This document summarizes a study that quantified raptor migration near a proposed wind turbine site at the UMD Farm in Duluth, Minnesota. Over 96 hours of observation, 1012 raptors from 18 species were recorded. The average flight height was 200 feet and average distance was 480 meters. Extrapolating these data, the total number of raptors passing through the area from September 7th to November 7th was estimated to be 4117. Approximately 590 raptors were estimated to fly within the height and distance range most at risk from the 80-foot turbine.

1. Raptor Migration Quantification at the UMD Farm
Lance Gauer | Dr. Gerald Niemi | Department of Biology | Natural Resources Research Institute | University of Minnesota Duluth
• SAP (Sustainable Agriculture Project)
• WindTech Inc.
• 5 kW Turbine
• 80 ft. structure
• Self-Raising Tower
• Zero Contact Transmission Technology
-Magnet based turbine
Purpose
• To obtain baseline data on the movement of
raptors near the UMD Farm, in light of a
proposed wind turbine installation.
Concern
• Hawk Ridge in Duluth, MN is the 2nd largest
migratory pathway in the country. With a wind
turbine proposed to be installed here, there is a
concern on mortality for these migrating raptors.
Project Overview
• Underwent training on Identification and the data
entry process in mid August before I began
research independently.
• Completed 96 hours of observation between the
dates of 9/7/2013 and 11/7/2013.
• Observation start times ranged from 9am to
3:45 pm
• Data were gathered in 1 hour increments
Wind Turbine Project
Materials
Procedure
Set Up
-Set up Equipment
-Enter
Environmental
Conditions
Scan Identify
-Scan 360 degree
horizon.
-Eyes 1st
-Binoculars 2nd
-Scope 3rd
Record
-Location
-Assign Number
-Flight direction
-Name
Data / Observations
• What was recorded?
• Height: 0=ground to canopy, 1=canopy-100m, 2=100m-
500m, 3=500m and above
• Distance: 1=0-400m, 2=400m-800m, 3=800m-1200m,
4=1200m-1609m, 5=1609m-2414m.
• Wind Speed & Direction
• Temperature in degrees F
• Sky
• Visibility
• Bird
Results
50
45
40
35
30
25
20
15
10
5
Flight Height + Distance vs. Individuals
Figure 1. Total # of individual raptors counted at the farm divided into the heights and distances they were observed at.
300
250
200
150
100
50
• Total # of raptors counted: 1012
• Estimated total # of raptors from
9/7/13-11/7/13: 4,117
Conclusion
• In 96 hours of observation at the UMD farm 1,012 raptors were counted.
The average flight height of these raptors according to our flight height
numbering system was 1.57; approximately 200 ft, or 60 m high. And
average distance from the point of observation was 2.19; approximately
480m.
• Based on obtained data, we were able to estimate, using average # of
raptors per hour, the total number of raptors that could have flown
through the UMD farm area from the dates of 9/7/2013 to 11/7/2013.
This estimation came out to be 4,117.
• Considering raptors within the height range of 0-1 and distance range of
1 to be the raptors at highest risk of mortality from the 80 ft. turbine, we
found 14.3% (145) of raptors within that range.
• Using that same percentage applied to our estimated total # of raptors (4,117)
it is estimated that approx. 590 raptors would have flown through the high-risk
range of mortality between our dates of observation.
-Flight
Style/Behavior
-Size and Shape
- Wing angle
• 10x42 Binoculars
• Swarovski Scope
• Deer Stand
• w/Harness
• Clip Board
• Tripod
• Compass
• Thermometer
• Pen
• Warm Clothes
• Field Guide
0
0 1 2 3 0 1 2 3 1 2 3 1 2 3 2 - (blank)
1 2 3 4 5 - (blank)
Individuals
Flight Height 0-3/Distance 1-5
-
AK
BE
BE
BW
CG
CH
GE
NG
NH
OS
PF
Raven
RL
RT
SS
TV
UA
UB
UE
UF
UR
(blank)
Bird Codes
• TV- Turkey Vulture
• NH- Northern Harrier
• OS- Osprey
• BW- Broad Winged Hawk
• RT- Red-tailed Hawk
• RL- Rough-legged Hawk
• BE- Bald Eagle
• GE- Golden Eagle
• SS- Sharp-Shinned Hawk
• CH- Coopers Hawk
• NG- Northern Goshawk
• AK-American Kestrel
• PG-Peregrine Falcon
• UB-Unknown Buteo
• UE- Unknown Eagle
• UA- Unknown Accipiter
• UF- Unknown Falcon
• UR- Unknown Raptor
0
- AK BE BE BW CG CH GE NG NH OS PF Raven RL RT SS TV UA UB UE UF UR (blank)
# of Individuals
Individual Totals
Figure 2. Total # of raptors in their individual amounts from all 96 hours of observation.
• Bald Eagle: 254
• Red-tailed Hawk: 215
• Broad-winged Hawk: 128