Abstract
Boundary trade-offs are common among ecological, life-history, behavioural and other traits. Depending on the traits studied, distances of data points to boundary trade-offs can indicate ecological or life-history strategies, or behavioural performance. Quantile regression tests the statistical significance of boundary trade-offs, but it is unknown whether it provides meaningful benchmarks for evaluating distances to the true trade-offs shaping the data. This is especially relevant when traits limit each other mutually, rather than one independent trait limiting another dependent trait. I used empirical and simulated data to evaluate how quantile regression assesses distance to boundary trade-offs. First, I reanalysed empirical datasets showing upper-bound trade-offs between acoustic traits, which is a field where distances to trade-offs are often used to infer behavioural performance. Second, I simulated data under different assumptions of how boundaries influence density distributions, to test the accuracy of assessing distance to the true trade-offs generating the data. Quantile regression assessed distance to upper-bound trade-offs incongruently in most empirical datasets, strongly influenced by arbitrary decisions on which trait to use as dependent. Simulated data showed that a double quantile regression approach — the consensus of two reciprocal quantile regressions — accurately and robustly assesses distance to the true trade-offs generating the data. The method was robust to low sample sizes and to different assumptions on how boundary trade-offs influence the density distribution of data. Double quantile regression can assess distances to the boundary trade-offs observed in various branches of ecology, from functional and behavioural ecology, to population and macro-ecology.
Original language | English |
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Journal | Methods in Ecology and Evolution |
Volume | 10 |
Issue number | 8 |
Pages (from-to) | 1322-1331 |
Number of pages | 10 |
ISSN | 2041-210X |
DOIs | |
Publication status | Published - 2019 |
Keywords
- behavioural performance
- boundary limits
- boundary trade-offs
- double quantile regression
- quantile regression
- statistical methods