HomeMy WebLinkAboutAPA696FINAL REPORT
PEREGRINE FALCON SURVEYS
OF SELECTED AREAS ALONG THE
UPPER TANANA AND SAGAVANIRKTOK RIVERS, ALASKA,
1982
Submitted by:
Robert J. Ritchie
F. Lance Craighead
ALASKA BIOLOGICAL RESEARCH
P.O. Box 81934
Fairbanks, Alaska 99708
Submitted to:
U.S. Fish and Wildlife Service
Endangered Species Office
Anchorage, Alaska 99503
Contract No. 14-16-0007-82-5222
September 1982
TABLE OF CONTENTS
List of Tables ..•......................................•..•...••• ii
List of Figures ••.....•........•................•.....•.•...••.•. iii
Acknowledgements ..•..•........•••.•................•.••••.••...•• iv
INTRODUCTION .•..••.•••••••...••...........•..•••...••.•••.•••.••• 1
STUDY AREA . • . . • . . • • • . • . . • • . . • . . . . . . . . . . . . • . . . . • . • • . • • • • . • . • • • • • . • 1
METHODS . . . . . • . • . . • • . . . • • • • • . . . . . • . • . . . . . • . . . . • . • • . • • • • • • • . . . • • . • • 4
RESULTS AND DISCUSSION ••.••••.•.....•...••••.•.....••••.•••••...• 6
Tanana River .••••••.•••.••....•••........••••...•...••.••..•.• 6
Peregrine Falcons .•.•.•.•.....•........•••..••••.••.•.••.•• 6
Go 1 den Ea g 1 es ••.•...•....•.•...•..•••.•.•.•••••••..•••••• • • 6
Bald Eagles ••••••••.••.•••••.••..•..•..•.•.. ~ •••••••••••••• 15
Other Rap tors • • • • • • • • • . . . . . . . . . . . • . • . . . . • • • . · . • •. · • · • · • • • • 15
Sagavanirktok River •.....•.•.•.•.•.•.••••.•.•..•••••••• • •.•• • · 17
Peregrine Fa 1 cons •.. · •.• · .•...•....•• • • · • • · · · • • • · • · • · • · · • • • 17
Rough-1 egged Hawks · .• • .•... · ......... · · · · · • • · · · • · · • · · • • • • • • 23
Gyrfalcons •••.••.•.••••.••..•..•..•.•...•...•••... •• .••.• ·• 23
LITERATURE CITED ••••.• • • · • · • • • • • • · • · • · · · · • • • • · • · • · · • • • · • • · • • • • • • • 25
Appendix A -Raptor Nest Locations······························· 26
ARLIS Alub~ Library & InfonadR Semces
Libraly Building, Suite 111
3211 Providence DIM
~.AK99508~14
Table 1.
Table 2.
Table 3.
Table 4.
Table 5.
Table 6.
Table 7.
Table 8.
Table 9.
Table 10.
Table 11.
Table 12.
Table 13.
Table 14.
Table 15.
LIST OF TABLES
Peregrine aerie locations and references to existing
systems of identification ••••••••.••..•••••••••••••••• 5
Peregrine falcons observed along the Tanana River,
Alaska, 1982 •••••••••••••••••••••••••••••••••••••••• ~. 7
Characteristics of peregrine nest sites found along
the Tanana River, Alaska, 1982 •••••••••••••••••••••••• 8
Peregrine falcon nestlings banded on the Tanana
River, •Alaska, 1982 •..•..•••.••..•••••..•.•...•.•••••. 9
Comparison of peregrine productivity for the Tanana
River, Alaska, 1979-1982 .•.••••••••••••••••••••••••••• 10
Estimated nesting phenology of peregrine falcons on
the Tanana River, Alaska, 1982 •••••••••••••••••••••••• 11
Adult behavioral response to aerie visits on the
Tanana River, Alaska,· 1982 •..•........................ 12
Prey identified at peregrine falcon aeries on the
Tanana River, Alaska, 1982 •........................... 13
Productivity of bald eagles, Tanana River, Alaska,
1978-82 •............................................•. 16
Peregrine falcons observed along the Sagavanirktok
River, Alaska, 1982 •.................................. 18
Peregrine falcon nestlings banded on the Sagavanirktok
River, Alaska, 1982 •.............•.......•............ 19
Characteristics of peregrine nest sites found along
the Sagavanirktok River, Alaska, 1982 •........•....... 20
Adult behavioral response to aerie visits on the
Sagavanirktok River, Alaska, 1982 ..•.................. 21
Comparison of peregrine productivity for the
Sagavanirktok River, Alaska.l979-1982 .........••..•.. 22
Raptors, except peregrine falcons, observed along the
Sagavanirktok River, 1982 ............................. 24
ii
iii
LIST OF FIGURES
la. Tanana River st·udy area and approximate locations of 1982
peregrine aeries •............................................ 2
lb. Sagavanirktok River study area and approximate locations
of peregrine aeries •...................•........•....... 3
ACKNOWLEDGEMENTS
This project was funded by the U.S. Fish and Wildlife Service
under contract no. 14-16-0007-82-5222. Doug Toelle,
Jill Oppenheim,and Brian Lawhead assisted with data collection.
