Buzz
In humans, the digestive system is vital for breaking down food, allowing nutrients to nourish our growth and health while also expelling waste from the body. Once digestion is complete, our waste is discarded, and we carry on without much thought to the process.
For humans, bodily waste is typically seen as an unpleasant byproduct—something we have no use for, nor do we think of using it as a tool for defense or as a resource for survival.
However, certain animals have evolved to use not only their own waste but also the waste from other organisms. They utilize it to regulate their body temperature, protect themselves from threats, boost the immunity of their young, and ensure their food sources remain plentiful in the wild.
Here are ten remarkable animals that leverage waste to not only survive but flourish in their environment.
10. Shoebill
The shoebill, scientifically known as Balaeniceps rex, is a large bird native to wetlands, standing between and 5 feet (1 to 1.5 meters) tall. With a distinctive, foot-long bill that closely resembles a Dutch clog, this bird’s name reflects its unique appearance.
This specialized bill enables the shoebill to easily capture and consume sizeable prey, including lungfish, eels, tilapia, snakes, and even baby crocodiles and Nile monitor lizards, which are found in the marshes and swamps of East Africa.
Known for their exceptional hunting abilities, these birds are also remarkable for their patience, remaining motionless for hours as they wait for their prey. In addition to their vital role in the ecosystem, they have an interesting way of adapting to the heat of the African climate—they cool themselves by pooping on their legs.
Like many bird species, shoebill waste is predominantly liquid. By excreting on their legs, they effectively cool the warm blood in their limbs. This process helps regulate their body temperature, allowing cooler blood to circulate through their body, even in the heat of the African sun.
9. Cassowary
Cassowaries are large, flightless birds that inhabit the tropical forests and wetlands of Northern Australia, New Guinea, and nearby islands.
These birds are adorned with unique, two-quilled, jet-black feathers, a large casque or ‘helmet’ on top of their head, and wattles—fleshy skin pouches hanging from their neck. These wattles come in a variety of vibrant colors, including blue, red, gold, purple, or white.
Not only are cassowaries visually striking, but they are also renowned as the world’s most dangerous birds, thanks to their powerful, dagger-like claws capable of slicing through predators with ease.
In addition to their formidable appearance and behavior, cassowaries possess a short digestive system, a highly active liver, and distinctive stomach enzymes, which allow them to safely consume toxic fruits and seeds. However, as they swallow fruits whole, much of it remains only partially digested and is later excreted in their feces.
However, the cassowary's short digestive tract and its ability to pass seeds make its droppings vital to the ecosystem. For this reason, they are often referred to as the rainforest’s gardeners.
Cassowaries consume fruit from 238 different plant species, and the seeds pass through their digestive system intact. These seeds are then fertilized and scattered across vast areas of the rainforest. The cassowary and its tree-growing feces play a crucial role in maintaining the diversity of their habitat, which is key to their survival.
8. Pika
Pikas are small, short-legged mammals that resemble a mix between a guinea pig and a rabbit, living in the mountains of North America and Asia. There are 29 species of pika globally, all of which remain small, measuring just 6 inches (15 cm) in length and weighing between 4.5 to 7.1 ounces (125 to 200 grams).
One particular species, the plateau pika, resides in the Qinghai-Tibetan Plateau in northwestern China, where winter temperatures can plummet to -20°F (-29°C). Unfortunately, these small mammals lack the blubber needed to insulate themselves from such cold and do not hibernate like many other animals in frigid climates.
Despite these difficulties, the plateau pika has found ways to endure the severe winter conditions by reducing its metabolism by up to 30% and supplementing its diet with yak droppings to gain essential nutrients.
Though this behavior might seem off-putting, the harsh, dry winter climate causes the plants the pika typically feeds on to wilt and grasses to become brittle, leaving the pika without its usual food supply. Without consuming yak droppings, the plateau pika would be unable to find the necessary nutrients to survive through the cold months.
7. Tortoise Beetle
As their name implies, tortoise beetles bear a striking resemblance to tiny turtles, though they measure less than 0.5 inches (5-12 mm) in length.
