Sloth versus Giraffe

Sloth versus Giraffe

This month we’ve got another weird one for you as we compare the world’s tallest mammal with the world’s slowest: yes, that’s right, we bring you Sloths vs Giraffes!

They’ve both got long necks! They both make some weird noises! Let’s take a look and see what giraffes have in common with sloths… and what they don’t.

Are sloths and giraffes related?

Trick question, sloths are hardly related to anybody except anteaters and armadillos, and them only barely. Giraffes are ungulates (hoofed mammals) of the superorder Laurasiatheria, originally from the supercontinent of Laurasia, which used to be part of Gondwana. Giraffes and sloths haven’t been related to one another for about 100 million years.


Longer or more?

It’s a common misconception that giraffes’ long necks must have more neck vertebrae than any other mammal. After all, a giraffe’s neck can easily reach 2 meters (6 ft) long! Giraffes in fact have seven cervical (neck) vertebrae, the same numbers as humans, dogs, and most mammals. The only difference is that in giraffes, the bones are stretched very long to enable the tall neck that lets the giraffes browse the tops of trees.

giraffe skeleton
Image: Gordon Johnson on Pixabay


Giraffes’ long necks aren’t just used to reach tasty treats; they also fight with them. Male giraffes establish dominance with other males by pushing each other with their necks, and sometimes swinging and butting each other with their necks and ossicones (the short horns on top of their heads). Recent research indicates that these dominance battles may have been the original driver of the long necks, with the treetop grazing abilities being a side effect.



Sloths use their impressive claws when they need to fight, and their necks are not as proportionally long as a giraffe, but some sloths actually do have more neck bones. While most mammals (including the giraffe) have seven cervical vertebrae, two-fingered sloths have six, and three-fingered sloths have nine! Sloths’ elongated necks can rotate 270° and are useful for scanning their surroundings and keeping their heads above water while swimming.



Where do they live?

Sloths live in trees, and giraffes live on the ground. More specifically, sloths live in trees in tropical rainforests in the Western Hemisphere, and giraffes live on the ground in sub-Saharan Africa.

What do they eat?

Sloths and giraffes are both big consumers of tree products. Sloths eat leaves, whereas giraffes eat tree leaves, twigs, and bark, and also feed on shrubs, grass, and fruit. They have occasionally been known to chew bones, which don’t grow on trees. Giraffes eat about 34 kg (75 lbs) of foliage daily.


Giraffe at Mala Mala reserve, South Africa. Photo: Suzi Eszterhas

Who sleeps more?

For the first time in a while, we’ve found an animal that sleeps less than our relaxed sloth! Giraffes sleep about four and a half hours per night  – mostly standing up, they only lie down for short periods of time. They spend most of their time chewing cud.

Are they social?

Unlike our solitary sloths, giraffes are quite social animals. They have long-lasting fission-fusion social groups that merge and split up in complex ways, usually based on sex and family ties. It’s possible that some giraffe herds are much larger than previously thought, as giraffes can use their great height to see and monitor other herd members from quite far away. Group sizes of more than 100 individuals have been observed.


A group of Giraffes , Okavango Delta, Botswana. Photo: Suzi Eszterhas


Like sloths, mother giraffes give birth to a single baby at a time and raise them without the help of the father. Unlike sloths, female giraffes may babysit each other’s offspring. Female sloths scream when in heat in order to attract males, whereas giraffes make a low humming noise that humans care barely hear, and we aren’t entirely sure why.

Do they have parasites?

Sloths have an entire ecosystem living in their fur, but most of the moths, algae, and fungi that live there have a symbiotic relationship with the sloths. Giraffes have as many as 11 chemicals in their fur that combine to repel many kinds of insects!

How do scientists study them?

Wild giraffes are recorded by ground survey methods such as mark-recapture photo surveys. Each giraffe has a unique pattern of spots, much like a human fingerprint, that is stable over time and a good way to recognize individuals. Sloths are studied exclusively by researchers in the field, as the thick jungle canopy prevents aerial observation. Both animals have different behaviors and feeding habits in captivity.


What problems do they have in common?

Like sloths and so many other wild animals, giraffes suffer from deforestation and habitat loss. Giraffes currently inhabit only 10% of their ancestral range, the other 90% has been lost to humans and habitat fragmentation. Giraffes are also hunted for bushmeat, which is sometimes sold as “beef”.

Habitat fragmentation can lead to inbreeding, though sloths may be more at risk for this than giraffes. The West African giraffe population rebounded from 49 individuals to a healthy population of over 600, proving that these are very resilient animals that only need us to give them a chance!


Lewa Conservancy, Kenya. Photo: Suzi Eszterhas

What is the IUCN classification?

