Geology topics

Scott A. Hatch

Publications and source records attributed to Scott A. Hatch.

At least 37 records · Page 2Linked to original sources

USGS2010

Sustained increase in food supplies reduces broodmate aggression in black-legged kittiwakes

The amount of food ingested by chicks has often been suggested as being the main proximate factor controlling broodmate aggression in facultatively siblicidal species. Although several experiments have demonstrated that short-term food deprivation causes a temporary increase in aggression, no study has, to our knowledge, experimentally manipulated overall food supplies and considered long-term effects on chick behaviour and life history traits. We provided supplemental food to breeding pairs of black-legged kittiwakes, Rissa tridactyla , over an entire breeding season and compared the aggressive behaviour of their chicks with that of chicks of control pairs. Control A-chicks (first to hatch) showed more frequent and intense aggression than their experimental counterparts. Furthermore, the more A-chicks begged and the lower their growth rate the more aggressive they were. The consequences of increased aggression for B-chicks (second to hatch) were lower begging rate, lower growth rate and lower survival. We thus provide evidence that a sustained increase in food availability affects broodmate aggression and chick survival at the nest and we discuss the various proximate and ultimate causes involved in the evolution of broodmate aggression.

Alaska↗

USGS2010

Individual and colony-specific wintering areas of Pacific northern fulmars (Fulmarus glacialis)

Seabird mortality associated with longline fishing in the eastern Bering Sea occurs mainly from September to May, with northern fulmars (Fulmarus glacialis) comprising the majority (60%) of the bycatch. Along the west coast of North America, winter dieoffs of fulmars may be increasing in frequency and magnitude, the most severe on record being a wreck that peaked in October-November 2003. We deployed satellite transmitters on fulmars from the four main Alaska colonies and tracked individuals for up to 2 years. Fulmars from Hall Island (northern Bering Sea) moved to Russian coastal waters after breeding, while Pribilof Island fulmars (southeastern Bering Sea) remained relatively sedentary yearround. Birds from Chagulak Island (eastern Aleutians) preferred passes between the Aleutian Islands in winter or foraged widely over deep waters of the central Bering Sea and North Pacific. Fulmars from the Semidi Islands (western Gulf of Alaska) migrated directly to waters of the California Current. Individuals from St. George Island (Pribilofs) and Chagulak were consistent in the places that they visited in two successive winters. The Pribilof Islands population is most affected by winter longlining for groundfish, whereas the Semidi Islands colony sustains most of the natural mortality that occurs off Washington, Oregon, and California.

Alaska↗

USGS2010

Unifying quantitative life-history theory and field endocrinology to assess prudent parenthood in a long-lived seabird

Question: Can field measurements of stress hormones help us to assess the prudent parent hypothesis in a long-lived seabird? Organism: Black-legged kittiwake, Rissa tridactyla . Location: Duck and Gull Islands, Cook Inlet, Alaska, USA. Methods: We examined the statistical relationship between the stress hormone corticosterone and mortality in black-legged kittiwakes. We built a demographic model of the kittiwake life cycle to determine whether the mortality rates associated with persisting in a breeding attempt despite high corticosterone caused the birds to sacrifice more lifetime reproductive output than they gain from one year’s breeding. Results: The probability of apparent mortality increased with corticosterone, suggesting some birds incurred increased mortality risk for the sake of breeding. For Duck Island (low reproductive success), it appears birds sacrificed more lifetime reproductive success than a prudent parent would. On Gull Island, it appears most but possibly not all birds were behaving in ways consistent with theory, although definitive statements require larger samples of highly stressed birds.

