Hybrid Domestic Cats

I’ve discovered something intriguing while researching wild-domestic hybrids. According to the cat fancy, the Bengal leopard cat/domestic cat hybrid is one of the most popular breeds in the world, yet shelters are overwhelmed by abandoned Bengals.

Two very reputable groups, with conflicting statements–what’s going on here?

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We See Ourselves in Cats

I finished this chapter in the upcoming ebook, “50 Facts About Domestic Cats,” today. Hope you like it.

You might have heard how people see companion animals as “little me’s.” The makers of pet food and other products certainly have. Advertising for their multi-billion-dollar industry appeals to our anthropomorphism with everything from human-style pet dinners to animal clothes and jewelry.

This certainly has worked out well for domestic cats, whose round faces, expressive eyes, and size make them adorable substitutions for a human baby–up to a point.


Said point. (Source)

Today cats are more numerous than their African wildcat ancestor and thrive on every continent except Antarctica.

What you might not know is that philosophers also use cats to illustrate difficult points they want to make. So do people who tell reality-based tall tales.

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Why Are Kittens Born Helpless?

It’s hard to believe that newborn kittens grow up to be predators. Cuteness is only part of it. These blind and deaf little furballs have a good sense of smell but little strength or coordination. They can’t even control their body temperature at first!

In contrast, a caribou calf can travel cross-country within a few hours of birth. Its lifestyle demands this.

People are somewhere in the middle. Unlike kittens, babies are born with eyes and ears open, yet it still takes us a while to develop the ability to sit up, let alone walk.

The technical name for animals that bear helpless young is “altricial.” It’s related to the word “altruism,” and the parents certainly do have to make sacrifices for their young.

Since there are obvious advantages to having youngsters that require less care after birth, like the caribou, why are some placental mammals altricial?

The short answer is brain size; also, the need to find a balance between feeding your young and protecting them from predators.

Here is more information.

How kittens develop

Adult cat brains are proportionately bigger than a caribou’s. But at birth the brain of a kitten weighs less than a quarter of its full-grown weight.

This probably comes as no surprise to anyone who has ever seen a kitten.

What’s inside those little heads will grow along with the rest of the body, and in the process, somehow acquire and store all the information they need to become apex predators (domestic cats are usually the dominant small predator in a human-dominated environment).

During the first month of life, a kitten learns about the world through smell and touch, developing attachment to the mother cat and interacting with litter mates.

By month two, the world is one big playhouse. The Internet community is not unaware of this life stage:

It’s adorable, but these kittens are instinctively learning and practicing survival skills–skills that the adult cats will never need if they stay close to loving and responsible human friends.

The outside world is harsher. Playtime lasts until about age six months for feral kittens–then Mom drives the males away from the den. If they can survive on their own, the young toms will eventually establish a territory somewhere else.

This seems horribly cruel, but such dispersal is common in mammals. It’s probably also a major reason why cougars have such a wide range today – from the tip of South America up into the Canadian Yukon!

Young domestic she-cats set up their territory closer to home, when they reach adulthood, and may become part of a feral cat colony.

Luckier kittens–those born indoors or found by someone–usually settle into their forever home around eight weeks, right after weaning.

However, cat breeders and savvy owners know that the kittens will be more comfortable around people later on if they are handled a little bit every day from around the ages of two to seven weeks.

No one knows why. But cats that don’t get that human contact at just the right time in early life tend to be a lot more anxious and wary; they even may have behavior problems.

Young cats don’t keep journals, so we have no idea what’s going on in their heads. But it’s obvious that the slower development of altricial animals, with its mysterious timing and unknown processes, has important long-term effects.

A cognitive buffer?

When feral kittens are about three months old, Mom starts bringing them live prey for hunting practice. It’s probably not a coincidence that this is also the age when a kitten’s brain reaches its adult size.

But even as the kittens stumble along, learning the age-old techniques of predation, they already see a slightly different world than their mother does.

Over the last three impressionable months, they have absorbed details of things as they are now, not as they were when Mom was born. Since the natural world is very complex and interconnected, these altricial youngsters have probably picked up on subtle changes and/or interconnections that not even their mother is aware of.

Some experts call this the cognitive buffer effect. It may or may not make a big difference later on in life, but it does raise a question.

Domestic cats always live near people, and we do make sudden, sometimes drastic changes in the environment. Could this built-in adaptability between generations be a reason why cats have kept up with us down through the years?

That’s an open-ended question. The benefits of having a relatively large brain aren’t obvious. It might also be connected to how animals forage for food (such an association has been found in bats) or even have something to do with social development.

But there must be benefits; otherwise, cats and other altricial animals would have gone extinct long ago–it’s very “expensive” in biological terms to develop so slowly after birth.

Too expensive, apparently, for precocial animals–those like caribou whose newborns (or newly hatched young’uns) are rarin’ to go.

Nourishing and protecting the young

Altricial and precocial animals are two extremes of a whole spectrum of developmental styles that researchers are trying hard to understand today.

And as mentioned above, people are roughly in the middle. So are parrots, oddly enough. Long ago in this dangerous and unpredictable world, our ancestors (and Polly’s) worked out a balance between feeding newborns and protecting them.

