Sydeman, William J.; Bradley, Russell W.; Warzybok, Pete; Abraham, Christine L.; Jahncke, Jaime; Hyrenbach, K. David; Kousky, Vernon; Hipfner, J. Mark; Ohman, Mark D.
In spring-summer 2005, anomalous atmospheric-oceanographic coupling caused unprecedented reproductive failures and redistribution of a planktivorous marine bird in both central California (37°N) and southern British Columbia (50°N). At SE Farallon Island, CA, the birds abandoned the breeding colony en masse between 10-20 May, a unique behavioral response; for the first time in 35 years, reproductive success was zero. At Triangle Island, B.C., only 8% of the nesting pairs were successful, the worst year on record. Surveys of birds at sea revealed a peak in relative abundance south of Point Conception (34°N) in summer and fall, suggestive of emigration from the north. Prey (euphausiid crustacean) biomass in the Gulf of the Farallones was reduced, but remained high south of Point Conception. Change in predator and prey may be explained, in part, by unusual atmospheric blocking in the Gulf of Alaska in May, which caused the jet stream to shift southwards resulting in poor upwelling-favorable winds and anomalously warm SST. This study demonstrates the deleterious consequences of this climate event for a top marine predator in the central-northern California Current System.
Hunt, George L.; Harrison, Nancy M.; Piatt, John F.
We review recent accounts of the foraging ecologies of five species of small auklets found in the Bering Sea. These birds eat a wide variety of zooplankton and micronekton. Least Auklets Aethia pusilla and Whiskered Auklets A. pygmaea, as far as is known, primarily eat copepods, whereas Created Auklets A. cristatella appear to specialize on euphausiids, at least during the breeding season. The diet of Parakeet Auklets Cyclorrhynchus psittacula is much broader than that of most other Aethia species, and includes many gelatinous species and their commensals. Little is known of the diet of Cassin's Auklet Ptychoramphus aleuticus in the Bering Sea, although elsewhere they take large copepods, euphausiids, and larval fish.There are considerable differences in the at-sea distributions and foraging behaviors of these five species of auklet. Least Auklets in the norhtern Bering Sea concentrate their foraging activities over strongly stratified water and near fronts where pycnoclines may approach the surface. In the Aleutian Islands, Least Auklets forage where oceanic and tidal currents strike the shelf between the islands and rise toward the surface carrying plankton. Least Auklets and Crested Auklets are often found in large flocks, whereas Parakeet Auklets are rarely found in groups of more than three birds and are usually widely dispersed. The few at-sea observations of Whiskered Auklets have been of small flocks in turbulent waters of island passes. We relate prey types taken, foraging dispersion, and the use of hydrographic features by these auklet species.
Richman, Samantha E; Lovvorn, James R
For small aquatic endotherms, heat loss while floating on water can be a dominant energy cost, and requires accurate estimation in energetics models for different species. We measured resting metabolic rate (RMR) in air and on water for a small diving bird, the Cassin's auklet (Ptychoramphus aleuticus), and compared these results to published data for other diving birds of diverse taxa and sizes. For 8 Cassin's auklets (~165 g), the lower critical temperature was higher on water (21 °C) than in air (16 °C). Lowest values of RMR (W kg⁻¹) averaged 19% higher on water (12.14 ± 3.14 SD) than in air (10.22 ± 1.43). At lower temperatures, RMR averaged 25% higher on water than in air, increasing with similar slope. RMR was higher on water than in air for alcids, cormorants, and small penguins but not for diving ducks, which appear exceptionally resistant to heat loss in water. Changes in RMR (W) with body mass either in air or on water were mostly linear over the 5- to 20-fold body mass ranges of alcids, diving ducks, and penguins, while cormorants showed no relationship of RMR with mass. The often large energetic effects of time spent floating on water can differ substantially among major taxa of diving birds, so that relevant estimates are critical to understanding their patterns of daily energy use.
Bertram, Douglas F.; Mackas, David L.; Welch, David W.; Boyd, W. Sean; Ryder, John L.; Galbraith, Moira; Hedd, April; Morgan, Ken; O'Hara, Patrick D.
To investigate the causal basis for patterns of seabird foraging distributions during breeding we integrated data from ship-board seabird and zooplankton surveys, aerial radio telemetry, and colony-based research programs. We examined the marine distributions of Cassin's Auklet (Ptychoramphus aleuticus) breeding on Triangle Island, in the Northeast Pacific off the coast of B.C., Canada using surveys conducted in 1999, 2000, and 2001. Concurrently, we sampled zooplankton at 16 stations along a cross shelf transect in the vicinity of Triangle Island. In 1999 and 2000, when populations of the preferred copepod prey Neocalanus cristatus were available at deep-water stations (1000-2000 m), the majority of the auklets were concentrated SW of the colony 40-75 km offshore and parallel to, but 35 -50 km beyond the shelf break in deep water (1200-2000 m). Birds did not fly farther out to sea to where prey was five times more abundant when N. cristatus could be found at lower abundance levels, closer to the colony. In 2001, N. cristatus were virtually absent at the deep-water stations, likely as a result of massive salp (family Salpidae) aggregations which may have consumed and displaced the seabirds' preferred prey. We demonstrate that while birds were still able to locate and provision chicks with N. cristatus in 2001, they had to forage farther away from the colony in order to do so. Our telemetry results are generally consistent with analyses of at-sea distributions of Cassin's Auklets derived from ship-board surveys (1990-2010) both of which have contributed to the design of the proposed Scott Islands marine National Wildlife Area, the first of its kind in Canada.
In Fall/Winter 2014-15, more than 100,000 Cassin's Auklets, Ptychoramphus aleuticus, washed ashore on U.S. West Coast beaches. A small-bodied, zooplanktivorous bird, Cassin's nest in colonies scattered along the Northeast Pacific coastline, with a particular concentration in the Scott Islands, northwest of Vancouver Island, BC where 80% of the world's population ( 3.5M) breeds. Standardized, effort-controlled beach surveys conducted by >500 volunteers for three citizen science organizations (BeachCOMBERS, Beach Watch, COASST) at >225 sites from Cape Flattery, WA to Monterey Bay, CA were used to document the event and contrast it to regionally specific long-term average carcass-fall. Data are abundance of independently verified carcass identifications collected (bi)monthly at known locations and dates, providing an instantaneous index of "new" carcass encounter rate. Two pulses were evident: A small but significant anomaly (+2-3 carcasses/km) in November primarily in California and a much larger (+20-25 carcasses/km) more sustained anomaly in December-January along the Washington and northern Oregon coastline. Four non-exclusive hypotheses were examined: surplus production of young-of-the year (i.e. elevated post-breeding mortality), severity of fall/winter storms (i.e. elevated winterkill), shifts in food diversity (proxied as copepod regional diversity along the Newport Line), and habitat compression calculated as location and relative area of wintering habitat (assessed by GLS-tagged birds) with a monthly SST anomaly event can be explained by the extreme compression of cold water habitat in July-September 2014, trapping dispersing Scott Islands birds as the warm water anomaly expanded eastward, leaving open the question of whether this event was anomalous mortality and/or anomalously high beaching rates.
Hatch, Shyla A.
