Tuesday, October 11, 2011

Barred Owl in Dearborn

[2017 update at bottom of post]

I get a fair number of calls to help rescue birds from various situations, often inside buildings. Usually they are very common species (European Starlings, in particular, seem to have a knack for falling down chimneys). Often there isn't much I can do but offer advice, which is often sufficient to solve the problem.

Late yesterday afternoon I got a message from Jim Barber at the First Presbyterian Church of Dearborn, directly across the Rouge River from campus. They had a large owl (he thought Great Horned) trapped in the basement boiler room of the church. He was at wits end -- the bird had been there for at least several days and nobody he called was taking any action. The notion of a Great Horned Owl getting down a ventilation shaft seemed pretty unlikely to me, and he told me the room was around 20 by 20 feet with high ceilings. This seemed like a difficult situation, but my curiosity, the plight of the bird, and Jim's frustration compelled me to immediately head up to the church and figure out how I could help.

Within 15 minutes I was looking in the boiler room. Not only was it big, it was cluttered with all sorts of equipment and supplies. This was the part of the room I saw when I walked in:

To the right was the large boiler, and the ceiling went up another 10 feet, criss-crossed with pipes and supports. A large owl did indeed take off from a ceiling beam and fly over to a pipe above the boiler. To my great astonishment it was not a Great Horned Owl (or a Cooper's Hawk, which I sort of expected), but a Barred Owl (Strix varia), a species with only a single record from Dearborn, in 1976 (see history, below).

I decided there were two possibilities for catching the owl. One, with a long-handled net, although with so many obstacles I thought this might result in a lot of chasing around, which would stress the bird. The other was to use a bal-chatri trap, a common way of catching raptors. Bal-chatris are wire traps topped with small nooses made of fishing line. A mouse is placed in the trap, and when the raptor pounces on the trap it gets its talons caught in the nooses. The mouse isn't harmed, and the bird can be quickly released from the nooses. I figured the owl would be very hungry after three days, and this should work pretty well.

After outlining my plan, I called my husband Darrin O'Brien to have him bring a bal-chatri from home as well as a net for back up. I also called my good friend Jim Fowler. Jim has a great deal of experience handling raptors, and also spent 30 years at Greenfield Village as the head of the grounds department, rescuing plenty of birds from buildings. He would bring a long-handled net and a second bal-chatri. I went up to the RRBO banding lab on campus to fetch my banding gear.

When we all reconvened at the church, a member of the Michigan Humane Society wildlife department had shown up. He and the church employees had ambushed the owl and had it wrapped in a shirt, saving us a great deal of trouble. We took the owl from him, and after one loud screech, it settled down and stared up at Jim, who held it while we checked the bird's condition and I measured the wing.

Considering its ordeal, the owl was in great shape. It had some fat, and had no injuries or even broken feathers. Jim Barber and his co-worker Jamie told us there were certainly mice in the boiler room (and they also put out water for the owl), so we can only assume it probably ate while holed up.

Darrin took the bird so we could band it.

I let Jim Fowler do the honors. While it looks like Jim's nose might be in danger here, it's really the talons you have to worry about. Sure enough, it did grab Jim's thumb at one point, drawing blood.

Outside the breeding season, Barred Owls cannot be sexed, so we don't know if the owl is a male or female. But looking at the color, shape, and wear of the wing and tail feathers can help determine age.

All the wing feathers and their coverts (the row of feathers covering the bases of wing feathers) are quite uniform in color and wear, which indicates that this is a hatching-year (HY) bird. The outer six wing feathers (primaries) are slightly more worn that the inner four, but that might be due to flying around a room full of close objects and brushing against them. Further, at no age would we really expect all the inner primaries to be replaced and the outer primaries retained. The shape of the primary coverts is rounded, with the pale areas more round than block-shaped, also an indication of HY.

In the photo above, we can count the number of pale bars on primary number 9, the second feather from the outside. Five bars are visible, not counting the pale tip. In the first set of wing feathers on a Barred Owl, p9 will have 4 to 5 bars; there will be only 3 to 4 bars on it after it is molted. This feather might be molted in the owl's second fall, or not until the third fall. This owl was not actively molting any wing or tail feathers. If it was older than HY, it should have been molting some feathers, or there should have been some new wing feathers that looked different -- less worn with narrower bars spaced further apart.

The photo above not only proves I was actually present at this event, but also shows the pointed, whitish tips of the tail feathers. These are the first tail feathers, which will probably not be replaced until the bird's third fall molt, after which they will have darker, blunter tips and narrower bars. All of this leads to my conclusion that this is an HY bird. By October 10, we would expect that any flight feather molt would be nearly or fully complete, so if it were an older bird, we would see the contrast in old and new feathers discussed above. It's always tricky determining the age of a bird with which you have no experience, so I'm happy to take any corroboration or contradiction in the comments!

We walked to the edge of the parking lot to release the owl. It took flight and landed in a tree, shook itself, gave us one last look, and took off toward the Rouge River and UM-Dearborn campus. 

Barred Owls in Wayne County

According to historical accounts, Barred Owls nested in Wayne County until about 1910, after which they were apparently extirpated, being hunted and pushed out by agricultural and urban development. The next record I found was a report from the UM-Dearborn campus on 12 May 1971. I was unable to confirm the veracity of this record, but it was by a reliable observer. The only reliable report I have had from Dearborn is a bird seen on 7 April 1976 by Gary Hutman on land that is now the TPC Golf Course. Over a decade passed before a report came from Grosse Ile on 27 December 1987. In 1994, one was seen at Lake Erie Metropark by my husband Darrin on 17 September.

In recent years, Wayne County reports have become more frequent. Daryl Asprey found one at Crosswinds Marsh (phase 1) on 6 December 2003. When RRBO was coordinating the breeding bird atlas work for the county, one or two were reported calling in a wooded area in Canton Township from 2004-2006; we were never able to confirm nesting. Several years ago, a pair took up residence at Oakwoods Metropark, first heard calling by Daryl Asprey on 23 February 2007. Feel free to add any further records in the comments.

Thanks to everybody who participated in this rescue. Good luck to the owl, and to the guys who I understand will be on the roof of the church today, closing off a certain ventilation shaft...

Update: I had a report of a Barred Owl being heard at the far north end of campus on 23 April 2017.   


Sue Paruszkiewicz said...

What an amazing adventure you had! So glad everything turned out so well. Good job, to everyone involved.

Heather said...

What a wonderful and fascinating post. Gorgeous pictures too!

Sally said...

Great story and wonderful photos. Good job!

ONNO said...

Incredible encounter. Beautiful owl and so happy to hear it was healthy after its ordeal.

Shelley said...

Lovely to see all these photos of this beautiful owl! Glad he/she had friends to help! :-)

Susan said...

Wow - how exciting, maybe it will decide to hang out around the EIC and the Rouge River. Take care -

pjhart said...

all's well that ends well, great job and I will use this blog in my class at UM-D!!

Dr. Deborah Smith Pollard said...

What a beautiful creature. Good story!

Maureen said...

Such a great story and so informative! Thanks!!