Finding food without becoming food yourself is quite a challenge for any living being in the wild. And on top of that, in order to avoid extinction, you must bring new life into the world and make sure that it survives long enough to reproduce.

Animals have solved this problem in different ways. Precocial caribou, for example, keep their young inside until they have developed enough to stand and walk. This is a very good solution to the predator problem, but it is physically very demanding on the mother. Too, it limits brain size.

As we’ve seen, altricial cats take months to develop after birth, ending up with comparatively big brains. But again, this is rough on the mother cat. She must hunt enough on her own to bring the kittens to term and then to produce milk for them. After that, she has to bring food back to the den as well as catch something for herself.

Including some rays now and then:

Life will always find some way to survive and reproduce, even if humans don’t fully understand it. Caribou continue to have calves because it works for them. Cats have kittens, and that works out, too.

People are in the middle of the spectrum, but unlike all other living beings, we just can’t resist wondering what it’s all about.

Featured image: Christian Holmér, CC BY 2.0.


Bateson, P. 2014. Behavioural development in the cat, in The Domestic Cat: The Biology of its Behaviour, eds Turner, D. C., and Bateson, P. New York: Cambridge University Press. Retrieved from https://play.google.com/store/books/details?id=m-NRAgAAQBAJ

Benson-Amram, S.; Dantzer, B.; Stricker, G.; Swanson, E. M.; and Holekamp, K. E. 2016. Brain size predicts problem-solving ability in mammalian carnivores. Proceedings of the National Academy of Sciences, 113(9): 2532-2537.

Bradshaw, J. 2013. Cat Sense: How the New Feline Science Can Make You A Better Friend to Your Pet. New York: Basic Books. Retrieved from https://play.google.com/store/books/details?id=iU8PAAAAQBAJ

Dukas, R., and Ratcliffe, J. M., eds, 111-134. Chicago: University of Chicago.

Ehrlich, P. R.; Dobkin, D. S.; and Wheye, D. 1988. Precocial and altricial young. https://web.stanford.edu/group/stanfordbirds/text/essays/Precocial_and_Altricial.html Last accessed April 20, 2018.

Gittleman, J. L. 1986. Carnivore brain size, behavioral ecology, and phylogeny. Journal of Mammalogy, 67(1): 23-36.

Isler, K., and Van Schaik, C. P. 2009. Why are there so few smart mammals (but so many smart birds)?. Biology Letters, 5(1): 125-129.

Pagel, M. D., and Harvey, P. H. 1988. How mammals produce large-brained offspring. Evolution, 42(5): 948-957.

Robertson, S. 2008. A review of feral cat control. Journal of Feline Medicine and Surgery. 10:366-375.

Sol, D 2009. The cognitive-buffer hypothesis for the evolution of large brains, in Cognitive Ecology II, Dukas, R., and Ratcliffe, J. M., eds, 111-134. Chicago: University of Chicago.

Turner, D. C. 2000. The human-cat relationship, in The Domestic Cat: The Biology of its Behaviour, Turner, D. C., and Bateson, P., eds, 193-206. Cambridge: Cambridge University Press.

Vonk, J. 2016. Bigger brains may make better problem-solving carnivores. Learning and Behavior, 44(2): 99-100.

What Is A Cat?

If I say “cat,” you know what animal I mean, though in some settings you might wonder whether it was a house cat or one of the wild species.

Now suppose you’re a paleontologist and you have just discovered one of those natural traps that carnivores and their prey sometimes fall into and can’t get out of. This one goes back millions of years and all that remains now is a messy jumble of bones.

How do you sort out the cats?


Here, kitty, kitty… (Ruth Hartnup, CC BY 2.0)

It’s not exactly easy, but all cats, past or present, do stand out from the carnivore crowd, if you know what to look for.

Experts in ancient life go by very subtle signs but there are also big clues that everybody can see, including these:

  • Cats have short, rather blunt faces
  • Their legs are relatively short, compared to pursuit predators
  • They have retractable claws

The biggest problem for paleontologists after they’ve separated the cats from the “dogs”–actually prehistoric members of the family Canidae, long extinct or still around today–is that all cat skeletons look alike, apart from size.

This is a headache for scientists trying to distinguish between ancient feline species, but it works out for us:

Structurally, [the domestic cat] can be seen as simply a scaled-down model of a lion or a leopard, and in evolutionary terms the larger cats may even be considered as scaled-up versions…[Fluffy] is also a more convenient example to refer to in the comfort of the home when some detail of anatomy or behavior is mentioned.
— Turner and Antón


Trish Hamme, CC BY 2.0

Defining a cat

So a cat–any member of the family Felidae, past or present–is a short-faced carnivore with retractable claws and legs that are long enough to catch food and to pace its territory daily but short enough to support the powerful musculature needed for sudden accelerations, a short chase, and the kill.

Why is a cat’s face shaped that way?

Short answer: The better to bite you.

Details: Cats kill prey with their mouths, more specifically, their upper fangs.

At the final moment of a hunt, a cat goes for the back of its prey’s neck. Muzzle whiskers reflexively stretch forward, finding exactly the right place to insert those fangs in between the cervical vertebrae and sever the spinal cord, which instantly kills the victim.

This killing bite must be powerful–those neck bones sit together fairly tightly.

A cat’s shortened face strengthens its bite for this maneuver.

