Tussey Migration Data

Overview

Fall raptor flights have been known to occur on Tussey Mountain for many years, with the former fire tower near Pennsylvania Furnace Rd, about 5 miles southwest of our count site, being a popular watch site (see Merrill Wood's classic Birds of Pennsylvania), as well as the Colerain Road near Spruce Creek. Part-time spring counts were begun by David Brandes in March 1995 and continued through 2000 with the help of Dan Ombalski, Nick Bolgiano, Chuck Widmann and other local die-hards. Full-time counts have been conducted from late Feb through April since 2001. Although conventional wisdom maintained that raptors do not follow ridges in the spring, we learned quickly that this did not apply to early season golden eagles.

Summary data can be found at HawkCount

Flight Description

The first three weeks of March is the peak time for golden eagles, although the flight can be delayed by wintry weather (as in 2011 and 2017). Look in particular for warm southerly winds in early March, such as occurs ahead of approaching rain or snow. Good flights also occur on northwest winds.
A large fraction of the eagles at Tussey are breeding-age, thus the early flight as compared to other hawkwatch sites in the northeast where many of the eagles passing are non-breeding juveniles (e.g., Braddock Bay and Derby Hill, NY). Other early raptor species include turkey vultures, red-tails, red-shoulders and rough-legs (like the one shown above).
April is the best month for big numbers of raptors, although the flight is highly weather-dependent. Warm days with southerly winds and clouds are usually good, particularly after extended damp weather when the flights can be spectacular (e.g. 2001). Sunny days are usually not productive in April because thermal lift is so strong that hawks and eagles are moving at high altitudes and are thus are very difficult to spot.
Common raptor species include turkey vultures, red-tails, broad-wings, sharp-shins, Coopers, ospreys, and kestrels. We usually see all 16 regularly-occurring species of eastern diurnal raptors each spring. Swainson's hawk has also been seen on 3 separate occasions.

Seasonal Records

Osprey = 272 in 2001
Bald Eagle = 91 in 2020
Northen Harrier = 125 in 2001
Sharp-shinned = 628 in 2001
Cooper's = 172 in 2001
N Goshawk = 6 in 2005
Red-shouldered = 82 in 2005
Broad-winged = 3599 in 2001
Swainson's = 1 (multiple years)
Red-tailed = 963 in 2001
Rough-legged = 18 in 2005
Golden Eagle = 239 in 2015
Am Kestrel = 167 in 2001
Merlin = 16 in 2001
Peregrine = 5 in 2001

Daily Records

Seasonal Records

Osprey = 83 on 4/27/17
Bald Eagle = 53 on 4/29/20
Northen Harrier = 46 on 4/08/01
Sharp-shinned = 161 on 4/08/01
Cooper's = 32 on 4/12/01
N Goshawk = 2 on 3/12/05
Red-shouldered = 24 on 3/14/14
Broad-winged = 2173 on 4/12/01
Swainson's = 1 (3 records)
Red-tailed = 227 on 4/08/01
Rough-legged = 4 (various dates)
Golden Eagle = 62 on 3/03/08
Am Kestrel = 42 on 4/08/01
Merlin = 5 on 4/29/20
Peregrine = 1 (many dates)

Tussey Mountain Spring Hawkwatch

Tussey Mountain Spring Hawkwatch

Tussey Migration Data

Overview

Flight Description

Seasonal Records

Seasonal Records

Seasonal Records

Daily Records

Seasonal Records

Seasonal Records

This plot shows the cumulative distribution of GOEAs by date for the past 20 years