HomeMy WebLinkAboutAPA3180CHAPTER I
DISTURBANCE EFFECTS OF AIRCRAFT ON
WATERFOWL ON NORTH SLOPE LAKES,
JUNE, 1972
R. SCHWEINSBURG
TABLE OF CONTENTS
INTRODUCTION ........................................... .
SITE DESCRIPTION •.......................................
METHODS
RESULTS
PAGE
1
3
7
10
DISCUSSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
SUMMARY •••..••..•••••.•.•••••••••••••••••••• • • • • • • • · • • • • 45
REFERENCES CITED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
TABLES
1
2
3
4
5
Bird Populations on Small Control and Experimental
Lakes, North Slope, Y.T.; 1972 ..................... .
Average Number of Birds Present Per Day (by species)
as a Percentage of the Original Population, Small
Experimental Lake, Y.T.; 1972 ...................... .
Average Number of Birds Present Per Day (by species)
as a Percentage of the Original Population, Small
Control Lake, Y .T.; 1972 ........................... .
Average Number of Birds Present Per Day (by species)
as a Percentage of the Original Population, Large
Experimental Lake, Y.T.; 1972 ...................... .
Average Number of Birds Present Per Day (by species)
as a Percentage of the Original Population, Large
Control Lake, Y.T.; 1972 ........................... .
FIGURES
1 Photograph of North Slope thaw lake .......... Follows
2 Map of study area showing the position of each lake
studied ...................................... Follows
ii
30
34
35
37
38
48
2
TABLE OF CONTENTS continued:
FIGURES continued:
3 Map of part of the study area showing the large and
small experimental lakes and the Babbage River
PAGE
camp . . . . . . . . . . . . . . . . . . . . . . . . . . • . . . . . . . . . . . • • . . . . . . . . • 2
4 Map of part of the study area showing the small
con tro 1 lake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . 5
5 Map of part of the study area showing the intermediate
experimental lake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
6 Map of part of the study area showing the large
con tro 1 lake ........................................ .
7 A float plane created disturbance by taxiing .. Follows
8 Hourly population counts on the first day
(undisturbed} at the small experimental lake, 20 June,
1972 ................................................ .
9 Hourly population counts on the second day (disturbed}
at the small experimental lake, 22 June, 1972 ........
10 Hourly population counts on the third day (disturbed}
at the small experimental lake, 23 June, 1972 ........
11 Hourly population counts on the fourth day (disturbed}
at the small experimental lake, 24 June, 1972 ........
12 Hourly population counts on the fifth day (disturbed}
at the small experimental lake, 25 June, 1972 . . . . . . . .
13 Hourly population counts on the first day at the small
control lake, 20 June, 1972 ..........................
14 Hourly population counts on the second day at the
small control lake, 22 June, 1972 ................... .
15 Hourly population counts on the third day at the small
control lake, 24 June, 1972 ......................••..
16 Hourly population counts on the first day
(undisturbed} at the large experimental lake, 20 June,
19 7 2 ................................................ .
17 Hourly population counts on the second day (disturbed}
at the large experimental lake, 22 June, 1972 ....•...
iii
8
48
11
12
13
15
16
17
19
20
21
22
TABLE OF CONTENTS continued:
FIGURES continued:
18 Hourly population counts on the third day (disturbed)
at the large experimental lake, 23 June, 1972 ...... .
19 Hourly population counts on the fourth day
(disturbed) at the large experimental lake, 24 June,
19 7 2 ............................................... .
20 Hourly population counts on the fifth day
(undisturbed) at the large experimental lake, 25 June
PAGE
24
25
1972 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
21 Hourly population counts on the first and second days
at the large control lake, 20 and 22 June, 1972 .....
22 Hourly population counts on the first and second days
(both disturbed) at the intermediate experimental
lake, 24 and 25 June, 1972 ....•.....................
23 Number of birds present on small experimental lake
expressed as maximum number present per day and the
average number per day ............................. .
24 Photograph of oldsquaw ducks .•.........•..... Follows
25 Percentage of oldsquaw population involved in
sleeping activity at the small experimental lake,
27
28
31
48
20-25 June, 1972 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
26 Percentage of scoters spp. involved in sleeping
activity at the small experimental lake, 20-25 June,
1972 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
27 Percentage of scaup spp. involved in feeding activity
at the small experimental lake, 20-25 June, 1972
28 Photograph of marsh affording protection for
waterfowl ................................... -Follows
APPENDIX
''A'' Photos -.......................... . . . . . . . . .. . . ..... .:. ............ .
iv
43
48
48
INTRODUCTION
This study was designed to test the effects of
float-equipped aircraft on populations of waterfowl
occupying the small ponds and thaw lakes of the North
Slope during the breeding season (Figure 1). Except for
the extensive channel systems of the larger river deltas,
these small bodies of water are the only available
habitat for many species and are important as breeding
and molting areas.
With the inception of exploration and produc-
tion activities associated with mining of the northern
hydrocarbon fields, floatplane traffic has greatly
increased within a relatively short time. The construc-
tion of a pipeline will create an even greater demand
for small aircraft to supply the multitude of associated
activities necessarily situated near bodies of water.
It had been empirically obvious that small
planes disturbed waterfowl when landing on lakes, but it
was not known to what extent. The objectives of this
study were: (1) to determine the effect floatplane
traffic has on the total number and behavior of birds;
(2) to determine if there was any species variability
in the birds' reaction to aircraft; (3) to determine
if there were differences in effect relative to lake
size; (4) to determine if there was any accommodation
by the birds to the aircraft.
