NATIONAL MUSEUM OF NATURAL HISTORY
How Leafcutter Ants and Other Culinary Creatures Prepare a Feast
Celebrate Thanksgiving with some of the animal kingdom’s greatest cooks, including marshmallow-roasting apes and salt-sprinkling monkeys
Each year at Thanksgiving, humans stock the table with the fruits of a successful harvest. However, few people can prepare a feast like a leafcutter ant.
According to Ted Schultz, a research entomologist and curator at the National Museum of Natural History, these tropical ants have developed an industrial-scale farming framework that rivals human agriculture in scale and efficiency. “Leafcutter ants are the ecological apex of fungal farming,” said Schultz, who monitors captive leafcutter colonies in the museum’s AntLab in addition to his field work. “Each colony is huge, and they’ve figured out how to take fresh plant material and turn it into fungus.”
Instead of sweet potatoes, cranberries and stuffing, the ants’ feast revolves solely around fungus. But first they have to round up some fresh ingredients. Like a cook making a run to the grocery store, leafcutter ants venture out of their nests to procure plant material, which they then lug back to their colony. Which is no easy feat — the weight is roughly equivalent to a human carrying a refrigerator on their back while running to their kitchen.
Once the leaf material is in the nest, a complex network of ants adept at performing around 30 different jobs gets to work. Certain groups of ants slice and dice the leafy material while others plant it in a series of subterranean garden chambers, allowing fungi to grow as it breaks down the plant material. The ants then harvest their fungal feast to feed a colony of ants that can number in the millions.
While leafcutter ants ability to take their food from farm to table is particularly impressive, there’s several other culinary creatures who are not afraid to mix it up in the kitchen. While the turkey and pumpkin pie will have to be provided, these animal chefs can provide salted sweet potatoes, roasted marshmallows, skewered grasshoppers and lots of fungi.
While several species season, store and even cook their food, few grow it as efficiently as leafcutter and other fungus-farming ants. Which makes sense because this mutualistic relationship has had plenty of time to blossom. Schultz’s genetic research has revealed that ants and fungi have been working together for around 66 million years. This happens to coincide with the asteroid impact that wiped out most of the dinosaurs and restructured forest ecosystems around the world.
Around 30 million years ago, ant agriculture became even more complex as the several fungal varieties became so dependent on the ants’ agricultural prowess that they could no longer survive on their own. The ants became similarly dependent, relying exclusively on the protein-packed fruiting bodies of the fungus variety for all their nutritional needs.
Today, roughly 250 different species of ants cultivate fungus, primarily in the tropics of Central and South America. However, few rival the industrial scale mastered by leafcutter ants. In their complex society, millions of individual ants perform a range of duties to ensure their fungal quota is met. Once a leaf reaches the nest, an assembly line of progressively smaller ants slice it into small bits before it is planted along the edges of their subterranean garden chambers. Different ants patrol these gardens, weeding out unwanted fungi and bacteria while applying antibiotics to the growing fungi. Another group is responsible for breaking down older fungal gardens, preventing pathogens from infecting the fresh crops.
Like human agriculture, farming ants have an outsized impact on their ecosystems. “They’re basically the insect equivalent of a large mammalian herbivore,” Schultz said. “They’re taking as much fresh vegetation every day as a medium-sized cow would take.”
While few animals practice agricultural systems as complex as these ants, there are several species who sport green thumbs. Earlier this year, scientists found evidence that pocket gophers tend to underground roots that they harvest for food. Several other species, including sea slugs that utilize their waste to promote fungal growth on marsh grass, actively cultivate delectable grub. “Lots of animals are farmers,” Schultz said. “If it has anything to do with growing your own food or even growing things for other purposes, there’s lots of animals that do it.”
For at least 5,000 years, humans have been sprinkling salt on their food. This likely resulted from humans diversifying their diets away from solely salt-infused animal meat during the advent of agriculture. But applying a generous amount of salt is not a uniquely human trait.
As the most northern-living non-human primate, Japanese macaques are famed for soaking in steamy thermal pools when temperatures plummet. This behavior, and a penchant for forming snowballs, has become ingrained in macaque culture. In the 1950s, researchers also observed that some troops of snow monkeys rinse off sweet potatoes in salt water. While the behavior originated as a way to wash dirt off their snacks, scientists have observed the macaques dunking the sweet potatoes in the briny water between bites, making it plausible they enjoy the salty taste.
Recent research has found that some Japanese macaques have a genetic mutation that allows them to tolerate bitter tastes. This allowed the snow monkeys to expand their palates and chow down on foods like citrus fruit, cabbage and radishes.
While macaques appreciate a prepared meal, they would not be much help when it came to preparing Thanksgiving dinner in the kitchen. But a bonobo named Kanzi can help work the stovetop. Researchers have taught the world-famous ape, who has utilized symbols to communicate with human scientists for decades, to light a fire and roast marshmallows, vegetables and even meat.
Kanzi is a particularly strong student in the kitchen, but researchers have also discovered that other apes can be capable cooks. During a 2015 study, researchers gave several chimpanzees — a close bonobo cousin — a fake microwave-like device that dispensed cooked food whenever the chimps inserted an uncooked vegetable. Many of the chimpanzees quickly realized they preferred cooked food, “warming up” any raw food the researchers gave them in their faux ovens.
The fact that chimpanzees and bonobos understand the concept of cooking carries intriguing evolutionary implications for their close cousins, humans. As our closest relatives on the primate family tree, chimpanzees and bonobos’ cooking expertise offers researchers a glimpse at how early hominins may have prepared their meals.
As a songbird sporting the hunting prowess of a raptor, the loggerhead shrike is an avian enigma. Native to North America’s prairies, these birds perch on fence posts and utility poles to scan the open grasslands for prey. While the shrike is only the size of a robin, it’s adept at tackling big prey including rodents, snakes and even other birds. Using a pair of tooth-like projections on the end of their hooked beak, the shrike severs a nerve on the animal’s neck before lugging its paralyzed prey off.
Hunting such large game leaves a lot of leftovers. Which is why loggerhead shrikes often impale their meals on barbed wire. These fences serve as the prairie equivalent to a pantry as the shrike stockpiles scraps of prey like grasshoppers, skinks and mice. And barbed wire even helps prepare some of the bird’s more noxious prey like poisonous monarch butterflies and toads. After they impale these critters, the shrike waits days for the toxins to break down before returning to enjoy their meals.
Whether you’re preparing, cooking, growing or even saving the Thanksgiving leftovers for tomorrow, you’re far from alone among this clade of culinary creatures.
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