Know your Sloth Predators: The Mighty Jaguar

Know your Sloth Predators: The Mighty Jaguar

Known for their impressive hunting abilities, jaguars (Panthera onca) are both feared and revered. Weighing a hefty 56-96 kg (120-200+ lbs) they are the biggest felines living in the Western Hemisphere and the third largest cat species on Earth (after lions and tigers).

Boasting one of the most powerful bites in the animal kingdom, their name comes from the indigenous word “yaguareté” which means “true, fierce beast” or “he who kills with one leap.”

So what do jumping jaguars and stealthy sloths have in common?  They are more intertwined than first meets the eye.

Sloths and Jaguars

Like most apex predators, jaguars are also a keystone species, helping to maintain a balanced ecosystem by keeping herbivore populations in check. Jaguars are opportunistic hunters, and prey upon almost anything they can get their jaws on. To name a few, they eat capybaras, deer, tortoises, iguanas, armadillos, fish, birds, and monkeys.

They even have the ability to take down South America’s biggest mammal, the tapir, and catch an equally formidable predator, the caiman.

Unfortunately for sloths, they are also on the list. Sloths have evolved their stealthy habits to remain hidden from their main predators jaguars and harpy eagles, who rely on their sense of sight to find them. If discovered, the sloth’s remarkable grip strength helps them to survive an attack by avoiding being pulled from the trees by these powerful predators.

They are both threatened by habitat fragmentation

Like sloths, jaguars are particularly vulnerable to the effects of habitat fragmentation, especially on the grand-scale. Although, jaguars have been sighted as far north as the deserts of Arizona their range of six million square km (over 2,316,000 square miles) extends from northern Mexico through Central America into Northern Argentina.

historic current range of jaguar
Although jaguars are widespread, their total population is estimated to be only 173,000./Image:

Jaguars require large amounts of primary rainforest in order to survive. A study that monitored the activity of jaguars in Southern Mexico using GPS collars, determined that a female jaguar used at least 180 square km over the course of a year and a male jaguar had a home range of 430 square km. A healthy population of 500 jaguars could require anywhere from 153,250-192,400 square kilometres (approximately 60,000-75,000 square miles)!

The jaguar’s main stronghold is the Amazon basin, with half of the world’s population of jaguars living in Brazil. In South America, the historic range of the jaguar has been reduced by half and overall jaguar populations are decreasing.


jaguar corridor panthera mesoamerican
In addition to protecting large swaths of jaguar habitat, Panthera aims to connect these areas through preserving and restoring and biological corridors./Image: Panthera

Although protected areas are key to their survival, maintaining and restoring connectivity throughout their range is essential for the health of the species. Reknowned jaguar scientist Alan Rabinowitz (1953-2018), known for establishing the first jaguar preserve in Belize in 1986, was particularly concerned about this issue. In 2006, he co-founded Panthera to protect jaguars and other wild cat species across their ranges.

Since jaguars require such vast amounts of intact forest, they are also known as an umbrella species. Conserving jaguars benefits a variety of other species, including sloths.

They are both hunted

In addition to habitat loss and fragmentation, one of the main threats to jaguars is poaching. Although sloths are protected in many places where they are found, they are still hunted. The endangered maned sloth in Brazil is particularly threatened by hunting.

Jaguars are victim to two main kinds of hunting: revenge killing and poaching to sell jaguar parts on the black market. Hunting jaguars out of revenge usually occurs after a jaguar has killed livestock. Fortunately, organizations such as Panthera, reduce conflict between jaguars and people by implementing a variety of anti-predator strategies, such as putting livestock in enclosures at night.

Surprisingly, the most sought after parts of the jaguar are their canines, which are used to make jewelry or traditional Chinese pseudo-medicine.

Sloth and Jaguar coats are designed for camouflage

Sloths and jaguars are both interested in staying camouflaged, although for opposite reasons! Sloth fur has specialized grooves along the shaft of each hair and microcracks which help to trap moisture and promote the growth of algae and fungi.

The algae and fungi growing on the sloth will eventually turn the sloth green, a perfect disguise for an animal that seeks to blend in with the canopy of a tropical rainforest.

Jaguars’ coats are also designed for camouflage. Like other spotted cats, their rosettes help them to camouflage and enable them to remain hidden while sneaking up on unsuspecting prey.

jaguar camouflage
The rosettes of the jaguar help them to blend into their surroundings./Image:


jaguar leopard difference
Although jaguars are sometimes mistaken for other big cats, such as leopards, their spot pattern is quite unique with small dots inside of their rosettes./Image: The Wildlife Diaries.

