Vermont

Ever plan an owling outing to locate a Long-eared Owl in Vermont?  You probably weren’t successful.  In fact virtually no one finds in Vermont a Long-eared Owl by design; encounters are universally by serendipity or luck.  The Second Atlas of Breeding Birds of Vermont begins its report with this revealing observation:  “The Long-eared Owl remains an enigma, poorly known, and seldom seen by the most active observers.” We three avid owlers – Tyler Pockette, Ron Payne, and Ian Worley – got together three years ago and decided to learn how to find Long-eareds in Vermont by intent, instead of accidentally coming upon one by chance.

The Beginning of the Quest

Wondering if it was possible that there are no active breeding populations of Long-eared Owls in Vermont, we reviewed literature, explored eBird and Vermont records, and sought the knowledge and advice of a few long-time researchers of the species.  This led us to two conclusions:  If there is a population it will most likely be near the largest water body of the state; and, the most likely habitat will be a combination of open fields (for prey) and tall conifers with abandoned nests of large birds or squirrels.

Based on this information, we decided the most likely location to search for Long-eared Owls would be in the Champlain Islands and the adjacent lowlands of Franklin, Chittenden, and Addison County.  Since the three of us are all from Addison County, it became the study area.  Our plan was simple, go to the locations that fit the conclusions above, and search for birds.  After two years and some 60-80 owling outings in that quest, we learned that there was plenty of prey, because on every single outing we encountered at least one owl, and often several.  But, we did not discover a single Long-eared Owl.

Those searches were conducted from late December into June, as this was the time frame in which owls are most vocal, and thus easiest to detect.  The basic method at a site was to move quietly through the site, or stand for long periods at one location for an hour or two.  Then, move back through the area playing a few recordings to solicit a response.  After the end of February no recordings were played out of respect for potential breeding.  A typical playing would be one 10-second hoot song, followed by 3-6 minutes of listening, sometimes another 10-second hoot song, followed by the same listening time, and sometimes ending with a 10-second playing of a female harsh-hoot song.  We were well versed in the extensive variety of vocalizations, wing-claps, and bill snaps made by the species.

The Breakthrough

Then this year came the breakthrough!  In his two years of birding employment in California, Tyler also did extensive birding while driving across the country, including photographing 596 U.S. species in 2014.  And in all of that he developed a new search image for possibly finding Long-eared Owls in Vermont, especially Addison County — dense red cedar thickets.  By the end of January of this year, he had become more and more intrigued with this possibility, and in February we set out again in our quest to find this enigmatic recluse, not by accident but by good planning.

On the very first visit, to the very first site, at the very first spot chosen for listening, at just about the end of Civil Twilight, the faint hoot song of a Long-eared Owl was heard from a cluster of cedars only 40 feet away!!  We had been able to walk right to a place we had reason to believe there might be a Long-eared Owl.  Moreover, this site had a nest that we were able to monitor to the successful fledging of three owl chicks in late May.

The next four sites we went to each had a Long-eared Owl.  The habitat signature was definitely working.  In all, we located 15 individuals at 10 different locations, which were in five western Addison County towns.  The first six birds were located either by volunteered vocalizations and/or were seen in flight, or on a branch. No recorderings were played or voice solicitations made. Once a bird was located, we left the site.  We never attempted to locate other birds at the same site complex, favoring expanding the known range of sites elsewhere with the owl.  Overall we have had 37 observations of Long-eareds in this project.

Due to our late start near the end of winter, and the success in finding birds, once volunteered vocalizations dropped off (as expected), we extended the calendar a couple of weeks in which we would consider playing a recording for the opportunity to add a new town to the list of towns in which birds were found.  Four of the last six birds located responded to part or all of the simple sequence mentioned above.  A much better time frame for seeking the birds, we feel, would be from mid-November through January, and not into February (due to breeding activity).

Even as late in the year that we got started we heard these identifying sounds:  male hoot song (very, very soft, sometimes audible from only a mere 50 feet away), female harsh hoot song, “meow” alarm call, “bark” alarm call, defense or anxiety “eek-eek-eek call, bill snaps, and wing claps.  When listening for the hoot song, occasionally we were temporarily deceived by a very similar, distant background sound or rhythm.

Birds were seen at late twilight commonly. They were also seen in daylight at roosts, the nest site, and in flight.  And we watched them in flight at night. Several times they flew right around our heads.  On one occasion at the nest site, the presumed male made several circles around us, then disappeared into the nest site only to reappear with the presumed female.  They looped interactively together over the thicket, then spiraled with each other upwards spectacularly higher and higher together at least 300 feet high.  Finally there were three quick bill snaps, and what we presume was the female flew back towards the nest into the thicket, and the male flew out of sight nearby.

The Habitat

The habitat we have identified, which has been so successful in this brief time, is comprised of thickets of Red Cedar (Juniperus virginiana) which have colonized open grazing land over recent decades.  All locations had nearby open fields adjacent or close by. The owls seem to prefer “middle-aged” tangles, old enough for individual trees to be significantly crowding each other, especially in the canopy, and at least 25-35 feet tall.

We have located birds in or associated with this habitat in Addison, Bridport, Cornwall, Shoreham, and Weybridge.  We have seen other potentially similar habitat in Waltham, Panton, Monkton, Salisbury, and Whiting, and expect there are locations in Orwell and maybe Sudbury as well.

