Spatial and temporal diet variability of Adélie (Pygoscelis adeliae) and Emperor (Aptenodytes forsteri) Penguin: a multi tissue stable isotope analysis

AbstractThe Ross Sea, Antarctica, supports large populations of Emperor Penguin (Aptenodytes forsteri) and Adélie Penguin (Pygoscelis adeliae), two key meso-predators that occupy high trophic levels. Despite these species are largely studied, little is known about their diet outside the breeding period. In the present study, we investigated the intra-annual diet of Adélie and Emperor Penguins belonging to five colonies in the Ross Sea through the stable isotope analysis of different tissues (feathers and shell membranes), synthetized in different seasons, and guano that indicates recent diet. Penguin samples and prey (krill and fish) were collected during the Antarctic spring–summer. δ13C and δ15N of tissues and guano indicate spatio-temporal variation in the penguin diet. The krill consumption by Adélie Penguins was lowest in winter except in the northernmost colony, where it was always very high. It peaked in spring and remained prevalent in summer. The greatest krill contribution to Emperor Penguin’s diet occurred in summer. The relative krill and fish consumption by both species changed in relation to the prey availability, which is influenced by seasonal sea ice dynamics, and according to the penguin life cycle phases. The results highlight a strong trophic plasticity in the Adélie Penguin, whose dietary variability has been already recognized, and in the Emperor Penguin, which had not previously reported. Our findings can help understand how these species might react to resource variation due to climate change or anthropogenic overexploitation. Furthermore, data provides useful basis for future comparisons in the Ross Sea MPA and for planning conservation actions.

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Stable isotope analyses of ancient and modern Adélie Penguin (Pygoscelis adeliae) mummies from the Ross Sea Region, Antarctica

Polar Biology ◽

10.1007/s00300-019-02513-4 ◽

2019 ◽

Vol 42 (6) ◽

pp. 1183-1192 ◽

Cited By ~ 1

Author(s):

Allyson K. Kristan ◽

Steven D. Emslie ◽

William P. Patterson

Keyword(s):

Stable Isotope ◽

Ross Sea ◽

Adélie Penguin ◽

Pygoscelis Adeliae ◽

Adelie Penguin ◽

Stable Isotope Analyses ◽

Isotope Analyses

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Morphology and stable isotope analysis demonstrate different structuring of bat communities in rainforest and savannah habitats

Royal Society Open Science ◽

10.1098/rsos.180849 ◽

2018 ◽

Vol 5 (12) ◽

pp. 180849 ◽

Cited By ~ 1

Author(s):

Ara Monadjem ◽

Adam Kane ◽

Peter Taylor ◽

Leigh R. Richards ◽

Grant Hall ◽

...

Keyword(s):

Stable Isotope ◽

Stable Isotope Analysis ◽

Niche Breadth ◽

Isotope Analysis ◽

Morphological Characters ◽

Trophic Levels ◽

Species Packing ◽

Dietary Niche ◽

The One ◽

Ellipse Area

Bats play important ecological roles in tropical systems, yet how these communities are structured is still poorly understood. Our study explores the structure of African bat communities using morphological characters to define the morphospace occupied by these bats and stable isotope analysis to define their dietary niche breadth. We compared two communities, one in rainforest (Liberia) and one in savannah (South Africa), and asked whether the greater richness in the rainforest was due to more species ‘packing’ into the same morphospace and trophic space than bats from the savannah, or some other arrangement. In the rainforest, bats occupied a larger area in morphospace and species packing was higher than in the savannah; although this difference disappeared when comparing insectivorous bats only. There were also differences in morphospace occupied by different foraging groups (aerial, edge, clutter and fruitbat). Stable isotope analysis revealed that the range of δ 13 C values was almost double in rainforest than in savannah indicating a greater range of utilization of basal C 3 and C 4 resources in the former site, covering primary productivity from both these sources. The ranges in δ 15 N, however, were similar between the two habitats suggesting a similar number of trophic levels. Niche breadth, as defined by either standard ellipse area or convex hull, was greater for the bat community in rainforest than in savannah, with all four foraging groups having larger niche breadths in the former than the latter. The higher inter-species morphospace and niche breadth in forest bats suggest that species packing is not necessarily competitive. By employing morphometrics and stable isotope analysis, we have shown that the rainforest bat community packs more species in morphospace and uses a larger niche breadth than the one in savannah.

