If the dog-like families of the Carnivora family tree amazed you in Parts 1 and 2 of this series, wait ’til we compare them with the cat side! The cat-like families, the Feliformia, are utterly incredible for entirely different reasons.
As we take this quick survey, see if you can identify major evolutionary differences between the Feliformia and the dog-like Caniformia families. In Part 4, we’ll dive more deeply into the mechanisms that may account for these distinct trajectories.
Fossil evidence and DNA analysis indicate the Carnivora order split into the Feliformia and Caniformia branches between 50 and 60 million years ago. Over the next tens of millions of years, the Feliformia line branched into 11 different families, six of which are still in existence today. Let’s begin with the earliest cat-like family .
The most ancient cat family: Nandiniidae
The first cat-like family to branch off the Carnivora family tree was Nandiniidae. Only one species of these critters still exists today- the African palm civet. This small animal is most closely related to the dog-like animals, and it kind of looks like a cross between a cat and a dog, too (Fig.1). Like many caniforms, the African palm civet has lots of teeth- 40 to be exact. To hold all those teeth, it has a long, pointy, dog-like snout.
The African palm civet lives high in forest and jungle canopies across equatorial Africa. It’s a small and solitary animal with a muscular body and short legs. It weighs an average of five pounds and measures about 20 inches in length, not including its long tail.
Unlike its dog-like cousins, African palm civets have fully retractable claws, which come standard or semi-retractable on almost all feliforms.
Another feliform characteristic that’s easy to spot, pardon the pun, is patterns on their fur. The African palm civet sports both spots and stripes. It’s perfect for camouflage! But why do feliforms have camouflage and caniforms don’t? Tuck that question away for a bit later.
This little animal eats just about everything. While it greatly prefers fruit, it also hunts insects, bird’s eggs, snakes and tiny rodents in a pinch.
In general, the smaller the animal, the fewer calories it needs to survive. The more diverse an animal’s diet, the more resilient it is to changes in the environment, like food sources dying off. So size and diet are important factors in an animal’s ability to adapt and ensure reproductive success.
So the African palm civet, due in part to its small size and varied diet, is thriving in most areas of its natural habitat.
While this animal is called a civet, DNA puts it in a family distinct from all the other civets. The rest of the civets, and their family members, the genets, are a similar but far-flung bunch.
The Viverridae: What the heck are civets and genets, anyway?
In the Western hemisphere, we aren’t terribly familiar with civets and genets, the Viverridae family. Perhaps this is because these animals live almost exclusively in Africa, Southern and Southest Asia, with a few on the Iberain peninsula. Because they’re nocturnal and so elusive, they’re hardly ever seen.
Civets and genets are a longer, leaner version of the African palm civet. Ranging from two to 20 pounds, and measuring from 13 to 33 inches, not including their long tails, they’re fairly small animals. They all sport variations of spots and striped bands on their tails.
Like the African palm civet, they have long, pointy faces that fit in 40 teeth.
Except for the 11 species of tree-dwelling palm civets, the members of the Viverridae family live on land. All members of this family live solo.
Civets do their foraging and hunting under cover of darkness. Their partially retractible claws are adapted for both tree climbing and hunting. The tree-dwelling palm civets are almost entirely frugivores, fruit-eaters, and yes, that’s an actual thing. But like all the other civets and genets, they also hunt the insects and tiny animals to round out their diet.
Genets are the longest, leanest of this family. Their agility, grace and semi-retractible claws make scampering up and around trees a breeze.
Although most species of civets and genets thrive in the wild, those with habitats closer to human populations are becoming threatened due to habitat loss as peoples’ communities spread. Civets and genets are also hunted by humans for food, placing even more stress on their populations.
The Southeast Asian linsang is strikingly similar to civets and genets but belongs to a completely different family. Are you beginning to see a pattern here that’s different from the dog families?
For the sake of consistency we’ll give the linsang family a heading here, although they hardly need one.
The Prionodontidae: Linsangs!
The spotted linsangs and the banded linsangs are the only two species still in existence in the Prionodontidae family. Notice the words “spotted” and “banded” are right there in their names!
Linsangs are an even smaller, sleeker versions of genets, weighing only about two pounds and measuring about 14 inches. They have 40 teeth and long, pointy faces. Compare the photographs of the common genet (Fig. 3) and the banded linsang (Fig. 4). You might agree the two animals look so similar it’s hard to believe they’re members of completely different families! But DNA analysis confirms they’re completely different kinds of critters.
