Cat reproduction rate

[Guest guest]

>A female cat generally breeds three times a year - three or five

>kittens each time - meaning cats can multiply in a geometrical

>manner, Liao said. Unfettered, a pair of cats can produce more than

>100,000 kittens within seven years, according to People's Daily.

 

 

The above claim, from " Sterilization can solve pet problems:

expert, " by Xie Ying, Global Times, August 26 2009, is utterly

untrue, though often said by people who should know better.

 

Animal advocates need to stop mindlessly repeating it,

because it tends to make people think not that they need to have

their cat sterilized, but rather that they need to declare war on

all cats, lest they take over and destroy civilization.

 

In 2007 I teamed up with Wall Street Journal " Numbers Guy "

columnist Carl Bialik to trace this ancient claim, in all variants,

back to source.

 

Apparently it started with a calculator logarithm of dog

reproduction used by the Animal Protection Institute in a January

1968 press release. It mysteriously picked up a zero by 1973, and

about a decade later picked up another zero when first applied to

cats, but there never at any point was any biological basis for it.

 

In fact, mammals have a maximum rate of sustained

reproductive capacity of about 33% population growth per year, IF

the habitat supports the increase -- whether it is a wild habitat, a

puppy mill, or any other type of environment.

 

Thus one female cat & her offspring, with normal mortality

for outdoor cats, might produce a surviving population of 14 cats

after seven years.

 

14 doesn't sound like much at all, but 33% population growth

per year is a cumulative rate of increase quite sufficient to explain

all of the actualities of dog and cat population over the past 80

years, going back to the first publication of reliable pet-keeping

and shelter flow statistics.

 

Incidentally, there was recently a real-life U.S. case in

which a pair of cats were kept in a house with abundant food, no

predation, and no disease to speak of, and were allowed to breed

unchecked. They produced 180 surviving offspring in 10 years.

 

This was extremely unusual for a hoarding case, in that the

cats in such situations usually are not properly fed and have high

mortality due to disease and neglect.

 

It is of value to note, because it appears to establish the

upper end for real-life feline reproduction.

 

 

 

 

--

Merritt Clifton

Editor, ANIMAL PEOPLE

P.O. Box 960

Clinton, WA 98236

 

Telephone: 360-579-2505

Fax: 360-579-2575

E-mail: anmlpepl

Web: www.animalpeoplenews.org

 

[ANIMAL PEOPLE is the leading independent newspaper providing

original investigative coverage of animal protection worldwide,

founded in 1992. Our readership of 30,000-plus includes the

decision-makers at more than 10,000 animal protection organizations.

We have no alignment or affiliation with any other entity. $24/year;

for free sample, send address.]

[Guest guest]

So just to be clear Merritt, the statement was off by a factor of say 1000?

That's to say that optimistically (or perhaps not so) that a pair of cats

could produce more then 100 kittens within 7 years? Crap at math...

Jigs in Nepal

 

 

 

Merritt Clifton <anmlpepl

Fri, 25 Sep 2009 13:42:52 -0700

<aapn >

Cat reproduction rate

 

 

 

 

 

>A female cat generally breeds three times a year - three or five

>kittens each time - meaning cats can multiply in a geometrical

>manner, Liao said. Unfettered, a pair of cats can produce more than

>100,000 kittens within seven years, according to People's Daily.

 

The above claim, from " Sterilization can solve pet problems:

expert, " by Xie Ying, Global Times, August 26 2009, is utterly

untrue, though often said by people who should know better.

 

Animal advocates need to stop mindlessly repeating it,

because it tends to make people think not that they need to have

their cat sterilized, but rather that they need to declare war on

all cats, lest they take over and destroy civilization.

 

In 2007 I teamed up with Wall Street Journal " Numbers Guy "

columnist Carl Bialik to trace this ancient claim, in all variants,

back to source.

 

Apparently it started with a calculator logarithm of dog

reproduction used by the Animal Protection Institute in a January

1968 press release. It mysteriously picked up a zero by 1973, and

about a decade later picked up another zero when first applied to

cats, but there never at any point was any biological basis for it.

 

In fact, mammals have a maximum rate of sustained

reproductive capacity of about 33% population growth per year, IF

the habitat supports the increase -- whether it is a wild habitat, a

puppy mill, or any other type of environment.

 

Thus one female cat & her offspring, with normal mortality

for outdoor cats, might produce a surviving population of 14 cats

after seven years.

 

14 doesn't sound like much at all, but 33% population growth

per year is a cumulative rate of increase quite sufficient to explain

all of the actualities of dog and cat population over the past 80

years, going back to the first publication of reliable pet-keeping

and shelter flow statistics.

 

Incidentally, there was recently a real-life U.S. case in

which a pair of cats were kept in a house with abundant food, no

predation, and no disease to speak of, and were allowed to breed

unchecked. They produced 180 surviving offspring in 10 years.

 

This was extremely unusual for a hoarding case, in that the

cats in such situations usually are not properly fed and have high

mortality due to disease and neglect.