- 1 -
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SITE DESCRIPTION
The 1972 season was quite late, and many of the
North Slope lakes were still frozen at the start of the
study (20 June), thus greatly narrowing the choice of
study sites. There were enough open lakes to do the
study, but it is not known if the concentrations of birds
varied from what would be expected in a more typical
year. Many open lakes had too few ducks to provide a
significant sample size, and some had no ducks at all.
We tried to select experimental and control lakes of
similar size and shape with adequate populations of
waterfowl. These lakes fell generally into three classes -
small, intermediate and large. Each lake was obviously
unique due to variations in topography, vegetation, water
depth, age and shape. Also, each lake differed in the
species composition of birds found on or near them. The
lakes studied in this experiment are shown in Figure 2.
A number of these lakes were surveyed later in the season
as part of a study of waterfowl populations and product-
ivity on North Slope lakes (Gollop and Davis 1974), and the
number assigned to the lakes in that study is ?resented in
brackets followinq the name given in this study.
SMALL EXPERIMENTAL LAKE (Lake #11 -Studies of Bird
Populations and Productivity
of Lakes on Yukon North Slope,
Gollop and Davis 1974)
This lake was located approximately 2 1/2 miles
ENE of the Babbage River camp (Figure 3). It was hook-
- 3 -
shaped with the wider hook end pointing NW. The hook bent
west and then back NW paralleling the shank for approx-
imately half its length. The lake was narrow, being less
than 0.2 miles wide and approximately 1.3 miles long with
an area of 0.08 square miles.
The hook end of the lake was shallow and choked
with emergent vegetation which graded into deeper water
at the shank end. The banks were lined with low willow
and sedge.
SMALL CONTROL LAKE (Not surveyed on Brood Survey)
The small control lake was approximately three
miles SE of Sabine Point (Figure 4). This lake was
almost touching another which was largely frozen at the
time of the study.
It was generally situated in a low, flat, sedge
marsh, except to the north where it was bounded by a
higher ridge which separated it from the ocean. Area
of the lake was 0.06 square miles.
INTERMEDIATE EXPERIMENTAL LAKE (Lake #20)
There were few intermediate sized lakes open.
The one used was approximately three miles SE of the
mouth of the westernmost channel of the Babbage River at
Phillips Bay (Figure 5). The lake was roughly triangular
in shape, with 1/2 mile sides and a total area of 0.10
square miles. The lake was surrounded by low hills. It
had the lowest waterfowl population of the lakes studied.
- 4 -
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CONTOUR INTERVAL
93 94
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98
MAP OF
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13J030'
PART OF THE STUDY AREA
SHOWING
THE SMALL CONTROL LAKE
64
63
62
61
60
59
58
76570001
69°00'
FIGURE 4
138°30' 25'
02 03 04 05 06
599000E 600 01
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7684000N
83
82
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80
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74
73
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- 6 -
LARGE EXPERIMENTAL LAKE (Lake #12)
This lake was located 4 miles SSE of the Babbage
River camp (Figure 3). It was roughly triangular in shape
with approximately 1 1/4 mile sides and a total area of
0.63 square miles. A large marsh area occurred on the
southwest corner. The east bank sloped steeply down from
rolling ridges and was covered with willow. A point of
land projected into the lake from the northwest, separa-
ting this side into two bays.
LARGE CONTROL LAKE (Lake #6)
Peat Lake, located approximately 5 miles WSW of
Shingle Point, was used as the large control lake
(Figure 6).
It was generally surrounded by low sedge marsh
except on the northern edge which was bounded by low
rolling tundra ridges. The area of the lake was 0.92
square miles.
METHODS
Baseline information on species composition,
numbers and behavior was gathered the first day on the
large and small experimental and control lakes. Single
observers were brought to each lake in a Bell 206
helicopter (without flying over the lake). They were
picked up the same way at the end of the day.
The observers were similarly placed on the
- 7 -
69°00'
7656000 N
55
54
53
52
51
50
49
48
55'47
46
45
13JC15'
'. ~
' .
401 OOOE 25'
02 03 04 05 06
20'
07 08
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MAP OF .
PART OF THE STUDY AREA
SHOWING
THE LARGE CONTROL LAKE
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CONTOUR INTERVAL!()() FEET
£QUIDISTANCE DES COURBES 100 PIEOS
- 8 -
ensuing days,and the experimental lakes were disturbed
by a Cessna 185 at hourly intervals, starting one hour
after the observers were in place and ending one hour
before they were picked up. The plane taxied approximat-
ely five minutes between landing and takeoff (Figure 7).
The numbers and reactions of the birds on the lake were
recorded by the observers.
The small experimental lake was disturbed for
four days after the baseline day. The large experimental
lake was disturbed for three days after the baseline
day, with the fourth day undisturbed. A final, undisturbed
day was not carried out on the small lake because of bad
weather.
The intermediate sized lake was disturbed two
days in succession using the first hour of each day as a
baseline. This part of the study was done largely as an
afterthought and was unsatisfactory in that there were
not enough birds present to give a trend.
There was little change in numbers and behavior
of the birds on the control lakes (with exceptions noted) and
so they were not observed for as many days as the exper-
imental lakes; the small control was observed three days
and the large control only two. For this reason and
because no two lakes were alike in species composition,
it was decided that the baseline data gathered at each
lake was the best control for that lake. The control
lakes were nevertheless important, yielding data on bird
behavior for undisturbed conditions, though these data
- 9 -
could not be directly compared with those of the
experimental lakes.
