Pittsburgh Project Owlnet

Project Owlnet – Scientists and Citizen Scientists Tracking the International Travels of the Northern Saw-whet Owl 

Project Owlnet is a coordinated, cooperative banding project to determine the timing, intensity and pace of migration of the Northern Saw-whet Owl, a species whose migration was little known until this project began in the mid-1990s.  A few banding mist nets (12 m long nets made of fine nylon mesh which harmlessly captures flying birds) are set up in suitable habitat and an audio lure of the owl’s own call is played to attract any migrating owls closer to the nets.  Several dozen of these tiny owls can be caught in a single night at some locations in the mountains of Pennsylvania and along the Lake Erie shore.  

Until the National Aviary’s ornithologist, Bob Mulvihill, initiated Pittsburgh Project Owlnet in fall 2013, we knew almost nothing about the occurrence of these owls in the Pittsburgh region, which is well outside the classic ridgetop, Great Lakes shores, and coastal areas where they are well known to concentrate during migration.  In just a few seasons of monitoring, we have already learned that they do migrate through an urban landscape like that found around Pittsburgh, both in spring and fall, and (based on recaptures of birds banded elsewhere) that they travel here from as far away as western Canada! 

 

The Upcoming Spring 2018 Season

The spring owl banding season will begin on Tuesday, February 27 and run through Tuesday, April 1.  Times are from 6:30 until midnight until March 10; 7:30 until midnight after March 10.  Visitors are welcome during those times on any Tuesday, Friday, or Saturday night, weather pemitting (banding will be cancelled in the event of steady rain or strong winds).  This is a Google map link to the banding site: Sewickley Heights Park Owl Banding

A Summary of the Fall 2017 Season

2017 was our fifth consecutive year of fall banding for  Northern Saw-whet Owls at Sewickley Heights Borough Park near the city of Pittsburgh.  With 25 nights of effort between October 6 and December 2 (six mist nets erected from sunset until midnight), we caught and banded eleven Northern Saw-whet Owls (our first on October 17; our last on December 1).  We recaptured two of these owls within the same season.  Our total of 13 owl captures this fall compares to a low of ten in fall 2015 and a high of 36 in fall 2016.  

 


Volunteers and Supporters

As always, we could not run this program without help from a dedicated crew of volunteers, especially Doug Cunzolo, Victoria Wefers, Debbie Kalbfleisch, Sue and Jim Ralston, Courtney Sikora, and Don Koch.  Our success is not only measured in numbers of owls caught, but also in the number of people we are able to engage in the process.  More than 200 people signed our visitors book this fall, and many visited our station on multiple nights. 

Our sincere thanks to all our volunteers and visitors, and also to April Claus at the Fern Hollow Nature Center and the Sewickey Heights Borough Police department for their help in facilitating our efforts every season.    

And special thanks go to 28 people who supported the continued operation of our Project Owlnet station by 'adopting' an owl this season--funds from these adoptions help defray the costs of mist net replacement, replacement batteries for our callers, other necessary field supplies, and incidental expenses.  Adopters receive a certificate with a photograph of one of the owls banded during the season, relevant banding data for that owl, and the promise of updates if their owl is ever recaptured!  If you'd like to adopt an owl, go to: https://www.aviary.org/adopt-a-saw-whet-owl

 

About Project Owlnet

Project Owlnet is a coordinated, cooperative banding project to determine the timing, intensity and pace of migration of the Northern Saw-whet Owl, which was a little known species until this project began in the mid-1990s.  A few banding mist nets are set up in suitable habitat and an audio lure of the owl’s own call is played to attract any migrating owls closer to the nets.  Several dozen of these tiny owls can be caught in a single night at some locations in the mountains of Pennsylvania and along the Lake Erie shore.  But, until Pittsburgh Project Owlnet was started in fall 2013, we knew very little about the occurrence of these owls in the Pittsburgh region, which is well outside the classic ridgetop, lakeshore, and coastal areas where these small owls are known to be concentrated during migration.

Uncovering the Mysteries of Owl Movements and Biology

Project Owlnet facilitates communication, cooperation and innovation among a network of dozens of owl migration researchers in North America.  It was the brainchild of Dave Brinker, an ecologist with Maryland Department of Natural Resources, and is managed by Brinker; Steve Huy in Maryland; and Scott Weidensaul in Pennsylvania.

By providing standardized methodologies, information on capture techniques, ageing and sexing resources, analytical tools, data archiving and other services, Project Owlnet has made it easier for ornithologists to lift the veil on owl movements and biology.

Project Owlnet in Pennsylvania

In fall 2013, with help from Fern Hollow Nature Center and Sewickley Heights Borough Park naturalist, April Claus, National Aviary ornithologist Bob Mulvihill established the very first Project Owlnet banding station anywhere in western PA west of the mountains, and one of very few stations located anywhere near a major urban center.

In just one season (22 nights from early October to early December), Bob and a team of volunteers learned that, yes, there is a migration of Northern Saw-whet Owls in the Pittsburgh region!  They netted eleven birds in this first pilot season—single birds on six nights; three birds on one night; and two birds on one night—all in November and early December.  With some good luck, the researchers also learned something about the direction and distance from which owls migrating past the city may come.  They learned this because one of the owls that they caught already had a band on its leg--and the number on the band didn't match the ones they were using!

It turns out that they had recaptured an adult female Saw-whet Owl banded just three weeks earlier at Long Point, Ontario, about 135 miles due north!  In fact, it is the not-too-infrequent exchange of banded owls among Project Owlnet cooperating sites that provides the bread-and-butter data for research into the timing and direction of movements of this once enigmatic species. 

banded owl foreign retrap

Since this initial foreign retrap, two more owls from Sewickley have been connected through band recoveries to the same stretch of the north shore of Lake Erie near Long Point, another was recaptured in Allegheny National Forest in northern Pennsylvania.  And amazingly, we recaptured a third banded owl that had been marked two years prior 1600 miles away in Elkwater, Alberta, Canada!!


So, What Are We Learning About Owl Migration?

We have now conducted owl banding at this location for five consecutive fall seasons, and some patterns are beginning to emerge:

Interpreting the Data

From the above charts it is evident that the fall migration of Northern Saw-whet Owls peaks between the last week of October and the second week of November.  On the nights when we caught owls, there seem to be two peaks, between 7:00pm and 8:00pm and again three hours later.  Moon phase also is a factor, with more than three-quarters of our captures coming on nights when the moon phase was less than 50%.

You can use the information about regarding peak dates and times as a rough guide for maximizing your chance of seeing an owl when you do visit.  As mentioned above, we have found that dark skies (a new moon or cloud cover) and northerly winds seem to improve our chances for catching owls during those dates and time periods.  But, there is always something to see, hear and learn if you stop by Sewickley Heights Borough Park on one of our scheduled banding nights, and visitors are welcome to come and go on whatever schedule is convenient for them.

Group watching owl banding

Again, weather is always a factor, so if steady rain or high winds are in the forecast, there may not be banding.  If you do plan to attend a banding session, be sure to dress appropriately (we are outdoors the whole time), bring a flashlight or headlamp, snacks and a thermos of coffee if you want, and plan to arrive anytime from a half hour before dark until midnight. 

So, why in the world would people spend hours and hours sitting outdoors at night, even when it's very cold?

Mighty cold!

 

Well, this is why!!