Nearshore counts of birds on the water and time-lapse photography were used to monitor seasonal activity patterns and interannual variation in numbers of Horned Puffins (Fratercula corniculata) and Parakeet Auklets (Aethia psittacula) at the Semidi Islands, Alaska. The best period for over-water counts was mid egg-laying through hatching in auklets and late prelaying through early hatching in puffins. Daily counts (07.00 h-09.30 h) varied widely, with peak numbers and days with few or no birds present occurring throughout the census period. Variation among annual means in four years amounted to 26% and 72% of total count variation in puffins and auklets, respectively. Time-lapse photography of nesting habitat in early incubation revealed a morning (08.00 h-12.00 h) peak in the number of puffins loitering on study plots. Birds recorded in time-lapse images never comprised more than a third of the estimated breeding population on a plot. Components of variance in the time-lapse study were 29% within hours, 9% among hours (08.00 h-12.00 h), and 62% among days (8-29 June). Variability of overwater and land-based counts is reduced by standardizing the time of day when counts are made, but weather conditions had little influence on either type of count. High international variation of population indices implies low power to detect numerical trends in crevice-nesting auklets and puffins.
Degernes, Laurel A; Wolf, Karen N; Zombeck, Debbie J; MacLean, Robert A; De Voe, Ryan S
A captive parakeet auklet at the North Carolina Zoo evaluated for weight loss, lethargy, and dyspnea had radiographic evidence of a distended, stone-filled ventriculus (bird 1). Multiple stones (n = 76) were removed surgically, but the bird died and a large ventricular diverticulum was diagnosed at necropsy. This bird and seven other parakeet auklets had been transferred 3 yr earlier from a zoo in Ohio. Radiographic investigation revealed that 6 of 7 Ohio birds had stones in their ventriculus (n= 2-26), but only 1 of 7 radiographed North Carolina Zoo auklets had one small stone. Further diagnostic imaging (survey and contrast radiographs, fluoroscopy, CT scans [n = 2]) of six Ohio and two North Carolina birds was conducted to determine if other birds had ventricular abnormalities (birds 2-9). No ventricular diverticula were diagnosed using imaging techniques, although two Ohio birds (birds 6 and 7) required surgical intervention to remove 12-26 stones. A small ventricular diverticulum was identified in bird 6 during surgery. That bird died of unrelated causes 11 mo after surgery, but bird 7 remains clinically normal more than 4 yr later, along with four other auklets with stones (n = 2-15; birds 2-5). It is possible that without surgical intervention, these birds may develop ventricular disease, presumably due to chronic mechanical trauma to the thin-walled ventriculus. It was hypothesized that the Ohio birds ingested stones in their previous exhibit, with a loose stone substrate, and retained them for at least 3 yr. Possible causes for stone ingestion include trituration (for grinding, mixing coarse ingesta), gastric parasite reduction, hunger suppression, accidental ingestion while feeding, or behavioral causes, but the underlying cause in these birds was not determined. Based on these results, parakeet auklets and other alcids should not be housed, or at least fed, on a loose stone substrate.
Drew, Gary S.; Piatt, John F.; Williams, Jeffrey C.
Crested Auklets (Aethia cristatella) and Least Auklets (A. pusilla) are crevice-nesting birds that breed in large mixed colonies at relatively few sites in the Aleutian Island archipelago, Bering Sea, Gulf of Alaska, and Sea of Okhotsk. Many of these colonies are located on active volcanic islands. The eruption of Kasatochi volcano, in the central Aleutians, on August 7, 2008, completely buried all crevice-nesting seabird habitat on the island. This provided an opportunity to examine the response of a large, mixed auklet colony to a major geological disturbance. Time-lapse imagery of nesting habitat indicated that both species returned to the largest pre-eruption colony site for several years, but subsequently abandoned it within 5 yr after the eruption. In 2010, a rockfall site in a cove north of the old colony site began to accumulate talus, and groups of auklets were observed using the site in 2011. Use of the new colony appeared to coincide with the abandonment of the old colony site by both species, though surface counts suggested that Least Auklets shifted to the new colony sooner than Crested Auklets. At-sea surveys of seabirds before and after the eruption indicated that both Crested and Least auklets shifted their at-sea distributions from the waters around Kasatochi Island to nearby Koniuji Island. In combination, at-sea counts and colony time-lapse imagery indicated that Crested and Least auklets using Kasatochi responded to the volcanic disturbance and complete loss of nesting habitat at the main colony on Kasatochi with dispersal either to newly created habitat on Kasatochi or to an alternate colony on a nearby island.
Douglas, Hector D.
Alloanointing, the transfer of chemicals between conspecifics, is known among mammals, but hitherto, the behavior has not been documented for birds. The crested auklet ( Aethia cristatella), a colonial seabird of Alaskan and Siberian waters, alloanoints during courtship with fragrant aldehydes that are released from specialized wick-like feathers located in the interscapular region. Crested auklets solicit anointment at the colony, and prospective mates rub bill, breast, head, and neck over wick feathers of their partners. This distributes aldehydes over the head, neck, and face where the birds cannot self-preen. The resulting chemical concentrations are sufficient to deter ectoparasites. Auklets that emit more odorant can transfer more defensive chemicals to mates and are thus more sexually attractive. Behavioral studies showed that crested auklets are attracted to their scent. Wild birds searched for dispensers that emitted their scent and rubbed their bills on the dispensers and engaged in vigorous anointment behaviors. In captive experiments, naïve crested auklets responded more strongly to synthetic auklet scent than controls, and the greatest behavioral response occurred during early courtship. This study extends scientific knowledge regarding functions of alloanointing. Alloanointing had previously been attributed to scent marking and individual recognition in vertebrates. Alloanointing is described here in the context of an adaptive social cue — the transfer of arthropod deterrents between prospective mates.
Bond, Alexander L; Jones, Ian L; Williams, Jeffrey C; Byrd, G Vernon
The ingestion of plastic marine debris is a chronic problem for some of the world's seabird species, contributing to reduced chick survival, population declines, and deposition of contaminants via absorption in birds' gastrointestinal tract. We analysed the frequency of ingested plastic in chick meals delivered by adults in four species of auklet - Crested (Aethia cristatella), Least (A. pusilla), Parakeet (A. psittacula), and Whiskered (A. pygmaea) - from three breeding colonies in the Aleutian Islands, Alaska, USA over a 14-year period from 1993 to 2006. Among 2541 chick meals, we found plastic in only one - from a Whiskered Auklet on Buldir Island in 1993. While adult Parakeet Auklets have a high frequency of plastic ingestion (over 90%), no chick meals contained plastic. Unlike other seabirds, the planktivorous auklets do not appear to offload plastic to their chicks, and we conclude that auklet chicks are probably at a low risk of contamination from plastic debris. Copyright 2010 Elsevier Ltd. All rights reserved.
