When I was growing up in New Hampshire, old-timers called this bird "stake-driver". At the right distance, the call sounded like "*oonk*-ka- *oonk*". The "oonks" sound like a distant sledge hammer hitting a wooden stake, but I don't know what the "ka" was thought to be. I haven't heard this call in Colorado, so I will be there at 0700 tomorrow. Thanks for the post.
On Friday, May 11, 2018 at 11:32:07 AM UTC-6, Kit Basom wrote: > > > Enjoyed watching and listening to two American bitterns at Sawhill/Walden, > between 7:15 and 7:50 this morning. The song always reminds me of an > old-fashioned hand pump or perhaps broken plumbing. I've been hearing it > occasionally in the area since May 5, but today was the first time I saw > the birds, stretched out, beaks pointed skyward (except when singing). > > --Kit Basom >