Studying Seabird Diet through Genetic Analysis of Faeces: A Case Study on Macaroni Penguins (Eudyptes chrysolophus)

Deagle, Bruce E.; Gales, Nick; Evans, Karen; Jarman, Simon; Robinson, Sarah; Trebilco, Rowan; Hindell, Mark A.

doi:10.1371/journal.pone.0000831

Cited by 201 publications

(190 citation statements)

References 47 publications

Supporting

Mentioning

187

Contrasting

Unclassified

Order By: Relevance

“…Each bird included in the study was sexed by bill measurement following Woehler (1995) and their breast feathers marked Dietary analysis. The dietary data presented here are a subset of those considered in a previous study that examined stomach contents of 69 birds and obtained diet data through genetic analysis of faecal samples (Deagle et al 2007). In the current study, only the stomach content data from birds equipped with data loggers (n = 43) are included, and the individual variation in diet composition is the focus rather than overall diet.…”

Section: Methodsmentioning

confidence: 99%

“…In addition, dive data have been recorded over the entire annual cycle for some birds from South Georgia (Green et al 2005). The diet of the species has been examined during the breeding season at several colonies and is usually dominated by euphausiids, but fish and other crustaceans can dominate the diet in some years or at some times of the annual cycle (Croxall & Prince 1980, Brown & Klages 1987, Klages et al 1989, Green et al 1998, Barlow et al 2002, Crawford et al 2003, Deagle et al 2007, Cherel et al 2007. No studies on macaroni penguins have related the diet of individual birds to their foraging behaviour.…”

Section: Resale or Republication Not Permitted Without Written Consenmentioning

confidence: 99%

See 1 more Smart Citation

Variability in foraging behaviour of chick-rearing macaroni penguins Eudyptes chrysolophus and its relation to diet

Deagle

Gales²,

Hindell³

2008

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

Flexibility in foraging behaviour and diet are characteristics of many penguin species. While these 2 aspects of foraging ecology are presumably tightly coupled, the connection between them is rarely examined directly. Using time-depth recorders and satellite telemetry we documented the foraging behaviour of 43 chick-rearing macaroni penguins Eudyptes chrysolophus at Heard Island. We also compared these behavioural data with prey recovered from the stomach contents of each tracked bird. During guard stage, foraging trips were significantly shorter (average duration = 23 ± 18 h, range = 47 ± 40 km) compared to crèche stage (average duration = 115 ± 112 h, range = 169 ± 102 km). Crèche stage trips also included significantly more shallow dives that appear to be related to travel (39% of dives <10 m versus 27% for guard stage). Three species dominate the birds' diet: 2 species of euphausiids and the myctophid fish Krefftichthys anderssoni. Over the breeding season, K. anderssoni was taken on trips further from the island with deeper dives compared to the euphausiids. Foraging characteristics also differed between trips targeting different euphausiid prey species; however, there was a temporal shift in the euphausiid species consumed and this was correlated with overall changes in foraging behaviour. Multivariate analysis of behavioural data from trips early in guard stage revealed 2 distinct foraging strategies: deeper and offshore versus shallower and inshore. Individual birds often switched between these strategies in successive trips. The characteristics of many dives performed during inshore trips were indicative of benthic foraging; a previously unrecorded behaviour for macaroni penguins. Euphausiids were captured on both offshore pelagic and inshore benthic trips, illustrating that when prey is found in different habitats substantial changes in foraging parameters can occur independent of dietary shifts. More detailed behavioural studies may allow prey-specific rather than habitat-specific foraging patterns to be distinguished.KEY WORDS: Dive behaviour · Prey-specific foraging · Time-depth recorder · Heard Island · Feeding ecology · Benthic foraging Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 359: [295][296][297][298][299][300][301][302][303][304][305][306][307][308][309] 2008 and the foraging range of Adelie penguins P. adeliae can shift quite drastically over the relatively short chick-rearing period (Ainley et al. 1998, Clarke et al. 2006. Appreciation of this behavioural variability is important if results from individual studies are extrapolated to make wider conclusions about the species' ecology. This is especially true in situations where the behavioural information is used in the design of marine protected areas, or to assess interactions between predators and commercial fisheries (e.g. Boersma et al. 2002, Wienecke & Robertson 2002.One of the assumptions of many studies on the behavioural aspects of foraging is that changes in behaviou...