Drafting was provided by Mary Moran. Additional observations
of raptors were supplied by Skip Ambrose, U.S. Fish and Wildlife
Service, Fairbanks. The final report was typed by Tina Picolo.
iv
INTRODUCTION
In 1979, the U.S. Fish and Wildlife Service initiated a
peregrine (Falco peregrinus anatum, f.Q. tundrius) banding program
on the Yukon, Porcupin~ and Colville rivers where high concentra-
tions of peregrines are located (Ambrose 1980; Roseneau et ~-1980).
During this time period peregrine populations on the Tanana River
above Fairbanks and along the Sagavanirktok were surveyed by Northwest
Alaskan Pipeline Company. Banding was not performed on these surveys,
except in 1981. In October 1981 a nestling banded along the Tanana
River in July was recaptured on Padre Island, Texas (unpublished notes)
rekindling interest in banding in these areas.
This report provides the results of the 1982 banding and
raptor survey program on the Tanana and Sagavanirktok rivers. Data
collected previously along these rivers have been summarized by
Haugh (1976), Roseneau and Bente (1981~ and Ritchie (1981).
The objectives of ~his study were:
1. To locate cliffs occupied by peregrine falcons
on the Tanana and Sagavanirktok rivers,
determine productivity, and band nestlings;
2. To collect prey items, addled eggs, and eggshell
fragments from active peregrine nests; and
3. To locate other raptors, raptor nests, and band
as many nestlings as possible.
STUDY AREA
The study area included all historic peregrine nesting areas
and probable nesting areas along the Tanana River between the
Tetlin Bridge crossing and Fairbanks, and selected areas in the
Sagavanirktok drainage, specifically Franklin and Sagwon Bluffs
and Slope Mountain (Figure$ la and lb). Area descriptions are presented
in Haugh (-1976) and Roseneii_u et.a1.(1976}.
1
~
I. Robertson River
2. Round Lake
3. Billy Creek
0 50km 4. Llttle Gerstle River Sawmill
5. Birch Lake
Figure la. Tanana River study area and approximate locations of 1982 peregrine
aeries.
N
N
5km
FRANKLIN
6 BWFFS
'®5
SAGAVANIRKTOK
RIVER
/. South Sagwon
2 Mid Sagwon
3. East Sagwon
4. South Franklin
5. Bruee (oJ
6. Bruce (b)
7. Greta Creek
8. North Sagwon
SLOPE" MOUNTAIN 40km+
Figure lb. Sagavanirktok River study area and approximate
locations pf peregrine aerie~.
3
METHODS
Tne Tanana River was surveyed for raptors from 16 June to
21 June and 9 July to 13 July, 1982. The Sagavanirktok River was
surveyed from 22 June to 26 June and 26 July to 29 July. An inflatable
raft was used on each river. The Slope Mountain site was visited
in a truck. Observations were made with spotting scopes and
binoculars. The more inaccessible sites were reached using climbing
gear. Peregrine falcon and golden eagle, Aguila chrysaetos, young
were banded with the appropriate size Avise bird bands. Peregrine
falcon nest sites were photographed and described. Raptor nest sites
were mapped on 1:63, 360 USGS topographic maps. Prey remains, addled
eggs,and eggshell fragments were collected. Prey remains were
identified in the field; unknowns were returned to Fairbanks for
comparison with specimens at the University of Alaska Museum and
Alaska Biological Research, Fairbanks. Eggshell fragments and whole
eggs were given to U.S. Fish and Wildlife Service for analysis.