Like the civets and genets, linsangs are solitary souls. They live in the forests and rain forests of the Southeast Asia, spending at least part of their lives high up in the trees.
Unlike civets and genet, however, linsangs eat more insects, snakes, tiny rodents, and no fruit. Because of their dietary preference for animal life only, they’re classified as hypercarnivorous.
Linsang populations are thriving in the wild.
So far, the earliest feliforms have been small creatures living quietly today only in the Eastern Hemisphere. About 25 million years ago, their evolution blasted out of that mold and around the world, with some of the most efficient predators ever!
Now we’re talking CATS!- the Felidae family
When we think of cats, we think Felidae– from the King of Beasts to the purring swirl of fur snoozing on our laps. This is the family of the big cats and the not-so-big cats.
The big cats, the Pantherinae branch of the Felidae, include lions, tigers, jaguars and leopards. The term “panther” is actually a generic name for a big cat. What about black panthers, you might be wondering? Black panthers are leopards whose spots have melted into a solid ebony sheen. All the better for night hunting!
The Felinae branch, or not-so-big cats, include cougars, cheetahs, lynxes, wildcats, ocelots and yes, house cats.
Cats have moved well beyond Africa and Southeast Asia. In fact, the only place you don’t find native cats are in Australia and Antarctica.
All the felids, as members of this family are called, have slender, incredibly muscular bodies. These lithe hunters are built for speed, not stamina.
The size range of felids is enormous. The smallest is the black-footed cat (Fig. 5), about half the size of a house cat, weighing in at about four pounds and measuring about 15 inches long, not including its long tails. This tiny cat lives in the dry savannas of at the southwest tip of Africa, where it’s endangerment status is vulnerable.
The largest of the big cats is the Siberian tiger. An average male Siberian weighs in at 475 pounds, measures over 6 feet long from head to rear, over 3 feet tall at the shoulders, with a tail a yard long. That’s just an average Siberian tiger. They can get even larger than that! You don’t want to get caught napping near this big boy! Unfortunately, all tigers around the world are endangered. We’ll explore some reasons why shortly.
Like all the carnivans, felids have refraction crystals inside their eyes called tapetum, which gives them super night vision!
Unlike linsangs from whom they’re descended, felids have heavy skulls relative to the rest of their bones in order to support the massive muscles needed for biting and sheering flesh.
Felids also have significantly fewer teeth than their ancestors. They only have 30, in fact. This gives felids a much shorter nasal bone and jaw. Compare the length of the Common genet’s snout (Fig.3) with that of a leopard (Fig. 7). You’ll see that in just a few million years the profile of of the more recently evolved feliform changed dramatically.
If felids have so many fewer teeth and short little mouths, how are they able to kill their prey? Well, if your sweet house cat has ever taken a swipe at you, you know already know the answer. And if you have ever watched a dog chase a squirrel, you know the cat-like families are very different kinds of hunters.
The dog-like families often hunt in packs and almost all chase their prey to exhaustion, going for the kill when their victims stop to catch their breath.
Cat-like animals exert far less energy. They stalk like lone assassins. Their keen eyesight and hearing is essential for the hunt rather than the acute sense of smell dog-like animals use to stay on the trail of dinner.
Unlike many caniforms, whose long rows of teeth both secure and kill their prey, cats use knife-sharp claws. Because cats’ claws are retractible or semi-retractible, they don’t become dulled by scraping on the ground. They’re finely honed, acting as cleats for instant speed and stilettos for the kill.
Each claw of a tiger, for example, is a four-inch dagger. Multiply that lethal weapon times four per paw and cats are packing eight blades, just up front.
Cats lie in wait, hidden in shrubs or tall grasses, watching. This is where their camouflage comes in. The spots and stripes on their coats help hide them in the rippling shadows of foliage. Silently, stealthily, they follow their prey, inching ever closer. When at last their victim is within reach, they spring before their prey can react.
Using their claws, cats inflict massive injury in one seamless motion, first as they trap and secure their target, and then sinking them deep into their flesh with eight individual knives. The cat’s deadly bite through the victim’s neck can finish the kill in an instant. Cats are among the world’s most efficient killers.