Alaska↗

USGS2010

Seabird bycatch in Alaska demersal longline fishery trials: a demographic summary

The seasonal and spatial demographics are summarized for seabirds killed incidentally during gear modification trials for a demersal longline fishery in the Bering Sea. We examined 417 carcasses, including Northern Fulmar Fulmarus glacialis (n = 205), Glaucous-winged Gull Larus glaucescens (n = 103), Short-tailed Shearwater Puffinus tenuirostris (n = 48), Glaucous Gull Larus hyperboreus (n = 23), Slaty-backed Gull Larus schistisagus (n = 4), Black-legged Kittiwake Rissa tridactyla (n = 1), Laysan Albatross Diomedea immutabilis (n = 1), and unidentified gull species Larus spp. (n = 32). There was a significant male bias in the sex ratio of fulmars but not of gulls or shearwaters. For the top three species killed, the age composition of resident species was dominated numerically by adults (Northern Fulmarâ€”86%; Glaucous-winged Gullâ€”63%), whereas migrant species were primarily immature birds (Short-tailed Shearwaterâ€”71%). The majority of migratory Short-tailed Shearwaters (88%) were caught in July and August, whereas 70% of resident fulmars and gulls were caught in October and November. Age-class frequencies did not differ by month of capture, indicating that adult mortality is substantial. Eighty percent of the fulmars caught during July and August were within 200 km of two colonies in the Bering Sea, whereas only 7% of fulmars were caught in the same area during September to November. This is one of the first demographic summaries of seabird bycatch in Alaska longline fisheries. Additional studies of the species, age and sex of seabirds subject to fisheries-related mortality will provide data necessary to evaluate population-level impacts.

Marine Ornithology: Journal of Seabird Research an↗

USGS2010

Seabird databases and the new paradigm for scientific publication and attribution

For more than 300 years, the peer-reviewed journal article has been the principal medium for packaging and delivering scientific data. With new tools for managing digital data, a new paradigm is emerging—one that demands open and direct access to data and that enables and rewards a broad-based approach to scientific questions. Ground-breaking papers in the future will increasingly be those that creatively mine and synthesize vast stores of data available on the Internet. This is especially true for conservation science, in which essential data can be readily captured in standard record formats. For seabird professionals, a number of globally shared databases are in the offing, or should be. These databases will capture the salient results of inventories and monitoring, pelagic surveys, diet studies, and telemetry. A number of real or perceived barriers to data sharing exist, but none is insurmountable. Our discipline should take an important stride now by adopting a specially designed markup language for annotating and sharing seabird data.

Marine Ornithology: Journal of Seabird Research an↗

USGS2009

GPS tracking devices reveal foraging strategies of black-legged kittiwakes

The Black-legged Kittiwake Rissa tridactyla is the most abundant gull species in the world, but some populations have declined in recent years, apparently due to food shortage. Kittiwakes are surface feeders and thus can compensate for low food availability only by increasing their foraging range and/or devoting more time to foraging. The species is widely studied in many respects, but long-distance foraging and the limitations of conventional radio telemetry have kept its foraging behavior largely out of view. The development of Global Positioning System (GPS) loggers is advancing rapidly. With devices as small as 8 g now available, it is possible to use this technology for tracking relatively small species of oceanic birds like kittiwakes. Here we present the first results of GPS telemetry applied to Black-legged Kittiwakes in 2007 in the North Pacific. All but one individual foraged in the neritic zone north of the island. Three birds performed foraging trips only close to the colony (within 13 km), while six birds had foraging ranges averaging about 40 km. The maximum foraging range was 59 km, and the maximum distance traveled was 165 km. Maximum trip duration was 17 h (mean 8 h). An apparently bimodal distribution of foraging ranges affords new insight on the variable foraging behaviour of Black-legged Kittiwakes. Our successful deployment of GPS loggers on kittiwakes holds much promise for telemetry studies on many other bird species of similar size and provides an incentive for applying this new approach in future studies.

