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

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.

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Activity levels of Marbled Murrelets in different inland habitats in the Queen Charlotte Islands, British Columbia

Canadian Journal of Zoology ◽

10.1139/z93-129 ◽

1993 ◽

Vol 71 (5) ◽

pp. 977-984 ◽

Cited By ~ 9

Author(s):

Michael S. Rodway ◽

Heidi M. Regehr ◽

Jean-Pierre L. Savard

Keyword(s):

British Columbia ◽

High Elevation ◽

Activity Levels ◽

Old Growth ◽

Marbled Murrelet ◽

Queen Charlotte Islands ◽

Old Growth Forest ◽

Second Growth ◽

Old Growth Forests ◽

Marbled Murrelets

We compared Marbled Murrelet (Brachyramphus marmoratus) activity levels in May, June, and July 1990 in four habitats in the Queen Charlotte Islands, British Columbia: alpine, old-growth forest at high elevation, old-growth forest at low elevation, and second-growth forest. The number of Marbled Murrelet detections was highest in old-growth forests. In alpine areas, small numbers of murrelet detections were mostly of distant birds flying over low-elevation forest. Numbers of detections were higher in low-elevation than in high-elevation old-growth forests in May and July, but not in June. Proportions of detections within smaller radii of survey stations were higher in low elevation forest in all months. The highest activity levels were associated with old-growth forest stands of large Sitka spruce (Picea sitchensis) and western hemlock (Tsuga heterophylla). The few detections that occurred in second-growth forests were mostly of distant birds. Stations in second-growth forest close to stands of old-growth forest had more frequent detections than stations with no old-growth forest nearby. Our results support the association of Marbled Murrelets with old-growth forests. Limitations of the survey methodology are discussed.

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

Canadian Journal of Zoology ◽

10.1139/z90-232 ◽

1990 ◽

Vol 68 (7) ◽

pp. 1572-1577 ◽

Cited By ~ 23

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.

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Factors affecting the availability of thick epiphyte mats and other potential nest platforms for Marbled Murrelets in British Columbia

Canadian Journal of Forest Research ◽

10.1139/x10-034 ◽

2010 ◽

Vol 40 (4) ◽

pp. 727-746 ◽

Cited By ~ 7

Author(s):

Alan E. Burger ◽

Robert A. Ronconi ◽

Michael P. Silvergieter ◽

Catherine Conroy ◽

Volker Bahn ◽

...

Keyword(s):

British Columbia ◽

Forest Canopy ◽

Tree Height ◽

Suitable Habitat ◽

Factors Affecting ◽

Marbled Murrelet ◽

Pooled Data ◽

Model Predictions ◽

Using Data ◽

Marbled Murrelets

Nest platforms (mossy pads, limbs, and deformities >15 cm in diameter) are key requirements in the forest nesting habitat of the threatened Marbled Murrelet ( Brachyramphus marmoratus (J.F. Gmelin, 1789)). Little is known about factors that affect the availability of platforms or the growth of canopy epiphytes that provide platforms. We examined variables affecting these parameters in coastal trees in British Columbia using data from 29 763 trees at 1412 sites in 170 watersheds. Tree diameter (diameter at breast height (DBH)) was the most important predictor of platform availability in the pooled data and within each of six regions. In most regions, platforms become available at DBH > 60 cm, but on East Vancouver Island, DBH needs to be >96 cm and possibly on the Central Coast >82 cm. Other regional predictors of platforms included tree height, tree species, and to a lesser extent elevation, slope, and latitude. Most (72%) trees providing platforms had epiphytes (mainly moss) covering one third or more of branch surfaces and 81% had intermediate or thick epiphyte mats. Mistletoe deformities provided <7% of platforms. Our model predictions help to define and manage suitable habitat for nesting Marbled Murrelets and also contribute to understanding forest canopy ecosystems.

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Activity Patterns of Marbled Murrelets in Old-Growth Forest in the Queen Charlotte Islands, British Columbia

The Condor ◽

10.2307/1369421 ◽

1993 ◽

Vol 95 (4) ◽

pp. 831-848 ◽

Cited By ~ 6

Author(s):

Michael S. Rodway ◽

Heidi M. Regehr ◽

Jean-Pierre L. Savard

Keyword(s):

British Columbia ◽

Activity Patterns ◽

Old Growth ◽

Queen Charlotte Islands ◽

Old Growth Forest ◽

Marbled Murrelets

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Techniques for Investigating Breeding Chronology in Marbled Murrelets, Desolation Sound, British Columbia

The Condor ◽

10.1093/condor/104.2.319 ◽

2002 ◽

Vol 104 (2) ◽

pp. 319-330 ◽

Cited By ~ 3

Author(s):

Cecilia Lougheed ◽

Brett A. Vanderkist ◽

Lynn W. Lougheed ◽

Fred Cooke

Keyword(s):

