02 September 2010

Onset of fall

With the onset of fall here in central Iowa, the birding has started to pick up for me.  For example, a hefty flock of CASPIAN TERNS was present yesterday at Cherry Glen, Saylorville.  I counted 280!  Come to think of it, I'm not sure if I've ever seen more CATE's in one place ever in my life.  Here is just a portion of the flock:

Also present at Saylorville:

15 Forster's Terns
2+ Common Terns
20 Black Terns
2 Franklin's Gulls
Least Sandpiper (Lincoln Access)
Semipalmated Sandpiper (Lincoln Access)
Baird's Sandpiper (Lincoln Access)

Birding along the entry road at Oak Grove gave us some good warblers and other migrants including this VEERY:

I mentioned warblers; we've seen 15 species in the last 2 days (Y = yard, EM = Emma McCarthy Lee Park, OG = Oak Grove).  They are:

Northern Parula (EM)
Tennessee Warbler (EM, Y)
Golden-winged Warbler (OG)
Nashville Warbler (EM)
Yellow Warbler (Y, OG)
Chestnut-sided Warbler (Y, EM, OG)
Magnolia Warbler (EM)
Blackburnian Warbler (EM)
Bay-breasted Warbler (EM)
Black-and-white Warbler (EM, OG)
American Redstart (Y, EM, OG)
Ovenbird (Y)
Northern Waterthrush (Y, EM)
Common Yellowthroat (OG)
Wilson's Warbler (Y, EM, OG)

Some other species we've seen lately include:

Rose-breasted Grosbeak
Scarlet Tanager (1 even in the yard!)
Blue-gray Gnatcatchers
Carolina Wren
Eastern Phoebe
Great Crested Flycatcher
Eastern Wood-Pewee (it was in the yard, I shall assume it was a migrant)
Common Nighthawk (quite a few during the big migration event that took place yesterday, probably 1000+)

Since I've started keeping track of bird species I have photographed, I've realized how pitiful my collection of particular species can be.  One of those species is BLACKBURNIAN WARBLER.  I had already taken some very sad shots before but I was able to improve "slightly" this evening at Emma McCarthy Lee Park in Ames.  And by that I mean... these are ID'able:


Also taken this evening, here is a NORTHERN PARULA chowing down at Emma McCarthy Lee Park:

Here is a BLACK-AND-WHITE WARBLER with the sun at my back:        

I've only seen 2-3 MAGNOLIA WARBLERS so far this fall (only lack of trying, I'm sure).   Here is one peaking around a tree:

As some of you know, I often wander into tough identifications without really having the proper background knowledge that I should.  For example, BLUE-HEADED VIREO versus CASSIN'S VIREO.  Of course, no one would expect CAVI to be here in Iowa... and neither would I.  That doesn't stop the question that I had this evening... "Would I know it if I were looking at a CAVI?"  If nothing else, it's good for me to brush up on some basic field marks...

Here are some shots of a vireo this evening at EMLP in Ames:

All sources mention the sharp contrast of the gray head with the white throat should be distinct for BHVI.  The above photos show the cheek/throat line but I'm not sure how to define "distinct" in this situation.  Surely there is a gradient of some sorts??

One source mentioned that the thin line of dark color between the bill and the eye ("within" the spectacles) is a good field mark between CAVI and BHVI.  They speculate that if the color of the spot matches the color of the head, it should be a BHVI.  Likewise, if the dark spot in the lores is darker than the head, it might be CAVI.  However, I have no experience using this field mark.  I found the top two photos here interesting (I think the dark line looks darker than the head).

Another sources says that BHVI has "distinct white on outer tail".  Looking at the photo below of the closed tail, can yellow maybe substitute for white in this situation?  Maybe someone out there that has banded BHVI's can comment on this?  

So what do I think the bird is?  Well, BHVI of course!  Ha.