Thermal stress and availability of potential mates drive decisions related to thermoregulatory burrow retreat and emergence in fiddler crabs

Behavioral tradeoffs are common, as many behaviors are incompatible. In ectotherms, these tradeoffs often result from incompatibility between thermoregulatory behaviors and other critical behaviors. These trade-offs are resolved by choice, with decisions expected to be based on the costs and benefits of each behavior to optimize fitness outcomes. We examined the social and abiotic factors driving resolution of the trade-off between thermoregulatory behavior and courtship behavior in the fiddler crab Austruca mjoebergi. Male fiddler crabs perform a courtship display on the high intertidal sediment surface, where they face extreme thermal stress; retreat into the burrow is an effective thermoregulatory strategy but requires a cessation of courtship behavior. Surface duration decreased as environmental temperatures increased, indicated that time available for courtship is limited by high temperature. Yet when exposed to a stimulus female, males remained on the surface longer, spent less ti..., , , # Data from: Thermal stress and availability of potential mates drive decisions related to thermoregulatory burrow retreat and emergence in fiddler crabs

[https://doi.org/10.5061/dryad.tmpg4f585](https://doi.org/10.5061/dryad.tmpg4f585)

## Description of the data and file structure

*Study Species and Site*

The fiddler crab *Austruca mjoebergi* is a small (<15 mm carapace width) fiddler crab that inhabits* *intertidal mudflats in the tropical Indo-Pacific. Males maintain and defend territories (~10-cm diameter) centred on a breeding burrow (Reaney and Backwell, 2007). Reproductive activity in *A. mjoebergi *occurs throughout the year. During a 6–8 d period during each neap tide, when the mudflat is exposed throughout the tidal cycle, sexually receptive females wander through the population searching for mates. Males perform a species-specific waving display using the greatly enlarged major claw on the sediment surface near their breeding burrows to attract mate-searching females. ...