Sexual selection and the physiological consequences of habitat choice by a fiddler crab

• Published in: Oecologia Vol. 176; no. 1; pp. 25 - 34
• Main Authors: Allen, Bengt J, Levinton, Jeffrey S
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.09.2014; Springer; Springer Berlin Heidelberg; Springer Nature B.V
• Subjects: Analysis; Analysis of Variance; Animal and plant ecology; Animal, plant and microbial ecology; Animals; Biological and medical sciences; Biomedical and Life Sciences; Body Temperature; Brachyura - physiology; Breeding; breeding season; Breeding seasons; burrows; Choice Behavior - physiology; claws; Courtship; Crabs; Crustaceans; Decapoda; Desiccation; Ecology; Ecosystem; Energy Metabolism - physiology; Female; Females; Food; Food availability; Foraging; Fundamental and applied biological sciences. Psychology; General aspects; High temperature; Hydrology/Water Resources; Life history; Life Sciences; Male; males; Marine; Mating behavior; Mating Preference, Animal - physiology; Microhabitats; Natural selection; New York; Physiological aspects; PHYSIOLOGICAL ECOLOGY; Physiological ecology - Original research; Physiology; Plant Sciences; Reproduction; Salt marshes; Sediments; sexual selection; summer; Temperature; Thermal stress; Tidal marshes; Uca pugilator; Water loss; Wetland ecology; New York; Microhabitat use; Resource acquisition; Constraint; Female choice; Trade-off; Microhabitat; Sexual selection; Brachyura; Habitat selection; Acquisition; Crustacea; Arthropoda; Female; Habitat; Decapoda; Invertebrata; Uca pugilator
• ISSN: 0029-8549; 1432-1939
• DOI: 10.1007/s00442-014-3002-y

In mid-Atlantic salt marshes, reproductively active male sand fiddler crabs, Uca pugilator, use a single greatly enlarged major claw as both a weapon to defend specialized breeding burrows from other males and an ornament to attract females for mating. During the summer breeding season, females strongly prefer to mate with males controlling burrows in open areas high on the shore. Food availability decreases while temperature and desiccation stress increase with increasing shore height, suggesting that the timing and location of fiddler crab mating activity may result in a potential trade-off between reproductive success and physiological condition for male crabs. We compared thermal preferences in laboratory choice experiments to body temperatures of models and living crabs in the field and found that from the perspective of a fiddler crab, the thermal environment of the mating area is quite harsh relative to other marsh microhabitats. High temperatures significantly constrained fiddler crab activity on the marsh surface, a disadvantage heightened by strongly reduced food availability in the breeding area. Nevertheless, when the chance of successfully acquiring a mate was high, males accepted a higher body temperature (and concomitantly higher metabolic and water loss rates) than when the chances of mating were low. Likewise, experimentally lowering costs by adding food and reducing thermal stress in situ increased fiddler crab waving display levels significantly. Our data suggest that fiddler crabs can mitigate potential life history trade-offs by tuning their behavior in response to the magnitude of both energetic and non-energetic costs and benefits.