Correction: Time- and depth-wise trophic niche shifts in Antarctic benthos

In communities structured by body size, coexistence can occur through combinations of ontogenetic changes in competitive ability and dietary niche. Using stable isotopes, we examined ontogenetic niche shifts in Trinidadian guppies (Poecilia reticulata) and killifish (Rivulus hartii) in three types of natural communities (both species with predators, KGP; both without predators, KG; killifish only, KO) and four experimental KG communities, initiated with KGP guppies and KO killifish between 13 and 45 years ago. In all communities, killifish occupied higher trophic positions and changed their diet (δ^13 C) with body size. Only KGP guppies displayed an ontogenetic niche shift. The KG guppies displayed a significant difference in trophic niche from KGP guppies, a character displacement that can facilitate coexistence with killifish. In the experimental communities, the guppy trophic niche was intermediate between those in KGP and KG communities, indicating that evolution has driven the niche shift in KG guppies.

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Evidence of a trophic niche shift in an omnivorous migratory bird in South America: A comparison of stable isotope signatures in feathers between migratory and sedentary subspecies of Tyrannus savana

10.31219/osf.io/k5ghq ◽

2021 ◽

Author(s):

Maggie MacPherson

Keyword(s):

Life History ◽

Trophic Level ◽

Trophic Niche ◽

Spring Migration ◽

Life History Strategies ◽

Niche Shift ◽

Wet Season ◽

Lower Trophic Level ◽

Trade Offs ◽

Niche Shifts

Understanding how diet and life history strategies interact is important for exploring constraints of available nutrition on energetically expensive life history events in wild animals (i.e., reproduction, annual migration, or molt). Previous research on migratory birds breeding in the Northern Hemisphere has demonstrated trophic niche shifts from invertebrates to fruit in order to fuel spring migration. We examined whether a trophic niche switch occurred in a Neotropical austral migrant bird, Tyrannus savana savana prior to spring migration by measuring stable nitrogen isotopes in feathers. We found that the austral migrant T. s. savana did appear to shift in diet from a higher to lower trophic level (consistent in pattern with a shift from a higher to lower ratio of invertebrates to fruit) but the shift occurred earlier than expected if it was preparation for migration. A sympatric sedentary subspecies (T. s. monachus) appeared to forage only at the lower trophic level during their annual molt and that show no evidence of a trophic niche shift. The timing of the trophic niche shift leads us to conclude that a higher trophic level diet early in molt is not related to preparation for spring migration in this species but suggest that it may be related to seasonal changes in food availability as the wet season concludes. A remaining challenge for understanding the ecological consequences of trophic niche shifts is to find ways to empirically measure trade-offs between different diets across energetically expensive life history activities and compare these between taxa with differing life history strategies.

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Trophic niche shifts and phenotypic trait evolution are largely decoupled in Australasian parrots

BMC Ecology and Evolution ◽

10.1186/s12862-021-01940-4 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Vicente García-Navas ◽

Joseph A. Tobias ◽

Manuel Schweizer ◽

Daniel Wegmann ◽

Richard Schodde ◽

...

Keyword(s):

Trophic Niche ◽

Phenotypic Trait ◽

Dispersal Capacity ◽

Trait Evolution ◽

Wide Range ◽

Niche Shifts ◽

Dietary Niche ◽

Evolutionary Trajectories ◽

Best Fitting ◽

Trophic Shifts

Abstract Background Trophic shifts from one dietary niche to another have played major roles in reshaping the evolutionary trajectories of a wide range of vertebrate groups, yet their consequences for morphological disparity and species diversity differ among groups. Methods Here, we use phylogenetic comparative methods to examine whether the evolution of nectarivory and other trophic shifts have driven predictable evolutionary pathways in Australasian psittaculid parrots in terms of ecological traits such as body size, beak shape, and dispersal capacity. Results We found no evidence for an ‘early-burst’ scenario of lineage or morphological diversification. The best-fitting models indicate that trait evolution in this group is characterized by abrupt phenotypic shifts (evolutionary jumps), with no sign of multiple phenotypic optima correlating with different trophic strategies. Thus, our results point to the existence of weak directional selection and suggest that lineages may be evolving randomly or slowly toward adaptive peaks they have not yet reached. Conclusions This study adds to a growing body of evidence indicating that the relationship between avian morphology and feeding ecology may be more complex than usually assumed and highlights the importance of adding more flexible models to the macroevolutionary toolbox.

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Trophic Niche Shifts and Phenotypic Trait Evolution are Largely Decoupled in Australasian Parrots

10.21203/rs.3.rs-652573/v1 ◽

2021 ◽

Author(s):

Vicente García-Navas ◽

Joseph A. Tobias ◽

Manuel Schweizer ◽

Daniel Wegmann ◽

Richard Schodde ◽

...

