I believe this bird is a late juv Brown Booby, possibly of the Atlantic form based on bill shape. The underwing pattern would suggest Cocos if this were an adult, but juvs of both species show a similar underwing. The clincher is the eye color. Cocos Boobies have dark eyes, Browns have pale eyes. Great photos for making an ID. -Doug Pratt
> On Jun 18, 2025, at 11:57 AM, Rachel Hopper <hopkohome8...> wrote:
>
> Colorado just had its second record of a booby, found on June 16th & seen early again on the 17th after which it disappeared.
>
> It was found in a tree out on the prairie in far SE CO. No water body even close.
>
> There are several photos of the bird, which did take flight a few times, always coming back to land in an Elm tree. At one point it was on the ground.
>
> We are trying to determine if this is a Brown Booby or Cocos Booby. Possibly not a full adult. Any help would be appreciated.
>
> You can view the photos of the bird here on these 3 checklists:
>
> https://ebird.org/checklist/S251486607 >
> https://ebird.org/checklist/S251577330 >
> https://ebird.org/checklist/S251215877 >
> -----------------------
> Rachel Kolokoff Hopper
> Ft. Collins, CO
>
>
> Archives: https://listserv.ksu.edu/birdwg01.html
"Some people have been kind enough to call me a fine artist. I've always called myself an illustrator. I'm not sure what the difference is." - Norman Rockwell
H. Douglas Pratt, Ph. D.
Ornithologist, illustrator, musician
1205 Selwyn Lane
Cary, NC 27511
Emeritus Curator of Birds
North Carolina Museum of Natural Sciences
11 West Jones Street
Raleigh NC 27601
