Behavioral correlations across activity, mating, exploration, aggression, and antipredator contexts in the European house cricket, Acheta domesticus

Recently, there has been increasing interest in behavioral syndrome research across a range of taxa. Behavioral syndromes are suites of correlated behaviors that are expressed either within a given behavioral context (e. g., mating) or between different contexts (e. g., foraging and mating). Syndrome research holds profound implications for animal behavior as it promotes a holistic view in which seemingly autonomous behaviors may not evolve independently, but as a "suite" or "package." We tested whether laboratory-reared male and female European house crickets, Acheta domesticus, exhibited behavioral syndromes by quantifying individual differences in activity, exploration, mate attraction, aggressiveness, and antipredator behavior. To our knowledge, our study is the first to consider such a breadth of behavioral traits in one organism using the syndrome framework. We found positive correlations across mating, exploratory, and antipredatory contexts, but not aggression and general activity. These behavioral differences were not correlated with body size or condition, although age explained some of the variation in motivation to mate. We suggest that these across-context correlations represent a boldness syndrome as individual risk-taking and exploration was central to across-context mating and antipredation correlations in both sexes. © Springer-Verlag 2009

Effects of juvenile and adult condition on long-distance call components in the Jamaican field cricket, Gryllus assimilis

Complex signals may arise through either content- or efficacy-based selection. Content-based signals are thought to evolve because of the information content they provide to the receiver. Such signals may function as multiple messages, each relaying different information or types of information. For example, some signals or signal components may indicate different aspects of condition, or condition at different life stages (quality signals), while others relay information on signaller location, or function in species recognition. Or they may act as redundant signals of overall condition, or as backup signals of the same aspect of condition. Efficacy-based signals are proposed to evolve because of the way in which they influence the production, transmission, reception or processing of the signal. We manipulated juvenile and adult condition in male Jamaican field crickets, Gryllus assimilis, to test whether changes in components of the male's long-distance acoustic mate attraction signal were consistent with content- or efficacy-based selection. Several call components exhibited condition-dependence, and may be under content-based selection. Interpulse duration, pulse rate and chirp duration appeared to honestly signal juvenile condition, while dominant frequency appeared to signal adult condition. Thus, these signal components appeared to be acting as multiple messages of quality. Pulse number, interchirp duration and chirp rate were highly stereotyped and probably function in species recognition. Call number increased with decreasing condition and was likely under efficacy-based selection. No call components appeared to have the potential to act as redundant signals

Phosphorus availability influences cricket mate attraction displays

Adopting a stoichiometric perspective (e.g. the balance of carbon, nitrogen and phosphorus in organisms and their resources) has enhanced our understanding of ecological phenomena at a variety of hierarchical levels of organization. Unfortunately, little is presently known about how stoichiometry directly influences animal behaviour. Here we use a stoichiometric perspective to investigate how phosphorus availability in the environment influences mate attraction behaviour in insects. Using adult male European house crickets (Acheta domesticus), we manipulated the availability of dietary phosphorus and we quantified how survival, propensity to signal acoustically or not ('signallers' versus nonsignalling 'silent' males) and lifetime mate attraction signalling were affected. Dietary phosphorus availability did not influence the proportion of signallers versus silent males. However, signallers fed a diet rich in phosphorus had significantly higher signalling efforts than those that consumed a phosphorus-poor diet. Interestingly, signallers also lived longer than silent males, but neither signaller nor silent male survival was influenced by diet. Our findings suggest that the availability of dietary phosphorus has the potential to impact mating system evolution