Adaptations to a World in Which Warm Air Rises

Thermals form when warm air is beside cooler air. Warm air rises (red) above cool air (blue).

An "adaptation" is a physical or behavioral feature that evolved in response to an organism's environment, due to pressures for survival. How a species looks (its anatomy), as well as how it behaves (how it moves, obtains food, reproduces, responds to danger, etc.) are examples of adaptations.

When we think about animals' adaptations, we sometimes overlook the invisible forces upon them. Can you find ways monarch butterflies and bald eagles are similarly adapted to the fact that warm air rises?

  • Draw and compare the silhouette of a monarch butterfly and a bald eagle. What adaptations do they both have for soaring flight?
  • How does their anatomy compare to that of a hummingbird, a bird famous for its powered flight? (One biologist speculates that powered flight uses twenty times more energy than soaring flight, in eagles!)
Monarchs riding in a thermal
Angangueo, Mexico

Monarch Butterflies Flying in a Thermal


National Science Education Standards

Life Science
An organism's behavior evolves through adaptation to its environment. How a species moves, obtains food, reproduces, and responds to danger are based in the species' evolutionary history. (5-8)

Biological evolution accounts for the diversity of species through gradual processes over many generations. Species acquire many of their unique characteristics through biological adaptation, which involves the selection of naturally occurring variations in populations. Biological adaptations include changes in structures, behaviors, or physiology that enhance survival and reproductive success in a particular environment. (5-8)

Living systems at all levels of organization demonstrate the complementary nature of structure and function. (5-8)