Offshore Marine Observation of Willow Ptarmigan, including Water Landings, Kuskokwim Bay, Alaska

2005·2.2 MB·English

by  Christian E Zimmerman

Wilson Bulletin 1 17(1):12-14, 2005
OFFSHORE MARINE OBSERVATION OE WILLOW PTARMIGAN,
INCLUDING WATER LANDINGS, KUSKOKWIM BAY, ALASKA
CHRISTIAN E. ZIMMERMAN,'-^ NICOLA HILLGRUBER,^ SEAN E. BURRIL,^
MICHELLE A. ST PETERS,' AND JENNIEER D. WETZEL'
—
ABSTRACT. We report an observation of Willow Ptarmigan {Lagopiis lagopus) encountered 8 to 17 km
from the nearest shoreline on Kuskokwim Bay, Alaska, on 30 August 2003. The ptarmigan wereobservedflying,
landing on our research vessel, and landing and taking offfrom the water surface. We also report on one other
observation ofptarmigan sitting on the watersurface and othermarine observations ofptarmigan fromtheNorth
Pacific Pelagic Seabird Database. These observations provide evidence that Willow Ptarmigan are capable of
dispersing across large bodies of water and landing and taking off from the water surface. Received 19 July
2004, accepted 4 January 2005.
Willow Ptarmigan {Lagopus lagopus) have ated with water and generally exhibit limited
a Holarctic distribution and are found flight endurance, it is not clear whether ptar-
throughout much of Alaska, typically occu- migan would be able to migrate long distances
pying alpine and arctic tundra (Hannon et al. over bodies of water. Determining the extent
1998). In contrast to the residential habits of of this ability may be a key element to un-
most other grouse species (Gruys 1993, Han- derstanding dispersal patterns and population
non et al. 1998), Willow Ptarmigan are known structure. Rock Ptarmigan (L. muta) breeding
to make seasonal migrations that may cover on the Aleutian Islands, for example, are char-
distances of several hundred kilometers. Al- acterized by genetic divergence among major
though their wing morphology and muscle island groups with little gene flow between
composition suggest that they are betteradapt- island populations (Holder et al. 2000, 2004).
ed to longer migrations and sustained flight Holder et al. (2000) further pointed out that
than other galliforms (Drovetski 1996), galli- no inter-island movement of individual ptar-
forms generally are considered to have limited migan has ever been reported, although the
ability for sustained flight (Tobalske et al. distances between islands are often less than
2003). For Willow Ptarmigan, migration be- those covered by migrations of inland ptar-
tween breeding and wintering habitats typi- migan.
cally occurs in early fall, with return migra- On 30 August 2003, during a survey for
tion occurring in spring (Hannon et al. 1998); pelagic juvenile salmon in Kuskokwim Bay,
Gruys (1993) reported that Willow Ptarmigan Alaska (60° 0' N, 162° 15' W), we encoun-
migrating from summer to winter habitats tered a group of 100 to 125 Willow Ptarmi-
moved in flocks ofup to 200 birds. Ptarmigan, gan. We observed the ptarmigan for approxi-
upland birds not commonly associated with
mately 2 hr (08:00 to 10:00 Alaska Standard
water, normally do not swim or dive (Hannon
Time) as we cruised south along the 162° 16'
eltowal.Pt1a99r8m)i,gabnutwDaidxeonin(t1o9s2h7a)lolbowsecrrveeedkawWaitle-r pWtarlmoinggaitnuwdehelninew.eWweerefirasptpreonxciomuantteelryed8 kthme
to forage on insects, and Hannon et al. (1998)
report that 1-day-old chicks can swim if they tfhreomeassthocroea.stOuofrKturasckkowkawsimroBuagyhlaynpdardailsltealncteo
fall into water.
Because ptarmigan are not usually associ- to shore ranged from 8 to 17 km. Initially, two
ptarmigan (a female and male) landed on our
vessel and rested for approximately an hour
' U.S. Geological Survey, Alaska Science Center, before flying away. Over the next hour
1011 E. Tudor Rd., Anchorage, AK 99503, USA. (09:00-10:00), approximately 125 birds re-
Oc2eaUnnivS.cioefnAcelsa,ska11F1a2ir0baGnlkasc,ieSrchoHowly.o,fFJiusnheearuie,saAnKd peatedly flew around the vessel. A few landed
99801, USA. on the vessel and rested for short periods
^Corresponding author; e-mail: (<15 min) before flying off in the distance
[email protected] and returning to the vicinity of the boat (Fig.
12
Zimmerman et al. • PTARMIGAN AT SEA 13
migan, the sea was calm, winds were light,
and the sky was overcast. The nearest weather
station, at Cape Newenham on the southern
boundary of Kuskokwim Bay and approxi-
mately 120 km from our location, reported
calm winds, visibility of 16 km, and an air
temperature of 13° C (Federal Aviation Ad-
ministration automated weather monitoring
station).
To determine whether other ptarmigan had
been observed at sea or landing on water, we