Giraffe populations are a little easier to estimate than sloth populations, but both are declining. Sloths range from “least concern” to “critically endangered” depending on the species.  The IUCN still recognizes only one species with 9 subspecies.



But according to The Giraffe Conservation Foundation’s peer-reviewed research, Giraffes have four different species with a variety of subspecies, some of which are “vulnerable”, and some of which are “critically endangered”.



The Nubian giraffe has lost 95% of its population in the last 30 years. Populations that benefit from good conservation are actually increasing, though some of these numbers may be due to better survey methods. With a current best population guess at 117,000 there are approximately half as many giraffes left on planet Earth as Ferraris.

What can be done to protect both species?

Don’t eat them, give them space, and don’t buy their bones. You probably aren’t tempted to go down to your local supermarket for a can of Sloth Soup, and if you live outside of Africa there isn’t much access to giraffe bushmeat, but you can support sustainable agriculture and initiatives to end poverty, which keeps people from being so desperate that they have to eat and exploit animals better left alone.

The Giraffe Conservation Foundation, much like the Sloth Conservation Foundation, works to help protect their respective species from extinction, so check out their amazing work and support them! A huge thanks to our colleagues from GFC and their valuable contributions to this ‘Sloth Versus Giraffe’.

Tall or small, neotropical or African, black-tongued or pink, both of these amazing animals help make our world what it is. Don’t let sloths or giraffes suffer from habitat loss or face extinction! We owe it to them, and to ourselves, to keep our world rich with diversity.

Rainbow month

Rainbow month

As a conservationist, I find myself thinking a lot about the word “diversity”. Concerning nature, the word is “biodiversity”, and we use it as a proxy for the health of ecosystems.

This refers not only to the types of plants and animals in an area, but also their genetic diversity, which produces the strongest, healthiest, and most adaptable organisms, as well as the types of landscapes they inhabit and adapt to. Diversity leads to resilience, and it is the reason we, and every other living thing on the planet exist. It is why we have fireflies that glow in the dark, and whales that sing across oceans, and feathery fractal ferns that drink water out of the air. It is the reason we have trees that live for millennia, oysters that make their own gemstones, and a fruit called a peacotum (which is what you get when you cross a plum with a peach with an apricot, and it’s every bit as awesome as it sounds).




Humans come up with a lot of strange ideas. Some of them are so strange that they make no sense at all out of context, and when I’m not pondering the etymology of the word “diversity” (from the Latin divertere, meaning “to face both ways”, for those of you curious) I wonder how humans came up with all these diverse ideas. Sometimes it helps to think of ideas as if they were living things. After all, they reproduce if we choose to share them with others, and they live in the context of other ideas, thoughts, and habits. We call this collection of self-replicating ideas a culture.

If a culture is an ecosystem of ideas, do the same rules for creating health, wonder, and resilience apply? What does it mean to cultivate diversity?

As a queer person, I find myself thinking a lot about rainbows. Not just because it’s Pride month and they’re everywhere, but what our flag represents: a spectrum of light, an infinite gradation of colors we have a limited vocabulary for.



Nature exists along a spectrum. This doesn’t always sit with our human desire to neatly label everything, because nothing natural exists in a homogeneous little box. Just as we like to label every species, sub-species, and variants of sub-species, we also like to label each other and ourselves. Lesbian, gay, bisexual, trans: we put a plus sign after LGBTQ because the diversity of human gender and sexuality was threatening to run out of alphabet before we ran out of identities-don’t worry, it’s not a test designed to fail the un-woke! It’s there because the grand spectrum of human potential has more words to describe it than we have letters to list.



Labels can be helpful even when they are not perfect. No one label strictly defines us, none fully captures us, and we all have a collection of labels for ourselves vying for relevance in any given situation. This collection of labels is called “intersectionality” (from the word “intersect”, meaning a thing that passes through or comes together with another). We usually talk about intersectionality when we are talking about privilege and people’s advantages and disadvantages in society. Sex, gender, race, class, religion, ability… these labels and more go into the variance within us; they make us who we are as much as our genetics shape our physical body, and much like our genetics, our intersectionality benefits greatly from a healthy dose of diversity.



As a scientist, I find myself thinking a lot about the truth. What is it, and how do we find it? How do we generate new ideas, and create a culture that promotes scientific discovery? Science is a process that concerns itself greatly with what is repeatable and relevant; what is true. We are human. The truth is our sex, sexuality, and gender exist along a spectrum, and we are as diverse in our internal identities as external ones. A culture that values those truths will reap the benefits of the people who live them-after all, we will never recognize the truth outside of ourselves if we do not begin by being true to ourselves.




