How does a rabbit regulate its temperature?

Rabbits primarily regulate their body temperature through their ears, which are highly vascularized. This means that the blood vessels in the ears can help to dissipate heat effectively. The large surface area of the ears allows for heat to be released when the rabbit is feeling warm, helping to cool down the body's overall temperature. Additionally, when the environment is colder, rabbits can minimize heat loss by constricting blood flow to the ears, thereby retaining warmth.

In contrast, the other options do not play significant roles in temperature regulation. The tail, whiskers, and paws are not designed for thermoregulation in the same way. While paws can have some influence due to their exposure, they do not provide as efficient a means of regulating temperature as the ears do. Thus, understanding the unique physiology of a rabbit's ears is key to grasping how they manage their body temperature effectively.