Think of an animal’s jaw as a lever. The closer its fangs are to the fulcrum, i.e., the jaw joint, the more power they can apply.

So, down through time, cats with shorter faces have had the evolutionary advantage over others, now extinct, that looked more like their long-snouted feliform ancestors and were more likely to fail in a hunt or even get injured by struggling prey.

Cats also have the fewest teeth of any carnivore–basically just the ones needed to process meat–but that probably didn’t influence the shape of a cat’s face as much as basic jaw mechanics did.


Tambako the Jaguar, CC BY-ND 2.0

Why do cats have retractable claws?

Short answer: The better to grapple you.

More information: A cat’s claws grow out of its “finger” and “toe” bones just like our nails do, and they are made out of the same material. There the resemblance ends.

Primates developed flat nails to help them grasp things like branches. Some other tree-dwellers–basically most mammals right after the K/T extinction–had claws, which are terrific for holding onto bark, no matter what your diet.

When mammals finally moved down to the ground (which has a lot more surface area than tree limbs), a group turned their “nails” into hoofs.

Not all of these early hoofers were vegetarians.

Mesonychids were rather wolf-like primitive carnivores with a little hoof on each toe instead of a claw! However, as time passed they disappeared and all predators had claws.

That’s an old story, but one that cats and most other feliforms have improved upon.


Nirmal KF, CC BY-SA 2.0

See how this annoyed kitty has its digits spread out?

Spreading your digits is a natural motion when reaching for something like prey (or an irritating photographer). It unsheathes the claws when cats grab prey at the end of a hunt. (Yes, they also do it intentionally sometimes, like this cat; they can even show subtle shades of annoyance this way, as every cat owner soon learns.)

Here’s how it works.  You may have noticed that a cat’s paw look shorter and rounder than a human hand, even though we have the same bones.  (Cats and people shared an ancestor many tens of millions of years ago.)

That’s because, when the cat is just hanging out or walking around, strong ligaments hold each claw and the bone it’s attached to alongside the second bone instead of end-to-end, like in primates.

Spreading out the paw, shown above, makes the ligaments extend the claw and tip bone, and Kitty is locked and loaded. Bring the digits together again, and the whole arrangement retracts back into its resting position.

Why does leg length matter?

Short answer: The better to stalk and ambush you.

More information: Like most animals, carnivores have to move around to make a living. Each has its own style, but they do mix it up a bit.

Bears, for instance, are ambulatory predators, like terrestrial raccoons, so they generally just shuffle along. But as somone once said, people have ended their lives being surprised by how fast a bear can run.

Cats climb almost as well as palm civets, but they’re not arboreal predators. The feline evolutionary path took cats to the zone where open land and forests meet. Here cats became stalk-and-ambush ground hunters (though some people probably have ended their lives surprised that big cats are so agile in trees).


The human environment has a similar blend of climbable things and open areas, but we only tolerate house cats in it. (Doanme at Pixabay, public domain)

A cat’s legs are proportionally longer than a bear’s because the cat needs to run more, as well as cover a lot of ground on its daily territory patrol. However, dogs have longer legs than cats because they chase their prey long distances instead of ambushing it.

Cats have evolved into a happy medium. Their legs are long enough for good acceleration and speed over short distances but not so short that the bone would snap under forces generated by powerful muscles needed for stalking and hunting.

Speaking of locomotion, of course this post closes with a cheetah video!

Cheetahs are extreme, but this excellent video does show what we’ve talked about (including retractable claws, sort of) and more of the sleek features that all cats, including Fluffy, have evolved, including (but not limited to) shoulder blades and clavicles designed to speed them on their way; all four legs underneath the body to conserve inertia; the knee joint next to the pelvis (can you do that while running?); and the head relatively immobile and focused on the moving prey.

Featured image: Marina del Castell, CC BY 2.0

Biknevicius, A. R. and Van Valkenburgh, B. 1996. Design for killing: craniodental adaptations of predators. Carnivore Behavior, Ecology, and Evolution, 2: 393-428.

Rose, K. D. 2006. The Beginning of the Age of Mammals. Baltimore: The Johns Hopkins University Press.

Martin, L. D. 1989. Fossil history of the terrestrial Carnivora, in Carnivore Behavior, Ecology, and Evolution, ed. Gittleman, J. L., 536-568. Ithaca, NY: Cornell University Press.

Taylor, M. E. 1989. Locomotor adaptations by carnivores, in Carnivore Behavior, Ecology, and Evolution, ed, Gittleman, J. L., 382-409. Ithaca, NY: Cornell University Press.

Turner, A., and Antón, M. 1997. The Big Cats and Their Fossil Relatives: An Illustrated Guide to Their Evolution and Natural History. New York: Columbia University Press.

Werdelin, L. 1989. Carnivoran ecomorphology: A phylogenetic perspective, in Carnivore Behavior, Ecology, and Evolution, ed. Gittleman, J. L., 582-624. Ithaca, NY: Cornell University Press.

Cats in the Lab

Uh, no, not this adorable assistance with human technology. We’re looking at animal testing today. Relax, it’s not as horrifying as you might think.

Leafing through old research papers can get really grisly when you read about some of the tests they performed on animals, including cats, to get their results.

