Observations on Arctic and Red-throated Loons at Storkersen Point, Alaska

Abstract

Habitat requirements of arctic loons (Ga@ia arctica) and red-throated loons (Guviu stellata) were studied at Storkersen Point on the Arctic coastal plain of Alaska from 1971 to 1975. Nest success ranged from 28 to 92 per cent and 33 to 78 per cent for arctic and red-throated loons, respectively. Loons were ecologically isolated in their feeding habits and use of wetlands. Arctic loons fed to their young invertebrates captured in the nest pond, and red-throated loons fed to theirs fish captured from the Beaufort Sea. Both species preferred islands as nest substrates, but arctic loons utilized large ponds with stands of Arctophila fulva wetlands for nesting, whereas, red-throated loons used smaller, partially-drained basins most frequently. RfjSUMk. Observations sur le huard arctique et sur le huard Ct gorge rousse, d Srorkersen Point, en Alaska. Entre 1971 et 1975, on a men6 des Ctudea sur lea conditions d'habitat du huard arctique (Gavia wctica) et du huard à gorge rousse (Gavia stellata), 21 Storkersen Point, dans la plaine c8tihre de l'Alaska. V i-h u i t B quatre-vingt-douze pourcent des huards arctiques, et trente-trois B soixante-dixhuit pourcent des huards B gorge rousse ont rCussi B Ctablir leurs nids en cet endroit. Les deux esphces de huard Ctaient isolkq du point de vue blogique: chacune avait ses habitudes d'alimentation et habitait un type particulier de mar& cage. Les huards arctiques ont nourri leurs couvQs d'invertCbrCs capturcS dans 1'6tang p r b du nid; les huards B gorge rousse ont d o n d B lems petits des poissons pêch6s dans la mer de Beaufort. Les deux & e s d'oiseaux ont pr6ffC6 construire leurs nids sur des îles, mais les huards arctiques ont établi leurs nids dans de grands 6tangs oh poussait l'arctophila fulva, alors que les huards B gorge rousse ont la plupart du temps utilise de plus petits 6tangs partiellement ass6ch6. PesmMe. Ha6amaenus 30 w nmobod u xpacumobdi eazapdi e nynxme Cmop~epcelta wa A~urcl~e. B nepHon 19'6-76 rr. B n y~~~e CTopxepcem, pacnonomeHaoM H& ~B H H H H O~ ~C T E apxTxsecxoro no6epemm AJLIICI~H, HsysaJracb YCJIOBEI~ O~H T~H H S sepaoso6oB (Gavia arctioa) E xpacHoso6oP (Gavia stellah) rarapu. &nS ycnalu~o saxomemm rResA xone6anacb B npenenax OT Z S S AO 92% ws sepH* H8OJIEpOBaHbI B CBWM o6pase IIHTaHHR E O~H T~H H R Ha S&JIO ¶eH€IOB MeCTHOCTE. S&B E OT 33% A0 78% xpac~oao60ft rarapw. h ' a bI ~~I J I E BKOJIOOFEI ¶eCf EH %pHO806bIe I'rtrapbI KOPMHnH lFTeHqOB BbIJI&BJIEB&e"H E8 MeCTHbM IXp AOB 6t?8IIOSBOHO ¶HbIME, a ~cpac~osobb~e rarapbI I I p E H O C a W CBOeMy IIOTOMCTBY pu&' E8 MOPS BdOpTa. 06a BHA& lIpe~lIO ¶ETaJIE X'He8AOBaTbCR Ha OCTPOBaX, IXpH ¶eM KpSOH0806bIe I'MYbphI ~b16xpam 6on~1u~e lTOpOCIIIHe &pIETO~HJIOfi pbmre& IIpYRbI, MeHblIIHx pa8MepOB. a xpac~oso6b1e rarapM game cenxmcb H a xacTmHo npemposamm Bonoemx

Breeding Biology of Red-throated Loons in the Canadian Beaufort Sea Region

“…Densities declined towards the eastern tip of the Tuktoyaktuk Peninsula, on the south side of the peninsula and along the Yukon coast. The densities of 0.6-0.8 pairs.lax" found at Storkersen Point on the Alaskan Beaufort Sea coast (Bergman and Derksen, 1977) were similar to what we recorded along the Yukon coast.…”

“…Regardless of the timing of spring thaw, most loons arrived on the nesting ponds within a day of the ponds' thawing. Bergman and Derksen (1977) likewise noted that the red-throated loon arrived at Storkersen Point, Alaska, concurrently with thawing of the nesting ponds.…”

“…Braun ef al. (1968), Davis (1972) and Bergman and Derksen (1977) all found that the youngest chick usually died within two weeks of hatch. Davis (1972) noted that because the eggs hatched a day apart, the oldest chick had an advantage over the other chick in competing for fish brought to them.…”

“…However, no previous study in the region has focused specifically on the red-throated loon. Elsewhere in its circumpolar breeding range, there have been several recent studies of red-throated loon breeding biology: in Canada on the Queen Charlotte Islands (Reimchen and Douglas, 1984;Douglas and Reimchen, 1988) and on the west side of Hudson Bay (Davis, 1972); in the United States on the Alaskan Beaufort Sea coast (Bergman and Derksen, 1977); in Scotland on the Shetland Islands (Bundy, 1976(Bundy, ,1978Furness, 1983;Gomersall et al, 1984;Gomersall, 1986) and in Orkney (Booth, 1982); and in southern Finland (Lokki and Eklof, 1984).…”

Lead Shot Poisoning of a Pacific Loon in Alaska

“…In western Alaska, red-throated and Pacific loons use similar coastal tundra habitats for nesting (Petersen, 1976). However, unlike more marine-foraging red-throated loons, incubating Pacific loons primarily feed in small terrestrial ponds during incubation and brood rearing (Bergman and Derksen, 1977;Petersen, 1989). Although little human fishing activity exists in these ponds, the coast of the YKD is hunted for waterfowl, and tundra ponds might contain unknown densities of spent lead shot (Flint et al, 1997;W.…”