To reduce confusion in interpreting results of these surveys
Tab1e 1 defines locations used in this text and cross references
these to numbering systems employed by Roseneau and Bente (1981)
and Haugh (1976).
4
Table 1. Peregrine aerie locations and references to existing
systems of identification.
Name Used in
This Text
Robertson
River
Round Lake
s...
Q)
>
~ Billy Creek
1'0 s:::
1'0 s::: ~ Little Gerstl e
River Sawmill
Birch Lake
South Sagwon
Mid Sagwon
~ East Sagwon
> .,....
0::::
Location
across from mouth of
Robertson River
1 mile west of Round Lake
(downstream from Robertson
River)
2 miles downstream of
Billy Creek mouth
8 miles downstream of
Little Gerstle River mouth
across from Little Delta
River
Sag C-4, T1S, Rl4E
(SECT. 15)
Sag C-4, TIS, R14E
(SECT. 3)
1.5 miles SE Pump Station
No. 2
~ South Franklin Sag D-3, T5N, R14E
~ (SECT. 21, 27, 28)
s...
·;: Bruce
1'0
Sag D-3, T5N, R14E
(SECT. 5, 9, 16) >
1'0
0"1
1'0
V) Greta Creek
North Sagwon
Sag D-3, T6N, Rl4E
(SECT. 20)
Sag D-3, T7N, R14E
(SECT. 21, 28, 33)
l From Haugh (1976) 2 From Roseneau and Bente (1981)
Other
Identification
21, 21a 2
31, 29b 2
4 1, 34a 2
71' 52 2
141' 73b 2
1962
194
201 2
P2112
P2122
P2162
P22Q2
P222-2242
5
.,
RESULTS AND DISCUSSION
Tanana River
Peregrine Falcons
Peregrine falcons were observed at five locations on the Tanana
River in 1982 (Figure 1a, Table 2). Pairs were observed at each
location; all five sites were occupied in 1981. Table 3 describes
nest sites.
Eight young were recorded at three successful aeries (2.7 yg/
successful pair, 1.6 yg/starting pair). Additionally, a single
punctured egg was collected at a site near Birch Lake and three
eggs were gathered by the U.S. Fish and Wildlife Service at the
Robertson River (Ambrose, pers. comm.). All young were banded (Table
4). A comparison of productivity, 1979-1982 is presented in Table 5.
The phenology of nesting appeared to be later than 1981 by at
least one week. The small sample size, however, limits any accurate
appraisal. Table 6 summarizes the range of egg-laying through
fledging dates based on estimated ages of nestlings on 10 July 1982.
Banding activities precipitated aggressive behavior of adult
falcons. Table 7 summarizes the responses to our banding efforts.
Fifty~nine prey items were identified at five nest ledges
in 1982 (Table 8). An fnteresting addition to prey items recorded
for the interior of Alaska was a snow bunting, Plectrophenax nivalis,
collected at the Round Lake site.
Golden Eagles
At least five cliffs have had recent use by golden eagles in
the study area. Only two produced two young in 1982. A nest at
Cathedral Bluffs had two recently hatched young on 17 June 1982; a
single young bird estimated at approximately 30 days was banded
there 9 July. Another nest near the Robertson River also produced
one young estimated at 30 days old 17 June 1982.
6
Table 2. Peregrine falcons observed along the Tanana River,
Alaska, 1982.
Cfiff
Location Date Adults Young Remarks
Robertson 17 June Pair U.S.F.W.S.
River co l1 ected eggs l
Round Lake 17 June Pair Adult female had
9 July Pair 4 band
Billy Creek 18 June Single Deep cuts o~ nestling,
10 July Pair 1 heavy maggot infestation
Little Gerstle 18 June Single
River Sawmi 11 11 July Pair 3
Birch Lake 20 June Pair 1 egg
12 July Pair
!Ambrose, R. pers. comm.
7
Table 3. Characteristics of peregrine nest sites found along the Tanana River, Alaska, 1982.
Approximate
Cliff
Location
Robertson
River
Round Lake
Billy Creek
Nest Dimensions
Rocky-soil ledge,
with slight overhang,
.8 mX .5 Jll,
Soil ledge at upper
limits of sagebrush
slope; overhang
.8 m X 8 Jll,
Soil scrape .6 m
X .8 m in old
stick nest with
overhang.