Jones, Timothy; Parrish, Julia K.; Peterson, William T.; Bjorkstedt, Eric P.; Bond, Nicholas A.; Ballance, Lisa T.; Bowes, Victoria; Hipfner, J. Mark; Burgess, Hillary K.; Dolliver, Jane E.; Lindquist, Kirsten; Lindsey, Jacqueline; Nevins, Hannahrose M.; Robertson, Roxanne R.; Roletto, Jan; Wilson, Laurie; Joyce, Trevor; Harvey, James
Climate change has exacerbated the occurrence of large-scale sea surface temperature anomalies, or marine heatwaves (MHWs)—extreme phenomena often associated with mass mortality events of marine organisms. Using a combination of citizen science and federal data sets, we investigated the causal mechanisms of the 2014/2015 die-off of Cassin's Auklets (Ptychoramphus aleuticus), a small zooplanktivorous seabird, during the NE Pacific MHW of 2013-2015. Carcass deposition followed an effective reduction in the energy content of mesozooplankton, coincident with the loss of cold-water foraging habitat caused by the intrusion of the NE Pacific MHW into the nearshore environment. Models examining interannual variability in effort-controlled carcass abundance (2001-2014) identified the biomass of lipid-poor zooplankton as the dominant predictor of increased carcass abundance. In 2014, Cassin's Auklets dispersing from colonies in British Columbia likely congregated into a nearshore band of cooler upwelled water and ultimately died from starvation following the shift in zooplankton composition associated with onshore transport of the NE Pacific MHW. For Cassin's Auklets, already in decline due to ocean warming, large-scale and persistent MHWs might represent a global population precipice.
Carle, Ryan D.; Beck, Jessie N.; Calleri, David M.; Hester, Michelle M.
We used stable isotopes (δ15N and δ13C) and compared prey provided to chicks by each sex to evaluate seasonal and sex-specific diets in Rhinoceros Auklets (Cerorhinca monocerata) in the central California Current system during 2012-2013. Mixing models indicated northern anchovy (Engraulis mordax) were important prey for adults during fall/winter and juvenile rockfishes (Sebastes spp.) were important prey during incubation both years. Adult trophic level increased between incubation and chick-rearing periods in both years. During 2012, δ15N and δ13C of chick-rearing males and females differed significantly; mixing models indicated that females ate more Pacific saury (Cololabis saira) and less market squid (Doryteuthis opalescens) than males. Likewise, females delivered significantly more Pacific saury and less market squid to chicks than males during 2012. Chick growth (g d- 1) and chick survival to fledging were significantly lower during 2012 than 2013, likely because chicks were fed lesser quality prey or fed less frequently in 2012. Lesser body mass of females during incubation in 2012 indicated sex-specific diet differences may have been related to female energetic constraints. The observed variability in Rhinoceros Auklet diet underscores the importance of managing multiple prey populations in this system so that generalist predators have sufficient resources through changing conditions.
Koniukhov, N B; Zubakin, V A; Williams, J; Fischer, J
This is the second publication on the results of studies of the whiskered auklet breeding biology on Buldir Island. In 1993, according to the time of chick hatching the egg-laying period began in late April-early May. The single egg was incubated by both parents, which relieved each other once a day, usually at early night. Among the chicks under observation, the first hatched on June 11; the median of hatching was on June 17. After hatching, the egg shell usually remained in the nest. The chick was continuously brooded by one of parents for the first several days but since the age of 7-9 days, it stayed in the nest by itself during the daytime. Each parent fed the chick once a day, at early night, although occasional feedings were recorded also during daytime and at dawn. A newly hatched chick was covered by typical embryonal (natal) down. The remiges, rectrices, their coverts, and large feathers on pteryla humeralis had a mesoptile stage during their growth (the second down generation). The juvenile plumage consisted of semiplumes of types I and II and contour feathers of type I and, possibly, type II. In fledglings, the ornamental feathers were underdeveloped: the crest was absent and facial plumes only began growing. By reaching 100 g, the chicks left their nests at the age of about 37 days. A longer nesting period than in other Aethia auklets appears to be related to a low feeding rate due to the nocturnal activity in the colony.
Pence, D B; Hoberg, E P
In the genus Thalassornectes, a new subgenus, Alcidectes, and a new species, T. (Alcidectes) aukletae, are described from deutonymphs in the subcutaneous adipose tissue of the crested auklet, Aethia cristatella (Pallas), and the parakeet auklet, Cyclorrhynchus psittacula (Pallas), from the eastern Pacific USSR. The new subgenus and species differ from one or both of the single species in each of the other two subgenera, Thalassornectes and Rallidectes, by (1) the normal size, position, and parallel arrangement of the genital papillae; (2) the larger size of seta sce; (3) the greater length and stronger development of setae sci, d1, l1, h, and sh; (4) the equal size of tarsi III and IV or their size subequal, with tarsus IV slightly longer than tarsus III; (5) both epimera I and sternum well developed and nearly equal in length; and (6) the free sclerotized posteriad extension from epimerite II on the ventral cuticular surface. This is the first hypoderatid reported from the host order Charadriiformes. The distribution of T. (Alcidectes) aukletae among auklets may be attributed to either cospeciation or may have an ecological basis; data are insufficient at present to sustain either hypothesis.
Hipfner, J.M.; Hobson, K.A.; Elliott, J.E.
In 2003 and 2004, we measured mercury concentrations and δ 15 N and δ 13 C values in the whole blood of adults of two species of seabirds, Cassin's auklet (Ptychoramphus aleuticus) and rhinoceros auklet (Cerorhinca monocerata), during their prelaying, incubation, and provisioning periods. We also collected whole blood from the offspring of both seabirds. Among prey items, δ 15 N values were higher in fish than in crustaceans, while δ 13 C did not vary systematically between prey types. Mercury concentrations in prey showed little relationship with either stable isotope. In the zooplanktivorous Cassin's auklet, year, reproductive stage, and δ 15 N and δ 13 C stable isotope values explained only 14% of the variation in mercury concentrations in adult blood, and none of these variables had a statistically significant effect. In contrast, these same variables explained 41% of the variation in mercury levels in the more piscivorous rhinoceros auklet, and all but δ 15 N values had statistically significant effects. Mercury concentrations in adult rhinoceros auklets were higher in 2003 than in 2004; higher prior to laying than during the incubation or provisioning periods; and increased with δ 13 C values - but in just one of two years. In both species, mercury concentrations were substantially higher in adults than in nestlings. Our results accord with previous studies in showing that mercury concentrations can vary among years, species and age classes, while the marked variation with reproductive stage is noteworthy because it is so rarely considered. Our results may help to explain the disparate conclusions of previous studies: while many factors influence mercury concentrations in marine predators, they apparently do so in a manner that defies easy characterization. We believe that there is a need for more studies that consider a range of physiological, ecological and behavioral factors that might affect mercury burdens in marine predators. - Research
Jones, T.; Parrish, J.; MacCready, P.; Peterson, W. T.; Bjorkstedt, E.; Bond, N. A.; Ballance, L. T.; Bowes, V.; Hipfner, J. M.; Lindquist, K.; Lindsey, J.; Nevins, H. M.; Burgess, H. K.; Robertson, R.; Roletto, J.; Wilson, L.; Joyce, T. W.; Harvey, J.
