| trace metals, stable isotope ratios, and trophic relations in seabirds from the north pacific ocean. | trace elements including mercury, cadmium, selenium, and stable nitrogen isotope ratios (sigma15n) were measured in tissues of pacific seabirds. two species of albatross (diomedea immutabilis, diomedea nigripes), four species of shearwaters (puffinus bulleri, puffinus carneipes, puffinus griseus, puffinus tenuirostris), northern fulmar (fulmarus glacialis), and horned puffin (fratercula corniculata) were collected opportunistically by an experimental fishery in the north pacific ocean. two speci ... | 2005 | 16445091 |
| effects of air and water temperatures on resting metabolism of auklets and other diving birds. | abstract 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) ... | 2011 | 21527823 |
| phylogenetic relationships within the alcidae (charadriiformes: aves) inferred from total molecular evidence. | the alcidae is a unique assemblage of northern hemisphere seabirds that forage by "flying" underwater. despite obvious affinities among the species, their evolutionary relationships are unclear. we analyzed nucleotide sequences of 1,045 base pairs of the mitochondrial cytochrome b gene and allelic profiles for 37 allozyme loci in all 22 extant species. trees were constructed on independent and combined data sets using maximum parsimony and distance methods that correct for superimposed changes. ... | 1996 | 8587501 |
| stable isotopes link diet to avian yolk carotenoid allocation: a comparative study of five auk species (charadriiformes: alcidae). | the allocation of important but environmentally limited nutrients, such as carotenoids, often represents a trade-off between homeostasis and reproduction. however, key questions remain about how diet and species traits influence carotenoid allocation. we studied yolk carotenoid profiles and yolk color in relation to trophic level (based on delta(15)n values) in five species of seabirds belonging to the family alcidae: common murre (uria aalge), pigeon guillemot (cepphus columba), cassin's auklet ... | 2010 | 20210648 |
| ecological factors differentially affect mercury levels in two species of sympatric marine birds of the north pacific. | in 2003 and 2004, we measured mercury concentrations and δ¹⁵n and δ¹³c 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, δ¹⁵n values were higher in fish than in crustaceans, while δ¹³c did not vary systematically between prey types. mercury concentra ... | 2011 | 21276602 |
| yolk carotenoids and stable isotopes reveal links among environment, foraging behavior and seabird breeding success. | nutrients that are limited in availability, such as carotenoids, are potentially involved in trade-offs between homeostasis and reproduction. despite their importance, factors that affect the capacity of female birds to meet their carotenoid requirements are poorly understood. we used delta(15)n stable isotope analysis to relate foraging behavior to yolk carotenoid deposition in two seabirds, cassin's auklet (ptychoramphus aleuticus) and rhinoceros auklet (cerorhinca monocerata), during each of ... | 2010 | 20397031 |
| are yolk androgens adjusted to environmental conditions? a test in two seabirds that lay single-egg clutches. | it is widely believed that female birds strategically allocate androgens to yolk in the manner that best equips offspring for feeding conditions during their development. because most avian studies have focused on multi-egg clutch species, and interpreted results within the framework of sibling competition, we still know little about how yolk androgens might be allocated in direct response to environmental conditions. most oceanic birds are long-lived and lay single-egg clutches, and their breed ... | 2008 | 18577385 |
| low incidence of plastics in food loads delivered to nestlings by a zooplanktivorous seabird over a 21-year period. | we quantified the amount of plastic found in food loads delivered to nestlings in cassin's auklet (ptychoramphus aleuticus), a small, zooplanktivorous seabird, on triangle island, british columbia, in 1996-2016. the density of plastic in surrounding waters is moderately high, yet few food loads contained any plastic (3 of 850), and none more than two pieces. that result accords well with previous observations on the other four north pacific auklets (aethia spp.), leading us to conclude that true ... | 2017 | 28625618 |
| plastic in cassin's auklets (ptychoramphus aleuticus) from the 2014 stranding on the northeast pacific coast. | oceanic plastic debris found in the digestive tracts of seabirds includes industrial plastic pellets and post-consumer user plastics. we examined whether the amount and type of plastic ingested by cassin's auklets (ptychoramphus aleuticus) is changing by surveying the stomach contents of 171 cassin's auklets stranded along the washington and oregon coasts in 2014. we found that 41.5% of the birds contained plastic in their ventriculi, similar to values from the north subarctic pacific reported i ... | 2017 | 28160979 |