RESULTS
POPULATIONS
Small experimental lake
On the first (baseline) day, there was a
maximum count of 45 birds during the first five hours.
This count rose to 61, when 16 birds flew into the lake
between the 5th and 6th hour, and remained at this new
level for the rest of the day (Figure 8).
There were 54 birds at the beginning of
the second day (Figure 9) which dropped to 51 just before
the first disturbance. After the first landing, the
numbers dropped dramatically to 16 birds which was the
lowest number recorded during the ensuing hourly distur-
bances; the highest was 32. There were 29
birds on the lake one hour after the last (6th) distur-
bance of the day.
Forty birds were on the lake at the beginn-
ing of the third day (Figure 10), and just before the
first disturbance. The number then fell to 27, then 11,
the lowest during the entire study. It rose to 16 just
before the 4th disturbance,but only 13 were left one hour
after the last disturbance. This was the lowest final
count for the five-day study.
-10 -
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70
60
50
40
30
20
10
FIGURE 8-HOURLY POPULATION COUNTS ON THE FIRST DAY
(UNDISTURBED) AT THE SMALL EXPERIMENTAL LAKE,
JUNE 20 I 1972.
OQ I 2 3 4 5 6 7 8
HOUR
z
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60
50
40
I
30 r
20 L.
10
FIGURE 9-HOURLY POPULATION COUNTS ON THE SECOND DAY
(DISTURBED) AT THE SMALL EXPERIMENTAL LAKE,
JuNE 2 2 I 19 72.
4TH DIST.
l \ -
3RD DIST. \ ~ \
5TH DIST.
\ I ./ " ~
0+--------------L-------------L------------~------------~------------~~------------L-------------~------------J 0 I 2 3 4 5 6 1 8
HOURS
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f-1 -
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V1
60
50
I
I
40
30
20
10
FIGURE 10-HOURLY POPULATION COUNTS ON THE THIRD DAY
(DISTURBED) AT THE SMALL EXPERIMENTAL LAKE 1
JUNE 23 I 1972.
1ST DIST.
!
_____-\
4TH OIST.
l
3RD DIST. 5TH DIST
~
0 +-----------~----------~--------~----------~----------~----------L---------~----------~ 0 I 2 3 4 5 6 7 8
HOURS
At the beginning of the fourth day (Figure 11),
25 birds were present. This number rose to 32, then dro-
pped to 14 after the first disturbance, rising to 20 after
the second, where it remained the rest of the day.
Nineteen were present one hour after the last disturbance.
Clearly, the population was beginning to stabilize
during the disturbance periods.
Population stabilization was also evident on
the fifth (last) day of the study (Figure 12). Again a
few birds returned during the night, some leaving after
the first disturbance with the remainder, between 15
and 22 birds, relatively constant after this time.
The number of birds present at each hourly count
on the fourth and fifth days were averaged and compared
with the average total number from the first, undisturbed
day. Only 40% of the total present on the first day
remained on the fourth and fifth day.
Small control lake
On the first day, the small control lake
was similar to the small experimental lake in that the
numbers of birds did not fluctuate greatly for the first
five hours (Figure 13). The total numbers dropped
drastically when a golden eagle passed low over the
lake three times during the next two hours. The total
dropped from 75 or 80 birds to 32, then to 18, on the
final count of the day. Totals recorded never reached
80 after this day. It is not known if the eagle hunted
-14 -
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60
50
40
I
30
I .,
I 20
10
FIGURE 11-HOURLY POPULATION COUNTS ON THE FOURTH DAY
(DISTURBED) AT THE SMALL EXPERIMENTAL LAKE,
JUNE 24,1972.
1ST DIST
l
\ 3RD DIST. 4TH DIST. 5TH DIST.
! l l
\
oto------------~~~------------2~------------3L-------------~4------------~5------------~s~----------~7
HOURS
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60
50
40
30
20
10
FIGURE 12-HOURLY POPULATION COUNTS ON THE FIFTH DAY
(DISTURBED) AT THE SMALL EXPERIMENTAL LAKE,
JUNE 25,1972.
1ST DIST.
-----!
3RO DIST.
l 4TH DIST.
l
2ND DIST.
l 5TH DIST.
l
0+-----------L---------~~--------~----------~----------L---------~~--------~ 0 I 2 3 4 5 6 7
HOURS
z
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aJ
fTI
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0
I-' ,
'-l
aJ -::u
0
Vl
80
70
60
50
40
30
20
FIGURE 13-HOURLY POPULATION COUNTS ON
THE FIRST DAY AT THE SMALL
CONTROL LAKE, JUNE 20,1972.
I0+-----------~------------7-----------~------------J-----------~------------~----------~----------~ Q I 2 3 4 5 6 7 8
HOUR
the lake in the observer's absence.
Beginning day two, 31 birds were recorded {Figure
14). This number varied between 23 and 29 for the next
5 hours. Forty-five birds were counted in the 6th hour
dropping to 42 at the end of the study day.
The third day had less fluctuation {Figure 15}.
Numbers ranged between 20 and 24 for the first six hours
rising to 31 in the last hour.
Totals remained relatively constant on any
given day, apart from the eagle disturbance. This was
similar to the first undisturbed day at the small
experimental lake. The increase of birds at the end of
the first day on the small experimental lake,and second
and third days at the small control lake,is of interest
and might be attributed to a normal movement of birds
to smaller lakes at this time each day.
Large experimental lake
Limited visibility hampered observers and
contributed to the vagueness of results from the large
experimental lake.