Citizen science data collection is a powerful tool for documenting mass mortality events, as they often occur without warning and can be extensive in space, precluding standard methods of data collection. The Coastal Observation and Seabird Survey Team (COASST) is one such citizen science program that specializes in the collection of information on beachcast seabird abundance and identity. Using the COASST dataset, in combination with federal monitoring data and novel modeling techniques, we investigated the 2014/15 mass mortality event of Cassin's Auklets (Ptychoramphus aleuticus), a small zooplanktivorous seabird, that occurred during the largest marine heatwave (MHW) ever recorded - the NE Pacific MHW of 2014-2016. Estimated at 275,000-530,000 birds, or 11% of the global adult population, and spanning 2,000 km of the North American Pacific coastline, this marine bird die-off is among the largest ever recorded. Carcass deposition followed an effective reduction in the energy content of zooplankton, coincident with the loss of cold-water foraging habitat caused by the intrusion of the NE Pacific MHW. Models examining interannual variability in effort-controlled carcass abundance (2001-2014) identified the biomass of lipid-poor zooplankton as the primary predictor of increased carcass abundance, suggesting that the relative abundance of smaller, lipid-poor zooplankton is a strong predictor of Cassin's Auklets overwinter survival. Furthermore, dispersing Cassin's Auklets were likely compressed into a nearshore band of upwelled water, and ultimately died from starvation following the shift in zooplankton composition associated with the onshore transport of the NE Pacific MHW. The information regarding the magnitude of this event, as well as its causal mechanism, comes as a direct result of rigorous data collection by citizen science volunteers, demonstrating that citizen science can, and does, contribute to our understanding of how climate change is altering marine
Yuri V. Albores-Barajas
Full Text Available During 2004, we followed 72 natural burrows to determine the effects of disturbance on breeding success of Cassin's auklets (Ptychoramphus aleuticus. We used distance from a human settlement or path in the analysis of disturbance. Birds whose burrows were closer to the path or the village had a higher rate of nest abandonment and lower breeding success compared to birds nesting further away from the path or the village. Also, older and more experienced individuals represented a larger proportion of the breeding population on less disturbed areas than on highly disturbed ones, probably as older individuals tend to arrive earlier at the breeding grounds, and failed breeders may change burrow sites to move away from disturbance. P. aleuticus are adversely affected by human activity at colonies even if birds are not handled and burrows are not opened, and this has implications for conservation, and planning of ecotourism. On the long term, this can have negative consequences for this species and others with similar characteristics.Durante el 2004 seguimos 72 nidos de la alcuela (Ptychoramphus aleuticus para determinar los efectos de disturbio en el éxito reproductivo. Utilizamos la distancia del nido a áreas asentamientos humanos o al camino como medidas de disturbio. Los nidos que estaban más cerca de los asentamientos o del camino tuvieron una tasa de abandono mayor y un éxito reproductivo menor en comparación con los nidos que estaban más alejados de las fuentes de disturbio. También observamos que en las zonas menos expuestas la proporción de adultos, con mayor experiencia, era más alta, posiblemente porque los individuos con mayor experiencia llegan antes a la zona de anidación. Las alcuelas son afectadas negativamente por la presencia de los humanos y sus actividades, aunque las aves no entren en contacto directo con los humanos. A largo plazo, esto puede acarrear consecuencias graves para esta especie y otras con caracter
Abstract.-Four species of alcids have now been recorded frorn Hawaii. Two of them, the Tufted Puffin (Fratercula cirrhata and the Cassin's Auklet (Ptychoramchus aleuticus) have been found only once; the occurrence of the latter is reported here for the first time. two other alcids, the Horned Puffin (Fratercula arctica) and the Parakeet .Auklet (Cyclorrhynchus psittacula) have been recorded frorn Hawaii in greater numbers; the latter may be of regular occurrence in subtropical waters near the northwestern portion of the Hawaiian archipelago. Occurrence in Hawaii does not appear to be strongly related to size of populations to the north but instead to the extent to which the species are known to disperse.
National Oceanic and Atmospheric Administration, Department of Commerce — The Office ofNational Marine Sanctuary Program (ONMS) updates and revises the management plans for each of its 13 sanctuaries. This process, which is open to the...
Adams, Josh; Felis, Jonathan J.; Mason, John W.; Takekawa, John Y.
counted (19,033) with Common Murres (Uria aalge) representing the majority of individuals counted (70.4% of total). The remaining six most abundant taxa included: Surf/White-winged Scoters (Melanitta perspicillata/M. fusca; 4.8% of total), Herring/Thayer’s Gulls (Larus argentatus/L. thayeri; 3.8% of total), Cassin’s Auklets (Ptychoramphus aleuticus; 3.8% of total), Glaucous-winged Gulls (Larus glaucescens; 3.7% of total), Black-legged Kittiwakes (Rissa tridactyla; 2.0% of total), and Western Gulls (Larus occidentalis; 1.9% of total). During summer, five species comprised >95% of the total number of birds counted (17,063) with the majority comprised of Common Murres (54.1% of total) and Sooty Shearwaters (Puffinus griseus; 34.4% of total). The remaining most abundant three taxa included: Fork-tailed Storm-Petrels (Oceanodroma furcata; 3.3% of total), Western Gulls (2.1% of total), and Leach’s Storm-Petrels (Oceanodroma leucorhoa; 1.1% of total). During fall, nine species comprised >85% of the total number of birds counted (23,376) with the majority comprised of Common Murres (50.0% of total) and Sooty Shearwaters (10.5% of total). The remaining seven taxa included Cassin’s Auklets (5.2% of total), Surf/White-winged Scoters (5.1% of total), Fork-tailed Storm-Petrels (3.8% of total), Red/Red-necked Phalaropes (Phalaropus fulicarius/P. lobatus; 3.2% of total), California Gulls (Larus californicus; 3.1% of total), Northern Fulmars (Fulmarus glacialis; 2.7% of total), and Sabine’s Gulls (Xema sabini; 2.2% of total). Throughout the entire PaCSEA survey area, average densities (± SE) at sea for all marine birds combined were similar between fall (23.7 ± 1.9 birds km-2) and winter (24.0 ± 1.9 birds km-2) and least during summer (16.3 ± 2.2 birds km-2). Marine bird densities at sea varied according to bathymetric domain and season. Throughout the entire PaCSEA study area average densities (± SE) for all marine birds combined were greatest over the inner-shelf domain
Full Text Available Understanding seabird habitat preferences is critical to future wildlife conservation and threat mitigation in California. The objective of this study was to investigate drivers of seabird habitat selection within the Gulf of the Farallones and Cordell Bank National Marine Sanctuaries to identify areas for targeted conservation planning. We used seabird abundance data collected by the Applied California Current Ecosystem Studies Program (ACCESS from 2004-2011. We used zero-inflated negative binomial regression to model species abundance and distribution as a function of near surface ocean water properties, distances to geographic features and oceanographic climate indices to identify patterns in foraging habitat selection. We evaluated seasonal, inter-annual and species-specific variability of at-sea distributions for the five most abundant seabirds nesting on the Farallon Islands: western gull (Larus occidentalis, common murre (Uria aalge, Cassin's auklet (Ptychorampus aleuticus, rhinoceros auklet (Cerorhinca monocerata and Brandt's cormorant (Phalacrocorax penicillatus. The waters in the vicinity of Cordell Bank and the continental shelf east of the Farallon Islands emerged as persistent and highly selected foraging areas across all species. Further, we conducted a spatial prioritization exercise to optimize seabird conservation areas with and without considering impacts of current human activities. We explored three conservation scenarios where 10, 30 and 50 percent of highly selected, species-specific foraging areas would be conserved. We compared and contrasted results in relation to existing marine protected areas (MPAs and the future alternative energy footprint identified by the California Ocean Uses Atlas. Our results show that the majority of highly selected seabird habitat lies outside of state MPAs where threats from shipping, oil spills, and offshore energy development remain. This analysis accentuates the need for innovative marine
...); Actitis hypoleucos (Common Sandpiper) is listed as Tringa hypoleucos (J & R); Aethia psittacula (Parakeet Auklet) is listed as Cyclorrhynchus psittacula (R); Anas americana (American Wigeon) is listed as Mareca... Cuculus optatus (AOU 2006); Cyclorrhynchus psittacula (Parakeet Auklet) becomes Aethia psittacula (AOU...