Alaska↗

USGS2009

Environmental forcing on life history strategies: Evidence for multi-trophic level responses at ocean basin scales

Variation in life history traits of organisms is thought to reflect adaptations to environmental forcing occurring from bottom-up and top-down processes. Such variation occurs not only among, but also within species, indicating demographic plasticity in response to environmental conditions. From a broad literature review, we present evidence for ocean basin- and large marine ecosystem-scale variation in intra-specific life history traits, with similar responses occurring among trophic levels from relatively short-lived secondary producers to very long-lived apex predators. Between North Atlantic and North Pacific Ocean basins, for example, species in the Eastern Pacific exhibited either later maturation, lower fecundity, and/or greater annual survival than conspecifics in the Western Atlantic. Parallel variations in life histories among trophic levels also occur in adjacent seas and between eastern vs. western ocean boundaries. For example, zooplankton and seabird species in cooler Barents Sea waters exhibit lower fecundity or greater annual survival than conspecifics in the Northeast Atlantic. Sea turtles exhibit a larger size and a greater reproductive output in the Western Pacific vs. Eastern Pacific. These examples provide evidence for food-web-wide modifications in life history strategies in response to environmental forcing. We hypothesize that such dichotomies result from frequency and amplitude shifts in resource availability over varying temporal and spatial scales. We review data that supports three primary mechanisms by which environmental forcing affects life history strategies: (1) food-web structure; (2) climate variability affecting the quantity and seasonality of primary productivity; (3) bottom-up vs. top-down forcing. These proposed mechanisms provide a framework for comparisons of ecosystem function among oceanic regions (or regimes) and are essential in modeling ecosystem response to climate change, as well as for creating dynamic ecosystem-based marine conservation strategies.

Progress in Oceanography↗

USGS2009

Evidence that pairing with genetically similar mates is maladaptive in a monogamous bird

Background Evidence of multiple genetic criteria of mate choice is accumulating in numerous taxa. In many species, females have been shown to pair with genetically dissimilar mates or with extra-pair partners that are more genetically compatible than their social mates, thereby increasing their offsprings' heterozygosity which often correlates with offspring fitness. While most studies have focused on genetically promiscuous species, few studies have addressed genetically monogamous species, in which mate choice tends to be mutual. Results Here, we used microsatellite markers to assess individual global heterozygosity and genetic similarity of pairs in a socially and genetically monogamous seabird, the black-legged kittiwake Rissa tridactyla . We found that pairs were more genetically dissimilar than expected by chance. We also identified fitness costs of breeding with genetically similar partners: (i) genetic similarity of pairs was negatively correlated with the number of chicks hatched, and (ii) offspring heterozygosity was positively correlated with growth rate and survival. Conclusion These findings provide evidence that breeders in a genetically monogamous species may avoid the fitness costs of reproducing with a genetically similar mate. In such species that lack the opportunity to obtain extra-pair fertilizations, mate choice may therefore be under high selective pressure.

Alaska↗

USGS2009

Spatial and temporal diet segregation in northern fulmars Fulmarus glacialis breeding in Alaska: Insights from fatty acid signatures

Northern fulmars Fulmarus glacialis in the North Pacific Ocean are opportunistic, generalist predators, yet their diets are poorly described; thus, relationships of fulmars to supporting food webs, their utility as indicators of variability in forage fish abundances, and their sensitivity to ecosystem change are not known. We employed fatty acid (FA) signature analysis of adipose tissue from adults (n = 235) and chicks (n = 33) to compare spatial, temporal, and age-related variation in diets of fulmars breeding at 3 colonies in Alaska. FA signatures of adult fulmars differed between colonies within years, and between seasons at individual colonies. Seasonal and spatial differences in signatures were greater than interannual differences at all colonies. Differences in FA signatures reflect differences in diets, probably because the breeding colonies are located in distinct ecoregions which create unique habitats for prey assemblages, and because interannual variation in the physical environment affects the availability of forage species. Differences between FA signatures of adults and chicks in 2003 and 2004 suggest that adults fed chicks different prey than they consumed themselves. Alternatively, if adults relied on the same prey as those fed to chicks, the differences in signatures could have resulted from partial digestion of prey items by adults before chicks were fed, or direct metabolism of FAs by chicks for tissue synthesis before FAs could be deposited into adipose tissue.

