The following was a message posted on the "BRDBRAINS" LISTSERV in Florida, titled "Identifying Crows In Florida". Fish Crow searchers in Ohio, may find this helpful, in finding their quarry.
 
Bob Lane / Mahoning County
 




Date: Sun, 8 Jul 2012 18:44:51 -0400
From: [log in to unmask]
Subject: Re: [BRDBRAIN] Identifying Crows in Central Florida
To: [log in to unmask]
 
Hi all, 
Here’s a belated round-up of the responses I received to the crow ID question I posted back at the end of June. 
First, the consensus was that the distinction between Fish Crow and American really does need to be made by ear. However, once one has made the distinction that way, one can pay attention to other physical, behavioral and habitat differences to build up personal knowledge of Fish vs. American from which to draw for future IDs. 
 
A: Voice. 
As we all know, the Fish Crow is the only one that calls with the nasal, double “uhn-uhn.”  (Example: http://macaulaylibrary.org/audio/13409/corvus-ossifragus-fish-crow-united-states-new-jersey-dwight-chamberlain). 
However, the FICR doesn’t always double caw and its single or unstructured cawing could be confused with the AMCR’s begging calls (which are given not just by nestlings, but also by adults in certain situations). According to the Cornell Lab’s wonderful article on Crow IDs (http://www.birds.cornell.edu/crows/FishCrow.htm -- sent to me by Bob Stalnaker), a good way to distinguish between crows in this case is to listen to how the call ends. Fish Crow calls have an abrupt ending whereas American Crows’ calls trail off. Or to quote the Cornell Lab article: 
 
The begging calls of the American Crow and the normal calls of the Fish Crow, although rather similar, can generally be distinguished by their construction. The overall quality and tone of the two are about the same. American Crow begs, however, are generally of longer duration and do not have the same abrupt ending that Fish Crows calls do. Think of if as "aaawwwwww" versus "aawwp". 
 
I think that this difference in crow calls’ endings can be generalized (or mostly generalized). All Fish Crow calls, whether begging calls, the double “uhn-uhn” or other, seem to have abrupt, clear-cut endings. Take a listen to this example of a Fish Crow reacting to an intruder at the nest: (http://macaulaylibrary.org/audio/13416/corvus-ossifragus-fish-crow-united-states-new-jersey-dwight-chamberlain). Now that is one unhappy Fish Crow! The duration of its “caw” is much longer than the typical Fish Crow call. But the ending is clear-cut. (It also doesn’t vary much in pitch – it is relatively uninflected.) 
On the other hand, most American Crow calls --  not just the begging calls -- seem to have less abrupt, more drawn-out endings, although this seems to be less universally the case. This example of an unspecified adult AMCR call includes both more drawn out and more abruptly ended calls: http://macaulaylibrary.org/audio/50111/corvus-brachyrhynchos-american-crow-united-states-oregon-geoffrey-keller. 
But, all in all, this is good news in a region where Fish Crow is the norm. Now if you do hear a drawn-out call ending, it seems you can say with relative certainty: “Ah ha! American Crow.” 
 
B. Behavior
1. Rob Bowden suggests observing ground-feeding crows: The American “tends to bob a bit and walk upright while the Fish usually is more hunched over and does no bobbing.” 
2. According to the Cornell Lab article (again -- http://www.birds.cornell.edu/crows/FishCrow.htm): 
“Fish Crows use a different posture for calling than American Crows. Fish Crows tend to stay more hunched and shorter necked, and typically fluff their throat feathers. American Crows tend to stretch their necks a bit, and do not substantially fluff their throat feathers.” 
If you click on the above link and scroll down, you’ll eventually get to photographic illustrations of these differences.
3. Flock size: In Florida, American Crows are not to be found in large flocks, unlike Fish Crows. (Rob Bowden)
4. In Florida, one might find flocks of Fish and American Crows very close to each other, but typically the species don’t mix. That is, one usually finds homogeneous flocks of either Fish or American Crow. 
 
C. Habitat
1. Fish Crows are no longer to be found only near water  (Bob Stalnaker).
2. Fish Crows are, in general, more coastal and urban/suburban. American Crows are more typically found “inland in more rural habitats” and, in general, “further from water.” But, of course, there are always exceptions! (Paul Hueber).
3. American Crows have recently been expanding their range and are now to be found on the coast as well (Rob Bowden, Harry Hooper).
 
D. Appearance.
There are many subtle physical distinctions between Fish Crows and American Crows. The Cornell Lab article lists a host of visual clues, including:
1. Fish Crows are smaller than American.
2. “Fish Crows are a bit more glossy purple.”
3. Fish Crows are shorter-legged than American.
4. “The feathers on the upper back of American Crows [have] a ‘ringed’ or ‘scaled’ effect not shown by Fish Crows.”
 5. FICR and AMCR have different “wing formulas.”
6. Fish Crows have a faster wing beat.
See the Cornell Lab article for more details and a lot of caveats. 
 
Finally, David Hartgrove urged caution and a liberal use of “crow species,” whenever there is a doubt as to specific ID. 
There you have it. I hope this helps. 
 
Janet Leavens
Oviedo, FL 
 

                                          
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