Tern ID (1 Viewer)

I saw a "different" Tern today at the tidal mud flats in Cd. del Carmen, Mexico. It caught my attention since it was not with any other terns. The most common here in winter are the Sandwich and the Royal Terns and they are generally in flocks. My first impression was that it was a Sandwich Tern due to size (about 14 inches) and the black bill. But then I saw that it didn't have the tell tale yellow tip on the bill. Then I started checking it out in detail. Red legs, ruled out Sandwich right there. Head was a black cap (including eye) on crown and nape but had a white "forehead" right down to the bill. The cap was a very "neat" looking cap, not like the winter caps of the Sandwich Tern.

Its body was white, wings were grey with darker primaries. Tail was light or white and slightly forked (like Gull-billed Tern tail). The wing tips appeared to extend to about the end of the tail.

I had good views of it perched on ground (with a flock of A. Avocets) and then flying (very easy flight) as passing joggers caused it to move twice.

I have never seen a Gull-billed Tern before so did not pay enough attention to the bill (see previous posts on "how do you identify birds"). Looking at my field guides when I got home, this looks like one good possibility (Juvenile). Other possible is a Juvenile Common Tern but I did not see any red coloring on bill, even at the base.

Any suggestions would be appreciated.
Thanks,

maybe a roseate Dave? Sounds good for one.

they occur in Yucutan (Cozumel) infrequently but how many folk are there looking! You're quite close to there so it may be a good bet

Tim,
Roseate looked real good for bill and legs. What put me off that one was the tail. My Peterson's guide shows a very forked tail while the bird I saw had more of a slightly forked tail. Is there much variation in this or can the outer tail streamers be missing?

Tim,
I just did a Google search on Roseate and came up with a pretty good shot that closely resembles what I saw today.Roseate Tern (Juvenile)

The only difference I can see between these two is that mine had a cleaner break of white forehead / black cap than this one but this is very close. Does the juvenile have a shorter tail streamer?

Thanks,

All,
When in doubt, try to go back and get another look. I did that this morning and found not the same individual but several others of the same species. First I checked the bill and definitely ruled out the Gull-billed.

Then I got my break. I found one in a flock of Sandwich Terns and I got a good size comparison. I was way off. It is a good bit smaller than Sandwich. Checking field guides again, I'm sure it is just Common Tern in basic plumage. Two factors had made me doubt this previously, bill was ALL black, no hint of red, and distribution has these guys as Uncommon to Rare in my area in winter. But I'm sure now of ID.

Thanks for the suggestions.

Hi Dave,

Another point to help rule out Roseate Tern is the "flying (very easy flight)" - Roseate has a rapid, flickery wingbeat more comparable to a Least Tern than the other medium/large terns.

I'd agree, Common Tern sounds the best bet.

Michael

Michael,
Thanks,

Hi Dave,
I was going to get back to you last night to say that winter Common,Arctic and Roseate Terns have all-black bills,and all have red/orange legs.ALso,none of these species retain the 'streamers' in winter.Common Tern is perhaps the most likely in your area at this time of year.
Harry H

Harry,
Thanks for the info on the "streamers". Luckily I saw him again with some known terns so could get a better size comparison, otherwise, I would have just given up.