Spider boldness measurements

Each spider’s boldness was measured once a week a total of 7 times, using an assay that recorded the recovery of a spider from exposure to air puffs, which mimic the approach of an avian predator. After placing spiders individually in a plastic container (15x15cm) we waited for 30sec until the spiders were acclimated and stopped moving around the arena. We then administered two puffs of air to the anterior prosoma using an infant nose-cleaning bulb. Spiders react to the air puffs by huddling, i.e. pulling their legs under their body, and remaining motionless. Boldness was measured as the latency to resume movement and move one body length. Because bolder individuals resume movement faster, the latency to resume movement was subtracted from the maximum duration of the procedure (600s) to create a metric that increases with boldness. We designated as ‘shy’ those individuals with a latency to resume movement of 400-600s (boldness of 0-200), while ‘bold’ individuals were those with a latency to resume movement of 0-200s (boldness of 400-600).