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Most crayfish species are capable of constructing underground burrows. Burrow construction provides crayfishes the potential to actively engineer microhabitat and optimize local environmental conditions. Little attention, however, has been paid to quantifying the environmental outcomes of burrow morphology. We examined the potential of chimneys to ventilate burrows via wind-assisted buoyancy ventilation. We first conducted proof-of-concept trials in the field using smoke tracers. We then used a wind tunnel to quantify effects of wind velocity, chimney height, burrow orientation, and tunnel angle on model burrow ventilation rates. We developed a predictive model to predict burrow airflow based on endogenous and exogenous factors, and proofed the model with field measurements from a natural burrow. Proof-of-concept trials showed that during breezy conditions (i.e., 8–16 km−h wind gusts), smoke generated near a natural burrow was rapidly drawn into the non-chimney entry, through the burrow, and out the chimney. Wind-tunnel trials revealed significant effects of chimney height and wind velocity on burrow airflow, but no significant effects of burrow orientation towards the prevailing wind direction, nor of the angle of the burrow beneath the chimney. A model developed from wind-tunnel trials predicted air velocities exiting a theoretical chimney that were within 85% of observed velocities exiting natural chimney-burrow complexes. We conclude that crayfish chimneys can serve as passive ventilation systems for crayfish burrows, with chimney height and wind velocity exerting particularly strong effects on airflow. Costs and benefits associated with chimney construction and ventilation are still speculative but should comprise a productive line of research for future studies focused on burrowing crayfish ecology and conservation.

Crayfish are a highly diverse group of freshwater crustaceans with great ecological and economic importance. Many species construct terrestrial burrows within which they reproduce, overwinter, and/or avoid desiccation. Basic life-history and environmental tolerance information is still lacking for many species, particularly in regards to terrestrial portion(s) of their life cycle. In this paper we present and evaluate a design for a crayfish burrowing chamber that allows for experimental control of burrowing conditions, including substrate, groundwater height and flow, as well as direct observation of burrow construction and measurement of groundwater quality. Results of evaluation assays with Cambarus striatus, a widespread secondary burrower native to the southeastern United States show that chambers are amenable to studies examining burrowing behavior, survivorship, growth and water quality. Water table height was easily manipulated in chambers. Seepage rates were strongly affected by substrat...