Renner, H.M.; Renner, M.; Reynolds, J.H.; Harping, A.M.A.; Jones, I.L.; Irons, D.B.; Byrd, G.V.
Monitoring populations of auklets and other crevice-nesting seabirds remains problematic, although numerous methods have been attempted since the mid-1960s. Anecdotal evidence suggests several large auklet colonies have recently decreased in both abundance and extent, concurrently with vegetation encroachment and succession. Quantifying changes in the geographical extent of auklet colonies may be a useful alternative to monitoring population size directly. We propose a standardized method for colony mapping using a randomized systematic grid survey with two components: a simple presence/absence survey and an auklet evidence density survey. A quantitative auklet evidence density index was derived from the frequency of droppings and feathers. This new method was used to map the colony on St. George Island in the southeastern Bering Sea and results were compared to previous colony mapping efforts. Auklet presence was detected in 62 of 201 grid cells (each grid cell = 2500 m2) by sampling a randomly placed 16 m2 plot in each cell; estimated colony area = 155 000 m2. The auklet evidence density index varied by two orders of magnitude across the colony and was strongly correlated with means of replicated counts of birds socializing on the colony surface. Quantitatively mapping all large auklet colonies is logistically feasible using this method and would provide an important baseline for monitoring colony status. Regularly monitoring select colonies using this method may be the best means of detecting changes in distribution and population size of crevice-nesting seabirds. ?? The Cooper Ornithological Society 2006.
National Oceanic and Atmospheric Administration, Department of Commerce — This project is examining contaminant loads of fish prey species of a resident marine bird (Rhinoceros Auklet) breeding in inland waters (Puget Sound) and in the...
Harrison, Nancy M.; L Hunt Jr., George; Cooney, Robert T.
We observed seabirds aggregated at a front marking the boundary between two water masses in the Bering Sea. Least Auklets (Aethia pusilla) were most abundant at the front; surface-feeding species including Northern Fulmars (Fulmarus glacialis), Black-legged Kittiwakes (Rissa tridactyla) and Red Phalaropes (Phalaropusfuscus) were also present.
S UNK Lichnanthe albopilosa White sand dune scarab beetle – S UNK Myotis ciliolabrum Small-footed myotis – S UNK Myotis evotis Long-eared myotis...many seabirds, including western gull and rhinoceros auklet (Cerorhinca monocerata). Regionally rare and declining species observed in the area
rhinoceros auklet; red-winged blackbird; red-tailed hawk; great horned owl; and golden eagle have also been spotted. (U.S. Department of the Air Force...Coleoptera ( beetles ). (WILC Supplemental EA, 1999) The main predators on the island include feral cats and rats. Skinks and geckos (introduced
Haney, J. Christopher
Systematic ship-board surveys were used to simultaneously record seabird abundances and resolve coarse-scale (3 to 10 km) horizontal and fine-scale (1 to 10 m) vertical variability in water-column structure and bathymetry for portions of the coastal zone in Anadyr Strait near western St. Lawrence Island, northern Bering Sea, Alaska, during August and September 1987. Three plankton-feeding alcids, parakeet (Cyclorrhynchus psittacula), crested (Aethia cristatella) and least (A. pusilla) auklets, each exhibited distinct associations for different pycnocline characteristics. Least auklets were more abundant in mixed water, but they also occurred within stratified water where the pycnocline and upper-mixed layer were shallow (≤8 m) and thin (≤10 m), respectively. Low body mass (85 g), high buoyancy, and relatively poor diving ability may have restricted this auklet to areas where water-column strata nearly intersected the surface, or to areas from which strata were absent altogether due to strong vertical mixing. Parakeet and crested auklets, which are larger-bodied (ca. 260 g) planktivores with presumably greater diving ability, were more abundant in stratified water, and both species exhibited less specific affinities for water-column characteristic at intermediate and shallow levels. All three auklets avoided locations with strong pycnocline gradients (≤0.22σtm−1), a crude index of the strong, subsurface shear in water velocities characteristic of this region. Auklet distributions in Anadyr Strait were consistent with: (1) strata accessibility, as estimated from relationships between body mass and relative diving ability, (2) possible avoidance of strong subsurface water motions, and (3) habits and distributions of plankton prey. In contrast, largebodied (>450 g) alcids [i.e., common (Uria aalge) and thick-billed (U. lomvia) murres, pigeon guillemots (Cephus columba), tufted (Fratercula cirrhata), and horned (F. corniculata) puffins feeding on fish or
Bodenstein, Barbara L.; Kimberlee Beckmen,; Gay Sheffield,; Kathy Kuletz,; Van Hemert, Caroline R.; Berlowski-Zier, Brenda M.; Shearn-Bochsler, Valerie I.
The first known avian cholera outbreak among wild birds in Alaska occurred during November 2013. Liver, intestinal, and splenic necrosis consistent with avian cholera was noted, and Pasteurella multocida serotype 1 was isolated from liver and lung or spleen in Crested Auklets (Aethia cristatella), Thick-billed Murres (Uria lomvia), Common Eider (Somateria mollissima), Northern Fulmars (Fulmarus glacialis), and Glaucous-winged Gulls (Larus glaucescens).
Sears, J.; Hatch, Shyla A.; O'Brien, D. M.
A growing number of studies suggest that an individual's physiology affects its carbon and nitrogen stable isotope signatures, obscuring a signal often assumed to be only a reflection of diet and foraging location. We examined effects of growth and moderate food restriction on red blood cell (RBC) and feather ??15N and ??13C in rhinoceros auklet chicks (Cerorhinca monocerata), a piscivorous seabird. Chicks were reared in captivity and fed either control (75 g/day; n = 7) or ~40% restricted (40 g/day; n = 6) amounts of high quality forage fish. We quantified effects of growth on isotopic fractionation by comparing ??15N and ??13C in control chicks to those of captive, non-growing subadult auklets (n = 11) fed the same diet. To estimate natural levels of isotopic variation, we also collected blood from a random sample of free-living rhinoceros auklet adults and chicks in the Gulf of Alaska (n = 15 for each), as well as adult feather samples (n = 13). In the captive experiment, moderate food restriction caused significant depletion in ??15N of both RBCs and feathers in treatment chicks compared to control chicks. Growth also induced depletion in RBC ??15N, with chicks exhibiting lower ??15N when they were growing the fastest. As growth slowed, ??15N increased, resulting in an overall pattern of enrichment over the course of the nestling period. Combined effects of growth and restriction depleted ??15N in chick RBCs by 0.92???. We propose that increased nitrogen-use efficiency is responsible for 15N depletion in both growing and food-restricted chicks. ??15N values in RBCs of free-ranging auklets fell within a range of only 1.03???, while feather ??15N varied widely. Together, our captive and field results suggest that both growth and moderate food restriction can affect stable isotope ratios in an ecologically meaningful way in RBCs although not feathers due to greater natural variability in this tissue. ?? 2008 Springer-Verlag.