Nesting

The very first site we went to was a nesting site.  Given the lack of knowledge of breeding activity of Long-eared Owls in Vermont, and that we discovered the nest prior to the beginning of occupation, we chose the location as a nesting monitoring site to follow until the departure of fledglings, and did not actively seek other occupied nests.

One other site was defended when first found.  Later it was checked for possible nesting, only to discover that the thicket had been extensively thinned to get rid of the cedars.  A third site was visited twice after the initial observation; bird behavior there indicated possible nesting so no further visits were made.  Daytime searches in numerous other tall Red Cedar groves in western Addison County found suitable nests left by other species to be common.  None happened to have any visible owls at the time.

The nest thicket was about 250 feet in diameter; there were other nearby thickets in the complex. Pasture and tilled lands were adjacent.  The roughly 2 feet in diameter nest was well hidden about 25 feet high, with another 8-10 feet of tree above.  Its twig structure indicated a bird origin.  It was occupied for at least 75 days, starting in early to mid-March.  The fledglings flew from the nest about May 31st/June 1st.

The nest structure and placement obscured virtually any birds that might be in it as viewed from the ground. During incubation we could only barely see through the jumble of nest twigs and tree branches about 2 inches of the tip of the tail of the incubating bird, and there was only one vantage point where that was possible.  Thus, monitoring visits had to be very close to the nest, meaning keeping the visit time as short as possible to minimize stress on the birds.  Visits were spaced to minimize stress, averaging 11 days apart, and lasted, on average, 6 minutes.  Only one observer went to the nest, while the other would stand outside the thicket to document any adults leaving the thicket because of our disturbance.

Brief Chronology

• Feb. 21st   First site visit.  Volunteered hoot song; owl came out and inspected us.
• Feb. 22nd  Nest discovered along with pair of adults.  Defense of nest suspected.
• Mar. 4th  Third adult flew in from south and interacted with one of the pair causing”meow” alarm call and bill snaps.
• Mar. 19th  Adult sitting low in nest, presumably incubating.
• April 5th Extended interactive, spiral flight by two adults above the nest, rising to 300 feet or more.
• May 5th  Possible brooding behavior.
• May 16th   One hatchling observed in nest.
• May 29th  Three fledglings 80 feet from nest on branches.  Significant difference in feathering between what appeared to be the oldest and youngest. The presumed oldest fledgling made a short flight. Neither of the other fledglings moved from their perch. Two adults nearby.
• Jun 3rd   Three fledglings 80 feet from nest on branches.  All three flew short distances.  Two adults nearby.  Many owl pellets in vicinity.

There are two previous Vermont reports of Long-eared Owl fledglings near nests in early July.  They would imply that there could be roughly 4-6 weeks variation in the start date for incubation.

Precautions

We have not identified the precise locations of the birds for reasons of protecting possible disturbances to nesting, and/or due to the desires of landowners.   The Vermont eBird markers were placed at a general location in the part of the town including the site.  Some sites are likely to have livestock present.

Long-eared Owls are known to be easily stressed.  A primary defense mechanism when stressed is to become motionless.  An individual perched motionless on a branch upon your approach is likely highly stressed.  Other stress related shows of defense are fleeing, posturing (note the photos of a chick in defense posture and an adult with raised ear tufts), distraction displays, and physical attacks.

The birds at the nest site, and one other possible nest site, were very much aware of us being nearby, as evidenced by them coming out to fly circles around our heads, and on one occasion to fly back and forth right in front of us at knee level.  Research reports state that stress levels are high in those circumstances.  Since an occupied nest likely can not be seen at a distance, to view it one will necessarily have to make a very close visit, which will create significant stress on birds at or near the nest.

Given our experience with volunteered hoot songs, the least stress on the birds when searching for them might start sometime in October and continue through January, and perhaps early February.  Defense of territory and breed may begin in early February.  There is yet a lot to be learned about these dates in Vermont.

 

Addendum (2 July 2016)

There appears to be a second successful nesting, with a possible three fledglings.

A local landowner lives between two mature red cedar groves. We had four Long-eared Owl encounters during our project within 650 feet of the house. The landowner reported to us that on June 24th three crow-sized owls, in rapidly fading light at the end of Civil Twilight, flew back and forth and in tight circles in her small back yard abutting a tall cedar grove.† When she spoke to them they responded by flying right up to her, then abruptly turning away. She could see their faces, and remarked about their longish wings and quite distinctive wing beats. Her descriptions and the proximity of the previous encounters are consistent with the birds being three juvenile Long-eared Owls.

We then searched for a suitable nest and found one well obscured in a tall red cedar in a thicket 650 feet from the house. The nest was of stick and twig construction, signifying a bird construction. It was very much like the nest at our previously reported monitoring site.

The nest location is exactly where a hoot song was heard on March 12th. The nest is 250 feet from where a Long-eared Owl flew at Ian just at the end of Civil Twilight on April 12th, as he quietly walked to a listening location. The owl circled his head twice making the distinctive abrupt turns of Long-eared Owls, then flew back and forth in front of him at knee height. The nest is only a few feet from where a Long-eared Owl was inadvertently startled from a daytime perch on April 22nd (the nest was unknown at that time).

The nest is less than 800 feet from extensive hay fields, at the edge of which a Long-eared Owl approached Ian, at late twilight in early March, from the cedar thickets and flew two circles around his head, did an abrupt turn, and then departed.

All these encounters are consistent with the nesting-to-fledging we monitored earlier in the year at the other location, and lead us to conclude there was a successful breeding also at this site.