Documentation of
Anhinga
2003-054
Observer Information
Reporter:
Randy Siebert
1426 Cypress Circle,
LAFAYETTE,
CO 80026-1246
E-mail:
rlsiebert52@gmail.com
Other Observers:
Glenda Brown; Glenda Brown found the bird.
Species, Date, Time and Location Information
Species:
Anhinga
First Date/Time:
5/3/2003
Last Date/Time:
Duration (total time in view):
< 5 minutes
County:
Adams
Specific Location:
100 feet north of footbridge by nature center at Barr Lake State Park
Number:
1
Age:
Unknown
Sex:
Female
Plumage:
Other/Unknown
Habitat
Bird was in flight the entire time it was observed flying over fields just east of Barr Lake.
Viewing Conditions
Optics:
Swarovski 7x42 SLC binoculars, Leica 77mm APO spotting scope with a 20-60x eyepiece
Distance:
probably less than 0.5 miles, hard to judge
Light:
very good, sun south of bird.
Description of the Bird
Size was very close to that of a Double-crested Cormorant. Had excellent view, through scope as the bird soared, gaining altitude. Bird showed a light band at the end of the tail. Neck was a light, tannish color as seen through scope. This color did not extend very far below the neck. Neck was very thin straight. Bill was thin and long. I did not get a good look at the back of the bird, as it was fairly high up and rising. I never saw the pattern on the back. The tail was very long.
Strange as it may seem, the previous day I was at Chatfield and met a couple of birders who thought they had seen an Anhinga. They showed me in their guide what features they had seen. I searched for their bird but did not find it. But this made me more sure of the differnces to look for. As a result I think I was better prepared to identify this bird when I saw it.
Behaviors: Bird was observed soaring and trying to gain altitude on thermals much as a raptor would. This flight behavior was not typical of a cormorant. The wing beat seemed very different compared to a cormorant. Later views of cormorants in flight did not match the appearance of this bird. Through scope bird was seen flying with a very thin neck extended out fully with no kink apparent.
Call: Not heard
Plumage: Adult
Similar Species Discussion
The one species to be most considered is Double-crested Cormorant. Flight patterns are reported as different. When I saw cormorants fly they looked very different. Cormorant flies with kinked neck. This bird had a very thin, straight neck. Color in neck of Anhinga was tannish, not the color shown for juvenile cormorant. The lighter color on juvenile cormorants goes considerably down below the neck-breast. This bird had a sharp cutoff between the tan and black. Tail also seemed too long for a cormorant. Cormorant has no light band at end of the tail.
When I wrote down my observations after returning home, my memory was of a bird very very like that shown in Sibley for an adult female Anhinga in flight. It does not match any image I have found for a cormorant in flight.
I found no data to make a Neotropic Cormorant any more likely than an Anhinga.
Resources Used
I looked in Sibley short after that. Female in flight still looked good. I read about differences in flight behavior. When I saw cormorants flying an hour or so later, I didn't think their flight matched what I had observed.
At home I checked Peterson, Audubon (Master Guide), and Cornell Lab (Thayer) Guide to Birds of North America. I saw more references to difference in flight. The light color on a juvenile Double-crested shown to extend much further down and to be more gray than tan. Also found more references to cormorants flying with kinked neck. I found references that cormorants do sometimes soar, but this bird simply flew differently than the cormorants did.
I later asked opinions of several Colorado birders. They pointed out things that I had not seen and generally thought my observations sounded plausible. Their comments have not influenced my identification.
I received information via Chris Wood and Scott Seltman that an Anhinga was seen the same day in NE Kansas. This didn't suggest the same bird but is a curious coincidence. Could there be some reason for Anhingas to be further north than normal?
Previous Experience
I have much experience with cormorants especially the local Double-crested. I have seen Anhingas in Florida, Texas, Ecuador, and Costa Rica.
Notes
Notes made AFTER observation
Materials Available
No files uploaded.
Date Documentation Submitted
7/6/2010 10:57:00 AM