Today, not so much.

It’s not the 1950s any more. Bad things still happen, sadly, but nowadays it results in big headlines and bad publicity more often than not. Government, media, the private sector, and fellow scientists are all watching.

The biggest recent animal-welfare story comes from the United States, where on February 3, 2017, the USDA removed warning letters, inspection reports, and other documents from a public database that included every commercial animal business in the country, including zoos and research centers. Information for some 8,000 facilities disappeared from public view.


Where’d it go? (Sagyle at Pixabay)

No one knows where it went.

The reason given for the removal of these records was privacy concerns, although the reports were edited for individual security and privacy purposes before going online.

Theoretically, the missing USDA inspection and abuse reports could still be obtained via a Freedom of Information Act (FOIA) request, but this process takes at least several months.

And often the information provided was heavily redacted. The National Geographic Society, for example–not known for its extreme positions on animal rights–got 1,771 completely blank pages in response to their FOIA request, which the Society put online.

The USDA says it can’t release information that is associated with ongoing lawsuits (and many were filed after the February 2017 federal move, in addition to ongoing animal-abuse cases using the formerly public information).

On April 9, 2018, some recent inspection reports–not those taken down in 2017 but a selection dating from March 2018 onward–appeared in the public database again. This only happened after Congress, while preparing to vote on the agency’s annual funding, pointed out that:

USDA’s actions to date do not meet the requirements in H. Rpt. 115-232 that the online searchable database should allow analysis and comparison of data and include all inspection reports, annual reports, and other documents related to enforcement of animal welfare laws. USDA is directed to comply with these requirements and is reminded that as part of its oversight responsibilities, Congress has the right to make any inquiry it wishes into litigation in which USDA is involved. USDA is directed to respond to any such inquiries fully.

It remains to be seen what will happen next.

In the meantime, zoos, research organizations, and others with an animal-related business, as well as anyone in a US jurisdiction that requires animal breeders and other sellers to show a clean USDA record, are all in the dark.


And shady deals go down in dark sometimes (though few probably involve Mayor McCheese). (Karl Palutke. CC BY-SA 2.0)

Meanwhile, in the sort of gentle “ahem” that sometimes wafts across the Atlantic during such US controversies, the Guardian posted an April 6, 2018, essay by a British researcher. It points out how well animal welfare legislation is working out in the UK.

Thinking back to my early days as a researcher, it is inconceivable . . . that any university would allow cameras into their animal units to film. This shows the culture change that is under way, but there is still work to be done. It is only by being more open with the public that we can show them the high welfare standards and the care that all research animals receive. In this way, I hope we can build trust in the organisations, and the scientists, engaged in animal research.

We all do want to believe that lab animals are treated well. Extremists who use threats, violence, or extravagant claims set this humane goal back by undermining trust in public institutions.

That trust has been shaken by the recent loss of transparency in the US, but researchers in the UK must follow some of the toughest animal-welfare laws in the world.

According to the RSPCA, scientists need need three licenses in order to use animals in their work: one for their establishment, a personal one for each individual who handles the animal, and a project license that is only granted if it can be proved that the project benefits people more than it harms the animals used in testing.

The “three R’s” for animal research are also promoted internationally:

  • Replacement of animal testing with other methods
  • Reduction of the number of animals tested
  • Refinement of tests to avoid life-long animal suffering

In India, a fourth “R”–rehabilitation–is added.

So how are cats faring in the midst of all this fuss?

The Office of Research Integrity (ORI) has a good page about cats in US research today (Here is a working link to those “Cats in Biomedical Research” notes).

The good news is that use of cats in the lab has plummeted in the US since the 1970s, when 74,000 cats were used in 1974. That number dropped, per ORI, to a little over 26,000 in 1997.

This was after the mid-1980s shift in public opinion, as well as passage of laws in several countries around the same time that made using cats in neurological research, once a common practice, much more costly in terms of both time and money. (National Research Council)

In 2016, according to the USDA’s last annual report (via Wikipedia), the lab cat population was down to 19,000. And in the UK that same year, the number of procedures on lab cats dropped almost 10%.

Maintaining openness is probably the biggest challenge for animal welfare in research labs. In some respects, scientists and government inhabit the same world–one that laypeople seldom see. This in itself isn’t bad: who wants to attend all those hearings in DC or London and show up at the lab every day to watch tests?

Human nature is the problem. Government officials and technologists get used to their work. Animal testing isn’t intended to be cruel. The testers and those who monitor them just get into a business-as-usual frame of mind that leads to horrors time and time again.

As G. K. Chesterton pointed out a century ago (in a very different context), the presence, via access by online databases, news documentaries, etc., of outsiders who aren’t numbed by familiarity and can spot inhumane practice instantly is the best way to prevent a lot of suffering and grief all around.

Featured image: Veronica Belmont. CC BY 2.0.


Badyal, D. K., and Desai, C. 2014. Animal use in pharmacology education and research: The changing scenario. Indian Journal of Pharmacology, 46(3), 257.

Daly, N. 2017. U. S. animal abuse records deleted–what we stand to lose. National Geographic, https://news.nationalgeographic.com/2017/02/wildlife-watch-usda-animal-welfare-trump-records/ Last accessed April 10, 2018.