Little Soil scrape, with
Gerstle River overhang 1 m X
Sawmill .8 m.
Birch Lake Soil scrape atop
old stick nest
in rock chute;
.8 m X 8 m.
Prev. Next Location
Below Above
Exposure Cliff Cliff
Distance Use
WSW 20 m
SE 15 m
SSE 5 m
s 25 m
ssw 25 m
to River Accessl Cliff Type2 (yrs)
50 m+ 10 m 1-2
50 m 20 m 1
40 m 20 m 1
25 m 20 m 1
20 m+ 10 m 3
A
A-B
A
B
A
1981
N.D. 3
1977 '78
81
1981
1981
lAccess: 1 =-walk, 2 =aid of rope, 3 ,;~climbing gear 2Cliff Type: A= steep cliffs, sheer walls; B =more gradual talus slope; C =low bluff or cliff.
3N.O = No data
00
Table 4. Peregrine falcon nestlings banded on the Tanana River,
Alaska, 1982.
Approx. Cliff Estimated Age
Location Date Banded (days) Sex Band Number
Round Lake 9 July 20 ~1a 1 e 987-51032
9 July 20 Male 987-51033
9 July 20 Male 987-51034
9 July 20 Female 987-51035
Billy Creek 10 July* 20 Male 987-51036
Little Gerstle 11 July 25 Male 987-51037
River Sawmi 11 11 July 25 Male 987-51038
11 July 25 Male 987-51039
* Young bird suffered from cuts (possibly inflicted by aerial
predator such as a great horned owl) on its abdomen; 18 maggots
were removed from the nestling'·s right ear. Wounds were
probably 5+ days old and healing; the bird's overall condition
was good.
9
Table 5. Comparison of peregrine productivity for the Tanana
River, Alaska, 1979-1982.
Location 1979 1
Robertson pr/2yg
River
Round Lake pr/2yg
Billy Creek -
Little Gerstle -
River Sawmi 11
Birch Lake pr
Total Number
of Pairs 3
Lone Adults 33
Number of Pairs
With Young 2
Total Number of
Young Observed 4
Young Fledged Per
Total Pairs 1.33
1 Roseneau et al., 1981
2 Ritchie 1981-
1980 1
pr/2yg
pr/3yg
-
pr
pr/1 egg
4
2
5
1.25
1981 2 1982
pr/3yg pr/3 eggs
pr/2yg pr/4yg
pr/3yg pr/1yg
pr/2yg pr/3yg
pr/2yg pr/1 egg
5 5
5 3
12 8
2.40 2.67
.,
3 Three single peregrines were reported by Roseneau et al. 1981 at
other cliff sites.
10
Table 6. Estimated nesting phenology of peregrine falcons
Dn the Tanana River, Alaska, 1982.
-,
Event ~1ean Date Range
Begin egg laying 11 May 9 May-14 May
Begin incubation 15 May 13 May-18 May
Hatching 18 June 16 June-21 June
Eledging 28 July 25 June-31 July
11
Time intervals used in these calculations: 7 days for clutch completion;
34 days for incubation beginning four days after first egg;
and 40 days for fledging (first flight). Ages of nestlings
(n=8) were estimated when banding; mean age was 22 days (10 July).
12
Table 7. Adult behavioral response to aerie visits on the
Tanana River, Alaska, 1982.
Cliff Duration of
Location Disturbance Male Response Female Response Remarks
Round 45 minutes vocal, soaring vocal (6 stoops) 2 people at nest
Lake
Billy 56 minutes vocal vocal, soaring 1 person at nest
Creek (3 stoops)
Little 43 minutes vocal, soaring vocal, soaring 2 people at nest
Gerstle (6 stoops) (2 stoops)
River
Sawmill
Birch 65 minutes perched perched, vocal 1 person at nest
Lake
13
Table F. Prey identified at peregrine falcon aeries on the
Tanana River, Alaska, 1982.
