Aethia Cristatella Research Articles

The Designated Shipping Avoidance Area Around St. Lawrence Island, Northern Bering Sea, Is not Sufficient to Protect Foraging Habitat of the Island’s Breeding Seabird Community

One direct consequence of Arctic warming is the expansion of navigable portions of the Arctic Ocean. As a result, vessel traffic and the accompanying threats of spills, strikes and disturbance is intensifying throughout the Arctic. In the Bering Sea, these threats to the environment, wildlife and to the people who rely on marine resources for food and cultural continuity, are acute. We examined the spatial relevance of an Area To Be Avoided (ATBA), a shipping-risk mitigation measure, established around St. Lawrence Island with respect to seabirds, as sentinel species, habitat use. We studied four seabird species (common murre Uria aalge, thick-billed murre U. lomvia, crested auklet Aethia cristatella, black-legged kittiwake Rissa tridactyla) breeding at St. Lawrence Island in the northern Bering Sea. GPS tracking data from 47 at-sea foraging trips showed that both murre species and crested auklets distributed outside the ATBA, during at least one stage of the breeding season. A larger dataset based on the birds’ red blood cell isotopic signatures confirmed that for murres, the tracked individuals covered the broad niche exploited by these species. Habitat modelling further showed that the birds’ most suitable marine habitats were associated with seasonal surface chlorophyll blooms, and largely extended beyond the ATBA on the shelf north of the island. Data on the murres’ diet and diving behavior emphasized the importance of the shelf as a foraging habitat for these birds. We suggest that extending the ATBA to the north by only 35 km, would include areas of maximal habitat suitability. This extension would better protect seabirds, their foraging habitats and the cultural continuity of St. Lawrence Islanders, against growing threats stemming from Arctic warming.

Breeding Biology of the Crested Auklet (Aethia cristatella, Alcidae, Charadriiformes) in the Northern Part of the Sea of Okhotsk

Breeding Biology of the Crested Auklet (Aethia cristatella, Alcidae, Charadriiformes) in the Northern Part of the Sea of Okhotsk

Brighter is better: bill fluorescence increases social attraction in a colonial seabird and reveals a potential link with foraging.

Crested auklets (Aethia cristatella) are colonial seabirds with brilliant orange bills during the breeding season. We characterized the bill pigment with spectroscopy methods (resonance Raman, fluorescence, absorbance). We excluded carotenoids as a possible chromophore and showed that the pigment most closely resembles pterins. Like pterins the bill pigment fluoresces, and it occurred in two phenotypes that may differ geographically, perhaps due to environmental heterogeneity. The pigment is unique in the Genus Aethia, and its spectra did not match any known molecule. The UV-Vis absorbance spectrum of the bill pigment overlaps with the extracted pigment of euphausiids, a favored food of crested auklets. A color preference associated with prey may have favored characteristics of the crested auklet's accessory bill plates. Crest size, a signal of dominance, tended to correlate positively with highest fluorescence in the single-band phenotype. Brighter bills may function in self-advertisement and verify the status signal of the crest ornament. We tested for a behavioral preference using identical decoys that differed only in bill fluorescence. Crested auklets approached models with fluorescent bills at a higher frequency. In cases where sex of crested auklets was known, males responded at a higher frequency to fluorescent bills, but females did not. In an evolutionary context, bill fluorescence could have conferred an advantage in social interactions, e.g., in dimly lit rock crevices. Bill brightness and color may communicate success in foraging and may function as an honest signal of mate quality.

Patterns of year-round colony attendance by VHF radio-tagged Crested Auklets (Aethia cristatella) at their prototypical Aleutian breeding site

Seabird colony attendance during their breeding seasons is driven by reproductive obligations of incubation and chick rearing, resulting in relatively predictable attendance patterns near breeding sites. Less is understood about patterns and function of activity ashore at colony sites outside the breeding season. We attempted to quantify year-round activity of crevice-nesting Crested Auklets (Aethia cristatella) at Gareloi Island, Alaska, a site with some of their largest colonies. In June and July 2013 and 2014, 94 Crested Auklets (92 adults and 2 subadults) were fitted with uniquely coded 1.0 g VHF radio-tags (0.6% of body mass) at 2 inland study plots in the southeast colony. Radio receiver–loggers remotely detected and recorded individuals present on the nearby colony site surface 24 h/d from date of tagging through autumn, winter, spring, and summer 2013–2015. Notably, we found Crested Auklets present in all months of the year, with half of our radio-tagged auklets (n = 47, 29 females, 10 males, 8 unknown sex) detected inland at the colony site during nonbreeding months (Sep–Mar). Visit duration for these individuals comprised about 0.4% of their total annual colony site activity; this is the first evidence of year-round Crested Auklet colony attendance that may be unique to Gareloi. Other findings included extreme individual variability and intersexual differences in colony attendance frequency, differences in attendance between breeding and nonbreeding birds, a lapse in surface activity prior to laying in May, and frequent nocturnal activity on the colony surface. Enhanced circannual patterns of Crested Auklet colony attendance at this island may relate to defense of nesting site and other social advantages, permitted by a nearby highly productive sea area with year-round foraging opportunities.