Daly, N., and Bale, R. 2017. We asked the government why animal welfare records disappeared. They sent 1,700 blacked-out pages. National Geographic. https://news.nationalgeographic.com/2017/05/usda-animal-welfare-records-foia-black-out-first-release/ Last accessed April 11, 2018.

National Research Council. 2012. International animal research regulations: impact on neuroscience research: workshop summary. National Academies Press. PDF download https://www.ncbi.nlm.nih.gov/books/n/nap13322/pdf/ Last accessed April 11, 2018.

Royal Society for the Prevention of Cruelty to Animals (RSPCA). n.d. Reports and resources. https://science.rspca.org.uk/sciencegroup/researchanimals/reportsandresources Last accessed April 10, 2018.

Speaking of Research. n.d. UK Animal Research Statistics. https://speakingofresearch.com/facts/uk-statistics/ Last accessed April 11, 2018.

United States House of Representatives, Bills This Week. 2018. Division A – Agriculture, Rural Development, Food and Drug Administration, and Related Agencies Appropriation Act 2018. Congressional Directives. PDF download: https://www.google.com/url?sa=t&source=web&rct=j&url=http://docs.house.gov/billsthisweek/20180319/DIV%2520A%2520AG%2520SOM%2520FY18%2520OMNI.OCR.pdf&ved=2ahUKEwj8-rCugLPaAhUL658KHW0TCvgQFjABegQIBxAB&usg=AOvVaw30lLEN-35gfGw0aUv8LNdp Last accessed April 11, 2018.

Wadman, M. 2017. Activists battle U. S. government in court over making animal welfare reports public. Science Magazine. http://www.sciencemag.org/news/2017/05/activists-battle-us-government-court-over-making-animal-welfare-reports-public Last accessed April 10, 2018.

Wadman, M. 2018. Update: After Congress complains, USDA restores animal welfare reports. Science Magazine. http://www.sciencemag.org/news/2018/03/congress-orders-usda-restore-transparency-completeness-animal-welfare-reports Last accessed April 10, 2018.

Black Cats and Black Panthers

Black house cats and black panthers (leopards) have a couple things in common. Beautiful, beautiful things.

(Here’s how they filmed that and other slow-motion cat videos.)

Domestic cats and leopards are both felids, i.e., they both belong to the cat family Felidae. They also show melanism (the technical name for black fur).

And that’s about it for the similarities between these two species. Size, of course, is a big difference. Where they hang out matters, too.

Black house cats cluster in urban centers around the world, while other melanistic cats are usually found in humid tropical environments.

Different genes are also involved in the mutation, including ASIP changes in the domestic cat and MC1R changes in some other melanistic felids.

Since the natural mammal fur pattern fur is agouti–a brindled appearance caused by alternating light and dark bands of color on each hair–scientists are fascinated by feline melanism. They study it with techniques ranging from mapping populations in the field to the latest molecular biology lab tools.

We don’t have to get into that much depth here, but some of their findings are very interesting.

Domestic black cats

Mapping and archaeological studies suggest that the fur mutation that turns domestic cats black is ancient. It probably happened around 2,500 years ago, somewhere in the eastern Mediterranean. (Todd) All of the cats shown in Ancient Egyptian artwork are tabbies, like their African wildcat ancestor, so this probably didn’t happen in the Land of the Pharaohs.

Black cats then spread west together with various Mediterranean commercial nations, including the Phoenicians. Today, despite being a target during the bad old days of witch hunting in Europe, black cats are very common in the UK, along the northwestern coast of Africa, and in a natural trading corridor along the Seine and Rhône river valleys that once saw heavy traffic as a barge shortcut between Britain and the Mediterranean. (Todd)

You can also find lots of black cats in urban settings like Utrecht (Netherlands), Chiang Mai (Thailand), Denton (Texas) and some other US cities, and Morocco. (Bradshaw)


It’s not always one big happy family. Ryusuke. CC BY 2.0.

No one really knows why this mutation has worked out so well for domestic cats. Whatever the secret, humans probably are involved because other black cat species have a very different story.

Black panthers and other wild cats

Black leopards and jaguars are very popular cultural icons, but more than a third of the cat family shows melanism in some individuals. (da Silva and others)

These include, but aren’t limited to:


I could only find a gray Asian golden cat (black with some other genetic things going on) online. Umeshsrinivasan. CC BY-SA 3.0.

Yes, the cat family is so beautiful and varied that it will take a separate ebook in this planned series to do its many members justice.

In case you’re wondering about the other three big-cat superstars, all-black lions and cheetahs have been reported (Sunquist and Sunquist) but not confirmed. Tigers are a special case.

It’s probably not coincidence that these black cats live in the tropics, but moisture rather than lush vegetation seems to be the deciding factor.

For instance, on the very wet southern part of the Thai/Malaysian Kra Isthmus, almost all leopards are black. Not so in the slightly drier northern section, where there is a mix of melanistic and mainstream spotted leopards, although the plants are exactly the same. (da Silva and others)

Why? No one knows. Proposed explanations run the gamut from camouflage to body temperature regulation and antibacterial effects.

Evolutionary advantages

All that is literally worlds away from the domestic black cat, which seems to do well around people no matter what the relative humidity may be. Nevertheless, black apparently gives cats some kind of advantage in life.

