Date: 10/25/24 2:58 pm From: flyingcarlini via groups.io <flyingcarlini...> Subject: Re: [NEBirds] Blue Jay imitating Red-shouldered Hawk
Hi William,
As fellow birders struggling to distinguish the calls of the newly-established Red-shouldered Hawk (RSHA) population in our neighborhood from imposter Blue Jays (BLJA), we feel your pain! The local BLJAs haven't wasted any time perfecting their RSHA imitations and a couple months ago at a known RSHA location, we snuck up on what sounded like a RSHA in the distance but turned out to be a BLJA at close range. On our imposter BLJA recordings, the BLJAs do indeed utter shorter series often consisting of only 2 calls or single calls as with your experience, but we've also recorded them uttering series of 3 calls which gets tricky because we've recorded a visible RSHA doing a series of 3 calls. We've also recorded a RSHA doing a series of 13 calls so the BOW span for call series maybe should be a tad broader than 5-12?
Your raising of this topic inspired closer scrutinization of our eBird RSHA recording submissions and we did find a recording of an unseen "RSHA" doing single and double calls that was suspect enough to delete so thank you for helping to keep us honest! We've reached out to Ross Silcock for guidance on distinguishing RSHAs from BLJAs since he now regularly encounters RSHAs living in Houston and he has advised to key in on the uniform sounding delivery of the calls/pause intervals between each call in the RSHA series, in addition to discounting series with too few calls as you pointed out, and also BLJAs' higher tonal quality. That being said, we've recorded a visible RSHA doing some kooky sounding whistles and higher squeaks that could have possibly been misconstrued for BLJA had we not witnessed the RSHA making those sounds, so this task of telling fake from real promises not to be a cakewalk. Here's that eBird checklist link with those odd RSHA sounds:
By the way, do you suppose the number BOW gives between call series should be seconds instead of minutes? Because our recordings of more than 1 RSHA call series have a spacing range of 4-20 seconds between calls, although our recordings of single calls could easily have many minutes between deliveries.