МОРСКИЕ КОЛОНИАЛЬНЫЕ ПТИЦЫ ОСТРОВА МЕДНОГО (КОМАНДОРСКИЕ ОСТРОВА)

The results of colonial seabird surveys on Medny Island were presented and the changes in numbers and distribution over the past 20–30 years were analyzed. The number of colonies on the island has not changed. The total number of individuals belonging to19 species is more than 200 thousand pairs. The colonies are distributed on the island relatively evenly along the whole coast and are based on five species – northen fulmar Fulmarus glacialis,black-legged kittiwake Rissa tridactyla, red-legged kittiwake Rissa brevirostris and two species of guillemots. The most numerous species is Northen fulmar. The abundance of the common guillemot Uria aalge has noticeably increased. The glaucous-winged gull Larus glaucescens, the crested auklet Aethia cristatella, the moth horned puffin Fratercula corniculata and the tufted puffin Lunda cirrhata has increased less. The number of parakeet auklet Cyclorrhynchus psittacula has decreased. There was not found significant changes for the rest of species.

Relationships between mercury burden, sex, and sexually selected feather ornaments in crested auklet (Aethia cristatella).

Individuals with higher contaminant burdens are expected to be in poorer physical health and be of lower individual body condition and energetic status, potentially resulting in reduced ornamentation or increased asymmetry in bilateral features. The degree and magnitude of this effect also would be expected to vary by sex, as female birds depurate contaminants into eggs. We tested for relationships among mercury in feathers, sex, and elaborate feather ornaments that relate to individual quality in crested auklets (Aethia cristatella), small planktivorous seabirds in the North Pacific Ocean. We found no relationships between mercury and the size of individuals' forehead crest or degree of measurement asymmetry in auricular plumes, both of which are favoured by intersexual selection. Females had significantly greater mercury concentrations than males (females. 1.02 ± 0.39μg/g; males, 0.75 ± 0.32μg/g); but concentrations were below that known to have physiological effects, as expected for a secondary consumer. Sex differences in overwintering area for this long-distance migrant species (more females in the Kuroshio Current Large Marine Ecosystem than males) could be the reason for this seemingly counterintuitive result between sexes. Further research relating mercury burden to overwintering ecology and diet contents would build on our results and further elucidate interrelationships between sex, sexually selected feather ornaments and contaminant burden.

Complete mitochondrial genome of Aethia cristatella (Charadriiformes: Alcidae)

The complete mitochondrial genome sequence of the crested auklet, Aethia cristatella, was obtained using high-throughput whole genome sequencing. This is the first report indicating that the complete mitochondrial genome of Aethia has been sequenced. The circular genome is 16,848 bp in length. It contains thirteen protein-coding genes, twenty-two transfer RNAs, two ribosomal RNAs, and a control region. The ND3 gene possessed an insertion mutation. Maximum likelihood phylogenetic analysis demonstrated that A. cristatella is the sister clade of P. aleuticus clustered with the Alcinae species, belonging to Alcidae.

Effect of Social Environment on Acoustic Variables and Occurrence of Trumpet Calls of the Crested Auklet (Aethia cristatella Charadriiformes, Alcidae)

