Photo by Christopher Michel December 2013
We humans could learn a few things from emperor penguins. In addition to being doting parents and extremely hardy, emperor penguins are a model of teamwork. These large, flightless birds live in Antarctica where wind chills can reach -75° F. They are well-adapted to this cold, but when the Arctic wind increases and the temperature drops, the penguins waddle closer together to huddle! The huddle includes thousands of birds.
Each one finds a place to tuck in, placing their head on the shoulders of the birds in front of them. The interior of this huddle can be as warm as 98° F! But the ones on the outside are not doomed to bear the brunt of the cold and wind. Instead, the dense huddle is always moving as the birds continually shift and rotate. The birds in the center move to the outside so others can have their turn on the inside!
By working together, no one is left out in the cold. And everyone thrives.
Christmas Island, a territory of Australia, sits in the Indian Ocean. In addition to the spectacular scenery of the island and the azure water surrounding it, Christmas Island is known for its crabs. More specifically, for the migration of millions of red crabs every year.
Photo by Ian Usher, December 2009
These crabs spend most of their lives inland and underground in the forest, feeding on decaying leaves. Yet once the wet season begins (usually in October or November), the crabs start their migration to the sea to mate and spawn. Their march is also dictated by the moon. They want to reach the ocean to spawn before the sun starts to rise, on an ebbing high-tide, during the moon’s last quarter. Somehow they know when it’s time to leave the nest and start the trek! Each female carries 100,000 eggs that she must shed into the sea. The only problem? While she’s a crab, she can’t swim. The goal is to release the eggs at the shoreline without being swept away by a wave.
There are an estimated 50 million red crabs on the island. Therefore, when they begin their migration, the ground, roads, bridges, and shorelines are literally swarming with crabs. In the words of Sir David Attenborough, “It is like a great scarlet curtain moving down the cliffs and rocks toward the sea.” To protect the crabs, some roads are closed during migration, and crab bridges have been built to usher the crabs up and over the road safely.
If you’ve ever seen a parade of leaf-cutter ants marching their harvest back to the nest, it’s a sight to behold. But that magnificent sight is only one small part of the story.
Those worker ants marching along may be part of a colony 5-10 million strong. Inside the nest there’s space for all the ants in the colony as well as chambers for nurseries, trash chambers, and more. Some nests can have thousands of chambers. Within the colony, each ant has a job, including the workers, those that defend the colony, trash gatherers, and the queen. There are other important jobs, but you’ll have to keep reading.
Photo by Filo Gèn’
When worker ants discover a suitable leafy tree, they leave a trail of pheromones from the nest to the source, for the others to follow. At the source, these ants use their knife-like jaws to cut or saw a leaf into pieces they can carry. And the pieces they do carry can be as much as 50x their own weight (comparably that would amount to an average person carrying a minivan!). Then they follow the trail of pheromones back to the nest.
Perhaps most amazing of all is that leaf-cutter ants do not eat the leaves they harvest. The leaves help grow a fungus garden. And that’s what the ants eat – the fungus! Now back to the other important jobs in the nest – those that grow and tend to this garden. Some ants’ job is to pick dangerous parasites off the leaf pieces before they are taken into the nest. Once in the nest, gardeners crush the leaves into moist pellets and add fecal droplets; then they tuck them into a garden chamber. As the fungus garden grows, some ants will remove pieces of fungus from dense areas and replant them in a new place. And still others watch over the garden and remove spores and hyphae of invading mold species.
And if all that is amazing enough, the ants doing the heavy lifting and marching are all female.
Like many people, I’m not a big fan of ants, especially those that find their way into my house or fire ants that bite and sting. But when I learned how fire ants survive a flood I couldn’t help but be amazed.
One of my current projects is about animal survival. As I researched, I tried to find a diversity of animals to include in the book, including insects. That’s when I came across an article about fire ants. Ants in general work together as a colony for all matters of survival. But fire ants go above and beyond. When their nests begin to flood,
they all leave at one. They clump together, then flatten themselves into a pancake shape – a raft. Linked like that they can float on the surface of the water for weeks, ensuring the survival of the colony.
It gets better. The raft isn’t merely a haphazard collection of ants desperately clinging to one another. Researchers found that the way they connect to each another is purposeful. For starters, 99% of ants’ legs will be connected to another ant, creating an intricate network that is strong enough to support the raft. Plus, the ants on the bottom create a base for the rest of the colony; others can actually move around atop the raft. That base is so tightly woven that water does not enter the raft so most of the ants stay try; this is also what creates buoyancy. Bonus fact: they can also form towers 30 ants tall!