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Resale or Republication Not Permitted Without Written Consenmentioning

confidence: 99%

Variability in foraging behaviour of chick-rearing macaroni penguins Eudyptes chrysolophus and its relation to diet

Deagle

Gales²,

Hindell³

2008

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

show abstract

“…However, in most systems stable isotope analyses lack the resolution to identify prey beyond broad trophic groups. DNA metabarcoding of predator scats is a useful alternate or complementary method for assessing seabird diet (Deagle et al, 2007;Bowser et al, 2013). It can provide highlevel taxonomic resolution and does not require prey remains to be physically identifiable (Pompanon et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

DNA Metabarcoding as a Marine Conservation and Management Tool: A Circumpolar Examination of Fishery Discards in the Diet of Threatened Albatrosses

et al. 2017

Self Cite

View full text Add to dashboard Cite

Almost all of the world's fisheries overlap spatially and temporally with foraging seabirds, with impacts that range from food supplementation (through scavenging behind vessels), to resource competition and incidental mortality. The nature and extent of interactions between seabirds and fisheries vary, as does the level and efficacy of management and mitigation. Seabird dietary studies provide information on prey diversity and often identify species that are also caught in fisheries, providing evidence of linkages which can be used to improve ecosystem based management of fisheries. However, species identification of fish can be difficult with conventional dietary techniques. The black-browed albatross (Thalassarche melanophris) has a circumpolar distribution and has suffered major population declines due primarily to incidental mortality in fisheries. We use DNA metabarcoding of black-browed albatross scats to investigate their fish prey during the breeding season at six sites across their range, over two seasons. We identify the spatial and temporal diversity of fish in their diets and overlaps with fisheries operating in adjacent waters. Across all sites, 51 fish species from 33 families were identified, with 23 species contributing >10% of the proportion of samples or sequences at any site. There was extensive geographic variation but little inter-annual variability in fish species consumed. Several fish species that are not easily accessible to albatross, but are commercially harvested or by-caught, were detected in the albatross diet during the breeding season. This was particularly evident at the Falkland Islands and Iles Kerguelen where higher fishery catch amounts (or discard amounts where known) corresponded to higher occurrence of these species in diet samples. This study indicates ongoing McInnes et al. Fishery Discards in Albatross Diets interactions with fisheries through consumption of fishery discards, increasing the risk of seabird mortality. Breeding success was higher at sites where fisheries discards were detected in the diet, highlighting the need to minimize discarding to reduce impacts on the ecosystem. DNA metabarcoding provides a valuable non-invasive tool for assessing the fish prey of seabirds across broad geographic ranges. This provides an avenue for fishery resource managers to assess compliance of fisheries with discard policies and the level of interaction with scavenging seabirds.

show abstract

“…Briefly, for example, in early dietary studies involving free-living marine wildlife, lethal sampling often was the simplest method available. However, recent studies involving stomach flushing of sharks (Barnett et al 2010;Hammerschlag and Sulikowski 2011) and elephant seals (Daneri et al 2015), fecal studies of fur seals (GalloReynoso and Esperón-Rodríguez 2013) and penguins (Deagle et al 2007), and stable isotope analysis of sea turtles (Shimada et al 2014) all illustrate how nonlethal methodologies can be made best practice for marine species. In cetacean biology, whale abundance trends and biological parameters can be obtained via boat surveys, land-based observations, and mark-recapture studies.…”

Section: Modern Nonlethal Alternativesmentioning

confidence: 99%

Opposing Lethal Wildlife Research When Nonlethal Methods Exist: Scientific Whaling as a Case Study

Waugh

Monamy

2016

Journal of Fish and Wildlife Management

View full text Add to dashboard Cite

As our understanding of sentience in certain wildlife species grows, and technological advancements promote nonlethal data collection, we believe that we ought to adjust our field methods to incorporate a regime of best practice that prioritizes nonlethal methodologies over inhumane methods of lethal sampling. In addition, progress already made toward nonlethal methodologies in wildlife research needs to be promoted widely. In this paper, we examine whether lethal methods of whale research, using Japanese lethal scientific whaling as a case study, are ethical when the scientific information can be gained from nonlethal methods, and humane methods of killing are not available. As a part of a simple ethical decision-making model, we explore if a requirement for ''refinement'' of scientific technique, promoted extensively for laboratory-based animal experimentation, has direct applicability to scientific research involving free-living wildlife. We argue that refinement is an appropriate ethical principle in all cases where scientific research involves a choice between nonlethal sampling and the deliberate killing of free-living wildlife for scientific purposes. We conclude that the welfare of individual animals and the conservation of free-living wildlife populations are both worthy of moral consideration and need not be incompatible in humane wildlife research and management.Keywords: animal ethics; animal welfare; nonlethal methodology; wildlife research; lethal scientific whaling; refinement; three Rs

show abstract

Studying Seabird Diet through Genetic Analysis of Faeces: A Case Study on Macaroni Penguins (Eudyptes chrysolophus)

Cited by 201 publications

References 47 publications

Variability in foraging behaviour of chick-rearing macaroni penguins Eudyptes chrysolophus and its relation to diet

Variability in foraging behaviour of chick-rearing macaroni penguins Eudyptes chrysolophus and its relation to diet

DNA Metabarcoding as a Marine Conservation and Management Tool: A Circumpolar Examination of Fishery Discards in the Diet of Threatened Albatrosses

Opposing Lethal Wildlife Research When Nonlethal Methods Exist: Scientific Whaling as a Case Study

Contact Info

Product

Resources

About