Keyword(s):

Trophic Niche ◽

Phenotypic Trait ◽

Dispersal Capacity ◽

Trait Evolution ◽

Wide Range ◽

Niche Shifts ◽

Dietary Niche ◽

Evolutionary Trajectories ◽

Best Fitting ◽

Trophic Shifts

Abstract Background: Trophic shifts from one dietary niche to another have played major roles in reshaping the evolutionary trajectories of a wide range of vertebrate groups, yet its consequences for morphological disparity and species diversity differs among groups. Methods: Here, we use phylogenetic comparative methods to examine whether the evolution of nectarivory and other trophic shifts have driven predictable evolutionary pathways in Australasian psittaculid parrots in terms of ecological traits such as body size, beak shape, and dispersal capacity. Results: Rates of lineage diversification appear to be constant over time and we find no evidence for an ‘early-burst’ scenario of morphological diversification. The best-fitting models indicate that trait evolution in this group is characterized by abrupt phenotypic shifts (evolutionary jumps), with no sign of multiple phenotypic optima correlating with different trophic strategies. Thus, our results point to the existence of weak directional selection and suggest that lineages may be evolving randomly or slowly toward adaptive peaks they have not yet reached. Conclusions: This study adds to a growing body of evidence indicating that the relationship between avian morphology and feeding ecology may be more complex than usually assumed and highlights the importance of adding more flexible models to the macroevolutionary toolbox.

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Reciprocal trophic niche shifts in native and invasive fish: salmonids and galaxiids in Patagonian lakes

Freshwater Biology ◽

10.1111/j.1365-2427.2012.02837.x ◽

2012 ◽

Vol 57 (9) ◽

pp. 1769-1781 ◽

Cited By ~ 33

Author(s):

CRISTIÁN CORREA ◽

ANDREA P. BRAVO ◽

ANDREW P. HENDRY

Keyword(s):

Trophic Niche ◽

Invasive Fish ◽

Niche Shifts ◽

Patagonian Lakes

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Integrative taxonomy revisits the ontogeny and trophic niches of Rimicaris vent shrimps

Royal Society Open Science ◽

10.1098/rsos.200837 ◽

2020 ◽

Vol 7 (7) ◽

pp. 200837 ◽

Cited By ~ 1

Author(s):

Pierre Methou ◽

Loïc N. Michel ◽

Michel Segonzac ◽

Marie-Anne Cambon-Bonavita ◽

Florence Pradillon

Keyword(s):

Early Life ◽

Morphological Characters ◽

Integrative Taxonomy ◽

Trophic Niche ◽

Rimicaris Exoculata ◽

Combined Use ◽

Niche Shifts ◽

Mid Atlantic Ridge ◽

Juvenile Stages ◽

Trophic Niches

Among hydrothermal vent species, Rimicaris exoculata is one of the most emblematic, hosting abundant and diverse ectosymbioses that provide most of its nutrition. Rimicaris exoculata co-occurs in dense aggregates with the much less abundant Rimicaris chacei in many Mid-Atlantic Ridge vent fields. This second shrimp also houses ectosymbiotic microorganisms but has a mixotrophic diet. Recent observations have suggested potential misidentifications between these species at their juvenile stages, which could have led to misinterpretations of their early-life ecology. Here, we confirm erroneous identification of the earliest stages and propose a new set of morphological characters unambiguously identifying juveniles of each species. On the basis of this reassessment, combined use of C, N and S stable isotope ratios reveals distinct ontogenic trophic niche shifts in both species, from photosynthesis-based nutrition before settlement, towards a chemosynthetic diet afterwards. Furthermore, isotopic compositions in the earliest juvenile stages suggest differences in larval histories. Each species thus exhibits specific early-life strategies that would, without our re-examination, have been interpreted as ontogenetic variations. Overall, our results provide a good illustration of the identification issues persisting in deep-sea ecosystems and the importance of integrative taxonomy in providing an accurate view of fundamental aspects of the biology and ecology of species inhabiting these environments.

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Character Displacement Through and Evolutionary Change in Ontogenetic niche shifts

10.22541/au.162240466.61712130/v1 ◽

2021 ◽

Author(s):

Jaime Anaya-Rojas ◽

Ronald Bassar ◽

Blake Matthews ◽

Joshua Goldberg ◽

David Reznick ◽

...

Keyword(s):

Body Size ◽

Poecilia Reticulata ◽

Character Displacement ◽

Trophic Niche ◽

Niche Shift ◽

Ontogenetic Niche Shifts ◽

Ontogenetic Niche Shift ◽

Significant Difference ◽

Niche Shifts ◽

Ontogenetic Niche

In communities structured by body size, coexistence can occur through combinations of ontogenetic changes in competitive ability and dietary niche. Using stable isotopes, we examined ontogenetic niche shifts in Trinidadian guppies (Poecilia reticulata) and killifish (Rivulus hartii) in three types of natural communities (both species with predators, KGP; both without predators, KG; killifish only, KO) and four experimental KG communities, initiated with KGP guppies and KO killifish between 13 and 45 years ago. In all communities, killifish occupied higher trophic positions and changed their diet (δ^13 C) with body size. Only KGP guppies displayed an ontogenetic niche shift. The KG guppies displayed a significant difference in trophic niche from KGP guppies, a character displacement that can facilitate coexistence with killifish. In the experimental communities, the guppy trophic niche was intermediate between those in KGP and KG communities, indicating that evolution has driven the niche shift in KG guppies.

Download Full-text