Path: utzoo!attcan!uunet!husc6!rutgers!att!whuts!picuxa!gpasq
From: gpasq@picuxa.UUCP (Greg Pasquariello X1190)
Newsgroups: rec.birds
Subject: Re: Forster's and Common Terns
Keywords: Differentiation, abundance
Message-ID: <719@picuxa.UUCP>
Date: 14 Dec 88 12:54:03 GMT
References: <114@arcturus.edsdrd.eds.com>
Reply-To: gpasq@picuxa.UUCP (Greg Pasquariello X1190)
Organization: AT&T/EDS Product Integration Center
Lines: 37

In article <114@arcturus.edsdrd.eds.com> gss@edsdrd.eds.com (Gary Schiltz) writes:
-I've been birding now for about ten years, and have yet to identify
-a Common Tern. 
-
-Does anyone on the net have any good rules of thumb for differentiating
-between Forster's and Common Terns? Specifically,
-
-
-  1) How can one visually tell the difference between the two?  The
-     Golden field guide shows slightly darker primaries and dark outer
-     edges of the tail in the Common, with lighter primaries and dark
-     inner edges around the tail in the Forster's.  I've looked at
-     hundreds of small terns, and even through a spotting scope, I've
-     been unable to see any of these markings.  Do these markings usually
-     show up well? During what seasons do the markings show up best? Do I 
-     just need new binoculars (maybe Santa Claus reads this newsgroup :-)
- 
-     /\   What cheer,  /\       | Gary Schiltz, EDS R&D, 3551 Hamlin Road |
-    / o<    cheer,    <o \      | Auburn Hills, MI  48057, (313) 370-1737 |
-\\/ ) /     cheer,     \ ( \//  |                                         |
-   \ /      cheer!!!    \ /     |         "Have bird will watch ..."      |


Usually the shade of the tops of the outer primaries works well.  The Forster's
has frosty white tops, while the common has dirty grey ones.  I am only able
to see the dark tail edges if the bird is very close, and then only if it is 
in the right light and position.  

In winter plumage, the black on the face of the Forster's usually forms a streak
through and behind the eye, and ends at the back of the face, while the same
black streak on the common usually wraps around the back of the head.

-- 
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By the time they had diminished from 		  Greg Pasquariello AT&T PMTC
50 to 8, the dwarves began to suspect Hungry.	  att!picuxa!gpasq  
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