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Habitat, trophic levels and migration patterns of the short-finned squid Illex argentinus from stable isotope analysis of beak regions

Polar Biology ◽

10.1007/s00300-019-02598-x ◽

2019 ◽

Vol 42 (12) ◽

pp. 2299-2304 ◽

Cited By ~ 1

Author(s):

José P. Queirós ◽

Richard A. Phillips ◽

Alexandra Baeta ◽

José Abreu ◽

José C. Xavier

Keyword(s):

Stable Isotope ◽

Stable Isotope Analysis ◽

Isotope Analysis ◽

Trophic Levels ◽

Migration Patterns ◽

Illex Argentinus ◽

And Migration

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Feeding Ecology of Three Euphausiid Species in the North Pacific Ocean Inferred From 18S V9 Metabarcoding and Stable Isotope Analysis

Frontiers in Marine Science ◽

10.3389/fmars.2021.756067 ◽

2021 ◽

Vol 8 ◽

Author(s):

Fanyu Zhou ◽

Junya Hirai ◽

Koji Hamasaki ◽

Sachiko Horii ◽

Atsushi Tsuda

Keyword(s):

Stable Isotope ◽

Stable Isotope Analysis ◽

Feeding Ecology ◽

North Pacific ◽

Prey Availability ◽

Trophic Position ◽

Isotope Analysis ◽

Trophic Levels ◽

Gut Contents ◽

North Pacific Subtropical Gyre

Euphausiids are abundant micronekton and important links between higher and lower trophic levels in marine ecosystems; however, their detailed diets cannot be fully understood by conventional microscopy, especially in subtropical areas. Here, we report the euphausiid community structure in the California Current (CC) area and the eastern/western North Pacific subtropical gyre (ESG and WSG) and detail the feeding ecology of the dominant species (Euphausia pacifica, E. brevis, and E. hemigibba) in each region using a combined approach of gut content analysis via 18S V9 metabarcoding and stable carbon and nitrogen isotope analysis. A pronounced omnivorous feeding of all studied euphausiid species was supported by both methods: phytoplanktonic taxonomic groups (Dinophyta, Stramenopiles, and Archaeplastida), Copepoda, and Hydrozoa were detected in the gut contents; all the three euphausiid species displayed an intermediate trophic position between the net plankton (0.2–1.0 mm) and the myctophid fish (15.2–85.5 mm). However, Hydrozoa found in euphausiid gut contents likely derived from a potential cod-end feeding, based on isotope analysis. E. pacifica in the CC province ingested more autotrophic prey, including pelagophyte and green algae, due to a greater abundance of Stramenopiles and Archaeplastida in shallow layers of CC water. On the other hand, non-autotrophic prey such as mixotrophic Kareniaceae dinoflagellates, Pontellidae and Clausocalanidae copepods, and Sphaerozoidae rhizarian contributed more to the diets of E. brevis and E. hemigibba because of a lower chlorophyll a concentration or potentially a scarcity of autotrophic prey availability in ESG and WSG. The feeding patterns of dominant euphausiid species conducting filter feeding were thus largely determined by phytoplankton prey availability in the environments. Dietary difference across three species was also indicated by stable isotope analysis, with a lower mean trophic level of E. pacifica (2.32) than E. brevis (2.48) and E. hemigibba (2.57). These results verify direct trophic interactions between euphausiids and primary production and suggest that the omnivorous feeding habit is a favorable character for dominant Euphausia species.