Populations of the first {undisturbed) day
fluctuated between 51 and 76 birds {Figure 16). The
second day showed a dramatic decline from 66 to 38 birds
after the first disturbance, with the number rising
during subsequent disturbances to 53 after the fourth,
then down to 27 on the fifth. There were 43 birds present
on the final count of the day {Figure 17). A steady
decline from 70 to 26 birds was recorded on the third
-18 -
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1-' 0 \.0 .,
ID -
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60
50
40
30
20
10
FIGURE 14-HOURLY
AT THE
POPULATION COUNTS ON THE SECOND DAY
SMALL CONTROL LAKE, JUNE 22, 1972.
0+----------L--------~~--------i----------L--------~~--------~--------~--------~ 5 6 7 8
0 2 3 4
HOURS
z c
s::::
tD
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:;o
0
N .,
0
tD -:;o
0
Vl
60
50
40
30
20
10
FIGURE 15-HOURLY POPULATION COUNTS ON THE THIRD DAY
AT THE SMALL CONTROL LAKE, JUNE 24, 1972.
0+-------------~------------L-----------~-------------L------------~------------~----------~ 0 I 2 3 4 5 6 7
HOURS
F I G U R E 16-H 0 U R L Y P 0 PU LA T I 0 N C 0 UN T S ON THE F I R S T DAY
(UNDISTURBED} AT THE LARGE EXPERIMENTAL LAKE,
JUNE 20,1972.
80
70
z
c
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!Il 60 ,.,
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N 0
I-' -n
!Il -::u
0 50 Ul
40
30
0
2~------------L-----------~------------L------------L------------L-----------~----------~~----------~ 2 3 4 5 6 7 8
HOUR
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III
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N III -
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0
(/)
70
60
50
40
30
20
FIGURE 17-HOURLY POPULATION COUNTS ON THE SECOND DAY
(DISTURBED) AT THE LARGE EXPERIMENTAL LAKE
JUNE 22 I 1972.
1ST DIST.
~
10+-------------~~------------~------------~--------------~------------~--------------~-------------L------------~ 0 I 2 3 4 5 6 7 8
HOUR
day (Figure 18).
The fourth day deviated from the norm (a decline,
or levelling off in number after a decline), with totals
rising steadily from 33 to 65 birds (Figure 19).
The fifth day was undisturbed, showing an initial
decline from 60 to 36 birds (Figure 20). A relatively
stable population of from 34 to 41 birds was recorded
for the remainder of the day as could be expected in
undisturbed conditions. Variation in counts on the last
two days was partly a result of birds swimming into and
out of a bay concealed from the observation point rather
than birds leaving the lake.
Large control lake
Counts remained relatively constant on
both days but populations were not large enough to give
a useful overall picture (Figure 21).
Intermediate experimental lake
The intermediate lake was disturbed on
the two days it was observed. The first hour each day
was used as the control. There was no detectable
difference in numbers of birds before or after distur-
bance, nor between the first and second day of disturbance
(Figure 22).
CALCULATIONS
Immediate effects of aircraft disturbance
To test the immediate effects of aircraft
-23 -
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3::
N ID
+:>-,
::0
0
"T1
~
::0
0
(/)
70
60
50
40
30
20
FIGURE 18-HOURLY POPULATION COUNTS ON THE THIRD DAY
(DISTURBED) AT THE LARGE EXPERIMENTAL LAKE,
JUNE 23, 1972.
2ND DIST. 3RD DIST. ~ ~
10+-------------~--------------~------------~--------------~------------~--------------~------------..J
0 I 2 3 4 5 6 7
HOUR
z
N c
U1 s:::
ID
fTI
;:o
0 ..,
ID
;:o
0
Vl
60
50
I
40
30
20
FIGURE 19-HOURLY POPULATION COUNTS ON THE FOURTH DAY
(DISTURBED) AT THE LARGE EXPERIMENTAL LAKE,
JUNE 24, 1972.
3RD DIST. 4TH DIST.
! !
21110 DIST.
!
1ST DIST.
!
10+---------------~------------~~-------------L---------------L---------------L--------------~------------~
0 I 2 3 4 5 6 7
HOUR
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~
m ,
N :::0
0'1
0 ...,
m -:::0
0
Vl
60
50
40
30
20
10
FIGURE 20-HOURLY POPULATION COUNTS ON THE FIFTH DAY
(UNDISTURBED) AT THE LARGE EXPERIMENTAL LAKE,
JUNE 25, 1972.
0+-----------~----------~------------L-----------~-----------L----------~----------~ 0 I 2 3 4 5 6 7
HOURS
z c s::
ID
N rr1
-.....] ::0
Vl
0 ..,
ID -::0
0
Vl
FIGURE 21-HOURLY POPULATION COUNTS ON THE FIRST a
SECOND DAYS AT THE LARGE CONTROL LAKE,
JUNE 20822,1972.
50-1ST DAY -JUNE 20,1972
----2ND DAY-JUNE 22,1972
40
30
20
/ /----..
/
/
_.-" ---_,..----
10 .....-~ ........ //
' / .............
0+-----------L----------L __________ j_ __________ ~----------L---------~----------J_--------~
0 I 2 3 4 5 6 7 8
HOURS
N z 00 c
~
Ill
ITI
::u
0 ...,
Ill -::u
0
Ul
FIGURE 22-HOURLY POPULATION COUNTS ON THE FIRST a
SECOND DAYS (BOTH DISTURBED) AT THE
INTERMEDIATE EXPERIMENTAL LAKE, JUNE 24 a 25,1972.
