1	Migration of Northern Saw-Whet Owls In Pennsylvania - 2004 Presented by Deborah Danila On February 17, 2005
2	Northern Saw-whet Owl Aegolius acadicus Smallest eastern owl : 18-21 cm (7-8 in) Wingspan: 42-48 cm (17-19 in) Weight: 65-151 g (2.29-5.33 ounces) No ear tufts. Face white, outlined in brown and white. Underparts white streaked with red-brown. Eyes yellow. Bill black. Back, wings, and tail brown spotted with white. White streaks on brown forehead. Y-shaped white marking between and above eyes. Habitat: dense coniferous or mixed forests, wooded swamps, tamarack bogs. In PA: (rarely) nest in deciduous forest, during migration roost in hardwood trees until leaf-fall, then evergreen cover (conifers, laurel, rhodo, greenbrier, old blowdowns, etc.) Diet: mainly rodents and insects, some small birds Nocturnal hunter Oldest known: 7 years 11 months.
3	Distribution Breeding Range: Breeding range from Northern PA to central Canada, west to southern Alaska and South in the Rockies to Mexico Winter: maps vary, this one generalizes, shows greatest extent of wintering range. See Sibley for more detailed breakdown of winter, summer, year-round, migration and rare ranges. Note that it’s rare in east below Virginia.
4	The Ned Smith Center’s Banding Project PURPOSE: To determine to what extent saw-whets migrate through PA - found to be a common migrant, and the project moved on to other issues: Monitor long-term changes in Saw-whet owl populations Track the time of migration of age/sex groups Study stopover paterns Study molt and other aspects of biology Migration Routes: To determine what routes the owls are using: broad fronts, ridges, and/or vegetation corridors SITE DATA RECORDED: Time of opening nets and closing nets Weather on opening and closing site: temp, wind, precipitation, cloud cover Moon phase: the data from the 3 previous years indicates darker nights produce more owls…except right at New Moon, suggesting owl like it dark, but not too dark. Identity of banders and volunteers
5	In the Net My first view of a Northern Saw-whet owl:
6	Processing the Owls:
7	"Band number" Band number
8	Owls Age, as determined by wing molt: Hatching Year (HY), a bird hatched the previous spring/summer - its entire plumage, grown at the same time, consists of uniformly new, deep brown, glossy feathers.
9	"After Hatching Year (AHY" After Hatching Year (AHY) owls are adults whose ages cannot be specifically determined; these owls tend to have a mix of two, three or even four generations of flight feathers in the wing, often in a jumble, showing varying degrees of wear and fading.
10	A Fun Trick!
11	Also recorded: Length of wing chord, and flat wing Gender (based on wing chord and owl’s weight)
12	"Tail length" Tail length Beak length Body fat Keel muscle
13	The Banding Stations Three stations are operated from October 1^st to Thanksgiving, from sunset to midnight (or later if the owls keep coming).
14	2004 Migration:
15	Recent Year Totals: 2004 - 528 owls 2003 - 393 owls 2002 - 298 owls 2001 - 653 owls 2000 - 270 owls 1999 - 714 owls
16	Low % of HY owls: In previous big flight years, a large % of the owls captured were HY birds (indicating a very successful breeding season), but this year adult birds dominated. Why? Unseasonably early cold snap in the upper mid-west and eastern Canada may have affected breeding cycle and/or migration. It is known that rodent populations were down at least in some parts of eastern Canada, and lack of food may have resulted in poor breeding season, and Continuing low rodent populations, may have caused adult birds that would normally stay farther north to migrate south. It is unknown whether or not disease played a role in low HY numbers.
17	"Greater Percentage of Foreign Recoveries" Greater Percentage of Foreign Recoveries: 2004: 528 owls, 35 foreign recoveries (6/6 %) 21 at Small Valley, 8 at Hidden Valley, 6 Kings Gap 2003: 393 owls, 14 foreign recoveries (3.5 %) 2002: 298 owls, 4 foreign recoveries (1.3 %) 2001: 653 owls, 19 foreign recoveries (2.9 %) 2000: 270 owls, 4 foreign recoveries (1.4 %) 1999: 714 owls, 7 foreign recoveries (.98 %) Increase in the number of banding stations in the eastern US and southern Canada. Perhaps because more adults that usual migrated this year, giving us the opportunity to net them.
18	Foreign Recovery Highlights: Where do they come from? Lake Timiskaming, Ontario, Canada, is at the northern end of the Ottawa River on the Ontario-Quebec border. 854-40967 banded 10/3/04 , showed up 10/27/04 at Hidden Valley The next day, 764-35397, also banded on 10/3/04, was recovered at Small Valley. These represent the farthest direct recoveries (same year) for the program to date, about 450 – 500 miles. 924-15510 was banded on 10/26/04 at Prince Edward Point Bird Observatory, Ontario, Canada, and recaptured on 11/9/04 at Hidden Valley. We recover a number of owls from PEPBO which bands many owls being located on the north shore of Lake Ontario where the owls congregate awaiting favorable conditions to cross. 844-76834 was banded on 9/21/04 in Freeport, Maine, and netted at Small Valley on 10/25/04. At DuBois, PA (NW corner of ClearfieldCo.), 833-99465 was banded on 10/31/04, and recovered at Small Valley on 11/5/04.
19	"Sometimes they’re in a hurry" Sometimes they’re in a hurry: 674-77712 (originally banded on 10/17/03 in Addison, VT) was recaptured and released at Hidden Valley at 9:45 EST on 11/3/04, and captured again that same night at 12:45 EST in Southern York County, PA, just north of the MD line, having traveled 56 miles. 924-00832 banded 10/5/04 at Small valley was recaptured on 10/12/04, approx. 150 miles to the WSW at a station near Bittinger in the western panhandle of Maryland. A number of ‘our’ owls have been netted at this station over the years. Two of ‘our’ owls banded at Small Valley and Hidden Valley this year, where later recaptured Eastern Mennonite University near Bergton, VA, in the Alleghenies of extreme NW Virginia. Bucking the trend: one owl, after being banded at Hidden Valley, flew 100 NE and was recaptured the following week at Skytop in the Poconos! But rarely, to Lamb’s Knoll, MD, only 60 miles due south of King’s Gap on the same ridge. Why? No one knows.
20	"Resources" Resources Scott Weidensaul – author, naturalist, and the projects coordinator Ned Smith Center for Nature and Art 176 Water Company Road, Millersburg, PA 17061 717-692-3699 www.nedsmithcenter.org Other Websites: www.projectowlnet.org www.owlpages.com/species/Aegolius-acadicus/northern_saw-whet_owl.html www.owling.com/Northern_Saw-whet.htm www.raptorcenter.org/saw-whet-owl.asp www.peregrinefund.org/Explore_Raptors/owls/nsawwhet.html