I have a question about Black Billed Cuckoo calls. From my home, six to eight weeks ago I heard a familiar BB Cuckoo call, the one that sounds like "cuckoo" repeated. I heard this call several times over the last eight years -- I usually hear the bird calling for four our five days and then that's it.
This last week, I've heard a second call that to my ear doesn't have the "cuckoo" sound. It took me a few days to ID the bird as the call came from around our yard/fields/woods (not stationary) and infrequently (a short call one or two times an hour). The cuckoo flew in and called right off of my porch -- I got a hasty look at it with my binoculars and confirmed that it was an adult.
I found a recording on line that has both of the sounds that I am hearing; it is here: http://www.flatheadaudubon.org/content/birds/songs/B/Black-billed%20Cuckoo.wav The first six seconds are what I have heard earlier this year, and in previous years. Starting at about 7 seconds in, and lasting only for a couple of seconds is the call that I am hearing now. The bird I'm hearing now does not s into the cuckoo call as it does on the sound recording.
So I'm wondering if anyone knows -- is there a difference between the male and the female calls? Is there a difference given the time of year -- with the cuckoo call being made early in the breeding season? Any insights?
Thanks very much,