Humans and cats go way back. The relationship sprouted around 2000 BC in Egypt, where humans first domesticated felines. Today, more than 90 million cats in the United States alone enjoy the companionship of humans, while another estimated 90 million are stray or feral.

As in most relationships, there are still secrets between humans and their feline friends. But a recent study published in the Journal of Wildlife Management shed light on one secret that may have been nagging cat owners: what do outdoor cats, otherwise known as “free-roaming,” do all day?

Since there are several cat enthusiasts at The Why Files, we, too, wondered about the answer to that question. And the answer belies a few thorny predicaments peculiar to the cat-human relationship.

A day in the life of a free-roaming cat

Decked with radio collars that tracked their every move, 42 free-roaming cats (18 of them pets, 24 of them owner-less) were the stars of the two-year University of Illinois study. The researchers’ goals were to compare what owned versus un-owned cats did all day, where and how far they wandered, and how likely they were to survive in the often risky outdoors.

Certainly, to no cat owner’s surprise, the felines spent much of their time lounging or sleeping, just like their strictly-indoor counterparts. However, the amount of time pet cats versus owner-less cats spent snoozing differed significantly. Pet cats lazed about for 80 percent of their days, while un-owned cats loafed for “only” 62 percent of the time.

“That alone is very interesting. It could be associated with their requirements. It’s possible that the cats without owners have to spend more time looking for resources to take care of themselves,” speculated Nohra Mateus-Pinilla, study co-author and wildlife veterinary epidemiologist at the Illinois Natural History Survey.

Another important finding, according to Mateus-Pinilla, were the differences in the cats’ ranges. While, not surprisingly, un-owned cats roamed further afield than owned cats, Mateus-Pinilla and her co-authors were surprised by how far the stray cats strayed and by the diversity of habitats they skulked in, as compared to pet cats. While most of the pet cats stuck close to home, the most itinerant stray cat wandered around a 547-hectare (1,351-acre) area.

From original map by Jeff Horn

Despite range differences, un-owned and owned cats’ territories can overlap. The red outline shows the largest range tracked for an un-owned cat in the study, and the yellow dot indicates one pet cat’s range.

“Because of the large home range sizes in the evidence of both cats without ownership and cats that are owned, their home ranges are overlapping. And because of the mortality evidence, these animals could be facing a certain amount of risks that we are unable to measure,” said Mateus-Pinilla.

Indeed, the risks of being a free-range cat are much higher than those of indoor cats, and if the cat has no owner, its fate is almost always bleak. In their study, six stray cats died, while only one owned cat died.

Mateus-Pinilla said their study raises many new questions. To The Why Files, however, it seems that living in the company of humans has its advantages for cats. But keeping this relationship indoors may have advantages for wildlife and people too—-implications that drive the otherwise curious research on free-roaming cats.

Too many kitties on the range

While the indoor-outdoor debate lives on in the cat owner community, and regardless of whether or not cats enjoy the out-of-doors, their secret lives outside entail some dirty secrets that are alarming scientists and laypeople alike.

The sheer number of free-range cats, owned or not, has become a conservation and health concern, some scientists say. Like any species, too many can spell trouble.

Cats, by nature, are superb predators. A cat stalking a bird or squirrel is simply doing what cats do. However, their prowess as hunters, combined with their overpopulation, has wildlife biologists and enthusiasts biting their nails over the potential endangerment or extinction of some prey species.

“There are a growing number of landscapes in which free-ranging cats are not only the most abundant mid-sized mammalian predator, but they can outnumber all of the native mammalian mid-sized predators combined. So they really do become the dominant mid-sized predator in many landscapes,” said Stanley Temple, an emeritus professor of forest and wildlife ecology at the University of Wisconsin-Madison, who was among the first to study the ecological impacts of free-roaming cats.

Because of their impacts on both native predators and prey, conservation scientists consider free-roaming cats invasive species. While not the greatest threat to wildlife, they add to the increasingly complex web of existing threats.

Species most at risk of death-by-kitty are birds that spend a lot of time on the ground, small mammals and reptiles, according to Temple. In fact, cats are second to habitat destruction as the cause of bird extinction. Thirty-three bird species have met their fate to the paws of cats since the 1600s.

The world’s ever-shrinking “islands” of wildlife habitat are hotspots of conservation concern over free-roaming cat populations, since the native species in these areas are the hardest hit by invading cats. For example, birds that live in America’s dwindling grasslands or on the increasingly crowded seashore are finding themselves in a precarious situation.

Open and fragmented landscapes, which also include forest outskirts and farmland, are the territories of choice for cats. And, except in subtropical locales, they tend to stick close to humans. Even if un-owned, most cats are still dependent on people for either food or shelter, or both.

“They are remarkably resourceful at taking advantages of the opportunities that we present,” said Temple, who clarified that free-roaming cats are only truly “feral” if they are completely independent of humans.

Their dependency on humans highlights another dilemma: free-range cats can easily spread diseases and parasites that can jump from cat to cat, cat to wildlife, and even cat to human. The list of contagions includes feline leukemia, feline immunodeficiency virus, worms, rabies and toxoplasmosis, a parasite-caused disease that can damage the developing brains of unborn human babies, if their mothers are infected.