| spatial distribution and temporal patterns of cassin's auklet foraging and their euphausiid prey in a variable ocean environment. | krill (euphausiids) play a vital ecosystem role in many of the world's most productive marine regions, providing an important trophic linkage. we introduce a robust modeling approach to link cassin's auklet (ptychoramphus aleuticus) abundance and distribution to large-scale and local oceanic and atmospheric conditions and relate these patterns to similarly modeled distributions of an important prey resource, krill. we carried out at-sea strip transect bird surveys and hydroacoustic assessments o ... | 2015 | 26629818 |
| range-wide reproductive consequences of ocean climate variability for the seabird cassin's auklet. | we examine how ocean climate variability influences the reproductive phenology and demography of the seabird cassin's auklet (ptychoramphus aleuticus) across approximately 2500 km of its breeding range in the oceanographically dynamic california current system along the west coast of north america. specifically, we determine the extent to which ocean climate conditions and cassin's auklet timing of breeding and breeding success covary across populations in british columbia, central california, a ... | 2009 | 19341144 |
| carry-over effects in a pacific seabird: stable isotope evidence that pre-breeding diet quality influences reproductive success. | 1. understanding the interactions between different periods of the annual cycle in migratory animals has been constrained by our inability to track individuals across seasons. in seabirds, virtually nothing is known about how diet quality during the non-breeding period, away from the breeding grounds, might influence subsequent reproductive success. 2. we used stable nitrogen (delta(15)n) and carbon (delta(13)c) isotopes to evaluate the effects of non-breeding diet quality on the timing of breed ... | 2009 | 19021778 |
| climate and demography of the planktivorous cassin's auklet ptychoramphus aleuticus off northern california: implications for population change. | 1. we performed demographic analyses on cassin's auklet ptychoramphus aleuticus, a zooplanktivorous seabird inhabiting the variable california current system, to understand how temporal environmental variability influences population dynamics. 2. we used capture-recapture data from 1986 to 2002 to rank models of interannual variation in survival, breeding propensity, breeding success, and recruitment. 3. all demographic parameters exhibited temporal variability. interannual variation in survival ... | 2007 | 17302841 |
| parental provisioning, nestling departure decisions and prefledging mass recession in cassin's auklets. | we investigated how parental provisioning and nestling departure behaviour interact to produce prefledging mass recession in cassin's auklets, ptychoramphus aleuticus. under our hypothesis, auklet parents are reluctant provisioners and should be increasingly likely to terminate or reduce provisioning of their single nestling as it matures. for the nestling, remaining in the nest presents a risk of losing mass (if the parent does not provision) but also a possibility of additional provisioning. a ... | 1999 | 10202095 |
| seasonal variability in vulnerability for cassin's auklets (ptychoramphus aleuticus) exposed to microplastic pollution in the canadian pacific region. | marine plastic pollution is an emerging global conservation challenge, potentially impacting organisms at all trophic levels. however, currently it is unclear to what extent plastic pollution is impacting marine organisms at the population, species or multispecies level. in this study, we explore seasonal exposure (i.e., vulnerability) of cassin's auklet (ptychoramphus aleuticus) to plastic pollution with exposure models during boreal summer and winter seasons. based on these models, we infer ex ... | 2019 | 30170215 |
| increased reproductive investment associated with greater survival and longevity in cassin's auklets. | individuals increase lifetime reproductive output through a trade-off between investment in future survival and immediate reproductive success. this pattern may be obscured in certain higher quality individuals that possess greater reproductive potential. the cassin's auklet (ptychoramphus aleuticus) is a long-lived species where some individuals exhibit greater reproductive ability through a behaviour called double brooding. here, we analyse 32 years of breeding histories from marked known-age ... | 2018 | 30158312 |
| egg size is independent of variation in pre-breeding feather corticosterone in cassin's auklets during favorable oceanographic conditions. | the measurement of corticosterone levels in feathers (fcort) is gaining recognition as an effective means for describing links between stages of the annual cycle in birds. many seabirds are especially good models for exploring these links, or carryover effects, due to their migratory behavior and reproductive investment in a single-egg clutch. here, we measure fcort in cassin's auklet (ptychoramphus aleuticus) breast feathers at two colonies in british columbia during 2011, a year of favorable o ... | 2018 | 30056135 |