This may be stating the obvious, but in my experience, the best bet for success at a short eared owl spot (and in fact with many wildlife situations), is to spend as much time there as you can. Some days they'll pop up and start hunting early in the afternoon, other days not till it's almost dark. Some mornings they're still flying past sunrise, other days not. Some days there's good light for flight shots, other days not so much. If you know their general area of preference, stay near some likely perches and hope that sooner or later one lands on a stump or fence post and you are in reasonable position for a shot. Pick a spot and stick with it rather than scurrying around the marsh. The more days you are there, the more likely you are to see a pattern on where they focus their hunting, or where they perch to rest. Obviously 90 mins away from your home is a lot of driving, but the best chance to get some good opportunities is to be there a lot and eventually have things line up just right. Also if there is snow on the ground, your available light will go further than if there isn't. Sometimes you spend the whole evening frustrated that they stayed on the far end of the meadow, only to have one land on a road sign by your car on the walk out.
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