But not all felids hunt the same way. Lions hunt in packs or prides, not unlike dogs, but are still stalkers, not chasers. Interestingly, lions are one of the few members of this family who don’t sport camouflage patterns, perhaps because they have no need to make their presence secret.
Tigers and some wildcats fish as well as hunt, much like bears.
Even with these variations, no cats have the stamina for a long chase. Even the cheetah, the fastest animal on land, can barely run a quarter mile, less than 400 meters, before its fast-twitch muscle fibers fatigue and its prey gets away.
Challenges at the top of the food chain
In an evolutionary paradox, life at the top of the food chain is most precarious for these greatest of hunters. How can this be?
Remember the little civets and genets with their diets of fruits, insects, rodents, reptiles and bird’s eggs? Because of their small size, they don’t need a lot to eat to survive and they happily munch on a wide array of foods. These are important reasons they’re doing so well.
Now consider the reverse.
Larger animals, like the big cats, require greater caloric intake to survive. For example, a tiger weighing 100 times that of an African palm civet requires approximately 100 times more calories to live. That’s a heck of a lot more food! And finding enough prey to fill a big cat’s tummy requires an enormous territory in which to hunt.
Unfortunately, cats’ habitats are shrinking smaller every day. All the critters who live in those habitats feel the crunch, too. There’s less and less space to hunt or forage, to safely nest and to raise their young.
Such stiff competition for fewer and fewer resources decimates some populations of plant and animal species. With every population that declines or becomes extinct, there’s that much less food in the food chain. Stress on the entire ecosystem grows.
Regardless of how stealthy and skilled, if there’s not enough prey to hunt, a cat’s life is in danger.
Adding to the stress on big cat populations is centuries of hunting by their only natural predator, humans. Their beautiful furs and the mythic medicinal properties of their body parts have drawn far too many humans to kill these magnificent animals.
This is why big cats and many smaller cats, though at the top of the food chain, are in danger of extinction.
In Part 4, we’ll look more closely at the evolutionary rise and extinction patterns of top-tier carnivans.
On a happier note, many cat-like families we have yet to meet are doing quite well in the wild and some have broken the out of the feliform mold completely!
Surprise! Hyenas are not cousins of dogs!
Oh, those sneaky, silly, giggling villains- the hyenas from cartoons and stage shows! But don’t be fooled by the fictional characterizations of these wild beasts. Members of the Hyaenidae family are fearless and deadly predators that even the king of beasts will not cross!
Before the discovery of DNA, hyenas were thought to be dog-like carnivans. In fact, one species in this family is called the aardwolf. Based on what we know of dog-like animals, this makes perfect sense. Hyenas look and behave like canids, not felids.
Hyenas have long, dog-like snouts and claws that don’t retract. They’re the size of a big dog, weighing over 135 pounds and measuring over four feet of strong and stocky body. Most hyenas chase down their prey, often in large packs, catching and killing with their teeth. Other hyenas have a scavenger lifestyle, snatching kill away from other predators, even from lions! Even a bit of rotting, leftover carrion is just fine with them.
The odd aardwolf, quite surprisingly, is an insectivore whose favorite lunch spot is a termites’ nest.
There are clues to the hyenas’ Feliformia ancestry, though. Most hyenas species have spots or stripes. Grooming to territory marking behaviors are distinctly cat-like. And like most of the feliforms, hyaenas prefer hunting at twilight or under cover of complete darkness.
Like many of their cousins, the hyenas are hypercarnivorous, with the exception of the aardwolf’s taste for termites.
Hyenas can be found from Africa across parts of Asia. They’re quite successful in the wild and are considered least threatened for extinction.
The next family of feliforms has surprising characteristics, too. When we think of cats, we probably don’t think of venom-resistance or complex social structures, but here they are!
Mongooses and Meerkats
Remember the dog-like family of weasels we met in Part 2 of this series? Well, mongooses and meerkats of the Herpestidae family are almost their cat-branch twins. Almost but not quite. Mongooses and meerkats are small mammals built similarly to weasels but more muscular, like their closer relatives, civets and linsangs. Mongooses and meerkats are unusual among feliforms in that their claws are non-retractable. Other unique characteristics set them apart from both caniforms and fellow feliforms.
Mongooses are known for being one of the few animals that can take on a King cobra and win! You would hardly guess this by their small size. What they lack in size they make up for with a neurotoxin-blocking agent that renders snake venom harmless to them! (Other animals with venom-resistant powers are honey badgers, hedgehogs and secretary birds.)