50.-1ST DAY -JUNE 24,1972
----2ND DAY-JUNE 25,1972
40
30
3RD DIST .
20
l 1ST DIST.
~
2ND DIST.
!
4TH DIST.
~ ---------..._ __ _ __ .... ------
5TH DIST.
10
0+------------L----------~----------~~----------~-----------L-----------i----------~ 0 I 2 3 4 5 6 7
HOURS
disturbance on waterfowl it was necessary to compare con-
trol lakes with disturbed lakes. This was done by
comparing the number of birds present on the lake during
the count (2nd reading of day) immediately prior to the
first aircraft disturbance of the day and the count
immediately prior to the second disturbance. The control
consists of 3 days on the small control lake and the first
day on the small experimental lake (no disturbance on the
first day). The experimental data were derived from the
4 days of disturbance on the small experimental lake
(Table 1) .
It is ap~arent from Table 1 that aircraft
disturbance si9ni ficantly ren.uce0 the number of waterfowl
using the experimental lakes (U = 0.0; P = 0.014).
Cumulative effects of aircraft disturbance
The cumulative effects of aircraft distur-
bance on waterfowl are examined in Figure 23. It can be
seen that the number of waterfowl decreased as distur-
bances continued (r = -1.0; Kendall's Correlation
Coefficient). In terms of the average number of birds
using the lake throughout the day there appears to be
a levelling-off at about 20 birds on days 3, 4 and 5.
The sample size was too small to indicate the signifi-
cance of the decrease in average numbers using the lake.
It is safe to conclude that,as the number of
aircraft disturbances increase, the number of waterfowl
using a lake decreases at least to a certain level.
This minimum level may be a function of what the water-
-29 -
TABLE 1. BIRD POPULATIONS ON SMALL CONTROL AND
EXPERIMENTAL LAKES, NORTH SLOPE, Y .T .; 1972 *
Small Experimental Lake
Number of birds present on --------------
2nd reading 3rd reading Ratio(~~)
51 16 0.31
43 27 0.63
32 14 0.44
27 16 0.59
Smal I Control Lake
2nd reading 3rd reading
45 45
80 80
23 26
24 23
Ratio (3rd) TnC
1.00
1.00
1.13
0.96
Mann-Whitney U-test to compare ratios on experimental versus control lakes:
U = 16; P < 0.05 (U is 1-tailed) .
* From counts immediately prior to the first (2nd reading) and second (3rd
reading) disturbances of the day or equivalent time periods on control
lakes.
-30 -
Vol z
f--1 c s:
tD
1"11
;o
FIGURE 23-NUMBER OF BIRDS PRESENT ON SMALL EXPERIMENTAL
LAKE EXPRESSED AS MAXIMUM NUMBER PRESENT PER
DAY S THE AVERAGE NUMBER PER DAY.
X -MAXIMUM NUMBER OF BIRDS PRESENT PER DAY
ITOTAL FOR DAY 2 OCCURRED BEFORE START
70 OF DISTURBANCE).
o -AVERAGE N UMBER OF BIRDS PRESENT PER DAY.
60
50
0 /coRRELATION IS r=I.O.
40 r \ KENDALL'S COEFFICIENT OF RANK
~ /
tD /
i /
0 /
(/) 30
20
10
0~--------~~--------~----------~----------~--------~ 0 I 2 3 4 5
DAY OF EXPERIMENT
(DISTURBANCE BEGAN ON DAY 2)
-KENDALL'S COEFFICIENT OF RANK
CORRELATION IS r: 0.6.
fowl are using the lakes for. If a duck has a nest or
young on the lake then it is less likely to be permanently
scared from the lake. Similarly, if the duck is molting
it will be flightless and incapable of leaving the lake.
The effect of aircraft disturbance on these birds may not
show up until the next year when they might not use the
lake for nesting or molting.
SPECIES COMPOSITION
The waterfowl frequenting the North Slope of
the Yukon Territory have not been thoroughly studied to
date. This doubtless is a contributing factor to the
omission of this area from breeding ranges of several
species of ducks by Godfrey (1966}. Moreover, some
species (eg. pintail} were known to breed east and west
of the Yukon North Slope (Anderson 1913, Kessel and Cade
1958}. More recent records for nearby areas (West and
White 1966, Gavin 1970, Hall 1972, Schmidt 1973} indi-
cate the possible occurrence of several species as yet
unrecorded for the Yukon tundra. Thus, the recording
of species composition during the current research was
important not only in terms of the experiment, but also
as a matter of scientific record.
Small experimental lake
Eleven (possibly thirteen} species of birds
were observed on the small experimental lake: arctic
loon, red-throated loon, whistling swan, pintail,
American wigeon, northern shoveler, canvasback, scaup
-32 -
spp., oldsquaw (Figure 24), scoter spp., and red-breasted
merganser. Scaup (possibly greater and lesser} and
seaters (both white-winged and surf} were present but
were not separated to species because of the difficulty
in identifying them (especially females} under varying
light and weather conditions.
The five main varieties in descending order of
abundance were: scaup spp., scoter spp., oldsquaw, loon
spp., and American wigeon. Table 2 compares the daily
mean in number of each species. The first (baseline}
day's average is considered as 100% for the lake. Scaup
(spp.) had 37% of the first day's mean remaining on the
5th day; scoter (spp.} 46%; oldsquaw 25%; loon (spp.)
33%; and American wigeon 33%.
Other species occurred rarely and not in
sufficient numbers to observe a trend.
Small control lake
The species found on this lake were arctic
loon, whistling swan, Canada goose, pintail, scaup (spp.),
oldsquaw, and scoter (spp.). Only pintails and oldsquaw
were present in sufficient number to set a meaningful
trend.