Non-agouti domestic cats–those that lack the alternate light/dark color bands that most mammal fur has–tend to be black, though other solid colors are possible. I’m not sure why, though I have read that the light brown background color on a tabby cat is an optical illusion caused by alternating bands of light color and black, with a light-colored band just under the hair tip. (Lyons) (Other mutations are involved in a true brown color in cats.)

Black may just be a very common pigment in the African wildcat/domestic cat’s color palette.

Genes can have more than one effect, and maybe black cats have been so successful because they are a little better at interacting with humans than other domestic cats. Their appearance is certainly striking; perhaps we just tend to choose black cats over others.

That’s all artificial selection, according to evolutionists. It’s human-mediated.

Natural selection may be at work, too. Since street lighting is a relatively recent invention, it’s possible that black fur may have given cats a better ability to hide at night as they roamed the urban streets. They lived longer and had more kittens.


Street lighting also works, by throwing shadows that black cats can use while hunting or hiding from predators. the2me at Pixabay. Public domain.

Zoologists get a little more technical. They know that most wild mammals have the agouti pattern and most domesticated mammals are non-agouti. However, overall the domestic cat population is about half agouti and half non-agouti.

This equilibrium makes some researchers suspect they have what is called a heterozygote advantage (Todd)–the non-agouti gene is recessive, meaning it can stay hidden for a long time, until more favorable circumstances arrive.

The bottom line may simply be that cats are only about halfway through the domestication process. They still have one paw in the wild world. Whatever is going on in evolutionary terms, history shows that black cats and people have been through some tough times together, but the bonds of love and friendship between us are still strong, even if we don’t understand what gives these little felines their lovely and very dramatic look.

Featured image: Pedro Ribeiro Simōes. CC BY 2.0.

Arendt, J., and Reznick, D. 2008. Convergence and parallelism reconsidered: what have we learned about the genetics of adaptation? Trends in Ecology and Evolution. 23(1): 26-32.

Bashir, T.; Bhattacharya, T.; Poudyal, K.; and Sathyakumar, S. 2011. Notable observations on the melanistic Asiatic Golden cat (Pardofelis temminckii) of Sikkim, India. NeBIO. 2(1): 2-4.

Bradshaw, J. 2013. Cat Sense: How the New Feline Science Can Make You A Better Friend to Your Pet. New York: Basic Books. Retrieved from https://play.google.com/store/books/details?id=iU8PAAAAQBAJ

da Silva, L. G.; Kawanishi, K.; Henschel, P.; Kittle, A.; and others. 2017. Mapping black panthers: Macroecological modeling of melanism in leopards (Panthera pardus). PLOS ONE. 12(4): e0170378. https://doi.org/10.1371/journal.pone.0170378.

Eizirik, E.; Yuhki, N.; Johnson, W. E.; Menotti-Raymond, M.; Hannah, S. S.; and O’Brien, S. J. 2003. Molecular genetics and evolution of melanism in the cat family. Current Biology. 13:448-453.

Graipel, M. E.; Oliveira-Santos, L. G. R.; Goulart, F. V. B.; Tortato, M. A.; and others. 2014. The role of melanism in oncillas on the temporal segregation of nocturnal activity. Brazilian Journal of Biology. 74(3): S142-S145.

Kawanishi, K.; Sunquist, M. E.; Eizirik, E.; Lynam, A. J.; and others. 2010. Near fixation of melanism in leopards of the Malay Peninsula. (Abstract only) Journal of Zoology. 282(3): 201-206.

Kinnear, J. 1983. Feline genetics, in Felis domesticus: A Manual of Feline Health 1982-1983, 121-134. Ithaca: Cornell Feline Health Center.

Lyons, L. 2015. DNA mutations of the cat: The good, the bad and the ugly. Journal of Feline Medicine and Surgery. 17(3):203-219.

Schneider, A.; Henegar, C.; Day, K.; Absher, D.; and others. 2015. Recurrent evolution of melanism in South American felids. PLoS genetics. 11(2): e1004892.

Sunquist, M. and Sunquist, F. 2002. Wild Cats of the World. Chicago and London: University of Chicago Press. Retrieved from https://play.google.com/store/books/details?id=IF8nDwAAQBAJ

Todd, N. B. 1977. Cats and Commerce. Scientific American. 237:100-107.

Misconception: Desexing Your Cat is a Simple Yes or No Decision

When you take your new pet kitten or cat for its first medical visit, the vet will probably bring up sterilization, if you don’t mention it first.

This isn’t done with cats used for breeding, obviously, but it is always recommended otherwise. Males are neutered by removing their testicles, while females are spayed either by removing their uterus and ovaries or just the ovaries and attached structures. Tubal ligation is also an option.

It’s true that sterilization is an individual extinction, unless the cat has already passed on its genes, but desexing has its benefits for pets and their owners:

  • Cats live longer and are more people oriented.
  • They are at less risk for certain diseases (including breast cancer and reproductive tract disorders in females and prostatic hypertrophy/testicular cancer in males).
  • The procedure eliminates breeding instinct-related behavior like spraying, calling, and trying to get out of the house.

There are also some disadvantages to spaying or neutering your pet, in addition to the usual surgical and anesthetic potential complications. (See details in the paper by Root Kustritz, listed under Sources below.)