To all of my fellow queer conservationists, scientists, and nature lovers; to all of our friends, families, and allies; and to everyone willing to protect and celebrate diversity and authenticity: Happy Pride!


-Ames Reeder

Canine Training To Prevent Attacks On Sloths and Wildlife

Canine Training To Prevent Attacks On Sloths and Wildlife

Certain wild animals, such as our sweet sloths, are slow-moving and would not be able to hide quickly. They are no match for a fast-running dog. It is not the dog’s fault that they have this instinct, but it is entirely up to us as pet owners to ensure that our dogs are trained well and learn not to attack wildlife.


dog aggressive attack


No matter where you live in the world, you share a habitat with local wildlife. Dogs and wild animals may run into each other from time to time, and the results can be severe. We have to take steps to protect both our dogs and wildlife from these encounters so that both dogs and wild animals can coexist peacefully.


Teach The Command “Wait”

The command “wait” is the command you will most want to focus on first. Your dog doesn’t have to hold a particular position, like when you use the phrase “stay” after the dog lays down so that it continues to stay in that position. But using the “wait” command is a way to make sure your dog pauses before going any further.

The animal hospital Bond Vet – Garden City, NY advises that you should start training this command when your dog is still a puppy, even though older dogs do have the ability to learn this.

The easiest way to help your pup understand this command is to have them wait before eating and before going outdoors. Praise and treats are highly recommended as well to help encourage good behavior when your dog waits.


dog training


In order to do this accordingly, you might consider enrolling your dog in socialization classes or dog training programs to make sure that your dog understands your commands and will obey you, no matter the situation.

As your dog progresses in learning the “wait” command, you can begin to take it outdoors and practice on more considerable challenges, such as using a toy, and eventually, another animal.

Some dogs may be easier to train than others, with some being more susceptible to learning commands quickly. However, once you have a solid “wait” command instilled within your pup, you can work to prevent it from chasing and confronting wildlife.


dog attack wildlife

Training With A Barrier

If you want to work training your dog specifically with other animals, it is a good idea to start with a barrier between your dog and the animal. Then you can work to find that optimal distance where your dog will not react when spotting the other animal and work more on the “wait” command.

If you find that your dog is too anxious and wants to move towards the animal, continue to work away from the animal and see when your dog can focus more on you.

Once you have established contact and your dog is obeying the command, reward it with a treat. If you find that the dog can’t concentrate on the treat, you need to continue working on your distancing.

You can use alternative rewards for treats here as well, such as a simple pet or a favorite toy, so that your dog understands it is receiving an award for exercising the correct behavior.



Training with a Toy

If you want to start with a toy, leave it in the middle of the room and step away. Then when you see your dog come upon it, use your command “wait.” Make sure you work with your dog and only reward it when it obeys the order on the first go.

You can experiment with intentionally leaving the toy unattended and wait to see if your dog goes towards it, not thinking that you are watching. When the dog starts to sneak towards the toy, use the command and see how quickly your dog reacts.

If you continue to do this often, your dog will understand that you are, in a sense, always watching. Enforcing this command when your dog can’t see you will also help catch your dog in a situation where things can escalate so that you can jump right to the command to get your dog to obey fast.

You should also know that it is essential not to let the dog play with this toy since it is only to be used for training purposes, and you want the illusion for your dog to treat it as if it was a real, live animal.


dog toy trainning

Dogs and Sloths

Sloths are particularly vulnerable wild animals to dog attacks since they are unable to jump or run. Costa Rica has a vast dog problem when it comes to wildlife attacks and the Oh My Dog! initiative has been initiated to work and stop dog attacks.




People like to let their dogs roam freely outside, particularly in Costa Rica and other parts of the South Caribbean, and it is all too common for a dog to attack other people, dogs, and wildlife.

Our job as owners is to keep a close eye on our pets and have commands like “wait” at the ready to keep them from chasing after other animals.

After all, your dog also has the susceptibility to end up with an injury from attacking wildlife, not just the wildlife becoming injured.



Dog Contact with Wildlife

Even if you have a dog with impeccable training, there is always the possibility that your dog will act on instinct first and not listen to your command. Minimizing your dog’s contact with any wildlife is part of ensuring that both your dog and other wildlife are safe.

Some steps you can take to keep your dog from encountering wildlife:

  • Don’t leave food outside that might bring about other animals.
  • Don’t hike with your dog far into the woods, especially right at dawn or sunset, when more wild animals are active.
  • If you want to hike and have your dog come with you, it is safer to hike in a group so that other wild animals will keep their distance.
  • Keep your dog on a leash when outdoors, especially if hiking or in a location where there might be wild animals.

dog running trainning


Your dog’s urge to chase will be a strong one, but if you take the time to practice and work closely and frequently with your dog, it can overcome its urge. If your dog learns to look to you for permission and commands, it strengthens your bond and prevents your dog from acting solely on its instinctive responses.


