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

2018 ◽  
Vol 5 (12) ◽  
pp. 180849 ◽  
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.

scholarly journals Splitting hairs: dietary niche breadth modelling using stable isotope analysis of a sequentially grown tissue

2020 ◽  
Vol 56 (4) ◽  
pp. 358-369
Author(s):  
Matthew C. Rogers ◽  
Grant V. Hilderbrand ◽  
David D. Gustine ◽  
Kyle Joly ◽  
William B. Leacock ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Niche Breadth ◽  
Isotope Analysis ◽  
Dietary Niche

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

Polar Biology ◽  
2019 ◽  
Vol 42 (12) ◽  
pp. 2299-2304 ◽  
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

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

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.

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

2012 ◽  
Vol 69 (7) ◽  
pp. 1277-1288 ◽  
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.

Increased trophic position of black bear (Ursus americanus) at the northern fringe of its distribution range

2020 ◽  
Vol 98 (2) ◽  
pp. 127-133
Author(s):  
Michaël Bonin ◽  
Christian Dussault ◽  
Steeve D. Côté
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Ursus Americanus ◽  
Trophic Position ◽  
Isotope Analysis ◽  
Black Bear ◽  
Distribution Range ◽  
Strong Positive Correlation ◽  
Dietary Niche ◽  
Foraging Tactic

Studies describing the diet of omnivorous species are abundant, but the drivers affecting the balance between animal and plant resources remain unclear. Among those drivers, latitude has been reported to positively correlate with the trophic position of consumers. Using stable isotope analysis, we tested the hypothesis that trophic position of black bears (Ursus americanus Pallas, 1780) is positively correlated with latitude in eastern North America. We sampled 57 bears over a 15° latitudinal gradient in Quebec, Canada, and used stable isotope analysis to assess individual trophic position and metrics of dietary niches. We found a strong positive correlation between trophic position of bears and latitude (r2 = 0.76), which persisted throughout seasons. The width of the dietary niche of bears also appeared to follow a latitudinal pattern, even though bears foraging at the southernmost part of the gradient also showed a wide dietary niche. The impact of latitude on the foraging tactic of omnivores fosters our understanding of their capability to deal with contrasting environmental conditions, especially for species whose distribution ranges are expanding due to climate change. The flexibility of black bear foraging tactic likely allows this species to expand its geographical distribution range toward northern habitats.

Using stable isotope analysis to validate effective trophic levels from Ecopath models of areas closed and open to shrimp trawling in Core Sound, NC, USA

2014 ◽  
Vol 282 ◽  
pp. 1-17 ◽  
Author(s):  
Rebecca A. Deehr ◽  
Joseph J. Luczkovich ◽  
Kevin J. Hart ◽  
Lisa M. Clough ◽  
Beverly J. Johnson ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Isotope Analysis ◽  
Trophic Levels

scholarly journals Variability in copepod trophic levels and feeding selectivity based on stable isotope analysis in Gwangyang Bay of the southern coast of the Korean Peninsula

2018 ◽  
Vol 15 (7) ◽  
pp. 2055-2073 ◽  
Author(s):  
Mianrun Chen ◽  
Dongyoung Kim ◽  
Hongbin Liu ◽  
Chang-Keun Kang
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Salinity Gradient ◽  
Isotope Analysis ◽  
Trophic Levels ◽  
Food Sources ◽  
Primary Producers ◽  
Model Calculations ◽  
Δ13c And Δ15n ◽  
Gwangyang Bay

Abstract. Trophic preference (i.e., food resources and trophic levels) of different copepod groups was assessed along a salinity gradient in the temperate estuarine Gwangyang Bay of Korea, based on seasonal investigation of taxonomic results in 2015 and stable isotope analysis incorporating multiple linear regression models. The δ13C and δ15N values of copepods in the bay displayed significant spatial heterogeneity as well as seasonal variations, which were indicated by their significant relationships with salinity and temperature, respectively. Both spatial and temporal variations reflected those in isotopic values of food sources. The major calanoid groups (marine calanoids and brackish water calanoids) had a mean trophic level of 2.2 relative to nanoplankton as the basal food source, similar to the bulk copepod assemblage; however, they had dissimilar food sources based on the different δ13C values. Calanoid isotopic values indicated a mixture of different genera including species with high δ15N values (e.g., Labidocera, Sinocalanus, and Tortanus), moderate values (Calanus sinicus, Centropages, Paracalanus, and Acartia), and relatively low δ15N values (Eurytemora pacifica and Pseudodiaptomus). Feeding preferences of different copepods probably explain these seasonal and spatial patterns of the community trophic niche. Bayesian mixing model calculations based on source materials of two size fractions of particulate organic matter (nanoplankton at < 20 µm vs. microplankton at 20–200 µm) indicated that Acartia and Centropages preferred large particles; Paracalanus, Calanus, Eurytemora, and Pseudodiaptomus apparently preferred small particles. Tortanus was typically carnivorous with low selectivity on different copepods. Labidocera preferred marine calanoids Acartia, Centropages, and harpacticoids; on the other hand, Sinocalanus and Corycaeus preferred brackish calanoids Paracalanus and Pseudodiaptomus. Overall, our results depict a simple energy flow of the planktonic food web of Gwangyang Bay: from primary producers (nanoplankton) and a mixture of primary producers and herbivores (microplankton) through omnivores (Acartia, Calanus, Centropages, and Paracalanus) and detritivores (Pseudodiaptomus, Eurytemora, and harpacticoids) to carnivores (Corycaeus, Tortanus, Labidocera, and Sinocalanus).

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

Polar Biology ◽  
2021 ◽  
Author(s):  
Vahideh Jafari ◽  
Deborah Maccapan ◽  
Giulio Careddu ◽  
Simona Sporta Caputi ◽  
Edoardo Calizza ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Ross Sea ◽  
Isotope Analysis ◽  
Trophic Levels ◽  
Emperor Penguin ◽  
Adélie Penguin ◽  
Pygoscelis Adeliae ◽  
Adelie Penguin ◽  
Aptenodytes Forsteri

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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