In some places, elective sterilization for human convenience is considered unethical. However, overpopulation is the usual reason vets recommend either sterilization or, where available, contraception.

It’s not unethical to feel bad that millions of healthy cats and kittens each year must either be killed (in most shelters) or serve a life sentence in ever more crowded, stressful conditions (in a no-kill shelter) simply because no one adopted them.


Ansel Edwards, CC BY 2.0.

And many of us have seen rough-looking feral or farm cats clustering around dumpsters or dockyards, looking for food.

It’s heartbreaking. Since domestic cats reproduce so quickly, sterilization seems like a logical way to at least limit the all-around suffering.

It probably does work, somewhat, but still we are knee-deep in domestic cats all over the world. The same study that estimated a world-wide total of 600 million owned cats also reported another 600 million unowned animals! (Driscoll and others)

Of course, domestic cats don’t like to be counted; there is actually quite a range of population estimates among various studies. The 600/600 million number is the highest reliable estimate I found.

Other information is difficult to come by, too. As Root Kustritz, who reviewed the scientific literature on cat sterilization, writes:

There is also great variability in number of studies supporting some of the findings described, and veterinarians are encouraged to be aware of the amount of evidence to support any given claim.

That’s not a warning you often see in science papers.

By all accounts, none of humanity’s efforts to control the domestic cat population are very effective.

Why not?

Because, again, cats reproduce very quickly. They also can adapt to almost any situation.

If just one tomcat escapes the local feral-cat roundup, he could go on to sire a thousand cats. A single queen (unaltered female cat) can have multiple litters of up to ten or more kittens each every year.

Unfortunately, irresponsible people also dump unwanted cats, especially when they see a colony or other place for outdoor cats to get food.

The only proven way to reduce the number of cats out there is the natural way, through loss of their ecological niche, and that’s not going to happen.

Whether we like it or not, the legacy of our long association with them is that domestic cats are the major small predator in any human-dominated environment. When that niche empties, another cat will move in.

Such an ecosystem is finely balanced, by the way. Even if it were possible, the consequences of reducing the number feline small predators might, depending on local circumstances, result in the awful disruption known as a mesopredator release.

An extreme example of this recently happened on subantarctic Macquarie Island.

So managing the cat population is a headache for conservationists as well as animal care specialists and cat owners.

A growing number of veterinarians and cat lovers recognize the complexities of feline population control. (Barchas) Probably the ultimate solution to the problem of too many domestic cats will work out as the sum of many individual decisions, including your own.

You can make a difference. All it takes is a little thought and some discussion with the vet before checking/not checking that box on the form next to the “spay or neuter” option.

The more thought each owners gives to their cat(s), the closer we are to a world where every kitten and cat is wanted and loved forever.

Featured image: US Air Force, Staff Sgt. E’Lysia Wray. http://www.holloman.af.mil/News/Photos/igphoto/2001570155/ Public domain.


American Veterinary Medical Association. 2017. New recommendations for feline spay/neuter surgery. https://atwork.avma.org/2017/07/10/new-recommendations-for-feline-spayneuter-surgery/ Last accessed March 13, 2018.

—. 2018. Spaying and neutering. https://www.avma.org/public/PetCare/Pages/spay-neuter.aspx Last accessed March 13, 2018.

Barchas, E. 2017. Is it always the right thing to spay or neuter a cat? Catster. http://www.catster.com/lifestyle/spay-neuter-cats-debate Last accessed March 13, 2018.

Breuninger, K. J., and Demos, L. E. 2016. Veterinary Task Force on Feline Sterilization Recommendations for Age of Spay and Neuter Surgery. Focus version. http://www.winnfelinefoundation.org/search-results?indexCatalogue=site-search&searchQuery=veterinary task force for feline sterilization&wordsMode=0 Last accessed March 14, 2018.

Driscoll, C.; Yamaguchi, N.; O’Brien, S. J.; and Macdonald, D. W. 2011. A suite of genetic markers useful in assessing wildcat (Felis silvestris ssp.) – domestic cat (Felis silvestris catus) admixture. Journal of Heredity. 102(SI):S87-S90.

Gehrt, S. D.; Wilson, E. C.; Brown, J. L.; and Anchor, C. 2013. Population ecology of free-roaming cats and interference competition by coyotes in urban parks. PLoS One. 8(9): e75718.

Hughes, K. L.; Slater, M. R.; and Haller, L. 2002. The effects of implementing a feral cat spay/neuter program in a Florida county animal control service. Journal of Applied Animal Welfare Science. 5(4): 285-298.

Humane Society of Charlotte. 2018. Spay/neuter myths and truths. humanesocietyofcharlotte.org/education/spayneuter-myths-truths/ Last accessed March 13, 2018.

Kelley, J. A. 2015. And now, 6 boneheaded myths about early spay and neuter. Catster. http://www.catster.com/lifestyle/cat-health-bust-6-myths-pediatric-early-spay-neuter-cats Last accessed March 13, 2018.

McKenzie, B. 2010. Evaluating the benefits and risks of neutering dogs and cats. CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources. 5(45):1-18.

