[cobirds] "millers"

I just got back from a long visit to Lamar and was privileged to see many great birds.  But this post is not about those awesome birds as much as it is intended to give millers their due as fuel for those birds.  A broad spectrum of birds species, especially those migrating here from points south to breed and those species we see mostly as pass-thru migrants, takes advantage of millers when it encounters them.  I see these blurbs on the news about millers and, yes, most of them mention the benefits of millers as pollinators and as food for birds, bears and bats.  But a sentence or two, 15 seconds of chatter, is not enough!  MILLERS ARE IMPORTANT.  Any birder who looks up from their Merlin app for more than 10 seconds in mid spring to early summer has to know birds eat these moths.  The main miller is the adult of the Army Cutworm (Euxoa auxiliaris).  There are several other related species of moths in the family Noctuidae that we collectively just call "millers".  They are mostly non-descript, scaley, brown and gray creatures to us, toys to our cats, flying food to birds.

The short generalization is they feed as caterpillars from fall thru early spring at the base of many low elevation plants (including winter wheat) on the eastern plains, transform into moths, migrate thru the Front Range to feed in the mountains in summer on montane flowers.  They migrate in protracted, unobvious fashion back down to low elevation in late summer-fall.

I will give just one example of their importance.  One day in early May I visited a famous yard in the Lamar area.  The hostess of this yard counted 44 species that day.  I estimated fully 40 of those were partaking of the miller throng.  The birds scoured the base of the outside walls, window sills and eaves.  They dug thru the grass.  They chased them thru the air like the Red Baron.  They went under vehicles, in open doors of out-buildings.  They probed tree bark.  It was incredible to witness.  The incomplete list of bird groups involved includes blackbirds, thrushes, warblers, sparrows, finches, swallows, flycatchers, buntings, tanagers, orioles and vireos.  About the only non-participants seemed to be doves.

When your neighbors complain about millers, tell them to chill.  Humans are still capable of patience that lasts 2-3 weeks.  If the news media calls on you because you're a nature person, skew the conversation to the benefits of these creatures and away from all the silly remedies involving soap and water, vacuums, fly swatters, pesticides and nuclear weapons.

Dave Leatherman

Fort Collins