Alaska↗

USGS2009

Can kittiwakes smell? Experimental evidence in a larid species

Birds have long been thought to have a poor sense of smell, although they have the proper anatomical and neurological structures for detecting olfactory cues ( Roper 1999 ). However, in the past decade several bird species have been shown to use smell in various contexts, such as foraging ( Nevitt et al. 1995 ), navigation ( Wallraff 2004 ), selection of nest materials ( Petit et al. 2002 , Gwinner & Berger 2008 ), nest location ( Bonadonna & Bretagnolle 2002 ), predator avoidance ( Amo et al. 2008 , Roth et al. 2008 ) and recognition of conspecifics ( Hagelin et al. 2003 ) or mates ( Bonadonna & Nevitt 2004 , for reviews see Roper 1999 , Hagelin & Jones 2007 , Nevitt 2008 ). The evidence, however, mainly concerns the Procellariiformes (petrels, shearwaters and albatrosses), a group that has long been suspected of using olfaction because of their strong body odour, highly developed olfactory bulb, nocturnal habits and burrow‐nesting ( Nevitt & Bonadonna 2005 , Nevitt 2008 ). Evidence of olfactory ability is scarce in other avian taxa. Exceptions include, for instance, Turkey Vulture Cathartes aura ( Smith & Paselk 1986 ), Brown Kiwi Apteryx australis ( Wenzel 1968 ), Homing Pigeon Columba livia ( Wallraff 2004 ), Blue Tit Cyanistes caeruleus ( Petit et al. 2002 , Amo et al. 2008 ), Domestic Fowl Gallus domesticus ( McKeegan et al. 2005 ), Kakapo Strigops habroptilus ( Hagelin 2004 ), Yellow‐backed Chattering Lory Lorius garrulus flavopalliatus ( Roper 2003 ), African Penguin Spheniscus demersus ( Cunningham et al. 2008 ) and Crested Auklets Aethia cristatella ( Hagelin et al. 2003 ). The Laridae, including Black‐legged Kittiwakes Rissa tridactyla , are diurnal, have relatively small olfactory bulbs ( Bang & Cobb 1968 ) and do not appear to use olfaction to locate food ( Frings et al. 1955 , Lequette et al. 1989 , Verheyden & Jouventin 1994 ). Kittiwakes use vocal cues in mate and parent/offspring recognition ( Wooller 1978 , Mulard & Danchin 2008 ), suggesting that olfaction may be at best secondary in those contexts. However, mates commonly allopreen, potentially exposing them to their mate’s chemical compounds. Moreover, the relative size of the olfactory bulb may be a poor predictor of olfactory abilities ( Hagelin 2004 , Mennerat et al. 2005 ). The aim of this experimental study was to assess whether Black‐legged Kittiwakes are able to detect odours added to the nest.

Alaska↗

USGS2008

Disentangling effects of growth and nutritional status on seabird stable isotope ratios

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 δ 15 N and δ 13 C 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 δ 15 N and δ 13 C 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 δ 15 N of both RBCs and feathers in treatment chicks compared to control chicks. Growth also induced depletion in RBC δ 15 N, with chicks exhibiting lower δ 15 N when they were growing the fastest. As growth slowed, δ 15 N increased, resulting in an overall pattern of enrichment over the course of the nestling period. Combined effects of growth and restriction depleted δ 15 N in chick RBCs by 0.92‰. We propose that increased nitrogen-use efficiency is responsible for 15 N depletion in both growing and food-restricted chicks. δ 15 N values in RBCs of free-ranging auklets fell within a range of only 1.03‰, while feather δ 15 N 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.