Ordeñana, M. A.; Crooks, K. R.; Boydston, E. E.; Fisher, R. N.; and others. 2010. Effects of urbanization on carnivore species distribution and richness. Journal of Mammalogy. 91(6): 1322-1331.

Plantinga, E. A.; Bosch, G.; and Hendriks, W. H. 2011. Estimation of the dietary nutrient profile of free-roaming feral cats: possible implications for nutrition of domestic cats. British Journal of Nutrition. 106(S1): S35-S48.

Ritchie, E. G., and Johnson, C. N. (2009). Predator interactions, mesopredator release and biodiversity conservation. Ecology Letters. 12(9): 982-998.

Robertson, S. 2008. A review of feral cat control. Journal of Feline Medicine and Surgery. 10:366-375.

Root Kustritz, M. V. 2012. Effects of surgical sterilization on canine and feline health and on society. Reproduction in Domestic Animals. 47(s4): 214-222.

Sontas, B. H., Kaysigiz, F., & Ekicia, H. 2012. Methods of oestrus prevention in dogs and cats: a survey of Turkish veterinarians’ practices and beliefs. Archivos de Medicina Veterinaria. 44(2). http://www.redalyc.org/comocitar.oa?id=173023986009 Last accessed March 14, 2018.

Wright, M., and Walters, S. 1980. The Book of the Cat New York: Summit Books.

Domestic Cat Territories, Part 2

Congratulations! You have just moved into a quiet, shady suburban neighborhood with lots of fenced-in back yards filled with sheds, trees, and other structures that add three dimensions to a roaming cat’s world.

As you and your kitty relax by the window, you note a few other cats out there: a black one two yards down, sitting high up on a shed roof; a ginger cat walking along the fence, across the alley; and something that just ducked under the laurel bush in your new back yard–ah! there it goes up a tree: brown and white spots, and quite a large cat it is.

Good! you say to yourself. With so many feline neighbors, Fluffy won’t be lonely while I’m at work.

Fluffy, on the other hand, is seriously considering switching over to 100% indoor living. Spots out there is huge and obviously owns the yard, while the other cats – including three more whose scent marks Fluffy can smell although you are oblivious to them – will all have to be faced, too.

New cat on the block

When we move, we plunk our pets down in the middle of a complex and foreign terrain. And it contains serious challenges.

Neighborhood cats may ignore a neutered cat, but they will gather and call out Fluffy to see what he’s made of.

We don’t usually see all this drama. Loveombra, at Pixabay.

The good news is that Fluffy only has to go through this “blooding” once to earn a place in the local pecking order.

House-cat territories

All cats need an organized space around them, just like people do. Walls work very well for indoor cats, even in a multi-cat household (as long as each animal respects the others’ core area, which is usually a favorite sleeping spot).

The house itself is a free-roaming pet’s central core. (In Fluffy’s case, though, the back yard isn’t–when push came to shove, he couldn’t take down Spots, who dominates the block. Fluffy did earn enough respect to claim time-sharing rights in both the yard and the tree. He also intimidated Ginger and one of the scent-mark cats with an impressive combination of vocals and threatening moves – no battles – but he blinked first in staring contests with each of the other two scent-marking cats. Never mind Blackie – he’s kind of a wuss and everybody picks on him. Oh, and there is a yellow she-cat with kittens, three yards down, who will not take harassment from anybody, not even Spots, at any time of the day or night.)

Each of these cats has its own territory–even Blackie, who can claim the shed roof, although the rest of his owner’s yard belongs partly to Ginger and partly to one of the scent-marking cats. Spots, of course, has the largest range of any of them.

The fences are neutral pathways, and there are also a couple of safe routes on the ground.

Most scratching is done along these paths rather than around the territorial borders. Urine spraying, however, is done throughout a cat’s range, except in its sleeping area.

These marks all let other felines know who is where at any given moment. Time sharing reduces stress and keeps down the number of fights in an area where people have brought so many pet cats together.

Domestic cat brotherhoods

Feral she-cats in a colony will share nursing duties, like lionesses do in a pride, but only domestic cats seem to have a “boys only” hangout.

Spots, Fluffy, Ginger, and the other neighborhood he-cats–even Blackie!–sometimes gather together on neutral ground and pull an all-nighter. They forget the hierarchy and just relax, chatting, purring, and grooming each other sociably until it’s time for the sun to come up. Then each goes back to his own territory and resumes business as usual.

Felinologists call this a brotherhood.

Feline brotherhoods reduce aggression in the neighborhood, but only for the cats! Library of Congress.

Have humans enabled this unusual behavior by building enough excess infrastructure for cats to expand their neutral ground into a commons?

Who knows. Maybe it’s just a side effect of domestication. African wildcats – Fluffy’s closest ancestor – are never seen socializing this way. But then, they don’t gather in groups, either, the way feral cats will around a food source (a dumpster, say, or a dockyard).

No human being understands the he-cat’s social club. But whatever is going on, it seems to be working.

Domestic cats are very adaptable, even when we force them into closer contact with each other than they would normally tolerate in the wild.

They adapt their territories to the limits we set for them, whether that is an interior wall or a fenced-in yard. When it all feels right, the domestic cat then does its thing, just as it has been doing for many hundreds of centuries while sharing its life with us.

Featured image: Nico Nelson CC BY 2.0.


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