Nicole McCray-


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



Sloths and Palm Oil: how can you help?

The world is waking up to the palm oil crisis that has driven orangutans to the brink of extinction, but is boycotting palm oil really the answer? Unfortunately no, but that doesn’t mean that we are powerless.

Last week the UK supermarket chain Iceland shone the international spotlight on palm oil after its controversial Christmas TV advert was banned from British television. The advert, which depicts an orangutan hiding in a child’s bedroom after loggers destroyed his rainforest home, has now been watched over 30 million times online making it one of the most successful Christmas adverts ever created. Similar to the anti-plastic movement that is sweeping across the world, this advert has stimulated an uproar against the palm oil industry. While it has been overwhelmingly successful at raising awareness of a very important issue, fears are growing as increasing numbers of people are demanding a boycott on palm oil. This is dangerous.

Palm oil is used in approximately 50% of everything that we buy, ranging from food and shoes to cosmetics and cleaning products. It is everywhere and the demand is huge. Consequently, palm oil plantations are responsible for the majority of Malaysian and Indonesian deforestation, with a football pitch-sized area of forest being cleared every 25 seconds in Indonesia alone! However this is not just an issue affecting Asia. Palm oil plantations are also springing up in place of the sloths rainforest habitat in South and Central America, further adding to the ecosystem destruction occurring due to crops such as soy, bananas and animal agriculture.

Boycotting palm oil, however, doesn’t mean that manufactures will simply remove oil from their products all together. It simply means that they will be forced to replace it with a different kind of vegetable oil. Unfortunately, palm oil is already the worlds most productive oil crop. All alternative oils such as soybean and rapeseed require up to 10 times more land to produce the same amount of product – increasing demand on these crops would be even worse. In addition, boycotting palm oil will drive the price down, consequently increasing the demand for use in biofuel and livestock feed, particularly in countries such as China and India.

So what can we do?
Thankfully the answer applies to all aspects of consumerism, and will have benefits for species and habitats globally (including sloths!): sustainable shopping. Think carefully about the products that you buy because as the consumer, you have the power. Only choose products from manufacturers and retailers who use ingredients from sustainable, certified, legal and deforestation-free sources. They exist, you just have to know which ones to look for! We know this sounds like a lot of hard work – who has time to read every label and search online for every product that you want to buy? But the good news is you don’t have to! There is a wonderful (and free!) bar-code scanning app called Giki that will do all of the hard work for you. Just scan the product that you want to buy and it will tell you all of the information you could ever want to know about that product. Whether it’s local pollution, global climate change, conservation, animal welfare or health, it will give you everything that you need to make an informed decision! Thankfully, using this app will also help you to avoid fruit and produce that is contributing to the sloth deformity epidemic in Costa Rica by way of rampant pesticide usage and forest fragmentation. It’s a win for everybody!

Do Sloths drink water?

Do Sloths drink water?

You have probably never seen a sloth drinking water. In fact, very few people have! As a result, it has been assumed for centuries that sloths get all of the water they need from the fresh rainforest leaves that they eat, and few documented observations exist of either of the two sloth genera drinking in the wild.

We photographed a male brown‐throated sloth (Bradypus variegatus) lapping water from the surface of a river in Costa Rica. Our latest work ‘Sloths hanging out for a drink’ has just been published in the scientific journal Frontiers in Ecology and the Environment.



This sighting prompts many additional questions. For example, how widespread is drinking behavior and how frequently does it occur? Methods used to assess water retention in wild sloths suggest that this behavior seldom occurs, so drinking is likely a method of maintaining osmotic balance when faced with extreme ambient temperatures, low precipitation, or increased consumption of mature (ie drier) leaves.



If freshwater access is indeed important, there are further implications relating to the captive husbandry of sloths in zoos and rescue centers (where they often face drier climes, typically don’t have access to water, and have a very low survival rate), and for conservation, especially after habitat fragmentation, where changes in land use can restrict water access (eg irrigation diverting stable water sources, roads that are difficult for strictly arboreal animals to cross).

Moving forward, the predicted trend toward a hotter, drier climate for Central and South American rainforests may negatively impact the sloths’ potentially delicate water balance, particularly in view of their limited energy budget and inability to travel long distances. If all sloths need a drink from time to time to stay healthy, it’s important to make sure they can get one.


drinking water


-Dr. Rebecca Cliffe