Road Billie Little Gerstle Birch Robertson
Lake Creek R. Sawrni 11 Lake River
Horned Grebe 1 1
Podiceps auritus
Green-winged teal 1 1 1 1
8.D.Q.s__~a
Northern pintail 1 1
Anas acuta -
American wigeon 1
Anas americana
Bufflehead 1 1 1
BuceQhala albeola
American coot 1
Fulica americana
Lesser Yellowlegs 1 6 1
Tringa flavipes
Solitary sandpiper 1 1 1
Tringa solitaria
Spotted sandpiper 1 1
Actitis macularia
Upland sandpiper 1
Bartramia longicauda
Common snipe 2 4 1
Gallina~ gallinago
Red-necked phalarope 1
PhalaroQUS lobatus
Bonaparte•s gull 1 1
Larus philadelphia
Mew Gull 1 2
Larus canus
Three-toed woodpecker 1
Picoides tridactylus
14
Table 8 (Continued)
Road Billie Little Gerstle Birch Robertson
Lake Creek R. Sawmill Lake River
Northern flicker 1
Cola2tes auratus
Unid. swallow 1 1
Gray jay 1
Perisoreus canadensis
Catharus thrush 1 1 1 1
Catharus spp.
American robin 1 1
Turdus migratorius
Bohemian waxwing 1 1 1
Bombycilla garrulus
Yellow rumped warbler 1
Dendroica coronata
Snow bunting 1
Plectrophenax nivalis
Unid.passerine 1 1 1
TOTALS: 14 18 13 7 7
Bald Eagles
Bald eagles, Haliaeetus leucocephalus, were the most abundant
raptor breeding along the Tanana River. An aerial surv.ey in May
succeeded in identifying 18 nests between Tetlin Bridge and Fairbanks.
Sixteen of these nests were visited during peregrine surveys.
Twenty-seven young were counted during July surveys at 15 of these
nests (1.8 yg/successful nests). Young could not be counted at one
nest. Two nests were not accessible from boat surveys. Nest sites
are identified and mapped in Appendix A.
Bald eagle productivity was higher per starting pair than ever
recorded. Bald eagle distribution and productivity has been
summarized in Ritchie {1982). Table 9 compares productivity data
for a five year period.
Other Raptors
Ospreys, Pandion haliaetus, were present at two Tanana River
nests on May aerial surveys. Only one (George Lake Lodge) was still
active with an adult brooding tiny young on 11 July 1982. A site at
Sam Creek was deserted by late June. Ospreys were also recorded
hunting near the mouth of Shaw Creek, Round Lake, and Tanacross.
Merlins, Falco columbarius, were recorded on a spruce-poplar
island .5 miles south of the Round Lake peregrine aerie. A vocal and
aggressive male was observed during June and July surveys.
A harlan's hawk, Buteo jamaiceasis, nest near Cathedral Bluffs
was active in 1982 producing one young. All raptor nest
locations are identified on maps in Appendix A.
15
16
Table 9. Productivity of bald eagles, Tanana River, Alaska. 1978-82.
No. Large Young .,
Young/
No. No. (%) Active Nest No. Nests with
No. Active Successful (Successful
Year Young Nests Nests Nests) 1 yg 2 yg 3 yg
1978 21 15 12 (80) 1.40 (1.75) 4 7 1
1979 12 13 7 (54) • 92 ( 1. 71) 3 3 1
1980 1 12 14 8 (57) .86 (1.50) 5 2 1
1981 6 10 6 (60) .06 (1.0) 5 1 0
1982 27 15 15 (100) 1.80 ( 1.80) 7 4 4
1 Nest visits were opportunistic, and often occurring after young had
fledged; these data should be considered minimum figures for numbers
of young produced.
Sagavanirktok River
Peregrine Falcons
Six pairs of peregrines were recorded on June surveys on the
Sagavanirktok River. By late July only four pairs remained at
cliffs or nest sites. Peregrine observations are summarized in
Table 10.
Four young were produced at two aeries (2.0 yg/successful pair,
.67 yg/starting pair). A third aerie contained a ~ingle egg,
and the fourth scrape was empty. Nest scrape characteristics are
summarized in Table 12. Banding data are presented in Table 11.
Few prey items were located at the two Sagavanirktok aeries
with young. Feathers of Black-bellied plovers, Pluvialis aquatarola,
Lesser golden plover, Pluvialis dominica, and juvenile Lapland
longspurs, Calcarius lapponitus predominated in scrapes and at
perches. Wings of a Calidri spp. and Catharus spp. were the only
other species identified. Adult reactions to our banding activities
are summarized in Table 13.