British Columbia ◽

Breeding Season ◽

Radio Telemetry ◽

Feeding Habits ◽

Brachyramphus Marmoratus ◽

Marbled Murrelet ◽

Breeding Synchrony ◽

Physiological Analysis ◽

Using Data ◽

Marbled Murrelets

AbstractWe used several methods to study the chronology and synchrony of breeding events of the Marbled Murrelet (Brachyramphus marmoratus) population at Desolation Sound, British Columbia, from 1996 to 1998. The timing of breeding events varied among years; on average the breeding season lasted from 21 April to 5 September. We assessed the biases of each method used by comparing the results to the estimate of the integrated breeding chronology. Counts of hatch-year birds at sea were biased toward earlier breeders, missing an estimated 24% of the fledglings. Two other methods, physiological analysis of the yolk precursor vitellogenin from blood samples and monitoring by radio-telemetry could produce a complete distribution of breeding events if sampling were done throughout laying. Observations in the forest, date of first observation of a fledgling at sea during the breeding season, and fish-holding behavior produced insufficient data to be used as sole indicators of breeding chronology of this species. In general, breeding synchrony in alcids, assessed using data from a literature review, was unrelated to feeding habits but increased with latitude (41% of the variation was explained by latitude). Marbled Murrelets, however, bred less synchronously than predicted for an alcid at this latitude (50°N).Técnicas para Investigar la Cronología Reproductiva de Brachyramphus marmoratus en Caleta Desolación, Columbia BritánicaResumen. Utilizamos varios métodos para investigar la cronología reproductiva de la población de Brachyramphus marmoratus en la Caleta Desolación de la Columbia Británica desde 1996 a 1998. Encontramos variaciones temporales en la época reproductiva entre años. En promedio, la estación reproductiva se extendió del 21 de abril al 5 de septiembre. Evaluamos el sesgo de los métodos utilizados comparando los resultados individuales con los resultados de la cronología obtenida al integrar todos los métodos. Los conteos de juveniles en el mar estuvieron sesgados hacia aquellas aves que anidan temprano, no detectando aproximadamente 24% de los juveniles producidos en la estación reproductiva. Los otros dos métodos, análisis fisiológico de muestras de sangre para detectar el precursor de vitelogenina en la yema y monitoreo por telemetría, podrían producir una distribución completa de las etapas reproductivas siempre que el muestreo se lleve a cabo a lo largo de todo el período de puesta. Las observaciones directas en los sitios de anidación, la fecha de la primera observación de juveniles en el mar y las observaciones de aves con pescado en el pico produjeron datos insuficientes para ser considerados indicadores únicos de la cronología reproductiva para esta especie. Con base en una revisión bibliográfica se investigó la sincronía reproductiva en álcidos, encontrándose que ésta no está relacionada con hábitos alimenticios pero que aumenta con la latitud (41% de la variación fue explicada por cambios latitudinales). Sin embargo, B. marmoratus se reprodujo menos sincrónico que lo predicho para un álcido a esta latitud (50°N).

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Marbled Murrelets (Brachyramphus marmoratus) foraging with gray whales (Eschrichtius robustus) off Vancouver Island, British Columbia

Canadian Journal of Zoology ◽

10.1139/cjz-2013-0033 ◽

2013 ◽

Vol 91 (12) ◽

pp. 847-852

Author(s):

K.A. Muirhead ◽

C.D. Malcolm ◽

D.A. Duffus

Keyword(s):

British Columbia ◽

Marine Mammals ◽

Prey Capture ◽

Vancouver Island ◽

Eschrichtius Robustus ◽

Brachyramphus Marmoratus ◽

Seabird Species ◽

Gray Whales ◽

Marbled Murrelet ◽

Marbled Murrelets

Seabirds are known to associate with marine mammals to facilitate prey capture. These occur when mammals either force prey near the surface or provide small scraps of larger prey victims. Gray whales (Eschrichtius robustus (Lilljeborg, 1861)) have been observed to provide invertebrate prey to a variety of seabird species; however, there are no published reports of Marbled Murrelets (Brachyramphus marmoratus (Gmelin, 1789)) feeding in association with gray whales. We observed Marbled Murrelets foraging within several metres of gray whales off Vancouver Island, British Columbia, feeding on epibenthic zooplankton in 2006 and 2008. Join-count statistics identified significant clustering (p = 0.1) of 258 Marbled Murrelets within 300 m of 39 feeding gray whales in June of 2006, and no association between 3 gray whales and 34 Marbled Murrelets in June and July of 2008, marking a foraging association conditional on the abundance of both gray whales and their prey, but potentially significant to Marbled Murrelet survival and fecundity.

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

Canadian Journal of Zoology ◽

10.1139/z93-346 ◽

1993 ◽

Vol 71 (12) ◽

pp. 2528-2540 ◽

Cited By ~ 39

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.

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