How resource acquisition influences the detection of trade-offs

Trade-offs should be ubiquitous in nature. Yet, direct trade-offs between traits essential for fitness are challenging to detect. Recent theory suggests that population-level variation in resource acquisition could play an important role in our ability to detect trade-offs. Here, we test experimentally the hypothesis that the detection of trade-offs depends on the underlying distribution of individuals with different resource acquisition in a population. Specifically, we resampled ecologically and experimentally relevant resource acquisition distributions from a population of male Australian field crickets (Teleogryllus oceanicus) subjected to a continuous range of diet manipulation. While we found evidence for trade-offs between different male fitness traits, the distribution of resource acquisition in the population had no systematic effect on the strength of these trade-offs. Interestingly, trade-offs were most pronounced between postcopulatory traits and immune function, but trade-offs involving precopulatory traits were relatively weak. Overall, our findings question the hypothesis that resource acquisition may influence our ability to detect trade-offs and instead suggest that other factors, like the hierarchical complexity of resource allocation, make detecting trade-offs so elusive.