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Trophic interactions of meso- and macrozooplankton and fish in the Iceland Sea as evaluated by fatty acid and stable isotope analysis

ICES Journal of Marine Science ◽

10.1093/icesjms/fss125 ◽

2012 ◽

Vol 69 (7) ◽

pp. 1277-1288 ◽

Cited By ~ 16

Author(s):

Hildur Petursdottir ◽

Stig Falk-Petersen ◽

Astthor Gislason

Keyword(s):

Fatty Acid ◽

Stable Isotope ◽

Stable Isotope Analysis ◽

Trophic Interactions ◽

Trophic Ecology ◽

Feeding Habits ◽

Isotope Analysis ◽

Trophic Levels ◽

Amphipod Species ◽

Blue Whiting

Abstract Petursdottir, H., Falk-Petersen, S., and Gislason, A. 2012. Trophic interactions of meso- and macrozooplankton and fish in the Iceland Sea as evaluated by fatty acid and stable isotope analysis. – ICES Journal of Marine Science, 69: . A trophic study was carried out in August of 2007 and 2008 on the pelagic ecosystem in the Subarctic Iceland Sea. Carbon and nitrogen stable isotopes and fatty acid biomarkers were used to study trophic linkages and the trophic ecology of the most important pelagic species in this ecosystem, with emphasis on capelin (Mallotus villosus). According to 15N enrichment results, there are 3–4 trophic levels in this ecosystem excluding organisms of the microbial loop and birds and mammals. The primarily herbivorous copepod Calanus hyperboreus occupies the lowest trophic level of the animal species studied, and adult capelin and blue whiting (Micromesistius poutassou) occupy the highest level. Calanus spp. proved to be an important dietary component of most of the species studied, the euphausiid species Thysanoessa inermis and T. longicaudata being exceptions. The chaetognath Eukrohnia hamata is a pure carnivore, feeding heavily on Calanus spp., whereas most of the other zooplankton species studied practice an omnivorous–carnivorous feeding mode. The amphipod species Themisto libellula is important in the diet of adult capelin. Adult capelin and blue whiting share the same feeding habits and could therefore be competing for food.

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Regional Differences in the Diets of Adélie and Emperor Penguins in the Ross Sea, Antarctica

Animals ◽

10.3390/ani11092681 ◽

2021 ◽

Vol 11 (9) ◽

pp. 2681

Author(s):

Seo-Yeon Hong ◽

Jong-Ku Gal ◽

Bo-Yeon Lee ◽

Wu-Ju Son ◽

Jin-Woo Jung ◽

...

Keyword(s):

Regional Differences ◽

Emperor Penguin ◽

Adélie Penguin ◽

Pygoscelis Adeliae ◽

Adelie Penguin ◽

Breeding Sites ◽

Terra Nova Bay ◽

Significant Difference ◽

Antarctic Silverfish ◽

Terra Nova

To identify the dietary composition and characteristics of both Adélie (Pygoscelis adeliae) and Emperor (Aptenodytes forsteri) penguins at four breeding sites, we performed stable carbon (δ13C) and nitrogen (δ15N) isotope analysis of down samples taken from penguin chicks. Adélie Penguin chicks at Cape Hallett mostly fed on Antarctic krill (Euphausia superba; 65.5 ± 3.5%), a reflection of the prevalence of that species near Cape Hallett, and no significant differences were noted between 2017 and 2018. However, Adélie Penguin chicks at Inexpressible Island, located near Terra Nova Bay, fed on both Antarctic silverfish (Pleuragramma antarctica; 42.5%) and ice krill (Euphausia crystallorophias; 47%), reflecting the high biomass observed in Terra Nova Bay. Meanwhile, no significant difference was noted between the two breeding sites of the Emperor Penguin. Emperor Penguin chicks predominantly fed on Antarctic silverfish (74.5 ± 2.1%) at both breeding sites (Cape Washington and Coulman Island), suggesting that diet preference represents the main factor influencing Emperor Penguin foraging. In contrast, the diet of the Adélie Penguin reflects presumed regional differences in prey prevalence, as inferred from available survey data.

