gss@edsdrd.eds.com (Gary Schiltz) (12/07/88)
I've been birding now for about ten years, and have yet to identify
a Common Tern. Most of my birding has been while I was a student at
Kansas State University in Manhattan. With several large reservoirs
in the area, and the Cheyenne Bottoms wildlife refuge close by, I was
able to see a fairly large number of small terns, and as far as I could
tell, they were all Forester's. At least, the people with whom I birded
all said the common small terns in the area were Forster's. Now that I
live in the Detroit area, I again see a large number of terns and am
still unable to see any that I am sure are Common.
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 :-)
2) Which tern would be more abundant around midwestern lakes (i.e. in
Kansas) and in the Great Lakes region, and in what seasons are each
more abundant?
3) Where is a good place to go to see both species in large numbers at
the same time?
Thanks in advance. You might as well post your responses rather
than email, since the birding traffic on the network has been
light, lately.
---
/\ 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 ..." |rising@utzoo.uucp (Jim Rising) (12/09/88)
Forster's Tern is the usual medium-sized tern in Kansas and Missouri,
where the Common Tern is rare (though perhaps overlooked).
In the Great Lakes region, however, Common Tern is the commonest one,
although Forster's also occur. I don't know about Detroit, but Forster's
seems to be increasing in SW Ontario, esp. around Lake St.Clair, and I
would expect that on any given day you could see either or both at
Detroit. In the spring at Pt. Pelee it seems that sometimes there are
mainly Forster's and at others, mainly Common---though others would know
more about this than I. Common may be a little later in the spring.
I, too, have trouble indentifying these birds. However, I find the
white on the dorsal surface of the primaries to be a useful mark,even
on sitting birds. Voices differ too, if you get used to them.
P.S., for people interested in birding in Kansas and Mo., I recommend
a new book, "A Guide to Bird Finding in Kansas and Western Missouri"
by John Zimmerman (of K State U.) and Sebastian Patti, which can be
obtained from: Univ. Kansas Press
Lawrence, KS 66045
I've forgotten price, but it is not expensive (in paper or cloth). As
bird finding guides go, this is the best illustrated, and thickest that
I have seen. Kansas ain't the Rio Grande Valley or SE Arizona, but is
a good place to see prairie birds (all 4 longspurs; both prairie-chickens;
snowy plover; Henslow's Sparrow; Sprague's Pipit) as well as a mixture of
both eastern and western stuff. Don't go there looking for Common Terns,
though.
--Jim Rising
--
Name: Jim Rising
Mail: Dept. Zoology, Univ. Toronto, Toronto, Ontario, Canada M5S 1A1
UUCP: uunet!attcan!utzoo!rising
BITNET: rising@utzoo.utoronto.bitnethansen@harris.cis.ksu.edu (Steven C. Hansen) (12/10/88)
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. Most of my birding has been while I was a student at >Kansas State University in Manhattan. With several large reservoirs >in the area, and the Cheyenne Bottoms wildlife refuge close by, I was . . . . . . > 1) How can one visually tell the difference between the two? The . . . . . . > 2) Which tern would be more abundant around midwestern lakes (i.e. in > Kansas) and in the Great Lakes region, and in what seasons are each > more abundant? Hello, Gary I'm still birding at K-State, but I have had some experiences with both species since I am originally from central Minnesota which is between the breeding areas of both species. During the summer I have been able to see the difference in the shading on the wing and tail feathers that you mention, however I'm not sure about winter plumage. I have seen many Common Terns along Lake Superior, according to maps you should have a number there in Michigan during the summer. Birding is still good back here in Manhattan. I've been birding with Chris Smith on Sunday mornings, and we've seen a couple of Prairie Falcons a number of Bald Eagles, Sharp-shinned Hawks, loads of Red-tails, a few Rough-legged Hawks, and of course the usual passerines... including many Harris Sparrows (for those of you not of the Great Plains). I hope birding is good for you out there. Steve Hansen hansen@harris.cis.ksu.edu
gpasq@picuxa.UUCP (Greg Pasquariello X1190) (12/14/88)
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.
--
=============================================================================
By the time they had diminished from Greg Pasquariello AT&T PMTC
50 to 8, the dwarves began to suspect Hungry. att!picuxa!gpasq
=============================================================================mjm@oliven.olivetti.com (Michael Mammoser) (12/16/88)
In article <719@picuxa.UUCP>, gpasq@picuxa.UUCP (Greg Pasquariello X1190) writes: > 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. Beware of first-winter Forster's Terns which can also show darkness on the tops of the outer primaries. However, first-winter Forster's should lack the dark bar on the top of the leading edge of the wing between the shoulder and wrist. Forster's Terns are quite common here in the Bay Area and Commons are quite rare (sounds like a contradiction). I remember watching for some time a perched tern, which I was hoping to ID as a Common. The bird was breeding plumaged (black cap and orange bill) but had dark-looking primaries on the folded wing. I was sure that breeding plumaged Forster's shouldn't show these dark primaries and was ready to call it a Common; then it took to the air and suddenly the dark primaries disappeared and the open wing showed the typical pale upper surface of a Forster's Tern. It also started calling, and sounded like a typical Forster's. It was quite a confusing moment for me. I now wonder if I'll be ready for the elusive Common when it does finally show up. Mike