They both have unique mating calls

When a female three-fingered sloths is in heat, she will call out (in the key of D sharp) to let males in the vicinity know that she is ready to mate. Since sloths are not known for their speed, she can call out for several days before a male sloth finally reaches her.

Jaguars are among the four species of big cats that can roar. To communicate during the breeding season, both male and female jaguars will roar to each other, which sounds like the sawing of wood.

They both have impressive teeth

Although their diets differ quite a bit, both two-fingered sloths and jaguars sport some pretty intimidating teeth.

Despite their peaceful reputation, two-fingered sloths have remarkably sharp teeth. Their teeth are also constantly growing, meaning that their upper teeth rub against their bottom ones in a way that grinds them down and sharpens them. Although their sharp teeth are not used to tear meat, they are useful for biting through tough leaves with ease.

sloth teeth canines two-fingered
This is why you don’t want to get too close to a two-fingered sloth/Image:

Jaguars have the strongest bite force of any big cat relative to their size.  Powerful jaw muscles paired with a shorter jaw enables the jaguar the leverage and the strength to pierce the skull of their prey.  The jaguar’s remarkable jaw strength and impressive canines allows them to bite through even the tough skin of caimans.

They are both great swimmers

Jaguars are one of the few cats that willingly go into water. Since they live in tropical rainforests, they need to be able to cross bodies of water in order to access all the parts of their habitat. The jaguar’s excellent swimming skills allow them to navigate rivers and prey upon the animals that live in them.


Sloths are also surprisingly good swimmers. Their stomachs, which are often full of fermenting gases, help them to float as they swim across open bodies of water. Male pygmy three-fingered sloths (Bradypus pygmaeus) will swim to follow the mating call of a female sloth.

They are the stuff of legends

Due to their elusive natures, sloths and jaguars are hard to study in the wild. GPS collars and well-placed camera traps have given us a glimpse into the lives of these fascinating creatures but myths still abound about both of them.

There is still so much we don’t know about sloths. Because of their curious attributes, a variety of myths have emerged about them. There was even a Greek God of slothliness.

Jaguars were revered by many ancient Mesoamerican cultures. Associated with light and dark, the jaguar’s duality was worshiped by many ancient civilizations. The Mayans believed that their keen night vision enabled them to move between worlds, and they were associated with death and the Underworld.

black jaguar cub melanistic
“Black panthers” are not a separate species but the result of extra melanin in the coats of jaguars and leopards./Image:

In order to effectively conserve jaguars and sloths, we must come to understand them. Scientists and concerned citizens continue to shed light on the behavior and habitat requirements of sloths and jaguars, which is essential information for us in learning how to live peacefully alongside them.

But beyond our understanding, these curious creatures deserve to be appreciated for their unique qualities and protected as integral parts of tropical ecosystems.

-Katra Laidlaw

Know your Sloth Predators: The Great Harpy Eagle

Know your Sloth Predators: The Great Harpy Eagle

Harpy Eagles Quick Facts

  • Biggest claws of any bird
  • Can lift their own body weight in prey
  • Females are much larger than males
  • They mate for life
  • Chicks grow so fast that parents can care for only one at a time
  • Broad wings give them aerial agility in the thick jungles
  • The largest bird of Central America

The Harpy Eagle holds the crown as the most powerful eagle in the world – and it also happens to be the sloth’s main predator! With talons larger than a grizzly bear and a grip strong enough to crush a human arm, you can see why sloths take camouflage so seriously. Here we explore the terrifying world of the Harpy Eagle and explain how protecting sloths also means protecting these magnificent birds!

A living myth

These eagles are named after the harpies of Greek mythology who were depicted as fearful, winged beasts with women’s heads. Known for their cruelty and destructive nature, they were nicknamed, the “Hounds of Zeus.


Photos: Animals LibraryFio, Second photo: kabeza


It’s not surprising that in some areas of Latin America, stories and local legends still exist about witches living on the tops of tall trees. For those few fortunate enough to see a harpy eagle in person, they do look like the silhouette of a robed person sitting on a branch, dressed in black, white, and grey.


harpy eagle
Photo: leon_moore_nature_experience

Claws as big as a grizzly bear’s

Unlike the creatures of Greek mythology, harpy eagles (Harpia harpyja) are very real and rank among the largest birds in the world. They can weigh up to 5 kilos (11 lbs) and females are often twice the size of their mates. They are also some of the most powerful birds: with the ability to lift prey the size of monkeys, sloths, or even a baby deer!

These massive birds of prey can be 3.5ft/1m tall and have an impressive wingspan of 6.5ft/2 meters! Unlike other raptors, they rarely soar through the canopy of the rainforest and instead prefer to move from tree to tree.