Vocal plasticity under changes in social environment is well-known for passerine birds that possess vocal learning, but it has remained almost unstudied for other species. In this paper we studied the effect of social environment (the presence of conspecifics, a pair-mate, and a vocal duel), breeding period, and individuality on the acoustic variables and occurrence of self-advertising calls (trumpet calls) in male crested auklets (Aethia cristatella). This species is a planktivorous seabird that breeds in dense colonies and displays complex social behavior on the colony surface. We collected data in 2008–2010 and 2015 on Talan Island (Sea of Okhotsk); in total we used 1047 calls from 25 individually marked and 62 unmarked males. We found that the majority of males most often emit self-advertising calls when a pair-mate is absent, but other conspecifics are present; most rarely they emit self-advertising calls when a pair-mate is present, but other conspecifics are absent. However, there are some individual differences in those preferences. We suggest that, in the presence of a pair-mate, auklets prefer to use duet displays to signal their social status and pair-mate “occupation.” We also found that the effect of the social environment and breeding period on all acoustic variables measured is weaker than the effect of individuality. However, some of the trumpet call variables (mainly the duration of some syllables inside the trumpet call) changed significantly under the influence of the social environment and breeding period. Thus, crested auklets can slightly change the acoustic variables of their calls depending on the social environment, but keep the overall signature of their calls stable to make vocal individual recognition possible during the entire breeding season.

Functional Morphology and Adaptive Significance of the Jaw Apparatus of the Parakeet Auklet (Aethia psittacula, Alcidae)

The jaw apparatus of the parakeet auklet (Aethia psittacula) has been investigated in comparison to that of the crested auklet (Aethia cristatella). The mechanical and biological effects of the distinctive bill structure in the parakeet auklet have been analyzed. The oral slit is concave; therefore, equilibrium is achieved without the need for disabling the posterior or anterior parts of the dorsal adductor of the lower jaw and the adductor can act with the maximal force regardless of the position of the object clamped in the bill. Shearing of large food objects, such as polychaetes and jellyfish, by the parakeet auklet bill is a jaw apparatus specialization unique among birds. Strengthening of the jaw apparatus, which was initially adapted for capturing small planktonic crustaceans, involved the development of additional aponeuroses in the internal adductor, consolidation of the latter, shortening of the bill, and changes of the shape of the oral slit opening.

한국 미기록종 뿔바다오리(Aethia cristatella)의 첫 기록

2016년 1월 13일 국내 미기록종 뿔바다오리(Aethia cristatella) 1개체가 부산광역시 서구 암남동 바닷가(35° 4"1.31"N, 129° 0"30.53"E)에서 발견되었다. 국내에서 Aethia 속으로는 작은바다오리(A. pusilla)가 기록되었으며, 본 연구는 뿔바다오리(A. cristatella)의 첫 기록으로 세부적인 특징 및 분포와 관련된 기초적인 자료를 제공한다. On 13 January 2016, one Crested Auklet Aethia cristatella was discovered by local Wild Animal Rescue Center on the beach (35° 4"1.31"N, 129° 0"30.53"E) in Amnam-dong, Seo-gu, Busan, South Koea. To date in Korea, only one species, Least Auklet A. pusilla in Aethia has been recorded and this is the first record of A. cristatella. This report provides a detailed description of the characteristics and an information of distribution in this species.

Unusual mortality of Tufted puffins (Fratercula cirrhata) in the eastern Bering Sea.

Mass mortality events are increasing in frequency and magnitude, potentially linked with ongoing climate change. In October 2016 through January 2017, St. Paul Island, Bering Sea, Alaska, experienced a mortality event of alcids (family: Alcidae), with over 350 carcasses recovered. Almost three-quarters of the carcasses were unscavenged, a rate much higher than in baseline surveys (17%), suggesting ongoing deposition and elevated mortality around St Paul over a 2–3 month period. Based on the observation that carcasses were not observed on the neighboring island of St. George, we bounded the at-sea distribution of moribund birds, and estimated all species mortality at 3,150 to 8,800 birds. The event was particularly anomalous given the late fall/winter timing when low numbers of beached birds are typical. In addition, the predominance of Tufted puffins (Fratercula cirrhata, 79% of carcass finds) and Crested auklets (Aethia cristatella, 11% of carcass finds) was unusual, as these species are nearly absent from long-term baseline surveys. Collected specimens were severely emaciated, suggesting starvation as the ultimate cause of mortality. The majority (95%, N = 245) of Tufted puffins were adults regrowing flight feathers, indicating a potential contribution of molt stress. Immediately prior to this event, shifts in zooplankton community composition and in forage fish distribution and energy density were documented in the eastern Bering Sea following a period of elevated sea surface temperatures, evidence cumulatively suggestive of a bottom-up shift in seabird prey availability. We posit that shifts in prey composition and/or distribution, combined with the onset of molt, resulted in this mortality event.