Piatt, John F.; Wells, John L.; MacCharles, Andrea; Fadely, Brian S.; Montevecchi, W.A.; Gaston, A.J.
In late August 1988, we studied the distribution of seabirds in the southeastern Chukchi Sea, particularly in waters near a major seabird colony at Cape Thompson. Foraging areas were characterized using hydrographic data obtained from hydroacoustic surveys for fish. Murres (Uria spp.) and Black-legged Kitttiwakes Rissa tridactyla breeding at Cape Thompson fed mostly on Arctic cod, which are known from previous studies to be the most abundant pelagic fish in the region. Our hydroacoustic surveys revealed that pelagic fish were distributed widely, but densities were estimated to be low (e.g., 0.1-10 g∙m-3) throughout the study area and a few schools were recorded. Large feeding flocks of murres and kittiwakes were observed over fish schools with densities estimated to exceed 15 g∙m-3. Fish densities were higher in shallow Alaska Coastal Current waters than offshore in Bering Sea waters, and most piscivorous seabirds foraged in coastal waters. Poor kittiwake breeding success and a low frequency of fish in murre and kittiwake stomachs in late August suggested that fish densities were marginal for sustaining breeding seabirds at that time. Planktivorous Least Auklets Aethia pusilla and Parakeet Auklets Cyclorrhynchus psittacula foraged almost exclusively in Bering Sea waters. Short-tailed Shearwaters Puffinus tenuirostris and Tufted Puffins Fratercula cirrhata foraged in transitional waters at the front between Coastal and Bering Sea currents.
Tsygankov, Vasiliy Yu; Boyarova, Margarita D; Lukyanova, Olga N; Khristoforova, Nadezhda K
Organochlorine pesticides (OCPs), such as HCHs and DDTs, are still used as pesticides in the Southern Hemisphere and can reach the North Pacific due to long range atmospheric transfer. Marine mammals (Pacific walrus Odobenus rosmarus divergens, gray whale Eschrichtius robustus), the seabirds (Pacific gull Larus schistisagus, crested auklet Aethia cristatella, auklet crumb Aethia pusilla, northern fulmar Fulmarus glacialis, and grey petrel Oceanodroma furcata) and Pacific salmon (pink Oncorhynchus gorbuscha, chum O. keta, chinook O. tshawytscha, and sockeye O. nerka) were collected near the Kuril Islands (the northern-western part of the Pacific Ocean), in the Sea of Okhotsk and the Bering Sea. The total OCPs concentration (HCHs + DDTs) was found in each organism, including the Pacific walrus (70-90,263 ng/g lipid), the seabirds (29-16,095 ng/g lipid), and the Pacific salmon (41-7103 ng/g lipid). The concentrations and possible sources of OCPs in marine organisms as biological indicators are discussed.
Bond, Alexander L.; Evans, William C.; Jones, Ian L.
We identified natural pits associated with avian mortality at the base of Kiska Volcano in the western Aleutian Islands, Alaska in 2007. Living, moribund, and dead birds were regularly found at low spots in a canyon between two lava flows during 2001–2006, but the phenomenon was attributed to natural trapping and starvation of fledgling seabirds (mostly Least Auklets, Aethia pusilla) at a colony site with >1 million birds present. However, 302 birds of eight species, including passerines, were found dead at the site during 2007–2010, suggesting additional factors were involved. Most carcasses showed no signs of injury and concentrations of dead birds had accumulated in a few distinctive low pits in the canyon. Gas samples from these locations showed elevated CO2 concentrations in late 2010. Analysis of carcasses indicated no evidence of blunt trauma or internal bleeding. Volcanic gases accumulating at these poorly ventilated sites may have caused the observed mortality, but are temporally variable. Most auklets breeding in the Aleutian Islands do so in recent lava flows that provide breeding habitat; our study documents a cost of this unusual habitat selection.
Will, Alexis P; Suzuki, Yuya; Elliott, Kyle H; Hatch, Scott A; Watanuki, Yutaka; Kitaysky, Alexander S
In nest-bound avian offspring, food shortages typically trigger a release of the stress hormone corticosterone (CORT). Recent studies indicate that CORT is passively deposited in the tissue of growing feathers and thus may provide an integrated measure of stress incurred during development in the nest. The current hypothesis predicts that, assuming a constant rate of feather growth, elevated CORT circulating in the blood corresponds to higher levels of CORT in feather tissue, but experimental evidence for nutritionally stressed chicks is lacking. Here, we examined how food limitation affects feather CORT content in the rhinoceros auklet (Cerorhinca moncerata). We (i) used captive chicks reared on control versus restricted diets, and (ii) applied this technique to free-living chicks with unknown nutritional histories that fledged at three separate colonies. We found that (i) feather growth was not affected by experimentally induced nutritional stress; (ii) captive chicks raised on a restricted diet had higher levels of CORT in their primary feathers; (iii) feather CORT deposition is a sensitive method of detecting nutritional stress; and (iv) free-living fledglings from the colony with poor reproductive performance had higher CORT in their primary feathers. We conclude that feather CORT is a sensitive integrated measure revealing the temporal dynamics of food limitations experienced by rhinoceros auklet nestlings. The use of feather CORT may be a powerful endocrine tool in ecological and evolutionary studies of bird species with similar preferential allocation of limited resources to feather development. © 2014. Published by The Company of Biologists Ltd.
Temporal trends of perfluoroalkyl substances (PFAS) in eggs of coastal and offshore birds: Increasing PFAS levels associated with offshore bird species breeding on the Pacific coast of Canada and wintering near Asia.
Miller, Aroha; Elliott, John E; Elliott, Kyle H; Lee, Sandi; Cyr, Francois
Perfluoroalkyl substances (PFAS) such as perfluoroalkyl carboxylates (PFCAs) and perfluoroalkyl sulfonates (PFSAs) have become virtually ubiquitous throughout the environment, and, based on laboratory studies, have known toxicological consequences. Various national and international voluntary phase-outs and restrictions on these compounds have been implemented over the last 10 to 15 years. In the present study, we examine trends (1990/1991-2010/2011) in aquatic birds (ancient murrelet, Synthliboramphus antiquus [2009 only]; Leach's storm-petrels, Oceanodroma leucorhoa; rhinoceros auklets, Cerorhinca monocerata; double-crested cormorants, Phalacrocorax auritus; and great blue herons, Ardea herodias). The PFCA, PFSA, and stable isotope (δ(15) N and δ(13) C) data collected from these species from the Pacific coast of Canada, ranging over 20 to 30 years, were used to investigate temporal changes in PFAS coupled to dietary changes. Perfluorooctane sulfonic acid (PFOS), the dominant PFSA compound in all 4 species, increased and subsequently decreased in auklet and cormorant eggs in line with the manufacturing phase-out of PFOS and perfluorooctanoic acid (PFOA), but concentrations continuously increased in petrel eggs and remained largely unchanged in heron eggs. Dominant PFCA compounds varied between the offshore and coastal species, with increases seen in the offshore species and little or variable changes seen in the coastal species. Little temporal change was seen in stable isotope values, indicating that diet alone is not driving observed PFAS concentrations. © 2015 SETAC.
