Diving depths and diet of Cassin's Auklet at Reef Island, British Columbia

1990 ◽  
Vol 68 (7) ◽  
pp. 1572-1577 ◽  
Author(s):  
Alan E. Burger ◽  
David W. Powell
Keyword(s):  
British Columbia ◽  
Juvenile Fish ◽  
Ammodytes Hexapterus ◽  
Queen Charlotte Islands ◽  
Cassin's Auklet ◽  
Ptychoramphus Aleuticus

Diving depths of Cassin's Auklets (Ptychoramphus aleuticus) breeding at Reef Island, Queen Charlotte Islands, British Columbia, were measured with miniature gauges attached to the birds. Maximum diving depths of 22 birds averaged 28 m, with a mode of 40 m. A time-at-depth recorder showed that one auklet dived to 29 m, but spent 80% of its time underwater at 3–13 m. Food delivered in gular pouches to chicks contained mainly euphausiids (predominantly Thysanoessa spinifera) and juvenile fish (Ammodytes hexapterus), with lesser amounts of copepods, amphipods, small pandalid shrimps, Brachyura larvae, and ctenophores. Euphausiid meals were most common during spring tides. Auklets that delivered significant amounts of euphausiids appeared to have dived deeper than those that delivered fish.

scholarly journals Introduced mammals, vegetation changes and seabird conservation on the Scott Islands, British Columbia, Canada

2010 ◽  
Vol 20 (3) ◽  
pp. 295-305 ◽  
Author(s):  
J. MARK HIPFNER ◽  
MOIRA J. F. LEMON ◽  
MICHAEL S. RODWAY
Keyword(s):  
British Columbia ◽  
American Mink ◽  
Breeding Population ◽  
Vegetation Changes ◽  
Population Declines ◽  
Seabird Conservation ◽  
Time Period ◽  
Cassin's Auklet ◽  
Vegetation Surveys ◽  
Ptychoramphus Aleuticus

SummaryThe Scott Islands, British Columbia, Canada, support the largest aggregation of breeding seabirds in the eastern Pacific Ocean south of Alaska. However, large seabird populations were eradicated by American Mink Neovison vison and Raccoons Procyon lotor introduced to Lanz and Cox islands in the 1930s, while the ecological consequences of the introduction of European Rabbits Oryctolagus cuniculus to Triangle Island in the 1920s are unknown. We have seen dramatic changes in the vegetation on Triangle Island in recent decades, chiefly a decrease in Tufted Hairgrass Deschampsia cespitosa cover and a concomitant increase in Salmonberry Rubus spectabilis cover. We carried out vegetation surveys at Triangle Island (1989 and 2004) and its nearest neighbour, rabbit-free Sartine Island (1987 and 2006), to test the hypothesis that rabbits have caused these changes. We found, however, that similar changes have occurred at Sartine Island as at Triangle Island over the same time period. Because these two islands support the bulk of the world's breeding population of Cassin's Auklet Ptychoramphus aleuticus, a small seabird that selects grass-covered habitat but avoids tall Salmonberry for nesting, the vegetation changes raise serious concerns for a species that has experienced dramatic population declines in recent years. Restoration of seabird nesting habitat by removing American Mink and Raccoons from Lanz and Cox islands will be vital for long-term seabird conservation in the Scott Islands.

scholarly journals Ocean climate and El Niño impacts on survival of Cassin's Auklets from upwelling and downwelling domains of British Columbia

2005 ◽  
Vol 62 (12) ◽  
pp. 2841-2853 ◽  
Author(s):  
Douglas F Bertram ◽  
Anne Harfenist ◽  
Barry D Smith
Keyword(s):  
British Columbia ◽  
El Niño ◽  
El Nino ◽  
Marine Ecosystem ◽  
California Current ◽  
Ocean Climate ◽  
The North ◽  
Mortality Response ◽  
Cassin's Auklet ◽  
Ptychoramphus Aleuticus

We report on the survival of populations of Cassin's Auklet (Ptychoramphus aleuticus) that breed on two oceanic colonies in British Columbia: Triangle Island, near the northern end of the California Current Ecosystem, and Frederick Island to the north in the Alaska Current Ecosystem. We captured and banded birds at both colonies from 1994 to 2000 and analyzed the recovery data with the computer program MARK. Average local adult annual survival (± standard error) was significantly lower (p = 0.0001) on Triangle Island (0.71 ± 0.02) than that on Frederick Island (0.80 ± 0.02), likely a result of poor production in the California Current Ecosystem during the 1990s. Coincident with a strong El Niño event, survival in 1997-1998 fell in unison to the lowest values observed for both colonies (to 0.54 ± 0.05 and 0.64 ± 0.04, respectively, for adults). A common winter environment in the California Current Ecosystem could explain the unified mortality response of both British Columbia populations to an exceptionally poor food period. The seabird colonies in this study occupy key positions in relation to major oceanographic domains and hence provide unique platforms for investigations of marine ecosystem response to ocean climate variability in the Northeast Pacific Ocean.