Harpy eagles have thick, powerful legs, keen eyesight, and keen hearing. Like some owls, the harpy eagle has what’s called a “facial disk” of feathers around its neck that turns its head into a radar dish, focusing sound and aiding in the eagle’s sharp hearing. This is an unusual trait in a diurnal bird, but harpy eagles are unusual birds!


With a grip strength up to 10x higher than humans: 13cm of pure raptor power. / Photo: DecorahPagent

It’s dinner time!

Harpy eagles don’t hunt every day because they can feed on the same kill for several days in a row. Their bodies have adapted to tolerate meat that has spent several days in the hot environment of the tropical forest. Because they don’t need to eat every day, they can actually spend an entire week or more without ingesting any food!

Although harpies prefer to use their nimble flying abilities to hunt tree-dwelling animals, such as sloths, monkeys, iguanas, and other birds, they can also prey on ground dwellings species such as coatis, large rodents, deer, or wild pigs. They have also been observed to eat parrots, porcupines, coatimundis, raccoons, black vultures, and foxes.


harpy eagle sloth
A harpy eagle catching a sloth. @LaSalle museum of natural sciences, Costa Rica

They make great parents

Harpy eagles reach adulthood when they are about five years old. Like a lot of bird species, they mate for life, which, for a harpy eagle could mean 25 to 30 years! Once an individual finds a partner, they build a nest in one of the tallest trees in the forest.

Both parents participate in the building of the nest, which is 2 meters (6 ft) in diameter and more than 40 cm (1 ft) deep. Two adult humans could easily fit in the nest! The female lays two eggs, and usually only one of the chicks survives.

Harpy eagle chicks are little balls of grey and white fluff that start off so small they could fit into a human hand, but quickly grow to reach their impressive adult size in only five or six months, after which they begin to fly. The parents look after their offspring for the first two years until they become a juvenile. At four or five years old the eagles are adults and will begin looking for a mate of their own.


The relationship between sloths and harpy eagles

Harpy Eagles are what scientists, biologists, and zoologists call an “umbrella species“. Just like several people are protected by one umbrella under the rain, different species of wildlife can also be protected by conserving one particular species.

Harpy eagles depend upon a healthy population of monkeys and sloths. Therefore, in order to safeguard the future of this raptor we must protect these species. By protecting harpy eagles, we conserve the amazing rainforest in which they live, which is also the home of sloths, monkeys, and many more incredible creatures.


Conservation status

Unfortunately, according to IUCN Red List, the population of harpy eagles is declining all over the continent.  It’s hard to accurately determine their population numbers. Some conservationists estimate that there are between 10,000 to 50,000 individuals remaining, although the data is still insufficient. In some countries, the species is considered extinct. The Harpy Eagle is near threatened or vulnerable in most areas of South America, and critically endangered in Central America.

In Brazil, they have been pushed out of the Atlantic Rainforest, though they exist still in some remote parts of the Amazon. The actual number of harpy eagles in Brazil is currently unknown. They are only found in Mexico in the Chiapas in the Selva Zoque regions and are so rare in Costa Rica that there have only been a couple of sightings in the last decade; they are possibly extinct in the country.


harpy eagle home range
Home range of harpy eagle


Big predators usually require large territories to provide all of their needs: hunting, mating, etc. Habitat loss, logging, and the effects of the climate crisis are undoubtedly the biggest threats to harpy eagles. Trophy hunting, poaching, and trafficking for the illegal pet trade are also big issues. Some people kill them because they fear that the harpy eagle could hurt them, their children or their livestock. As mentioned earlier, there are a lot of misconceptions and mysticism surrounding these raptors.



However not all hope is lost: several organizations across the continent are working hard to conserve and protect harpy eagles. The Peregrine Fund has a fantastic project that breeds harpy eagles in captivity and releases them into the wild in Panama. You can also read this great article about the experiences of Ph.D. Eduardo Alvarez Cordero in Venezuela – one of the first people to study harpy eagles.

There are even a few local traditions that may help this magnificent bird: some South American cultures consider it bad luck to cut down the kapok tree in which they nest. The harpy eagle has been named the national bird of Panama, features on the Venezuelan 2,000 bolívares Fuertes note, and was even the inspiration for Dumbledore’s pet phoenix in the Harry Potter film series.


harpy eagle
Photo: Jitze Couperus


A witch of the rainforest, a mythological creature, an inspiration for movie characters. Harpy eagles not only capture our imagination but are indispensable to the health of our tropical ecosystems.


Thunderbird from Fantastic Beasts and Where to Find Them, Photo: Gavin


-Cecilia Pamich