Wisconsin Natural Resources magazine

Wisconsin Natural Resources magazine

ADD NEW DESC © James Hays/Mighty Mammoth Media

© James Hays/Mighty Mammoth Media

June 2014

Nature's Superheroes

Animals amaze us with their adaptations.

Story by Emily Stone and graphics by James Hays/Mighty Mammoth Media

Peregrine falcons fly with super speed, dragonflies dart in all directions, caterpillars change identities and take flight, and dung beetles move objects with super strength. Gray tree frogs don a cloak of invisibility, spiders spin webs of steel–strong silk, and bats use super senses to catch prey. The real accomplishments of these incredible Wisconsin critters deserve the same respect as the antics of comic book heroes.

For the kid in all of us who marvels at the fastest, the strongest, the best of anything, learning about animal adaptations can be a BAM! WOW! SHA–ZAM! experience. Those adaptations, which are things that animals (or plants) have or do that help them survive, can be as simple as moving fast, or as complex as ingesting toxins to deter predators. Many adaptations remind us of the super powers wielded by our favorite fictional characters.

Peregrine falcons can dive at speeds over 200 mph, making them the fastest animals on Earth. Peregrines use their super speed to attack other birds from high above. When a peregrine locks its sights on a pigeon or duck, it tucks its wings close to its torpedo–shaped body and rockets down in a dive called a "stoop." Stoops have been clocked at up to 242 mph. True, that isn't faster than a speeding bullet, but a bullet doesn't have to survive its high velocity.

Reaching such high speeds requires special safety equipment — a.k.a. adaptations. Peregrines have a third, clear eyelid, called the nictitating membrane, which protects the eye from dust and debris as they dive. Small, bony baffles in their nostrils regulate the amount of air that can enter the nasal cavity. The baffles (copied by engineers and applied to jets) allow peregrines to continue breathing at high speeds and protect their airways from damage.

While dragonflies can't match peregrine falcons' speed (dragonflies can only reach about 30 mph, compared with a peregrine's 35 mph flat–flight speed), these mosquito–eating insects may win the agility contest. Each of a dragonfly's four wings operates independently, powered by its own set of muscles, resulting in fantastic maneuverability. Dragonflies can fly backward and forward, straight up and straight down, hover, accelerate to full speed in a split second and make hairpin turns.

Dragonflies have adapted to see faster, too. Together, a dragonfly's eyes and brain can detect movements separated by only 1/300th of a second! Dragonflies also possess an almost super–human capacity for selective attention. They can focus on a single mosquito in a swarm, track the moving target and adjust their path to intercept the prey.

While we like it when dragonflies eat mosquitoes, their prey also includes other insects we would rather see alive. Dragonhunter dragonflies sometimes munch on monarch butterflies, despite the presence of milkweed toxins that deter other predators. Those toxins, first ingested by the monarch caterpillars, remain after metamorphosis and bestow continued protection on the adult.

Metamorphosis itself is an incredible phenomenon, perhaps more impressive than Clark Kent's transformation to Superman. Inside a bejeweled chrysalis, the caterpillar's body dissolves and imaginal disks grab cells out of the soup to assemble each new wing, leg and organ. The caterpillar's mission was to eat. With an entirely different set of needs and adaptations, the adult butterfly does not compete with its offspring.

Dung beetles also undergo complete metamorphosis, pausing in a resting stage similar to the butterfly's chrysalis. Beautifully iridescent dung beetles can roll at least 10 times their own weight, just like Superman.

While not exceptionally strong themselves, spiders spin super strength into their webs. A single strand of spider silk is stronger by weight than steel. Hypothetically, a pencil–thick strand of silk could stop a plane in flight. Luckily, spiders weave much thinner webs, and use them to catch the buzzing villains who steal our blood.

Despite the daintiness of spider silk, another one of Nature's Superheroes can detect webs in mid–air, using only their ears. Bats exemplify super senses, since their excellent hearing and echolocation techniques allow them to catch insects on the wing, hear an insect walking six feet away, and maneuver around your head, all in complete darkness.

Bats emit super–sonic "shouts" in sync with their wing beats exhaling on every stroke. Each shout lasts only a few thousandths of a second, and silences between the calls enable bats to listen to the echoes. The information contained with the echoes allows bats' brains to calculate the size and hardness of the body of the insect, detect the flutter of a prey's wings and compute their flight speed.

It would take a super sense of sight for any animal to decode the gray, brown, and green blotches of gray tree frogs. Those patterns, along with a light sprinkling of warts, help gray tree frogs become seemingly invisible when on tree bark.

Even with all these amazing powers and adaptations, Nature's Superheroes each face their own "kryptonite." Peregrine falcons were almost wiped out by DDT in the mid–1900s. Humans became their sidekicks and launched an incredible effort to ban the pesticide and increase the birds' numbers through captive breeding. In 1999, the peregrine was removed from the Federal Endangered Species List, although they remain listed as endangered in Wisconsin.

Dragonflies face the kryptonites of pollution, low oxygen and habitat destruction during the years they spend in rivers and ponds as immature nymphs. Gray tree frogs also need good water quality and habitat protection. You can become their sidekick by getting involved in stream monitoring through UW–Extension's Water Action Volunteer program and by supporting nature reserves.

Spiders, bats and dung beetles all face human misconceptions as their kryptonite. These critters need sidekicks who will educate others about their importance in ecosystems.

Monarch butterflies face numerous kryptonites, with insecticides, herbicides and habitat loss in the forefront. Become a superhero sidekick by letting milkweed grow in your ditch or planting more of the beautiful flowers in your garden.

To learn more about the amazing adaptations of Wisconsin's animals, their kryptonites and how you can become a conservation sidekick, visit the Cable Natural History Museum's new exhibit: Nature's Superheroes — Adventures with Adaptations, and participate in the conservation sidekick programs this summer. For more information visit cablemuseum.org.

Emily Stone is the naturalist/educator at the Cable Natural History Museum in Cable. She teaches kids of all ages about amazing adaptations and has been known to wear a superhero cape.