scholarly journals Overlap in Diets and Foraging of Common Murres (Uria Aalge) and Rhinoceros Auklets (Cerorhinca Monocerata) After the Breeding Season

The Auk ◽  
2005 ◽  
Vol 122 (3) ◽  
pp. 887-901 ◽  
Author(s):  
Monique M. Lance ◽  
Christopher W. Thompson
Keyword(s):  
Breeding Season ◽  
Prey Species ◽  
Dietary Diversity ◽  
Puget Sound ◽  
Pacific Herring ◽  
Uria Aalge ◽  
Sand Lance ◽  
Cerorhinca Monocerata ◽  
Common Murres ◽  
Pacific Sand Lance

AbstractCommon Murres (Uria aalge; hereafter “murres“) and Rhinoceros Auklets (Cerorhinca monocerata; hereafter “auklets“) breed and forage sympatrically over much of their range. They have similar diets during the breeding season, which suggests that they partition prey during the breeding season by foraging (1) at different locations, (2) at different times of day, (3) at different water depths, (4) on different proportions of the same prey species, or (5) some combination of the four. We examined possible mechanisms of niche partitioning during late summer and fall in Puget Sound, Washington, in 1993-1996. Murres and auklets fed mainly on Pacific herring (Clupea pallasii, occurring in 74.2% and 48.1%, respectively, of gastrointestinal tracts with contents), Pacific sand lance (Ammodytes hexapterus; 45.8% and 62.3%), and salmonid (Oncorhynchus spp.) species (21.9% and 9.7%). Auklets also consumed considerable amounts of threespine stickleback (Gasterosteus aculeatus; 26.6%). Murres and auklets did not differ significantly (1) in their diet (between age classes or sexes of either species, or among years); (2) in mean lengths of Pacific herring (101 and 109 mm, respectively) and Pacific sand lance (82 and 86 mm) they consumed; or (3) in the mean depth (7–8 m) at which they were entangled in gill nets. Dietary diversity was low, with most gastrointestinal tracts containing only one or two prey species in both murres and auklets. Murres were caught and therefore presumably feed more frequently in the afternoon and evening; whereas auklets were entangled more often in early morning. We found differences between murres and auklets in the diel chronology of prey taken, which may partly explain how murres and auklets coexist during the breeding season and months thereafter, prior to auklet emigration from Puget Sound.Chevauchement du Régime Alimentaire et de la Quête Alimentaire chez Uria aalge et Cerorhinca monocerata après la Saison de Reproduction

scholarly journals Sighting rates and prey of Minke Whales (Balaenoptera acutorostrata) and other cetaceans off Cormorant Island, British Columbia

2019 ◽  
Vol 133 (2) ◽  
pp. 144
Author(s):  
Jared R. Towers ◽  
Christie J. McMillan ◽  
Rebecca S. Piercey
Keyword(s):  
British Columbia ◽  
Pacific Herring ◽  
Balaenoptera Acutorostrata ◽  
Sand Lance ◽  
Clupea Pallasi ◽  
Use Patterns ◽  
Minke Whales ◽  
Ammodytes Personatus ◽  
Pacific Sand Lance ◽  
Lunge Feeding

From June to August 2012, we conducted over 500 h of visual surveys from Cormorant Island, British Columbia, to determine behaviour and habitat use patterns of nearby cetaceans. Seven species were documented, but Minke Whales (Balaenoptera acutorostrata) were by far the most common and were observed lunge feeding at the surface on 15 occasions. In addition, this species was documented surface lunge feeding on Pacific Herring (Clupea pallasi) and Pacific Sand Lance (Ammodytes personatus) on 32 occasions during vessel-based cetacean surveys around Cormorant Island between 2010 and 2014. Although Minke Whales are relatively uncommon in British Columbia, these results indicate that they can regularly be found in specific feeding areas during the summer.