Tocidlowski, M E; Cornish, T E; Loomis, M R; Stoskopf, M K
Sixteen horned puffin (Fratercula corniculata) and six parakeet auklet (Cyclorrhynchus psittacula) chicks of various prefledging ages were caught in Alaska and transported to the North Carolina Zoological Park (USA) in August 1995. Six of the 16 puffin chicks died within a 5-day period beginning 2 days after their arrival into quarantine at the zoo. The birds that died were collected at a young age, weighed 45.4-65.7 g, and had been fed a diet of thawed frozen ocean silversides (Atherinidae) that was not supplemented with vitamins. Clinical signs were nonspecific, and gross necropsies, insecticide toxicology screens, and bacterial cultures were unremarkable. Microscopic examination of tissues from five of the six birds showed myocardial necrosis and degeneration suggestive of vitamin E deficiency and intestinal protozoa resembling Microsporidia. The mortality pattern and histopathologic lesions observed in this case support the use of selective age capture and vitamin supplementation for wild alcid chick collection.
Robards, Martin D.; Piatt, John F.; Wohl, Kenton D.
We examined gut contents of 1799 seabirds comprising 24 species collected in 1988-1990 to assess the types and quantities of plastic particles ingested by seabirds in the subarctic waters of Alaska. Of the 15 species found to ingest plastic, most were surface-feeders (shearwaters, petrels, gulls) or plankton-feeding divers (auklets, puffins). Of 4417 plastic particles examined, 76% were industrial pellets and 21% were fragments of ‘user’ plastic. Ingestion rates varied geographically, but no trends were evident and rates of plastic ingestion varied far more among species within areas than within species among areas. Comparison with similar data from 1968 seabirds comprising 37 species collected in 1969-1977 revealed that plastic ingestion by seabirds has increased significantly during the 10–15-year interval between studies. This was demonstrated by: (i) an increase in the total number of species ingesting plastic; (ii) an increase in the frequency of occurrence of plastic particles within species that ingested plastic; and, (iii) an increase in the mean number of plastic particles ingested by individuals of those species.
Avery-Gomm, S; Provencher, J F; Morgan, K H; Bertram, D F
In addition to monitoring trends in plastic pollution, multi-species surveys are needed to fully understand the pervasiveness of plastic ingestion. We examined the stomach contents of 20 bird species collected from the coastal waters of the eastern North Pacific, a region known to have high levels of plastic pollution. We observed no evidence of plastic ingestion in Rhinoceros Auklet, Marbled Murrelet, Ancient Murrelet or Pigeon Guillemot, and low levels in Common Murre (2.7% incidence rate). Small sample sizes limit our ability to draw conclusions about population level trends for the remaining fifteen species, though evidence of plastic ingestion was found in Glaucous-Winged Gull and Sooty Shearwater. Documenting levels of plastic ingestion in a wide array of species is necessary to gain a comprehensive understanding about the impacts of plastic pollution. We propose that those working with bird carcasses follow standard protocols to assess the levels of plastic ingestion whenever possible. Copyright © 2013 Elsevier Ltd. All rights reserved.
Koval, M. V.; Gorin, S. L.; Romanenko, F. A.; Lepskaya, E. V.; Polyakova, A. A.; Galyamov, R. A.; Esin, E. V.
New data on the abiotic conditions; species composition; abundance, distribution, and migrations of fauna; and feeding interactions in an estuary ecosystem were obtained during expeditions in the mouths of Penzhina and Talovka rivers (northwest Kamchatka). It is revealed that in the ice-free season, the hydrological regime of the estuary is determined by seasonal fluctuations of river runoff, as well as fortnightly and daily variation of tides. The estuary is characterized by hypertidal fluctuations (up to 10-12 m); strong reverse flows (up to 1.0-1.5 m/s), considerable tidal variations in salinity (from 0 to 6-9‰ at the river boundary and from 6-8 to 14-16‰ at the offshore boundary), and high water turbidity (up to 1 000 NTU or more). Based on the spatial structure of the community, three ecological zones with mobile boundaries are distinguished: freshwater (salinity 0-0.1‰), estuarine (0-12.3‰), and neritic (11.2-18.9‰). High turbidity prevents the development of phytoplankton in the estuarine zone (EZ), and the local benthic community is significantly depleted due to the desalination and wide spread of aleuritic silts. Neritic copepods and nektobenthic brackish- water crustaceans generate the maximum abundance and biomass here. The species that have adapted to the local extreme hydrologic conditions dominate and form the basis of the estuarine food chain. Dominant among the EZ vertebrates are such groups as anadromous fishes (smelts, pacific salmons, charrs, and sticklebacks); waterfowl (terns, kittiwakes, cormorants, fulmars, puffins, guillemots, auklets, and wadepipers); and predatory marine mammals (larga, ringed seal, bearded seal, and white whale). The total abundance and biomass of these animals are much higher in the pelagic EZ in comparison to neighboring zones.
Sydeman, William J.; Piatt, John F.; Thompson, Sarah Ann; Garcia-Reyes, Marisol; Hatch, Scott A.; Arimitsu, Mayumi L.; Slater, Leslie; Williams, Jeffrey C.; Rojek, Nora A.; Zador, Stephani G.; Renner, Heather M.
Long-term studies of predator food habits (i.e., ‘predator-based sampling’) are useful for identifying patterns of spatial and temporal variability of forage nekton in marine ecosystems. We investigated temporal changes in forage fish availability and relationships to ocean climate by analyzing diet composition of three puffin species (horned puffin Fratercula corniculata, tufted puffin Fratercula cirrhata, and rhinoceros auklet Cerorhinca monocerata) from five sites in the North Pacific from 1978–2012. Dominant forage species included squids and hexagrammids in the western Aleutians, gadids and Pacific sand lance (Ammodytes personatus) in the eastern Aleutians and western Gulf of Alaska (GoA), and sand lance and capelin (Mallotus villosus) in the northern and eastern GoA. Interannual fluctuations in forage availability dominated variability in the western Aleutians, whereas lower-frequency shifts in forage fish availability dominated elsewhere. We produced regional multivariate indicators of sand lance, capelin, and age-0 gadid availability by combining data across species and sites using Principal Component Analysis, and related these indices to environmental factors including sea level pressure (SPL), winds, and sea surface temperature (SST). There was coherence in the availability of sand lance and capelin across the study area. Sand lance availability increased linearly with environmental conditions leading to warmer ocean temperatures, whereas capelin availability increased in a non-linear manner when environmental changes led to lower ocean temperatures. Long-term studies of puffin diet composition appear to be a promising tool for understanding the availability of these difficult-to-survey forage nekton in remote regions of the North Pacific.
Causey, D.; Bargmann, N. A.; Burnham, K. K.; Burnham, J. L.; Padula, V. M.; Johnson, J. A.; Welker, J. M.