queried the North Pacihe Pelagic Seabird Da-
tabase (www.absc.usgs.gov/research/NPPSD/),
which contains pelagic seabird survey data
collected over the last 30 years in the North
Pacific Ocean, Bering Sea, an—d adjacent wa-
ters. Of 57 ptarmigan records including 16
Willow Ptarmigan, 6 Rock Ptarmigan, and 35
—
unidentified ptarmigan all were associated
with shorelines of the Chuckchi Sea, Arctic
Ocean, or Norton Sound, Alaska. Only ptar-
1
migan was sitting on the water, 12 were not
classified according to behavior, 12 were fly-
ing in a consistent heading, 9 were flying be-
low the crests of waves or swells (suggesting
flight over water), 2 were bathing, 15 exhib-
ited courtship behavior (likely terrestrial ob-
servations), and 6 were sitting or standing fol-
lowed by flushing (likely terrestrial observa-
tions). Ofthe behaviors reported, 12 appear to
have been associated with water, including sit-
ting on water, bathing, or flying below wave
crests. The single record ofa ptarmigan sitting
on the water was of a Rock Ptarmigan ob-
served on 26 June 1976 at Kasegaluk Lagoon
(68° 51 ' N, 165° 50' W), adjacent to the Chuk-
chi Sea.
It is not clear why the ptarmigan we ob-
served on Kuskokwim Bay were Hying off-
shore. Since the weather was calm at the time
and had been so for several days, it is unlikely
F’lG. 1. Willow Ptarmigan in flight, on a research that this group had been displaced by wind.
Aveusgsuels,tan2d003o.n tSheeewaatdedri,tiKounaslkopkhwoitmogrBaapyh,sAlaatskwa,ww3.0 Willow Ptarmigan are common on the coastal
absc.usgs.gov/research/Fisheries/Western_Alaska/ plain adjacent to Kuskokw—im Bay and typi-
ptarmigan.htm. cally migrate in September from the coastal
plain to mountains in the east (approximately
90 km; M. Rearden i^eis. comm.). It seems
I ). All birds appeared to be exhausted after likely that the ptarmigan we encountered had
landing on the vessel, exhibiting rapid breath- gathered as they migriited from breeding hab-
ing with open beaks. At least 10 ptarmigan itats on the coastal plain to wintering habitats.
were observed landing on the wtiter suilaee, (liven the distribution of ptarmigan on off-
resting (<1() min), then taking off from the shore islands, such as the Aleutian Islands,
water surfaee. When we encountered the ptar- Alaska, it is not unlikely that dispersal occurs
14 THE WILSON BULLETIN • Vol. 117, No. 1, March 2005
over water. Understanding the dispersal ca- LITERATURE CITED
pabilities and patterns of animals is a critical
step in examining population structure and Dixon, J. 1927. Contribution to the life history ofthe
metapopulation dynamics (Weins 1996). Dis- Alaska Willow Ptarmigan. Condor 29:213-223.
persal among islands is regulated by the dis- Drovetski, S. V. 1996. Influence of the trailing-edge
persal capabilities of a species and the dis- no1t3c:h80o2n-81f0li.ght performance of galliforms Auk
tance between islands. Our observation of Gruys1, R. C. 1993. Autumn and winter movements
Willow Ptarmigan on Kuskokwim Bay and and sexual segregation ofWillow Ptarmigan. Arc-
the observation of Rock Ptarmigan at Kase- tic 46:228-239.
galuk Lagoon are the first records of ptarmi- Hannon, S. J., P. K. Eason, and K. Martin. 1998.
gan not only landing and sitting on the water Willow Ptarmigan (Lagopus lagopus). The Birds
surface, but also successfully taking off after ofNorth America, no. 369.
resting on the water surface. These observa- Holder, K., R. Montgomerie, and V. L. Friesen.
tions add to our understanding ofdispersal by 2000. Glacial vicariance and historical biogeog-
ptarmigan and may provide insight concern- rBaeprhinygofregRioocn.kMPotlaercmuilgaarnE{cLoalgoogpyus9:m1ut2i6i5s-)12in78t.he
ing dispersal ofptarmigan across large bodies Holder, K., R. Montgomerie, and V. L. Friesen.
of water. 2004. Genetic diversity and management of Ne-
ACKNOWLEDGMENTS arctic RockPtarmigan {Lagopusmutus).Canadian
Journal ofZoology 82:564-575.
We thank Captain J. Peacock ofthe research vessel Tobalske, B. W., T. L. Hedrick, K. P. Dial, and A.
Eileen O’Earrell. J. E Piatt encouraged us to publish A. Biewener. 2003. Comparative powercurves in
our unusual observation. Eunding for the Kuskokwim bird flight. Nature 421:363-366.
Bayjuvenile salmon research is provided by the North Weins, J. A. 1996. Wildlife in patchy environments:
Pacific Research Board; the North Pacific Pelagic Sea- metapopulations, mosaics, and management. Pag-
bird Database is funded by the North Pacific Marine es 53-84 in Metapopulations and wildlife conser-
Research Institute. We thank three anonymous review- vation (D. R. McCullough, Ed.). Island Press,
ers for comments on an earlier draft. Washington, D.C.