The above-mentioned species were disturbed by
an eagle at the end of the first day which was reflected
in a lower but stable count in the next two days (Table 3}.
Thirty-six per cent of the original population of pintail
and oldsquaw were present on the second and third day
of the study.
-33 -
TABLE 2. AVERAGE NUMBER OF BIRDS PRESENT PER DAY (BY SPECIES) AS A PERCENTAGE OF THE ORIGINAL
POPULATION, SMALL EXPERIMENTAL LAKE, Y.T .; 1972
1st Day 2nd Day 3rd Day 4th Day 5th Day
(Undisturbed) (Disturbed) (Disturbed) (Disturbed) (Disturbed)
Average Average Average Average Average
Species % Number % Number % Number % Number % Number
Present Present Present Present Present -
Loon (spp.) 100 6 83 5 17 1 67 4 33 2
Swan --100 .4 250 1 250 1 250
I
c.M Pintail 100 ~ .4 --100 .4 250 1 100 .4
I
Widgeon 100 6 33 2 17 1 33 2 33 2
Shoveler ------100 • 1
Canvasback 100 1 100 1 30 .3
Scaup (spp.) 100 19 42 8 37 7 37 7 37 7
Oldsquaw 100 8 75 6 75 6 25 2 25 2
Scoter (spp.) 100 13 69 9 38 5 31 4 46 6
Red-breasted Merganser --100 .3 233 .7 33 • 1
53 32 22 21 20
TABLE 3. AVERAGE NUMBER OF BIRDS PRESENT PER DAY (BY SPECIES)
AS A PERCENTAGE OF THE ORIGINAL POPULATION, SMALL
CONTROL LAKE, Y .T .; 1972
Species
Arctic Loon
Swan
Canada Goose
Pintail
Scaup
Oldsquaw
Scoter
1st Day
Average
% Number
Present
100 3
100
100
100 14
100 2
100 42
100
64
-35 -
2nd Day
Average
% Number
Present
100 3
36 5
50 1
40 16
25
3rd Day
Average
% Number
Present
67 2
36 5
100 2
36 15
24
Large experimental lake
Seven {possibly nine) species of birds
were recorded on the large experimental lake: arctic
loon, whistling swan, pintail, scaup {spp.), oldsquaw,
scoter {spp.) and red-breasted merganser. Oldsquaw,
scaup (spp.), seaters (spp.) and arctic loons were the
most numerous.
The average number of each species present on
the first {baseline) day was considered 100% for the
lake. Table 4 compares the daily mean, in total
numbers of each species with the baseline day's average.
The main difference between the large and small lake
was that the last day on the large lake was undisturbed.
Results are similar to those of the small lake.
Bird numbers, except for seaters, declined as the study
progressed. On the last day, scaup decreased to 20%,
oldsquaw to 63% and arctic loons to 25%. It is
interesting that this trend continued on the last day
although there was no airplane disturbance, other than
the helicopter used to place the observer.
Large control lake
Only three species were on the large
control lake: arctic loon, pintail, and oldsquaw. These
decreased by 50%, 25% and 61% respectively from the first
to second day (Table 5).
Intermediate experimental lake
Six (possibly eight) species were observed
on the intermediate-sized lake: arctic loon, whistling
-36 -
TABLE 4. AVERAGE NUMBER OF BIRDS PRESENT PER DAY (BY SPECIES) AS A PERCENTAGE OF THE ORIGINAL
POPULATION, LARGE EXPERIMENTAL LAKE, Y .T .; 1972
1st Day 2nd Day 3rd Day 4th Day 5th Day
(Undisturbed) (Disturbed) (Disturbed) (Disturbed) (Undisturbed)
Average Average Average Average Average
Species % Number % Number % Number % Number % Number
Present Present Present Present Present
Arctic Loon 100 4 25 1 100 4 50 2 25
Swan 100 1 100 1 100
VI
'-1
Pintail 100
Scaup spp. 100 5 20 1 20 1 40 2 20
Oldsquaw 100 48 73 35 90 43 88 42 63 30
Scoter sp. 100 4 200 8 100 4 125 5 225 9
Red -breasted Merganser --100 11
Unidentified 100 5 40 2 40 2
YAiaterfowl
68 59 55 51 41
TABLE 5. AVERAGE NUMBER OF BIRDS PRESENT PER DAY (BY SPECIES)
AS A PERCENTAGE OF THE ORIGINAL POPULATION, LARGE
CONTROL LAKE, Y .T .; 1972
1st Day
Average
Species % Number
Present
Arctic Loon 100 2
Pintail 100 .4
Oldsquaw 100 18
20
-38 -
%
50
25
61
2nd Day
Average
Number
Present
• 1
11
12
swan, pintail, scaup spp., oldsquaw, and scoter spp.
Oldsquaw were the only species present in any
numbers and these showed a slight increase over the two
day study.
BEHAVIOR
Quantitative behavioral data were gathered on
two major activities -sleeping and feeding. It was hoped
that by comparing the time the birds spent engaged in
these activities on undisturbed days with the time spent
on disturbed days, we could discover whether the normal
behavioral activities of the birds were affected by the
aircraft. The undisturbed day on each of the experi-
mental lakes was to act as a measure of the normal
behavior. Later analysis of the data indicated that the
single undisturbed day did not cover a long enough period
to encompass a sufficient number of normal conditions
which might affect behavior patterns (e.g. weather). The
undisturbed day on an experimental lake was probably
the most valid "control" for that lake since behavioral
patterns on selected "control" lakes probably differed
from those of experimental lakes due,in part,to the
unique features of each lake and to the different species
composition on the different lakes. The lack of suitable
control data,then, makes it unrealistic to attempt to
compare behavioral data from undisturbed days with those
of disturbed days.
