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Boreal Owl Study Year 10

First night out
by Dan Hartman

March 2, 2019

     March 1st finally arrived, which means the start of my yearly boreal owl study.  Saying goodbye to February felt good this year!

     I started the study in 2010 basically because nothing was known about the possibility of boreal nesting in Yellowstone, for that matter, even existing in the park.

     My first year was good, hearing 92 songs coming from what I figured were 14 individual owls.  I even found the first nest ever officially recorded in Yellowstone.

     Over the next 6 years I had mixed success with good owl years in 2012, 2015 and 2016, finding three more nests.

     Then in 2017 and 2018, owls were basically non-existent.  I heard only 13 songs last year, probably from 2 individuals.

     Over the 9 years I found different variables that lead to good and bad owl years.  The two most important were the moisture the summer before and snow depth.

     For example, 2013 had only 25 inches on the level, comparable to my first year when the level was 23 inches.  Difference was, 2012 was a dry summer and the mouse and vole population plummetted. So no owls.  2018 followed a wet summer, but the snow level was 43 inches. So no owls.

    We were experiencing an extremely mild winter.  On the first of February the snow level read 24 inches.  Coupling this with a wet summer last year promised a good owl year.  Cindy and I even stopped at one of our listening posts and heard a boreal singing.  Even into mid February the conditions looked good.

     Then it began to snow!

     On March 1st our snow stake showed the snow level had climbed to 42 inches.  I've never had a good owl year when snow level passed 40 inches.

     So with low expectations,Cindy and I ventured out to make our owl run.  It's 13 miles long and consists of eight listening posts.

     At post #1 all was silent.  Posts #2 and #3 sounded the same.  It was a dark night with no moon and just enough clouds to dim the stars.

     At post #4 the wind had picked up but we could have heard an owl singing.  This is also where we heard one a month ago.


     Post #5, #6 and #7 had the same results.  We didn't even bother going on to post #8.

     Back at the cabin we were greeted by a flying squirrel.

     I'm not giving up, but will wait till later next week when it's supposed to warm up.  Already, as I'm writing this the snow level has dropped to 40 inches.  Is it in time??????