Aggressive spider colonies have higher rates of survival and reproduction following tropical cyclones than more docile colonies, finds a study published online this week in Nature Ecology & Evolution. The research suggests that extreme events could play a role in shaping animal behaviours.
Tropical cyclones create large-scale disturbances to natural habitats. However, studying the ecological effects of these infrequent and often unpredictable events is challenging, as it requires a comparison of habitats both before and after a storm strikes land.
Alexander Little and colleagues sampled colonies of the group-living spider Anelosimus studiosus before and after three tropical cyclones hit the Gulf and Atlantic coasts of the United States in 2018. By anticipating the trajectory of the tropical cyclones, the authors assessed the size of colonies in the projected path and tested how aggressively each colony responded to simulated prey. The authors vibrated the web and counted the number of spiders that subsequently attacked. They then returned 48 hours after the cyclone to see which colonies had survived, and on two later occasions to count how many eggs had been produced and how many spiderlings hatched. Colonies that were more aggressive before a cyclone had higher rates of reproduction and juvenile spider survival following a storm strike. In regions unaffected by the tropical cyclones, more docile colonies were favoured.