Free-roaming cats’ close proximity to both humans and other animals thus creates a potentially strong reservoir for these diseases. While vaccinating both owned and un-owned cats can help reduce the spread of disease, vaccines are not 100 percent effective and the logistics of vaccinating every single cat may be impossible, especially since many vaccinations are annual.

Photo: Rodrigo Basaure

These street cats certainly benefit from a human handout, but do humans benefit from the cats’ potential disease threat?

It’s complicated

Indeed, solutions to these predicaments aren’t easy. While the science may seem to imply that rounding up every cat on the range may be the best solution, the ubiquity of free-roaming cats and the emotions wrapped up in some people’s relationship with felines complicate the matter.

Studies suggest that many free-range cats are people’s beloved pets that are allowed outside, said Temple. But, while keeping every pet cat indoors would significantly and immediately cut the number of free-range cats, not every cat owner agrees that indoor life is best for kitty.

To further complicate things, one of the often promoted “humane” methods of attempting to reduce un-owned cat populations — trap, treat, neuter, release — repeatedly fails. Not only are there always the cats that get away, but releasing the cats back into the “wild” still does not eliminate the risks to wildlife.

Temple believes that for a cat-control method to work, three criteria must be met: the strategy must actually control cat numbers over large areas, it can’t harm any other part of the ecosystem, and it is socially acceptable. The last criteria can be the trickiest to meet and often creates tension between humans.

Photo: Flickr

Is this outdoor kitty taunting his indoor pal? But who has the better life?

“The divide over how to deal with cat overpopulation, in one way, can be simplified as the group of people who are really concerned about ecological impacts of cats versus those that are really concerned about the welfare of individual animals,” said Temple, based on his years of experience conducting public outreach on the issue. He clarified that he likes cats and is actually the owner of a 21-year-old feline.

Temple believes solutions that meet both factions on common ground do exist. Keeping pet cats inside and trapping, treating, neutering and confining un-owned, free-roaming cats are two strategies that meet his criteria. Though, for some people, it will take some convincing.

Mateus-Pinilla was careful to emphasize that their study did not seek to evaluate management options. They were focused on adding to the science and remaining neutral in the debate about solutions to the issue of free-roaming cats.

– Jenny Seifert

Harvey the Cat sleeping on his back

Tired of being told to exercise more, eat less, and gobble expensive pills to stay healthy? The Why Files has finally located some medical news you can use. It’s organic. It’s painless, and it’s effective.

If you’re worried about your blood pressure, a pet cat or dog may control your pressure during stressful times.

That, at least, is the implication of research presented by social psychologist Karen Allen to an American Heart Association meeting on Nov. 7. Her work follows several other studies that suggested pets help control blood pressure. But while previous studies compared pet owners to non-owners, this was the first to look at what happens when a non-owner gets a pet.

As her guinea pigs, Allen, a researcher at the State University of New York at Buffalo, recruited 48 New York City stockbrokers who had hypertension — high blood pressure. The brokers, 24 men and 24 women, lived alone, and their average resting systolic pressure was 160 millimeters of mercury, well into the danger zone. (Systolic pressure is the higher of the two numbers in a blood-pressure reading.)

As the experiment began, the subjects started controlling their blood pressure with lisinopril, an inhibitor of angiotensin converting enzyme (ACE). Although lisinopril reduced systolic pressure to an average of 123 mm, it was far less effective in controlling the rise in pressure that occurs during stress.

Better than drugs!

At the outset, half the broker-guinea pigs were directed to choose a cat or a dog as a pet. The fun part came when these guinea pigs were asked to do mental arithmetic — or (we love it!) — to respond to an experimenter who, posing as a client, demanded: “Upon your advice, I lost $86,000. What are you going to do about it?”

The demand stressed the non-pet owners enough to essentially cancel the benefit of the ACE inhibitor, Allen says, yet the systolic pressure among pet owners rose only 9 mm. Furthermore, their pulse rose by 10 beats per minute, less than half the 21-beat rise seen in the control group.

In other words, pets were much better at reducing the stress-induced rise in blood pressure than the drug.

Cats rule? Dogs drool?

Oddly, dogs and cats were equally effective at controlling blood pressure, and even more oddly, owners got the benefits even if they were not paying attention to the animals. (Allen says she was present during the pressure measurements, and the pets seemed more interested in her than in their owners.)

Why do pets work? Allen says other observations during the study indicate that they offer a non-judgmental presence that influences how owners see difficult events: “To have something in your life that’s totally on your side has a very powerful effect. Somehow their presence changes your perception of what’s going on from a threat to a challenge.”

Young Great Dane

Hypertension being a serious problem that can lead to deadly strokes, Allen stresses that cats and dogs are not intended as replacements for drugs in controlling blood pressure, but rather as supplements.

Still, even if Shoo-shoo the poodle would be chary of the chaos of a stockbrokerage, pets may eventually play a greater role in stress reduction. It’s possible that Shoo-shoo’s photo — or even a poodle in the form of a stuffed animal — may provide on-the-job restraint for soaring blood pressure.

Despite the findings, Allen does not argue that pets will work for everyone. “If you treat a pet as a piece of furniture, you will derive roughly as much benefit as you would from a sofa.”

A couple of final notes: when you pet your pet, your blood pressure probably falls — as does your pet’s. And when the stockbrokers in the control group learned of Allen’s results, many went out and — you guessed it– invested in some pets of their own.

– David Tenenbaum