Yellowstone Reports

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Boreal Owl Study

Year 12
by Dan Hartman

March 1, 2021

     March 1st!

     Not only have we entered a month when we could possibly receive our Covid shots, it's the start of my annual Boreal Owl Study.

     Hard to believe it is year 12, as it began in 2010.

     Having 11 years behind me gives me some idea of what to expect when Cindy and I go out tonight.

     As you can see the snow depth seems to determine probability of hearing boreals singing.

2010  23"  4 calls        2016  30"  4 calls

2011  42"  0 calls        2017  34"  0 calls

2012  37"  4 calls        2018  43"  1 call

2013  25"  1 call         2019  42"  0 calls

2014  42"  0 calls       2020  33"   5 calls

2015  36"  2 calls

     So it appears snow levels above 40" is the kiss of death for courting then nesting boreal owls.  You'll notice 2013 and 2017 had low snow levels but had drought the previous years which means no prey.

     Last year had a great start but quickly went south as snowstorm after snowstorm soon raised the snow level to 4 feet and silenced the owls.

     Also as the boreals go seems to reflect the type of year I'll have with great gray owls and pygmy owls.  We had a pygmy owl call at the cabin last week.

     So now we are sitting at 33" of snow and are following a decent year for moisture.  On top of that, the ten day forcast has mild temperatures which should mean sinking snow.  I would expect a good night of owling ahead.

     To be continued........