CATALYST

Corals are animals that build massive reef structures, but they depend heavily on microscopic algae called zooxanthellae. The algae live inside coral tissues and photosynthesize, using sunlight to produce sugars and oxygen. Much of this energy is passed to the coral, providing up to 90% of its food. In return, the coral provides the algae with a protected home and nutrients like carbon dioxide and nitrogen, which the algae need for photosynthesis. 

This partnership is so important that coral reefs, among the most diverse ecosystems on Earth, wouldn’t exist without it. But rising ocean temperatures and pollution can stress corals, causing them to expel their symbiotic algae in a process called bleaching. Scientists are now experimenting with “coral probiotics” and heat-resistant algae strains to restore damaged reefs. 

The Galapagos finch flies in front of the tortoise to show their presence, at which point the tortoise then stretches out its neck and legs so that the bird can eat ticks and parasites off the tortoise’s skin and shell. This means that the tortoise is relieved of parasites and the finch gets an easy snack, benefiting both species. Mutual grooming behaviors aren’t unique to the Galapagos, oxpecker birds do something similar with rhinos and buffalo in Africa! 

Flowering plants and their pollinators have developed special mutualistic relationships; pollinators are essential for many plants to reproduce! Pollinators are insects, like bees, or animals, like hummingbirds, that carry pollen between flowers. In this case, bees collect their food nectar  from flowers like pansies and unintentionally carry pollen from one bloom to another, helping the plant reproduce. 

Plant and pollinator relationships are vital to our food supply. In fact, scientists estimate that about one in every three bites of food you eat depends on pollinators like bees. The U.S. alone has over 3,500 species of native bees supporting crops and wild plants alike. 

Wildebeest and zebra often travel together during the Great Migration, when millions of animals move across the Maasai Mara and the Serengeti in search of fresh grazing grounds and water. Though they’re both herbivores, they eat different grasses; zebras prefer tall, tough grass, which clears the way for softer grass preferred by wildebeest. 

Even their senses complement each other. Zebras have excellent eyesight and hearing, while wildebeest have a sharper sense of smell. By sticking together, they increase their chances of spotting predators and surviving the journey. 

Monarch butterflies are perhaps the most well-known and beloved butterflies in North America, and they depend on one plant for survival: milkweed. Monarch caterpillars must eat milkweed leaves, which contain toxins that transfer to the caterpillars, a defensive gift from the plant that makes them unpalatable to predators!  

Adult monarchs also drink nectar from milkweed flowers and pollinate them in the process. Without milkweed, monarchs can’t complete their lifecycle, which is why conservationists encourage planting native milkweed to support this threatened species. 

Want to see how these amazing partnerships come to life — in LEGO® bricks and in nature? Come explore Brick Planet at the Denver Museum of Nature & Science and discover the incredible connections that keep our planet thriving.

Learn more, here!