Alaska↗

USGS2008

Multiple deleterious effects of experimentally aged sperm in a monogamous bird

Sperm aging is known to be detrimental to reproductive performance. However, this apparently general phenomenon has seldom been studied in an evolutionary context. The negative impact of sperm aging on parental fitness should constitute a strong selective pressure for adaptations to avoid its effects. We studied the impact of sperm aging on black-legged kittiwakes ( Rissa tridactyla ), a monogamous seabird. Kittiwakes comprise a model system because ( i ) of evidence that females eject their mates' sperm to prevent fertilization by sperm that would be old and degraded by the time of fertilization and result in reduced reproductive performance and ( ii ) the lack of extra-pair fertilization in this species makes cryptic female choice an unlikely explanation of postcopulatory sperm ejection by females. We experimentally manipulated the age of the sperm fertilizing kittiwake eggs by fitting males with anti-insemination rings for variable periods of time preceding egg-laying. We found evidence that sperm aging negatively affected four sequential stages of reproduction: fertilization potential, rate of embryonic development, embryonic mortality, and chick condition at hatching. These results may be produced by a continuum of a single process of sperm aging that differentially affects various aspects of development, depending on the degree of damage incurred to the spermatozoa. The marked impact of sperm age on female fitness may thus drive postcopulatory sperm ejection by females. These results provide experimental evidence of deleterious effects of sperm aging on a nondomestic vertebrate, underlining its taxonomic generality and its potential to select for a wide array of adaptations.

PNAS↗

USGS2008

Incubation rhythm in the Fulmar Fulmarus glacialis : Annual variation and sex roles

I monitored the incubation schedules of Fulmars Fulmarus glacialis in an Alaskan colony by observing nests where the male and female were of different colour phases. Complete shifts of up to 16 days were recorded; the average shift in mid-incubation was 4–6 days. Mean shift length was inversely correlated with hatching success in 5 years, suggesting that Fulmars adjusted their foraging patterns to annual differences in food availability. Males assumed the larger share (55%) of incubation on average, and a larger share in years with lower hatching success. Serial correlation in the length of incubation shifts had two components - the influence of prior shift lengths on time spent foraging and individual variation. Failure of the male to relieve the female soon after laying resulted in a few breeding failures and egg losses were associated with exceptionally long shifts throughout incubation.

Alaska↗

USGS2008

Adult survival of Black-legged Kittiwakes Rissa tridactyla in a Pacific colony

Breeding Black-legged Kittiwakes Rissa tridactyla survived at a mean annual rate of 0.926 in four years at a colony in Alaska. Survival rates observed in sexed males (0.930) and females (0.937) did not differ significantly. The rate of return among nonbreeding Kittiwakes (0.839) was lower than that of known breeders, presumably because more nonbreeders moved away from the study plots where they were marked. Individual nonbreeders frequented sites up to 5 km apart on the same island, while a few established breeders moved up to 2.5 km between years. Mate retention in breeding Kittiwakes averaged 69% in three years. Among pairs that split, the cause of changing mates was about equally divided between death (46%) and divorce (54%). Average adult life expectancy was estimated at 13.0 years. Combined with annual productivity averaging 0.17 chick per nest, the observed survival was insufficient for maintaining population size. Rather, an irregular decline observed in the study colony since 1981 is consistent with the model of a closed population with little or no recruitment. Compared to their Atlantic counterparts, Pacific Kittiwakes have low productivity and high survival. The question arises whether differences reflect phenotypic plasticity or genetically determined variation in population parameters.

Alaska↗

USGS2008

Experimental evidence of vocal recognition in young and adult black-legged kittiwakes

Individual recognition is required in most social interactions, and its presence has been confirmed in many species. In birds, vocal cues appear to be a major component of recognition. Curiously, vocal recognition seems absent or limited in some highly social species such as the black-legged kittiwake , Rissa tridactyla . Using playback experiments, we found that kittiwake chicks recognized their parents vocally, this capacity being detectable as early as 20 days after hatching, the youngest age tested. Mates also recognized each other's long calls. Some birds reacted to their partner's voice when only a part of the long call was played back. Nevertheless, only about a third of the tested birds reacted to their mate's or parents' call and we were unable to detect recognition among neighbours. We discuss the low reactivity of kittiwakes in relation to their cliff-nesting habit and compare our results with evidence of vocal recognition in other larids.