Yet mongooses rarely seek out snakes for dinner. Even with this venom-blocking super power, they eat a less glamorous diet of mice, insects, fruit, and among the swimming mongooses, shellfish.
While mongooses’ ability to kill venomous snakes is a novel quality, they’re also renowned rodent hunters. Mongooses have been exported form their native habitats of Africa and Asia to agricultural regions around the globe in hopes of reducing rodent and snake populations.
However, the introduction of this non-native species to North America has had catastrophic results. Reptile, amphibian, bird and plant species which haven’t evolved to withstand the tactics of mongooses have taken a huge hits to their populations. Efforts to reduce and ultimately eliminate mongooses in these non-native regions are an on-going challenge in many places. In their native habitats, mongooses are thriving.
In the same family as mongooses are their gregarious relatives, the meerkats. Meerkats, too, are about the size of civets and genets, but are anything but solitary souls. Their complex matriarchal social structures can have as many as 30 members. The gang or mob, as a meerkat group is called, is led by a single alpha female and her alpha male consort.
Only the alpha couple produces offspring, but the entire gang helps out with babysitting, raising and teaching the young.
Gang members also share sentry duty while the others hunt, forage, babysit or otherwise leisurely sun and groom one another. If danger is spotted, the sentry will call out to the others to scamper underground for cover.
Meerkats are perfectly adapted for life in the Kalahari desert where they live. Thin fur reduces overheating. Dark markings around their eyes act as shades to reduces the sun’s glare. Long snouts are ideal for nosing narrow holes where insects and rodents, their main meals, escape searing heat.
Unlike all the other feliforms, meerkats are mostly subterranean dwellers, taking refuge from blazing temperatures underground. Elaborate burrows house their sizable communities, but meerkats prefer pre-existing fixer-uppers rather than tunneling new dens from scratch. Abandoned lairs are ideal but when need be, meerkats drive out current tenants for prime real estate.
Like mongooses, meerkats have venom-resistance. This is fortunate because they love to eat crunchy scorpions whenever they can find them. When training young meerkats to hunt, adults will catch scorpions, snap off their venomous tails, and let them loose for the kids to chase and capture.
Just off the mainland of Africa, across the Mozambique channel, is the island Madagascar. Plants and animals from the mainland have floated, flown and swum to it for millions of years. About 20 million years ago, a mongoose from the mainland came ashore and started a whole new feliformia family.
Mongooses and Fossa of Madagascar
From the first mongooses to arrive on Madagascar comes the two branches of the Eupleridae family, the Madagascan mongooses and the fossas. Like so many other feliforms, those in Madagascar are strikingly similar to their closely-related families. Madagascan mongooses are quite similar to those on the mainland but with bushy, banded raccoon-like tails.
Fossas, the largest carnivans on Madagascar, are beautiful, muscular, lithe animals that look more like small cougars than mongooses. This is another instance in which, though the DNA evidence shows wide divergence, the feliformia families seem so similar.
A bit larger than the majority of small feliforms, fossas measure about 30 inches long and weigh under 20 pounds. Their tails are as long as their entire bodies! They come equipped with semi-retractible claws, 36 teeth, and mottled striped fur. These forest dwellers hunt endangered Madagascan lemurs, but because these small primates are few and far between, fossas make due with small mammals, reptiles and birds, too. Between habitat loss and declining populations of their food sources, fossas are listed as a vulnerable species.
Why so much alike?
The subtle variations among the feliforms are many. But striking similarities in habitats, physical characteristics and behaviors of the Feliformia, just slightly tweaked over tens of millions of years, are in wild contrast to the range and diversity of the dog-like Caniformia families. It’s as if nature came up with one basic model so well-adapted to a wide range of environments, no changes were needed.
Of course, this view of feliforms evolution is a vast over-simplification. Nevertheless, in general terms, we have to wonder why the two branches of the Carnivora order, originating and splitting at the same place and time, evolved in such staggeringly different ways. This question has both fascinated and mystified evolutionary biologists for decades. In Part 4 of this series we’ll explore the possible drivers of these two distinct paths of evolution.
Next time you throw a ball and watch your dog chase it with delight, or catch your cat observing your every move while hidden behind a house plant, you can enjoy the vast trajectories nature has taken, from a single common ancestor, to all the incredible cousins of cats and dogs.
See you at Part 4!