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Spatial relationships of Adélie penguin colonies: implications for assessing population changes from remote imagery

Antarctic Science ◽

10.1017/s0954102098000546 ◽

1998 ◽

Vol 10 (4) ◽

pp. 449-454 ◽

Cited By ~ 14

Author(s):

Eric J. Woehler ◽

Martin J. Riddle

Keyword(s):

Population Density ◽

Ross Sea ◽

Aerial Photographs ◽

Adélie Penguin ◽

Pygoscelis Adeliae ◽

Data Set ◽

Adelie Penguin ◽

Pair Density ◽

The Relationship ◽

Colony Area

The relationship between colony area and population density of Adélie penguins Pygoscelis adeliae was examined to determine whether colony area, measured from aerial or satellite imagery, could be used to estimate population density, and hence detect changes in populations over time. Using maps drawn from vertical aerial photographs of Adélie penguin colonies in the Mawson region, pair density ranged between 0.1 and 3.1 pairs m−2, with a mean of 0.63 ± 0.3 pairs m−2. Colony area explained 96.4% of the variance in colony populations (range 90.4–99.6%) for 979 colonies at Mawson. Mean densities were not significantly different among the 19 islands in the region, but significant differences in mean pair density were observed among colonies in Mawson, Whitney Point (Casey, East Antarctica) and Cape Crozier (Ross Sea) populations. The relationship between colony area and population may be locality-and/or species-specific, and a robust data set is required to validate the relationship.

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Evaluating and using stable-isotope analysis to infer diet composition and foraging ecology of Adélie penguins Pygoscelis adeliae

Marine Ecology Progress Series ◽

10.3354/meps07235 ◽

2008 ◽

Vol 355 ◽

pp. 297-307 ◽

Cited By ~ 41

Author(s):

M Tierney ◽

C Southwell ◽

LM Emmerson ◽

MA Hindell

Keyword(s):

Stable Isotope ◽

Stable Isotope Analysis ◽

Diet Composition ◽

Foraging Ecology ◽

Isotope Analysis ◽

Pygoscelis Adeliae ◽

Adélie Penguins

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Ancient Adélie penguin colony revealed by snowmelt at Cape Irizar, Ross Sea, Antarctica

Geology ◽

10.1130/g48230.1 ◽

2020 ◽

Cited By ~ 1

Author(s):

Steven D. Emslie

Keyword(s):

Ross Sea ◽

Bone Collagen ◽

Adélie Penguin ◽

Pygoscelis Adeliae ◽

Adelie Penguin ◽

Terra Nova Bay ◽

Penguin Colony ◽

Marine Productivity ◽

First Time ◽

Adélie Penguins

The Ross Sea (Antarctica) is one of the most productive marine ecosystems in the Southern Ocean and supports nearly one million breeding pairs of Adélie penguins (Pygoscelis adeliae) annually. There also is a well-preserved record of abandoned penguin colonies that date from before the Last Glacial Maximum (>45,000 14C yr B.P.) through the Holocene. Cape Irizar is a rocky cape located just south of the Drygalski Ice Tongue on the Scott Coast. In January 2016, several abandoned Adélie penguin sites and abundant surface remains of penguin bones, feathers, and carcasses that appeared to be fresh were being exposed by melting snow and were sampled for radiocarbon analysis. The results indicate the “fresh” remains are actually ancient and that three periods of occupation by Adélie penguins are represented beginning ca. 5000 calibrated calendar (cal.) yr B.P., with the last occupation ending by ca. 800 cal. yr B.P. The presence of fresh-appearing remains on the surface that are actually ancient in age suggests that only recently has snowmelt exposed previously frozen carcasses and other remains for the first time in ~800 yr, allowing them to decay and appear fresh. Recent warming trends and historical satellite imagery (Landsat) showing decreasing snow cover on the cape since 2013 support this hypothesis. Increased δ13C values of penguin bone collagen further indicate a period of enhanced marine productivity during the penguin “optimum”, a warm period at 4000–2000 cal. yr B.P., perhaps related to an expansion of the Terra Nova Bay polynya with calving events of the Drygalski Ice Tongue.

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