Bearing in mind these limitations of the data
obtained, several examples of possible disruptions in
-39 -
regular behavioral patterns are presented in Figures
25, 26 and 27. Our comments must perforce be considered
highly tentative,but it seemed that in many cases the
feeding and sleeping activities of the birds became
extremely irregular. Generally, the same amount of
time was allotted to each activity during disturbed and
undisturbed days, but on disturbed days the pattern
seemed far more erratic.
DISCUSSION
The most conclusive data in this study came from
the small experimental lake. The population of waterfowl
on this lake was reduced by 60% during the four days of
disturbance. A degree of accommodation was reached
during the last two days of this study, but not until
significant population disruption had already occurred.
There was also a general population decline on
the large experimental lake but the reduction was not as
marked as on the smaller lake. There were a number of
problems involved with making consistent counts on the
large lakes. The position of floating ice on the lake,
reflection of the sun on the water, fogging of the
spotting scope from the rain which fell more or less
consistently through the study, and the presence of a number
of "blind spots" on the lake where waterfowl could go and
not be seen during the counts undoubtedly contributed
to the inconsistencies on the large lake. It remains to
be tested whether or not large lakes will accommodate a
-40 -
~ .......
NUMBER BIROS
0/o
SLEEPING
1001
95~
9+
::~r
75
70
65r
60
25
20
15
10
!5
0
FIGURE 25-PERCENTAGE OF OLD SQUAW POPULATION INVOLVED IN
SLEEPING ACTIVITY AT THE SMALL EXPERIMENTAL LAKE
JUNE 20-JUNE 25, 1972.
2ND. DAY 4TH DAY I ST DAY
55!547666 8 9 5 4 4 6 4 6
3 RD DAY
6666855 2224 221
I
11;1
lll!lil I I _j
""'"'"'
TI I
l!l.
·:·:·: ::::::.
'!1
::::::: ·.·.·.·
·····•· ~~m~~ ······· :::::::
!i!i!i!
.::::::
lilili I~~ I ·:::::: •·•··· ······ :::::: ~~~~~-w ¥ :::::: ......
;¥·:
I
1@: II l~ .. ~~f ~~~~ ·····• ·=~=~ ==~=~ ••····
M ~~~~~ :!~lll~ :::::: I
1''111
~~m~ mt I fJ I
II ~~I ~I~
I li~i
~M ·.·.·•·
II
:-:·:· :-:·:·: !I~ l~i
~;~~~~ ;~~t ·:>.;: ... :
~~~~~~ r ==~~~ .~: ~····
Ill ==~~ t~~~ ····:..: :::::: ···••·· :::::: ······· :::::::
::::::: .·.·.· .·.·.·•
······· ~lllll illllil II l~ :;:~;:
:;:*: :-:·: :::::: :::::::
·=·=·:
Ill :::::: H~ ::::::.
mm tf ~fl tm ~~~~~ ll~ili iii~ ·•···· ·:·:·: :-:·:· ~=~=~=
1234!5678 2345678 1234567 2345 67
HOUR
5TH DAY
3 2 2 0 0
1 I I J
2 3 4 5 6
+>o
N
NUMBER BIROS
0/o
SLEEPING
70
65•-
25
FIGURE 26-PERCENTAGE OF SCOTERS SPP. INVOLVED IN SLEEPING
ACTIVITY AT THE SMALL EXPERIMENTAL LAKE
JUNE 20-JUNE 25, 1972.
I ST DAY
7 II II 13 14 13 13 13
1234 567 8
2 NO DAY
12 12 7 7 14 3 5 12
r.:;:;:
I I I
2345678
HOUR
L
3 RD DAY
7 12 4 3 4 5 4
TI
:ll·
tl
2 3 4 5 6 7
_j
4TH DAY
4454444
2 3 4 5 6 7
5TH DAY
557777
2 3 4 5 6
FIG. 27-PERCENTAGE OF SCAUP SPP. INVOLVED IN FEEDING
AT THE SMALL EXPERIMENTAL LAKE 1 JUNE 20-JUNE
ACTIVITY
251 1972
I ST DAY 2 N D DAY 3 RD DAY
NUMBER BIROS 15 15 15 15 14 15 15 15 16 16 15 6 6 7 6 6 18 14 10 3 0 2 4
100
95
90
85 i
80
75
~ 70
tN
65•-
0/o 60 I I
FEEDING 55
50
45
40 I ::::::
35 -~li~ii'
30
10
5
0 I I I
~:::::::: ~lit: ~
1234!567 8 2 3 4 5 6 7 8 2 3 4 !I Cl 7
HOUR
4 TH DAY 5TH DAY
10 13 3 1; 5 9 2 12 2 !I 7 6 2
~
m t=:
~:::
.j~~~
::::;
I 2 3 4 !5 6 7 2 3 4 !I •
greater degree of disturbance than will small ones.
Certainly on the larger lakes, the waterfowl have more
room to avoid the aircraft and hence are possibly less
prone to completely abandon the area. This has been
shown for arctic and red-throated loons in response to
human disturbance on the coastal tundra of Hudson Bay
(Davis 1972). It should be pointed out that the species
composition varied between lakes of different sizes and
depths. Ducks from larger, deeper lakes may be depen-
dent upon a food supply which can be obtained only in the
deeper water so that,when they are forced to repair to
shallower regions to escape the movements of the air-
craft, they are in effect losing access to their best
feeding areas. More study, possibly using more than one
observer, will be necessary in order to ascertain to
any degree of confidence the effects of aircraft distur-
bance on the large lakes.