Manipulation and Investigation Activity in Seabirds: Behavioral Response to Artificial Objects Exposed to a Colony

This study was conducted in 1987–1988 and 2008 on Talan Island (59°20′ N, 146°05′ E), Sea of Okhotsk; in 2005 and 2011 on the Medvezhii Island (74°23′ N, 19°02′ E), Svalbard; and in 2009 on Saint Jonah (Iony) Island (56°24′ N, 143°23′ E), Sea of Okhotsk. Seabirds demonstrated interest in some small objects that concerned neither their life nor reproduction. To study this feature in natural conditions, we performed 64 experiments with crested auklets (Aethia cristatella), 47 with little auks (Alle alle), 15 experiments with other alcids, and one with a representative of Procellariiforms, the Northern fulmar (Fulmarus glacialis). Birds paid extra attention to small objects that stood out against the natural background. They tried to investigate these objects in visual and tactile ways. This feature was more prominent in such highly social seabirds as little auks and crested auklets. Crested auklets definitely preferred white or yellow objects. Reactions to orange or green objects were considerable as well. Birds preferred brighter objects even if they were of an unusual color. Brighter objects stimulated auklet responses to nearby less bright objects. More complicated objects were preferred over simple ones. Little auks in the experiments with a full range of colors in similar objects definitely preferred white ones. In the experiments with similar objects of colors other than white, auks first manipulated the nearest object of any color. Little auks tried to touch and manipulate objects, but paid less attention to their color and shape than crested auklets did. Objects artificially covered with substances with a heavy odor or a spicy taste were not an obstacle to сrested auklets if they wanted to manipulate these objects. Little auks ceased attempts at manipulating objects smelling of menthol.

PERSISTENT ORGANIC POLLUTANTS IN SEABIRDS FROM THE OKHOTSK SEA

Persistent organic pollutants as organochlorine pesticides are lipophilic anthropogenic substances. Isomers of HCH and DDT and their metabolites are detected in organs of the seabirds Larus schistisagus, Aethia cristatella, Aethia pusilla, Fulmarus glacialis, and Oceanodroma furcata collected in the Okhotsk Sea. Total content of the pesticides in the certain examined organs varies from 28 ng to 16095 ng per 1 g of lipids: 28–8289 ng/g in feathers, 1567–16095 ng/g in feathers with skin, 1679–2478 ng/g in liver, 2230–3000 ng/g in muscles. Their average content in the whole body changes in the range from 12.5 to 15112.0 ng/g. Species specific features of the lipophilic xenobiotics accumulation are conditioned mainly by feeding habits and lipid content in the organs.

Organochlorine pesticide accumulation in seabirds and marine mammals from the Northwest Pacific

Bioaccumulation of organochlorine pesticides by marine organisms is one of the methods of environmental quality. Concentrations of organochlorine pesticides (HCH isomers (α-, β-, γ-HCH), p,p′-DDT and its metabolites (p,p′-DDD, p,p′-DDE)) in samples of seabirds (Northern fulmar Fulmarus glacialis, Crested auklet Aethia cristatella, Auklet-crumb Aethia pusilla, Pacific gull Larus schistisagus, and Gray petrel Oceanodroma furcate) and marine mammals (Gray whales Eschrichtius robustus and Pacific walrus Odobenus rosmarus divergens) were measured by a GC–MS. The total concentration of OCPs in mammals was higher than in seabirds. Environmental biomonitoring with the use of seabirds and marine mammals, as a long-lived species, is used for global monitoring, since bioaccumulation in these organisms occurs throughout life. The environmental assessment of the Northwest Pacific marine ecosystems revealed that the levels of OCP contamination in this area are similar to the other subarctic regions of the World Ocean.

Biological responses of Crested and Least auklets to volcanic destruction of nesting habitat in the Aleutian Islands, Alaska

ABSTRACT 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 ...

Bioindicators of Organochlorine Pesticides in the Sea of Okhotsk and the Western Bering Sea.

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 (70-90,263ng/g lipid), the seabirds (29-16,095ng/g lipid), and the Pacific salmon (41-7103ng/g lipid). The concentrations and possible sources of OCPs in marine organisms as biological indicators are discussed.