Alaska↗

USGS2008

Forage fish of the Pacific Rim as revealed by diet of a piscivorous seabird: Synchrony and relationships with sea surface temperature

We tested the hypothesis of synchronous interannual changes in forage fish dynamics around the North Pacific Rim. To do this, we sampled forage fish communities using a seabird predator, the rhinoceros auklet ( Cerorhinca monocerata ), at six coastal study sites from Japan to California. We investigated whether take of forage fishes was related to local marine conditions as indexed by sea surface temperature (SST). SST was concordant across sites in the eastern Pacific, but inversely correlated between east and west. Forage fish communities consisted of anchovy ( Engraulis spp.), sandlance ( Ammodytes spp.), capelin ( Mallotus spp.), and juvenile rockfish ( Sebastes spp.), among others, and take of forage fish varied in response to interannual and possibly lower-frequency oceanographic variability. Take of primary forage species were significantly related to changes in SST only at the eastern sites. We found synchrony in interannual variation of primary forage fishes across several regions in the eastern Pacific, but no significant east–west correlations. Specifically in the Japan Sea, factors other than local SST or interannual variability may more strongly influence forage fishes. Predator diet sampling offers a fishery-independent, large-scale perspective on forage fish dynamics that may be difficult to obtain using conventional means of study.

Canadian Journal of Fisheries and Aquatic Sciences↗

USGS2007

Fatty acid signatures of stomach oil and adipose tissue of northern fulmars (Fulmarus glacialis) in Alaska: Implications for diet analysis of Procellariiform birds

Procellariiforms are unique among seabirds in storing dietary lipids in both adipose tissue and stomach oil. Thus, both lipid sources are potentially useful for trophic studies using fatty acid (FA) signatures. However, little is known about the relationship between FA signatures in stomach oil and adipose tissue of individuals or whether these signatures provide similar information about diet and physiology. We compared the FA composition of stomach oil and adipose tissue biopsies of individual northern fulmars ( N = 101) breeding at three major colonies in Alaska. Fatty acid signatures differed significantly between the two lipid sources, reflecting differences in dietary time scales, metabolic processing, or both. However, these signatures exhibited a relatively consistent relationship between individuals, such that the two lipid sources provided a similar ability to distinguish foraging differences among individuals and colonies. Our results, including the exclusive presence of dietary wax esters in stomach oil but not adipose tissue, are consistent with the notion that stomach oil FA signatures represent lipids retained from prey consumed during recent foraging and reflect little metabolic processing, whereas adipose tissue FA signatures represent a longer-term integration of dietary intake. Our study illustrates the potential for elucidating short- versus longer-term diet information in Procellariiform birds using different lipid sources.

Alaska↗

USGS2007

Food availability affects the maternal transfer of androgens and antibodies into eggs of a colonial seabird

Mothers can improve the quality of their offspring by increasing the level of certain components in their eggs. To examine whether or not mothers increase deposition of such components in eggs as a function of food availability, we food‐supplemented black‐legged kittiwake females (Rissa tridactyla) before and during egg laying and compared deposition of androgens and antibodies into eggs of first and experimentally induced replacement clutches. Food‐supplemented females transferred lower amounts of androgens and antibodies into eggs of induced replacement clutches than did non‐food‐supplemented mothers, whereas first clutches presented no differences between treatments. Our results suggest that when females are in lower condition, they transfer more androgens and antibodies into eggs to facilitate chick development despite potential long‐term costs for juveniles. Females in prime condition may avoid these potential long‐term costs because they can provide their chicks with more and higher quality resources.

Alaska↗