bill. At least some of the guides (Advanced Birding esp) show the Red-throated Loon as having a tiny bill, much smaller than on this bird but those illustrations do not match those in other guides which emphasize more the shape of the bill than the size. | The original documentation form event lasted from 07:45:00/08:45:00. |
| Occurrence Status |
present |
| Field Number |
|
| Event Remarks |
Viewing Conditions: Great for a loon. The birds were below me and at times less than 5 feet from the shoreline. I often had both birds together in view in the scope. The light was great (soft morning light from the right) and the birds were perhaps 100 yards away. Couldn't ask for better viewing conditions for a loon and they stayed there for at least 20-30 minutes. |
| Supporting Documentation |
Robbins CS, Bruun B, Zim HS. Birds of North America: a guide to field identification. New York: Golden Guides from St. Martin's Press. | Kaufmann K. Kaufman field guide to advanced birding. Peterson Field Guide Series. New York: Houghton Mifflin Harcourt. | National Geographic Society. National geographic field guide to the birds of North America. Washington D.C.: National Geographic Society. |
| Date Digital |
17 Nov 2017 |
| File Type |
image/jpeg |
| Hardware / Software |
Epson - sheet feed |