Feeding ecology of the ancient and marbled murrelets near Langara Island, British Columbia

1975 ◽  
Vol 53 (4) ◽  
pp. 418-433 ◽  
Author(s):  
Spencer G. Sealy
Keyword(s):  
British Columbia ◽  
Feeding Ecology ◽  
Prey Availability ◽  
Breeding Cycle ◽  
Marbled Murrelet ◽  
Ammodytes Hexapterus ◽  
Queen Charlotte Islands ◽  
Early Portion ◽  
Marbled Murrelets

Two field seasons (1970 and 1971) were spent studying the feeding ecology of the ancient murrelet (Synthliboramphus antiquus) and the marbled murrelet (Brachyramphus marmoratus) near Langara Island, Queen Charlotte Islands, British Columbia. The relatively offshore-feeding ancient murrelet nests in colonies, lays two-egg clutches, and has truly precocial young. The inshore-feeding marbled murrelet is apparently a solitary nester, has one-egg clutches, and semiprecocial young. The ancient murrelet feeds predominantly on two species of euphausiid crustaceans, Euphausia pacifica and Thysanöessa spinifera, during the early portion of the terrestrial phase of its breeding cycle (early April to late May), but takes a fish, Ammodytes hexapterus, toward the end of the cycle. It is believed that this change in diet as the season progresses reflects a change in prey availability. The apparent patchy distribution of the prey of the ancient murrelet, which requires more time to locate the food source, has probably promoted the evolution of the 72-h incubation shifts found in this species.During the terrestrial phase of the marbled murrelet's breeding cycle (early May to late August), the fish Ammodytes hexapterus and Cymatogaster aggregata are predominantly taken. During the very early part of its breeding season, Thysanöessa spinifera constitutes a considerable part of its diet.

Cassin's Auklet (Ptychoramphus aleuticus)

2020 ◽  
Author(s):  
David G. Ainley ◽  
D. A. Manuwal ◽  
Josh Adams ◽  
A. C. Thoresen
Keyword(s):  
Cassin's Auklet ◽  
Ptychoramphus Aleuticus

III.—Recent Observations on the Glaciation of British Columbia and Adjacent Regions

1888 ◽  
Vol 5 (8) ◽  
pp. 347-350 ◽  
Author(s):  
Geo. M. Dawson
Keyword(s):  
British Columbia ◽  
Glacial Period ◽  
Coast Range ◽  
Coast Mountains ◽  
One Stage ◽  
Queen Charlotte Islands ◽  
Glacier Ice ◽  
Inland Ice ◽  
Great Valley ◽  
The U.S

Previous observations in British Columbia have shown that at one stage in the Glacial period—that of maximum glaciation—a great confluent ice-mass has occupied the region which may be named the Interior Plateau, between the Coast Mountains and Gold and Eocky Mountain Kanges. From the 55th to the 49th parallel this great glacier has left traces of its general southward or southeastward movement, which are distinct from those of subsequent local glaciers. The southern extensions or terminations of this confluent glacier, in Washington and Idaho Territories, have quite recently been examined by Mr. Bailley Willis and Prof. T. C. Chamberlin, of the U.S. Geological Survey. There is, further, evidence to show that this inland-ice flowed also, by transverse valleys and gaps, across the Coast Range, and that the fiords of the coast were thus deeply filled with glacier-ice which, supplemented by that originating on the Coast Range itself, buried the entire great valley which separates Vancouver Island from the mainland and discharged seaward round both ends of the island. Further north, the glacier extending from the mainland coast touched the northern shores of the Queen Charlotte Islands.

Occella impi, a New Species of Sea Poacher from British Columbia with Notes on Related Species (Agonidae, Pisces)

1970 ◽  
Vol 27 (6) ◽  
pp. 1109-1114 ◽  
Author(s):  
C. G. Gruchy
Keyword(s):  
British Columbia ◽  
New Species ◽  
Related Species ◽  
Single Specimen ◽  
Queen Charlotte Islands ◽  
A New Species

Occella impi, a new species of sea poacher, is described from a single specimen captured in the Queen Charlotte Islands, British Columbia. Occella impi differs from other species of Occella in having spinous plates on the breast, the anus nearer the anal fin, and fewer anal rays; also, the numbers of bony body plates are distinctive. A key to the known species of Occella, based primarily on the numbers of bony body plates, is included. The size of the maxillary barbel and number of infralateral plates are shown to be characteristic of the genera Occella and Stellerina.

The abundance and effects of ticks (Ixodes uriae) on nestling Cassin's Auklets (Ptychoramphus aleuticus) at Triangle Island, British Columbia

1996 ◽  
Vol 74 (8) ◽  
pp. 1585-1589 ◽  
Author(s):  
Y. E. Morbey
Keyword(s):  
Tick Infestation ◽  
Host Record ◽  
New Host ◽  
Ixodes Uriae ◽  
New Host Record ◽  
Cassin's Auklet ◽  
Peak Mass ◽  
The Common ◽  
Ptychoramphus Aleuticus ◽  
Wing Growth

Cassin's Auklet (Ptychoramphus aleuticus) nestlings hosted the common seabird tick Ixodes uriae. This is a new host record for this species of tick. Ixodes uriae were distributed nonrandomly on nestlings within and among sites. Soil substrate was thought to be an important factor influencing tick distribution. Nestlings with severe tick infestation had slower rates of wing growth, reached peak mass at older ages, and fledged with shorter wings at older ages than nestlings with fewer ticks. By remaining in the nest for longer periods, nestlings with severe tick infestation may have been compensating for the delay in wing development.

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