When living in Hinesburg I had a barred owl that continuously sat in a maple tree, flying frequently to the ground near my bird feeder. However, upon its return to the same perch, what it had in its mouth often seemed much smaller than a mouse. Now I wonder if that owl was sometimes catching worms. You, and others, have probably been searching online for information about barred owl vermivorous behavior.
I found an article (and downloaded a free PDF), "Barred Owls Eating Worms and Slugs: The Advantage in not Being Picky Eaters"; (5 authors including Peter A Cott, published in Northwestern Naturalist 89;185-190 Winter 2008). This article discusses barred owl feeding behavior in several regions, including regions that have trees common to the northeast, such as white pine, yellow birch and sugar maple. However, much of the article's focus is where the barred owl lives in western regions, overlapping with the spotted owl. The authors point out that the barred owl eats a much wider variety of prey than do spotted owls, including worms, slugs and even an observation of (yikes!), a salamander. The authors conducted this study to... "add insight into a facet of the apparent competition between spotted owls and barred owls by providing the first published direct observations of barred owls preying on earthworms...and discusses the ramifications of the use of innocuous prey by barred owls on the future of the spotted owl."
The vermivorous eating habits of the barred owl must certainly enhance its adaptability and survival, and sparked the interest of this article's authors who are concerned about the effect of competition where barred owl and spotted owl ranges overlap. This concern led to research on the feeding habits of both species, with interesting results.
From: Tyler <[log in to unmask]>
To: VTBIRD <[log in to unmask]>
Sent: Sun, Apr 2, 2017 9:59 am
Subject: [VTBIRD] Vermivorous Barred Owl
I'm curious if anyone else on this listserv has observed this behavior in
Barred Owls before. I have found a small amount of literature on this, but
it doesn't seem to be a very common behavior.
My house has been hosting a Barred Owl every night (from dusk til dawn) in
an Ash tree in our backyard for over a week now. Sometimes it even shows up
before sunset. It is always there, no matter what time of night I look out
there, always on the same branch. I had assumed it was feeding on the many
rabbits and mice we have running around, but a few nights ago I started
noticing 'her' dropping down onto the lawn, where there is no brush or
vegetation anywhere nearby. I thought this would be strangely open
territory for a mouse to be venturing, and then I saw what she was after.
She was picking up earthworms. I've been observing her now and it appears
that she is specializing in hunting worms. Last night I observed a rabbit
feeding DIRECTLY BELOW HER (her perch is only 6 feet off the ground) and
she completely ignored the rabbit, flew past it, and returned to her perch
with another worm.
Has anyone else observed this vermivorous behavior in owls before?