The history of peregrine falcon site occupancy along the
Sagavanirktok has been complicated by the instability of nesting
substrates, differences in survey techniques,and timing of these
surveys. Table 14 summarizes productivity and occupancy for
peregrines along the Sagavanirktok River. Locations are discussed
in terms of general regions of the bluffs and where survey data is
available since 1979. A more detailed history of specific ledges
occurs in Roseneau et ll· (1981} and Ritchie (1982).
References have been made to as many as six nest sites on
Franklin Bluffs, five nest sites on Sagwon Bluffs,and one site on
the Slope Mountain area (Roseneau et ~-1981). Since at least
1970 and until this past season three to four pairs have occurred
along both bluff regions of the Sagavanirktok River. The increase
in 1982 over 1981 may in part be due to more intense search effort;
in 1981 only historical sites were resurveyed.
17
18
TablelO.. Peregrine falcons observed along the Sagavanirktok
River, Alaska, 1982.
Cliff
Location Date Adults Young Remarks
South 24 June Pair None observed
Sagwon July 82
East 24 June Pair
Sagwon 27 July Pair 1
South 25 June Pair None observed
Franklin Pair July 82
Bruce a 25 June Pair 1 egg
27 July Pair
Bruce b 25 June Pair
28 July Pair
Greta 25 June Pair
Creek 28 July Pair 3
19
Table 11. Peregrine falcon nestlings banded on the
Sagavanirktok River, Alaska, 1982.
Cliff Date banded Estimated Age Sex Band Number
(days)
East Sagwon 27 July 25 days female 987-62212
Greta Creek 28 July 15 days male 987-62213
28 July 15 days male 987-62214
28 July 15 days male 987-62215
Table 12. Characteristics of peregrine nest sites found along the Sagavanirktok River, Alaska, 1982.
Approximate
Cliff Locationl
East Sagwon
Bruce (a)
Bruce (b)
Nest Dimensions
Rough-legged hawk
nest .5 m X .5 m,
rock overhang.
Soil scrape, .6 m
X .6 m with
overhang of willow
base.
Soil scrape .2 m
X .2 m in willows.
Nest Location
Below Above
Exposure Cliff Cliff
sw 15 m 5 m
w 40 m 0
WSW 40 m 0
Prev.
Distance Use
to River Access 2 Cliff Type3 (yrs)
200 m 2 A N.D.
5 m 1 A 1981
400 m 1 A N.D.
Greta Creek Grassy ledge,
.5 m X .5 m
ENE 15 m 15 m 400 m+ 1 B 1980-81
1
2 Access: 1 = walk, 2 = aid of rope, 3 = climbing gear
3 ~·liff Type: A= steep cliffs, sheer walls; B =more gradual talus slope; C =low bluff or cliff.
·N.D. = no data
N
0
21
Table 13. Adult behavioral response to aerie visits on the
Sagavanirktok River, Alaska, 1982.
Cliff Duration of Male Female Remarks
Location Disturbance Response Response
East Sagwon 36 Min. vocal, vocal, 1 person at nest
soaring soaring
Bruce (a) 30 Min. perched, perched, 2 persons at nest
silent silent
Bruce (b) 40 Min. perched, perched, 2 persons at nest
soaring, flying,
voca 1 si 1 ent
Greta Creek 35 Min. vocal, voca 1, 2 persons at nest
flying flying,
(20 stoops) (20 stoops)
22
Table 14. Comparison of peregrine productivity for the
Sagavanirktok River, Alaska, 1979-1982.
Location 19791 19802 19813 1982 4
Sagwon -
South 4 eggs -pr/broken eggs pr
Mid
East pr/3 yg. pr/?yg. pr/3 yg. pr/1 yg.
Franklin Bluff
South pr/3 yg. pr
Bruce (a) -pr/1 egg
Bruce (b) pr/2 yg. pr
Greta Creek -pr/3 yg.
pr
North pr/4 yg.
Tota 1 Number
of Pairs 31 3 4 6
Lone Adults 0 0 0 0
Number of Pairs
With Young 31 2 3 2
Tota 1 Number of
Young Observed 9 2 8 4
Young Fledged
Per Total Pair 2.25 4 .67 2.0 .67
l;2oata from Roseneau et al. 198lo
3 Data from Ritchie 1982---
4 Figure estimated using four pairs, assuming pair occurred at
South Sagwon.
