Forster's vs Common Tern Discussion - 31 Oct 2004
31 October 2004 Discussion regarding Common vs. Forster’s Tern
Richard,
Yes, it is a tern.
I'd say this looks more like a molting adult Forster's Tern. Adult Common
Terns molt the black from their foreheads to white, showing a similar
pattern to the bird in your photo, but they also attain a black "carpal bar"
which shows up as a black shoulder patch on a perched bird. Adult Forster's Terns molt the black from their foreheads back to their nape, eventually ending up with a black ear patch. But, I believe your bird has not completed its head molt, and indeed the orange and black bill is also a
transitional condition (the bill will be black in winter).
pattern to the bird in your photo, but they also attain a black "carpal bar"
which shows up as a black shoulder patch on a perched bird. Adult Forster's Terns molt the black from their foreheads back to their nape, eventually ending up with a black ear patch. But, I believe your bird has not completed its head molt, and indeed the orange and black bill is also a
transitional condition (the bill will be black in winter).
Adult Forster's Terns do not attain a black "carpal bar" in winter plumage.
Another point. It is difficult to see in your two photos, but the outer web
of the outer tail feather appears to be white, which would point to
Forster's Tern. This would be blackish in Common Tern.
Another point. It is difficult to see in your two photos, but the outer web
of the outer tail feather appears to be white, which would point to
Forster's Tern. This would be blackish in Common Tern.
And, a suggestive feature, the legs are bright orange, which tend to be
darker in winter adult Common Terns and retained as orange in Forster's.
Forster's Terns have been seen in Michigan as late as the third week of
November, but typically this is on Lake Erie, not at such an inland locale
as Thorn Lake.
darker in winter adult Common Terns and retained as orange in Forster's.
Forster's Terns have been seen in Michigan as late as the third week of
November, but typically this is on Lake Erie, not at such an inland locale
as Thorn Lake.
You owe me $0.25?
Have you thought about signing up for a birding class in the Ann Arbor area? I think you'd find it quite enjoyable and informative.
Give a man a fish and you'll feed him for a day, teach him to fish and
you'll feed him for a lifetime.
you'll feed him for a lifetime.
Allen Chartier
amazilia1@comcast.net
1442 West River Park Drive
Inkster, MI 48141
Website: http://www.amazilia.net
Michigan HummerNet: http://www.amazilia.net/MIHummerNet/index.htm
amazilia1@comcast.net
1442 West River Park Drive
Inkster, MI 48141
Website: http://www.amazilia.net
Michigan HummerNet: http://www.amazilia.net/MIHummerNet/index.htm
