10.5061/DRYAD.KN0V7
Costa-Pereira, Raul
Rice University
Sao Paulo State University
Tavares, Luiz E. R.
Universidade Federal de Mato Grosso
de Camargo, Plínio Barbosa
University of Sao Paulo
Araújo, Márcio Silva
Sao Paulo State University
Data from: Seasonal population and individual niche dynamics in a tetra
fish in the Pantanal wetlands
Dryad
dataset
2016
floodplain
Astyanax lacustris
mixing models
resource fluctuation
individual specialisation.
2016-12-27T14:17:53Z
2016-12-27T14:17:53Z
en
https://doi.org/10.1111/btp.12434
3316869 bytes
1
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
In seasonal tropical regions, rainfall and/or temporary floods during the
wet season generally increase the abundance and diversity of food
resources to many consumers as compared to the dry season. Therefore,
seasonality can affect intraspecific competition and ecological
opportunity, which are two important ecological mechanisms underlying
population and individual niche variations. Here, we took advantage of the
strong seasonality in the Pantanal wetlands to investigate how within- and
between-individual diet variations relate to seasonal population niche
dynamics of the tetra fish Astyanax lacustris. We quantified dietary niche
using gut contents and stable isotopes. Tetras had higher gut fullness and
better body condition in the wet season, suggesting that competition is
more intense in the dry season. The population niche was broader in the
wet season due to an increase in diet divergence between individuals, in
spite of potential stronger competition in the dry season. We posit that
low ecological opportunity in the dry season limits the diversifying
effect of intraspecific competition, constraining population niche
expansion. Our results add new insights on how seasonality affects
population and individual diets, indicating that intraspecific competition
and ecological opportunity interact to determine temporal niche variations
in seasonal environments.
Data_Costa-Pereira_Biotropica2017GutFullness_BodyCondition: Residual body
mass and gut fullness of the tetra fish Astyanax lacustrus in the wet and
dry seasons in the Pantanal wetlands. Presence_preys_diet: Food items and
respective trophic categories consumed by the tetra fish Astyanax
lacustris in the Pantanal wetlands during the wet and dry seasons.
Population_diet_proportions: Proportions of the mass of resources in the
diet of the tetra fish Astyanax lacustris in the wet and dry seasons in
the Pantanal wetlands. Individual_diet_proportions: Relative proportion of
food categories in the diet of individuals of the tetra fish Astyanax
lacustris in the wet and dry seasons in the Pantanal wetlands. PSi is the
proportional similarity index of each individual, which quantifies the
overlap between individual i’s niche and the population niche.
Source_contribution_isotope: Confidence intervals (CI 95%) and modes of
source contribution distributions to the isotopic composition of the tetra
fish Astyanax lacustris in the wet and dry seasons in the Pantanal
wetlands. Simulations_V_dry: Simulated V values in the dry season based on
the isotope variances (adaptation of the method proposed by Araújo et al.
2007a). Rows represent simulated populations with different degrees of
individual specialization and variance in individuals’ isotope values
(Varδi). Simulations_V_wet: Simulated V values in the wet season based on
the isotope variances (adaptation of the method proposed by Araújo et al.
2007a). Rows represent simulated populations with different degrees of
individual specialization and variance in individuals’ isotope values
(Varδi).
Pantanal
Brazil
19°34’34” S 57°00’46” W