Rough-legged Hawks
Rough-legged hawks, Buteo lagopus, were present at nine cliff
sites along Sagwon and Franklin Bluffs. Few pairs appeared to·'.
reconstruct nests, however, or actively defend a nesting area. Only
one nest produced young (one young, East Sagwon). Numerous
mudslides have destroyed some nest sites present in 1980 and 1981.
Besides a later spring which affected other raptors also, low micro-
tine populations observed in the area may have influenced low pro-
ductivity.
Gyrfalcons
Gyrfalcons, Falco rusticolus, nested at two locations on Sagwon
Bluffs. Apparently only a single pair along middle Sagwon
produced young. A pair of very light birds was also noted at South
Franklin Bluffs 27 July. A single adult was present there in 1981
(Ritchie 1981). The status of a nesting attempt at the Ice Cut was
not determined, although adults were observed there as late as 26
July. A summary of gyrfalcon and other raptor observations is
included in Appendix A and Table 15.
23
24
Table 15. Raptors, except peregrine falcons, observed along
the Sagavanirktok River, Alaska, 1982.
Species Location 1 Date Adults Yg. Remarks
Rough-legged RLH 195 27 July 1
hawk RLH 197 24 June 1
RLH 199 24 June 2
1. 5 mi. NE 24 June 2
of RLH 199 (27 July) 1
GYR 2086 28 July 2
Near P210 27 July 2 1
p 212 28 July 1
RLH 217 28 July 2
p 218.1 28 July 1
Gyrfalcon 1/2 mi. 27 July 1 With ground
South squirrel prey
GYR 198
GYR 204 27 July 1 Young flying
RLH 209 24 June 2 Incubating
28 July 1
R 215b 28 July 2
p 218.1 28 July 1 Flying,
immature
Golden Near P212 28 July 1 Immature
Eagle plumage
Near RLH 28 July 1 Immature
218 plumage
!Numbering system follows Roseneau and Bente (1981).
LITERATURE CITED
Ambrose, R.E. 1980. Results of 1980 peregrine falcon surveys
on the upper Yukon, Charley, and Colville rivers, Alaska.
U.S. Fish and Wildlife Service. Office of Endangered Species,
Anchorage. 20 p.
Haugh, J. 1976. Tanana River of Alaska. Pp. 254-256 in Fyfe, R.,
S. Temple, and T. Cade (eds). The 1975 North American
Peregrine Falcon Survey. Can. Field-Naturalist 90(3):228-273.
Ritchie, R. 1981. P~regrine falcon surveys along the Northwest
Alaskan Pipelin~ Route, Alaska, 1981. Final Report, prepared
for Northwest Alaskan Pipeline Company. 26 p.
Ritchie, R. 1982. Investigations of Bald Eagles, Tanana River,
Alaska, 1977-80. Pp. 55-67 in Ladd, W. and P. Schempf (eds).
Proceedings of a Symposium and Workshop, Raptor Management and
Biology in Alaska and Western Canada. U.S. Fish and Wildlife
Service, Anchorage, Alaska. 335 p.
Roseneau, D. and P. Bente. 1981. Peregrine falcon surveys in
selected areas of nesting habitat along the Northwest Alaskan
Pipeline Company Gas Pipeline route in Alaska, 1980. Unpubl.
Final Report to Northwest Alaskan Pipeline Company.
Roseneau, D.G., C.E. Tull and R.W. Nelson. 1981. Protection
strategies for peregrine falcons and other raptors along the
proposed Northwest Alaskan Gas Pipeline route. Unpubl. Final
Report to Northwest Alaskan Pipeline Company.
Roseneau, D.G., P.J. Bente, and A.M. Springer. 1980. Numbers
and status of peregrine falcons on the middle Yukon River,
lower Yukon River, and in selected areas of the Arctic Wildlife
Range, Alaska. 1980. Unpubl. Final Report to U.S. Fish
and WildlifeService. Endangered Species Office, Anchorage. 54 p.
Roseneau, D.G., H. Reynolds III, and C.M. White. 1976. Pp. 243-245
in Fyfe, R., S. Tempie, and T. Cade (eds). The 1975 North
American Peregrine Falcon Survey. Can. Field-Naturalist
90(3):228-273.
25