Complex sentence: Lionesses do the majority of the hunting for their pride, they are more effective hunters because of being smaller, swifter and more agile than the males, and unencumbered by the heavy and conspicuous mane, which causes overheating during exertion.
Split into simpler sentences: Lionesses do the majority of the hunting for their pride. They are more effective hunters as they are smaller, swifter and more agile than the males, and unencumbered by the heavy and conspicuous mane, which causes overheating during exertion.