What trait are advantageous in cold climate according to Bergmann's rule?

According to Bergmann's rule, larger body sizes are advantageous in cold climates. This is because larger animals have a lower surface area-to-volume ratio, which helps them conserve heat more effectively. Additionally, increased body mass allows for greater insulation and energy reserves to endure colder temperatures. Consequently, species in colder regions tend to be larger than their counterparts in warmer areas.