These beetles have a dome-shaped carapace that closely mirrors a turtle's upper shell, ranging in colors from dull orange to green to gold, with some species even being translucent. The tropical tortoise beetles are known for being the most vividly colored of all species, making them highly sought after for jewelry-making.
These remarkable beetles not only possess unique physical traits but many species also have the fascinating ability to shift the appearance of their carapace, changing from glossy to matte or even shifting colors in seconds. For instance, when under stress, the golden tortoise beetle can transform its color from gold to bright red or golden orange, and it can even develop black spots by maneuvering pigments through microscopic ducts in its exoskeleton.
In addition to their ability to change color, tortoise beetle larvae use a strange form of camouflage to protect themselves from predators. They fashion an “umbrella” made from their fecal matter (or frass) and shed exoskeletons, which hides them while they feed on leaves.
The slightly flattened tortoise beetle larvae have an abdominal section that features a “fecal fork,” which it uses to attach its waste, creating the protective umbrella. These fecal shields not only help conceal the larvae, but they also act as a stinky deterrent against predators. The larvae are also able to adjust the position of their fecal shield to face potential threats.
Due to their slow-moving nature and leaf-based diet, tortoise beetles are vulnerable to various dangers, and the fecal umbrellas provide crucial protection for their survival.
6. Egyptian Vulture
Egyptian vultures are found across southern Europe, the Middle East, Central Asia, and parts of North Africa. These remarkable birds are among the few species known to use tools, such as pebbles, to crack open the tough shells of ostrich eggs.
In ancient Egypt, these vultures were revered as sacred symbols of the goddess Isis, the goddess of fertility, motherhood, and magic. Their image was so sacred that it was even used in hieroglyphics.
Though small in size, measuring between 21 and 25 inches (54 to 66 cm) long and weighing between and 5.2 pounds (1.6 to 2.4 kg), Egyptian vultures possess a striking appearance, with contrasting white and black primary and secondary feathers and a vivid yellow face. The reason for their bright yellow face is both fascinating and unpleasant.
Carotenoids, the pigments responsible for the red, yellow, and orange hues in many animals, are vital for biological coloration. However, because Egyptian vultures primarily feed on rotting flesh and garbage, they don't get enough carotenoids from their usual diet. To make up for this, they consume cow, sheep, and goat droppings, which helps maintain their bright yellow color.
This dietary behavior not only helps the vulture retain its striking yellow appearance but may also play a role in attracting mates and intimidating rivals, as the bright yellow coloration is seen as a sign of health and vitality in the species.
5. Opossum
Opossums are marsupials characterized by their gray or whitish fur, elongated pointed snouts, and long, hairless tails, which make up over a third of their 2.5-foot-long (76-cm) bodies. They are the only marsupials that are native to North America.
With 50 teeth—more than any other land mammal in North America—opossums have a diverse diet, feeding on fruit, snakes, mice, rats, ticks, cockroaches, and even venomous snakes. Remarkably, they are immune to the venom of rattlesnakes, cottonmouths, and other pit vipers.
Despite their wide range of food sources, opossums have a notably short lifespan, typically living only two to four years. Due to this brief life expectancy and the constant threat from predators such as owls, coyotes, bobcats, foxes, and domestic dogs, they have developed a highly effective self-defense tactic.
Known as “playing possum,” this survival strategy involves collapsing, pretending to be dead, defecating, and secreting a foul green slime from their anal glands. This grotesque display causes predators to believe the opossum is lifeless and lose interest.
4. Baleen Whales
Baleen whales possess unique bristle-like structures in their mouths called baleen, composed of keratin, the same material found in human fingernails. Instead of teeth, these whales open their mouths to let large volumes of water flood in. They then close their mouths and expel excess water through the sides, leaving behind krill that gets trapped in the baleen's bristles.
Species of baleen whales, such as humpback, fin, right, bowhead, gray, and blue whales, all feed on krill. For example, a single blue whale can consume an astounding 16 tons of food daily. This massive intake of food also results in a significant amount of excrement being released into the water.