Fitting in with the crowd: the role of prospecting in seabird behavioural trends

Prebreeding, subadult seabirds have been documented prospecting or visiting multiple sites throughout the breeding season to gather information on colony reproductive success, identify suitable habitat, evaluate prey abundance, and locate potential partners; however, many aspects of prospector biology remain unknown. We explored prospector behaviour as a means of furthering our understanding of postnatal seabird dispersal and colony attendance using Least Auklets (Aethia pusilla (Pallas, 1811)) and Crested Auklets (Aethia cristatella (Pallas, 1769)) breeding at Gareloi Island, Alaska, in 2014 and 2015. We recorded age class, length of time spent on the colony, and behaviour for individuals attending a study plot over the course of two breeding seasons. Although prospectors typically spent more time on the colony surface than adults, prospectors rarely socialized with conspecifics during their visits to the colony, possibly due to the absence of a citrus-like feather odour used in olfactory communication. Additionally, we found substantial differences between observed and predicted data between years, demonstrating that other factors (likely prey abundance or quality) influenced behaviour in 2015. Our results suggest that the collective knowledge of seabird prospecting behaviour is not necessarily transferable between taxa and there may be a range of strategies employed by prospectors when assessing colonies.

Glowing in the light: fluorescence of bill plates in the Crested Auklet (Aethia cristatella)

ABSTRACT We examined the fluorescence of ornaments among three auklet species: Least Auklets (Aethia pusilla), Crested Auklets (Aethia cristatella), and Parakeet Auklets (Aethia psittacula) on Gareloi Island, Alaska during the 2015 breeding season. We found that the ornamental bill plates of Crested Auklets fluoresced, but bill ornaments of Least Auklets and bills of Parakeet Auklets did not. We also found that none of the feathers in these three species exhibited fluorescence. We suggest that differences in ornamentation and fluorescence may be related to life-history strategies associated with sexual selection and predator avoidance.

Habitat modification as a means of restoring crested auklet colonies

ABSTRACTSeabirds that forage in dense groups can be especially vulnerable to anthropogenic threats at sea. To mitigate these threats to populations, nesting habitat restoration may be a viable option by reducing negative density dependence. Accordingly, we undertook a before‐after control‐impact (BACI) experiment to test whether habitat modification could be an effective means of restoring nesting habitat of crested auklets (Aethia cristatella) breeding on Gareloi Island, Alaska, USA. Despite supporting large numbers of crevice‐nesting auklets, many lava flows at Gareloi Island are in a stage of late vegetative succession that may prevent birds from accessing subterranean nesting habitat. We hypothesized that crested auklet density is highest in unvegetated blocky and porous lava, and predicted that removing vegetation from the surface would allow new recruits to secure previously unavailable nesting sites. In 2009 and 2010, we delineated 34 200‐m2 plots throughout the southeast colony at Gareloi, and color marked a subset of crested auklets landing in each plot to measure movement and abundance. We removed vegetative overgrowth and peat from half of each plot at the end of the 2009 (4 plots) and 2010 (30 plots) breeding seasons. Before and after vegetation removal, we counted the number of active nesting sites and calculated the ratio of banded to un‐banded breeders on the surface of each plot half. Overall, active nesting sites, number of individuals on the surface, and number of breeders landing did not increase after vegetation removal. However, among banded individuals that moved among plot halves, birds were 1.7 times more likely to move to a de‐vegetated plot half. Based on our experimental results, we found no evidence that vegetation removal increased crested auklet numbers at Gareloi Island, and thus in the short term this may not be a viable option for increasing crested auklet abundance. © 2016 The Wildlife Society.

Ecological shift from piscivorous to planktivorous seabirds in the Chukchi Sea, 1975–2012

Sea ice now forms later and melts earlier than it did 4 decades years ago, and it now melts completely in all parts of the Chukchi Sea. This decline in sea ice is expected to have repercussions on the trophic structure in this environment, and there are indications that changes already have taken place in the seabird community. We compared boat-based densities of seabirds in the eastern Chukchi Sea between July and October during 1975–1981 (historical data) with densities during 2007–2012 (recent data). We related the composition of the seabird community to sea-ice cover to explore how the community may be responding to changes in oceanography. The seabird community historically was composed predominantly of piscivorous Black-legged Kittiwakes (Rissa tridactyla) and murres (Uria spp.). In contrast, the seabird community now is composed predominantly of planktivorous seabirds such as Crested Auklets (Aethia cristatella) and Short-tailed Shearwaters (Puffinus tenuirostris). Total abundance of seabirds declined in three of four strata in the eastern Chukchi Sea, largely due to declines in densities of piscivorous and omnivorous species. These changes in the abundance and community composition of seabirds were associated with changes in ice cover. Earlier ice retreat appears to contribute to an environment that is more favorable to the sustained production of large oceanic copepods and euphausiids. We propose that long-term changes (4 decades) in the abundance and composition of the seabird community reflect an increase in the availability of large zooplankton prey in the region.