It appears certain from our studies that the
birds on different lakes, even of relatively the same
size (e.g. small experimental and intermediate experi-
mental), vary in their ability to adjust to aircraft
disturbance. Lakes affording areas of protection such
as marshes or shallow bays may be better suited to
withstand sustained pressure (Figure 28).
The measurable effect on waterfowl population
at the small control lake caused by the hunting activity
of the golden eagle is interesting. If,in fac~ the
eagle did not return to the lake after its initial
hunting activity,then its effect, in terms of length of
-44 -
time that birds remained off the lake, was greater than
the effect of the floatplane from which birds made some
recovery between disturbance days. It should be pointed
out, however, that an eagle was noted hunting on the small
experimental lake, at one point attacking a swan on a
nearby nest yet the presence of the eagle there did not
have a measurable effect on the population. Conceivably,
the difference in available cover and the difference in
species composition on the small control and small
experimental lakes might have been the reason for the
difference in impact of the eagle on the two lakes. Such
differences might also explain the difference in effect
of floatplane activity on the different lakes.
Further, in order to accurately determine the
effects of disturbance, it is necessary to learn more
about the normal behavior of waterfowl in undisturbed
conditions. Daily cycles in population-levels on the
various water bodies are not sufficiently understood. It
is likely that many birds come in to feed on the larger
lakes at various times during the day, possibly returning
to the smaller lakes sometime towards evening. Trends
of this nature were noted in this study, but because
of the exceptionally late season and the manpower demands
of other studies,the time available in 1972 was insuffic-
ient to allow us to gather enough baseline data.
SUMMARY
1. The waterfowl population present on the small
-45 -
2.
3.
4.
5.
6.
7.
experimental lake during the first (undisturbed)
day, was reduced by 60% after four days of
disturbance.
After the 60% decrease on the small experimental
lake, the population began to stabilize. This
stabilization began on about the third day of
disturbance.
Numbers remained relatively constant on the small
control lake, except when an eagle passed low over
the lake causing about 45 -50 birds to leave
the lake. The population never returned to its
original level following this disturbance.
The numbers of waterfowl on the intermediate
experimental lake did not change markedly
during the two days of disturbance.
Population data from the large lakes were incon-
clusive due to limited visibility that made it
difficult to get consistent counts.
Behavioral data did not provide positive results
because of a lack of baseline data.
Further study is required involving more base-
line data, more lakes and more prolonged dis-
turbance periods.
-46 -
REFERENCES CITED
Anderson, R.M. 1913. Report on the natural history collec-
tions of the expedition. Pages 436-527. In
V. Stefansson, My life with the Eskimos. Macmillan
Co., New York. 538 pp.
Davis, R.A. 1972. The use of habitat by arctic and red-
throated loons. Unpublished. Ph.D. thesis,
University of Western Ontario, London. 280 pp.
Gavin, A. 1970. Ecological survey of Alaska's
North Slope. Atlantic Richfield Co. 35 pp.
Godfrey, W.E. 1966. The birds of Canada. Nat. Mus. Canada,
Bull. No. 203, Biol. Series No. 73. Ottawa.
428 pp.
Gollop, M.A. and R.A. Davis. 1974. Studies of bird popu-
lations and productivity on lakes on the Yukon
North Slope, July 1972. C.A.G.S.L. Biol. Rep. Ser.
Vol. XII, Ch. 1.
Hall, G.E. 1972. A summary of observations of birds at
Oliktok Point -Summer 1971. Pages 245-275. In
P.J. Kinney et al. Baseline data study of the-
Alaskan arctic aquatic environment. Institute
of Marine Science, Univ. Alaska, College, Alaska.
No. R72-3. 275 pp.
Kessel, B. and T.J. Cade. 1958. Birds of the Colville
River, Northern Alaska. Biol. Papers. Univ.
Alaska, No. 2. 83 pp.
Schmidt, W.T. 1973. A field survey of bird use at
Beaufort Lagoon, June -September 1970. Mimeo.
report : prepared for U.S. Bur. Sp. Fish and
Widl., Arctic Nat. Wildl. Range. 35 pp.
West, G.C. and C.M. White. 1966. Range extensions and
additional notes on the birds of Alaska's
Arctic Slope. Condor 68 (3): 302 -304.
-47 -
-sv -
SHdVH~O.LOHd
FIGURE' 1 -North slope Thaw Lake.
FIGURE 24 -Oldsquaw Ducks .
FIGURE 7-A float plane that created disturbance
by taxiing on the lakes.
FIGURE 28 -Marsh affording protection for waterfowl.
BIOLOGICAL REPORT SERIES
VOLUME FOURTEEN
DISTURBANCE TO BIRDS BY GAS COMPRESSOR
NOISE SIMULATORS, AIRCRAFT AND HUMAN
ACTIVITY IN THE MACKENZIE VALLEY AND
THE NORTH SLOPE, 1972
Edited by
W. W. H. GUNN, JOHN A. LIVINGSTON
Prepared by
L.G.L. LIMITED, ENVIRONMENTAL RESEARCH ASSOCIATES
FEBRUARY, 1974
CANADIAN ARCTIC GAS STUDY LIMITED
ALASKAN ARCTIC GAS STUDY COMPANY