Whale feces, however, is among the most iron-rich substances in the ocean. As these whales consume, digest, and expel krill through their feces, the waste floats to the surface, where it aids in the growth of tiny phytoplankton through photosynthesis, providing food for krill.
As a result, whale waste serves as a natural fertilizer for the ocean, promoting the regrowth of phytoplankton, which in turn nourishes the krill, forming a crucial part of their food chain.
3. Vampire Squid
The vampire squid, scientifically known as Vampyroteuthis infernalis, meaning ‘vampire squid from hell,’ is a creature that, despite sharing traits with both squids and octopuses, is not a squid at all. Instead, it has its own unique scientific classification.
Vampire squid come in shades of reddish rust or black, depending on their habitat. They possess large eyes—the biggest of any living creature. Although their eyes are clear, when illuminated, they reflect the surrounding water, making them appear blue.
Found at depths of 2,000 to 3,000 feet (609 to 914 meters) below the ocean's surface in the temperate and tropical waters of the Pacific, Atlantic, and Indian Oceans, vampire squid dwell in an environment with low oxygen levels. While this deep-water habitat means few predators can thrive there, it also limits the squid's available food sources.
Despite these challenges, the vampire squid thrives by acting as 'the garbage disposal of the ocean.' It feeds on 'marine snow,' a term used to describe a mixture of dead animals, feces, and mucus that sinks from higher up in the ocean.
As a result, the vampire squid is the only known living cephalopod species that operates as a scavenger. It has evolved to not only rid the ocean of waste but also to secure a food supply, allowing it to flourish in such a challenging environment.
2. Mistletoebird
The mistletoebird, which is also referred to as the Australian flowerpecker, mistletoe flowerpecker, or fire-breasted flowerpecker, is commonly found throughout mainland Australia and on several northern islands where mistletoe thrives.
Male mistletoebirds are easily recognizable by their glossy blue-black back and tail, complemented by a striking red throat and chest. In contrast, the female mistletoebird has a more subdued appearance, with a grayish upper body and a white underbelly featuring a gray streak.
Their diet consists of nectar, pollen, insects, and spiders, but their primary food source is the berries from mistletoe, which is where they get their name.
Despite lacking a gizzard, a part of the stomach used to grind food, the mistletoebird has a highly specialized digestive system that allows mistletoe seeds to pass through its tract within about 25 minutes without being harmed.
Once the seeds are excreted, they are coated in a sticky substance. To remove this coating, the mistletoebird performs a behavior called the waggle-dance, rubbing itself against tree branches. This helps the seeds remain on the mistletoe plants, ready to germinate.
Because mistletoe is a parasitic plant that requires a host for germination, the mistletoebird’s unique behavior and specialized excrement play a crucial role in sustaining the plant’s food supply.
1. Koala
The term “koala” is believed to derive from the Dharug language of the Australian Aboriginal people, meaning “no drink” or “no water,” which aligns with the fact that koalas primarily obtain their water intake from eucalyptus leaves.
These marsupials inhabit the eucalyptus forests of southeastern and eastern Australia, where they consume over 1 pound (0.45 kg) of eucalyptus leaves daily. Despite the toxic compounds present in these leaves, koalas possess a specialized digestive system that enables them to process these harmful oils.
Koalas begin by grinding the leaves with their molars into a paste, which helps extract the remaining nutrients. The liver then works to isolate the toxins from the eucalyptus, which are later eliminated through the koala’s urine and feces. The remaining plant matter is broken down by specific bacteria in their digestive tract.
Sadly, koalas are born without these essential bacteria. As infants, they rely on their mothers to provide this bacteria so that they can eventually digest eucalyptus as adults.
To acquire this necessary bacteria, baby koalas consume a special type of their mother’s feces known as pap. Although it may seem unpleasant, this practice is crucial for the koala to develop the gut bacteria needed to survive on eucalyptus. Without it, a koala would not be able to thrive.