Rhinoceros Auklet (Cerorhinca monocerata) Nestling Diet May Gauge Pacific Sand Lance (Ammodytes hexapterus) Recruitment

1993 ◽  
Vol 50 (9) ◽  
pp. 1908-1915 ◽  
Author(s):  
Douglas F. Bertram ◽  
Gary W. Kaiser
Keyword(s):  
British Columbia ◽  
Sand Lance ◽  
Ammodytes Hexapterus ◽  
Nestling Diet ◽  
Cerorhinca Monocerata ◽  
Pacific Sand Lance ◽  
Term Monitoring ◽  
Rhinoceros Auklet ◽  
Seabird Colonies

We studied (1984–86) the diet of rhinoceros auklet (Cerorhinca monocerata) nestlings at three colonies on the British Columbia coast (Lucy islands, Pine Island, and Triangle Island). On the Lucy Islands, Pacific sand lance (Ammodytes hexapterus) dominated nestling food loads in all years. In 1985, 0+ sand lance dominated the nestling diet on all colonies. Concurrent measures of nestling growth rate, independent indexes of ocean production, and the proportion of sand lance in groundfish stomach samples were also highest in 1985. This suggests a linkage between ocean production, 0+ sand lance abundance, and events on seabird colonies over a broad geographic range. We emphasize the importance of sand lance to temperate seabirds and contrast British Columbia with areas where sand lance are commercially exploited. Rhinoceros auklet nestling diet, growth, and other data collected on colonies suggest that long-term monitoring on seabird colonies can contribute timely and inexpensive information on the recruitment of sand lance stocks in Canadian waters.

Diving depths, diet, and underwater foraging of Rhinoceros Auklets in British Columbia

1993 ◽  
Vol 71 (12) ◽  
pp. 2528-2540 ◽  
Author(s):  
Alan E. Burger ◽  
Rory P. Wilson ◽  
Don Garnier ◽  
Marie-Pierre T. Wilson
Keyword(s):  
British Columbia ◽  
Prey Availability ◽  
Clupea Harengus ◽  
Pacific Herring ◽  
Ammodytes Hexapterus ◽  
Bite Marks ◽  
Important Prey ◽  
Cerorhinca Monocerata ◽  
Pacific Sand Lance ◽  
The Mean

Rhinoceros Auklets (Cerorhinca monocerata) were studied at Triangle Island, Cleland Island, and Seabird Rocks, British Columbia, in 1986–1989. Epipelagic schooling fish were consistently the most common prey delivered to auklet chicks at all three localities. Pacific sand lance (Ammodytes hexapterus), Pacific herring (Clupea harengus), juvenile salmon (Onchorhyncus spp.), Pacific saury (Cololabis saura), and juvenile rockfish (Sebastes spp.) were important prey. Bite marks on the fish showed that 73% were attacked from below. The mean deepest depth recorded for 16 auklets was 30 m (range 12–60 m). Eleven time-at-depth records showed that the auklets were epipelagic foragers: 90% of the mean underwater time was spent in the upper 10 m, although most birds had a few deeper dives of 20–60 m. Shipboard transects showed that Rhinoceros Auklets usually foraged in water considerably deeper than 15 m. A model of diving efficiency indicated that a relatively large proportion (> 40%) of the average dive cycle was spent foraging rather than travelling or resting, and prolonged dives invoking anaerobic glycolysis were avoided. We discuss the implications of diving limitations on foraging behaviour and the use of Rhinoceros Auklets as indicators of prey availability.

scholarly journals Ecological interactions and habitat modification in nesting Common Murres, Uria aalge

1996 ◽  
Vol 6 (3) ◽  
pp. 261-269 ◽  
Author(s):  
Julia K. Parrish ◽  
Robert T. Paine
Keyword(s):  
Reproductive Output ◽  
Habitat Modification ◽  
Haliaeetus Leucocephalus ◽  
Uria Aalge ◽  
Ecological Interactions ◽  
Bald Eagles ◽  
Predator Removal ◽  
Common Murre ◽  
Corvus Caurinus ◽  
Common Murres

SummarySeabird populations suffer from a variety of natural and human-induced sources of mortality and loss of lifetime reproductive output. On the outer coast of Washington State, Common Murre Uria aalge populations have been in decline for approximately the last decade and are currently reproductively active only at Tatoosh Island. These murres nest in two basic habitat types: crevices (25% of the population) and larger cliff-top subcolonies (75%). Murres in cliff-top subcolonies have suffered dramatic reductions in reproductive success in recent years relative to conspecifics nesting in the crevices, primarily due to egg predation by Glaucous-winged Gulls Larus glaucescens and Northwestern Crows Corvus caurinus, facilitated by the presence of Bald Eagles Haliaeetus leucocephalus. Because predator removal is not feasible and creation of additional crevice habitat is difficult, expensive and potentially ineffective, we have designed a temporary habitat modification (the “silk forest”) which replaces the natural vegetation cover and modifies the interaction between murres and eagles. Within the test subcolony, murres nesting under and immediately adjacent to the silk forest produced nearly twice as many eggs per square metre as their conspecifics nesting in adjacent exposed-ground areas.

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