Facultative polyandry protects females from compromised male fertility caused by heatwave conditions

Why is polyandry such a common mating behaviour when it exposes females to a range of significant fitness costs? Here, we investigated whether polyandry protects females against reduced male fertility caused by thermal stress from heatwave conditions. Sperm production and function are vulnerable to heat, and heatwave conditions are forecast to increase as our climate warms, so we examined these effects on female reproduction and mating behaviour...