Understanding the complex dynamics of environmental change in northern latitudes is of paramount importance today, given documented rapid shifts in sea ice, plant phenology, temperatures, deglaciation, and habitat fidelity. This knowledge is particularly critical for Arctic avian communities, which are integral components by which biological teleconnections are maintained between the mid and northern latitudes. Furthermore, Arctic birds are fundamental to Native subsistence lifestyles and a focus for conservation activities. Avian communities of marine and terrestrial Arctic environments represent a broad spectrum of trophic levels, from herbivores (eg., geese Chen spp.), planktivores (eg., auklets Aethia spp.), and insectivores (eg., passerines: Wheatears Oenanthe spp., Longspurs Calcarius spp.), to predators of marine invertebrates (eg., eiders Somateria spp.), nearshore and offshore fish (eg., cormorants Phalacrocorax spp, puffins Fratercula spp.), even other bird species (eg., gulls Larus spp., falcons Peregrinus spp.). This diversity of trophic interconnections is an integral factor in the dynamics of Arctic ecosystem ecology, and they are key indicators for the strength and trajectories of change. We are especially interested in their feeding ecology, using stable isotope-diet relations to examine historical diets and to predict future feeding ecology by this range of species. Since 2009, we have been studying the foodweb ecology using stable isotopes (δ13C, δ15N, δ34S) of contemporaneous coastal and marine bird communities in High Arctic (Northwest Greenland) and Low Arctic (western Aleutian Islands, AK). We are quantifying the isotopic values of blood, organ tissues, and feathers, and have carried out comparisons between native and lipid-extracted samples. Although geographically distant, these communities comprise similar taxonomic and ecological congeners, including several species common to both (eg., Common Eider, Black-legged Kittiwake, Northern
Cochrane, Guy R.; Dartnell, Peter; Greene, H. Gary; Johnson, Samuel Y.; Golden, Nadine E.; Hartwell, Stephen R.; Dieter, Bryan E.; Manson, Michael W.; Sliter, Ray W.; Ross, Stephanie L.; Watt, Janet T.; Endris, Charles A.; Kvitek, Rikk G.; Phillips, Eleyne L.; Erdey, Mercedes D.; Chin, John L.; Bretz, Carrie K.
area), although its associated phylogeographic group of marine fauna may extend beyond to the area offshore of Los Angeles in southern California. The ocean off central California has experienced a warming over the last 50 years that is driving an ecosystem shift away from the productive subarctic regime towards a depopulated subtropical environment. Seafloor habitats in the Offshore of Half Moon Bay map area, which lies within the Shelf (continental shelf) megahabitat, range from significant rocky outcrops that support kelp-forest communities nearshore to rocky-reef communities in deep water. Biological productivity resulting from coastal upwelling supports populations of sea birds such as Sooty Shearwater, Western Gull, Common Murre, Cassin’s Auklet, and many other less populous bird species. In addition, an observable recovery of Humpback and Blue Whales has occurred in the area; both species are dependent on coastal upwelling to provide nutrients. The large extent of exposed inner shelf bedrock supports large forests of “bull kelp,” which is well adapted for high wave-energy environments. Common fish species found in the kelp beds and rocky reefs include lingcod and various species of rockfish and greenling.
Cochrane, Guy R.; Dartnell, Peter; Greene, H. Gary; Watt, Janet T.; Golden, Nadine E.; Endris, Charles A.; Phillips, Eleyne L.; Hartwell, Stephen R.; Johnson, Samuel Y.; Kvitek, Rikk G.; Erdey, Mercedes D.; Bretz, Carrie K.; Manson, Michael W.; Sliter, Ray W.; Ross, Stephanie L.; Dieter, Bryan E.; Chin, John L.; Cochran, Susan A.; Cochrane, Guy R.; Cochran, Susan A.
over the last 50 years that is driving an ecosystem shift away from the productive subarctic regime towards a depopulated subtropical environment. Seafloor habitats in the Offshore of San Gregorio map area, which lies within the Shelf (continental shelf) megahabitat, range from significant rocky outcrops that support kelp-forest communities nearshore to rocky-reef communities in deep water. Biological productivity resulting from coastal upwelling supports diverse populations of sea birds such as Sooty Shearwater, Western Gull, Common Murre, Cassin's Auklet, and many other less populous bird species. In addition, an observable recovery of Humpback and Blue Whales has occurred in the area; both species are dependent on coastal upwelling to provide nutrients. The large extent of exposed inner shelf bedrock supports large forests of "bull kelp," which is well adapted for high wave-energy environments. Common fish species found in the kelp beds and rocky reefs include lingcod and various species of rockfish and greenling.
Cochrane, Guy R.; Dartnell, Peter; Johnson, Samuel Y.; Erdey, Mercedes D.; Golden, Nadine E.; Greene, H. Gary; Dieter, Bryan E.; Hartwell, Stephen R.; Ritchie, Andrew C.; Finlayson, David P.; Endris, Charles A.; Watt, Janet T.; Davenport, Clifton W.; Sliter, Ray W.; Maier, Katherine L.; Krigsman, Lisa M.; Cochrane, Guy R.; Cochran, Susan A.
phylogeographic group of marine fauna may extend beyond to the area offshore of Los Angeles in southern California. The ocean off of central California has experienced a warming over the last 50 years that is driving an ecosystem shift away from the productive subarctic regime towards a depopulated subtropical environment.Biological productivity resulting from coastal upwelling supports populations of Sooty Shearwater, Western Gull, Common Murre, Cassin’s Auklet, and many other less populous bird species. In addition, an observable recovery of Humpback and Blue Whales has occurred in the area; both species are dependent on coastal upwelling to provide nutrients. The large extent of exposed inner shelf bedrock supports large forests of “bull kelp,” which is well adapted for high-wave-energy environments. The kelp beds are the northernmost known habitat for the population of southern sea otters. Common fish species found in the kelp beds and rocky reefs include lingcod and various species of rockfish and greenling.
Johnson, Samuel Y.; Dartnell, Peter; Hartwell, Stephen R.; Cochrane, Guy R.; Golden, Nadine E.; Watt, Janet T.; Davenport, Clifton W.; Kvitek, Rikk G.; Erdey, Mercedes D.; Krigsman, Lisa M.; Sliter, Ray W.; Maier, Katherine L.; Johnson, Samuel Y.; Cochran, Susan A.
swells from the northwest throughout the year. Wave heights range from 2 to 10 m, the larger swells occurring from October to May. During El Niño–Southern Oscillation (ENSO) events, winter storms track farther south than they do in normal (non-ENSO) years, thereby impacting the map area more frequently and with waves of larger heights.Benthic species observed in the map area are natives of the cold-temperate biogeographic zone that is called either the “Oregonian province” or the “northern California ecoregion.” This biogeographic province is maintained by the long-term stability of the southward-flowing California Current, the eastern limb of the North Pacific subtropical gyre that flows from southern British Columbia to Baja California.Biological productivity resulting from coastal upwelling supports populations of Sooty Shearwater, Western Gull, Common Murre, Cassin’s Auklet, and many other less populous bird species. An observable recovery of Humpback and Blue Whales has occurred in the area; both species are dependent on coastal upwelling to provide nutrients. The large extent of exposed inner shelf bedrock supports large forests of “bull kelp,” which is well adapted for high-wave-energy environments. The kelp beds are well-known habitat for the population of southern sea otters. Common fish species found in the kelp beds and rocky reefs include lingcod and various species of rockfish and greenling.