[cobirds] black witch food plants and a comment about the cemetery tanager

I said in my earlier post about the black witch moth that larval (caterpillar) host plants do not occur in Colorado.  That is not exactly correct.  I remembered a few years ago Duane Nelson informed me a private ranch he has access to in Baca County has a few mesquite trees.  Yet another example of southern flora and fauna expanding northward.  Leaves of mesquite, along with Cassia trees and probably some other leguminous plants, are black witch caterpillar foods.  Overwintering survival of pupae, given the possibility of severe cold snaps, is probably a more likely limiting factor at present to establishment of this impressive beast in Colorado.

To legitimize this for COBIRDS, Ted Floyd asked if the young bird being fed by the adult male Western Tanager in my post the other day about low-elevation nesting at Grandview Cemetery in Fort Collins could be a cowbird.  While I have not seen a cowbird at Grandview in a couple years, they are stealthy and I was gone for two weeks in the latter half of June.  Several years ago I witnessed the fledging process of a cowbird raised by Ruby-crowned Kinglet parents.  The bird being fed by the tanager did not act or sound like the cowbird youngster at roughly the same stage of development.  To quote current politicians, I'll add, "to the best of my knowledge".  On the day of the feeding photos, the young bird gave a single, somewhat musical, chirp when it was hungry or otherwise wanted to let the parents know its location.  Two days later (July 5th) I heard it but could not see it during a couple feedings.  At that time it gave a two-syllable phrase that to my ear sounded like the intro notes to the regular adult Western Tanager song.  I do not have a recording of any of this, unfortunately.  Someday I'll be a real birder.  I think it's a tanager fledgling, it would be interesting even if it is a cowbird, and maybe somebody, somewhere can solve the question once and for all from the photos.  I have tried two more times to see feeding, including today, without success.  Both parents were present today, and I think the female made a couple deliveries to the young bird high in a green ash.  I just couldn't get focused on the right tree and right part of the right tree in time to see or photograph any of the action.  When I finally thought I knew which tree the youngster was in, I waited for another delivery, camera at the ready.  Instead of adult tanagers, here came all five of the cemetery mowers to start doing the section right where I stood.  Observing the feeding of a young bird away from the nest requires a heavy dose of listening.  Forget that, so I left.  It should be mentioned that in the process of homing in on which tree harbored the young bird, I saw both parents aggressively go after blue jays.  Perhaps the jays are to blame for why only one young bird from the tanager nest made it out of the nest.

Dave Leatherman

Fort Collins