 

It is of value to note, because it appears to establish the

upper end for real-life feline reproduction.

 

--

Merritt Clifton

Editor, ANIMAL PEOPLE

P.O. Box 960

Clinton, WA 98236

 

Telephone: 360-579-2505

Fax: 360-579-2575

E-mail: anmlpepl <anmlpepl%40whidbey.com>

Web: www.animalpeoplenews.org

 

[ANIMAL PEOPLE is the leading independent newspaper providing

original investigative coverage of animal protection worldwide,

founded in 1992. Our readership of 30,000-plus includes the

decision-makers at more than 10,000 animal protection organizations.

We have no alignment or affiliation with any other entity. $24/year;

for free sample, send address.]

[Guest guest]

>So just to be clear Merritt, the statement was off by a factor of say 1000?

>That's to say that optimistically (or perhaps not so) that a pair of

>cats could produce more then 100 kittens within 7 years? Crap at

>math...

 

 

The entire premise of the statement is off, because life

forms of any size, from blue whales to the swine flu virus, do not

reproduce in a logarithmic manner. Successful reproduction results

from the availability of food and habitat, and is limited by

mortality.

 

In the case of cats, population growth appears to occur in

half-lives: about half of all kittens die before weaning, half of

all weaned cats do not live long enough to reproduce, half of all

who bear litters will never bear another, half of all who bear a

litter in any given year will not survive to breed next year.

 

Therefore, assuming that a habitat is optimum for feral

cats, you might have a population model that looks like this, with

alternate letters being toms.

 

A + B have 2 litters in the first year, producing C & D surviving to maturity.

 

A dies. B & D are both toms. C produces E surviving to maturity.

 

B dies. D & C & E produce F & G surviving to maturity.

 

C dies. D, E, F, & G produce H & I surviving to maturity.

 

D and E die. F, G, H, & I produce J, K, L, and M surviving to

maturity. After five years, you are up to 3ight cats

 

F, G, & H die. I, J, K, L, and M produce N, O, P, and Q

surviving to maturity.

 

I, J, K, and L die. M, N, O, P, and Q produce R, S, T, and

U surviving to maturity. After seven years, you have nine cats.

 

 

Coincidentally, the U.S. pet cat population went from

seventy million to 90 million within about seven years , at the peak

of growth.

 

 

--

Merritt Clifton

Editor, ANIMAL PEOPLE

P.O. Box 960

Clinton, WA 98236

 

Telephone: 360-579-2505

Fax: 360-579-2575

E-mail: anmlpepl

Web: www.animalpeoplenews.org

 

[ANIMAL PEOPLE is the leading independent newspaper providing

original investigative coverage of animal protection worldwide,

founded in 1992. Our readership of 30,000-plus includes the

decision-makers at more than 10,000 animal protection organizations.

We have no alignment or affiliation with any other entity. $24/year;

for free sample, send address.]

[Guest guest]

Thx MC, so that means the original statement was exaggerated by a factor of

10,000. Sounds about right for animal rights activists:)

Jigs

 

 

 

 

Merritt Clifton <anmlpepl

Sat, 26 Sep 2009 00:26:08 -0700

<aapn >

Re: Cat reproduction rate

 

>So just to be clear Merritt, the statement was off by a factor of say 1000?

>That's to say that optimistically (or perhaps not so) that a pair of

>cats could produce more then 100 kittens within 7 years? Crap at

>math...

 

 

The entire premise of the statement is off, because life

forms of any size, from blue whales to the swine flu virus, do not

reproduce in a logarithmic manner. Successful reproduction results

from the availability of food and habitat, and is limited by

mortality.

 

In the case of cats, population growth appears to occur in

half-lives: about half of all kittens die before weaning, half of

all weaned cats do not live long enough to reproduce, half of all

who bear litters will never bear another, half of all who bear a

litter in any given year will not survive to breed next year.

 

Therefore, assuming that a habitat is optimum for feral

cats, you might have a population model that looks like this, with

alternate letters being toms.

 

A + B have 2 litters in the first year, producing C & D surviving to

maturity.

 

A dies. B & D are both toms. C produces E surviving to maturity.

 

B dies. D & C & E produce F & G surviving to maturity.

 

C dies. D, E, F, & G produce H & I surviving to maturity.

 

D and E die. F, G, H, & I produce J, K, L, and M surviving to

maturity. After five years, you are up to 3ight cats

 

F, G, & H die. I, J, K, L, and M produce N, O, P, and Q

surviving to maturity.

 

I, J, K, and L die. M, N, O, P, and Q produce R, S, T, and

U surviving to maturity. After seven years, you have nine cats.

 

 

Coincidentally, the U.S. pet cat population went from

seventy million to 90 million within about seven years , at the peak

of growth.

 

 

--

Merritt Clifton

Editor, ANIMAL PEOPLE

P.O. Box 960

Clinton, WA 98236

 

Telephone: 360-579-2505

Fax: 360-579-2575

E-mail: anmlpepl

Web: www.animalpeoplenews.org

 

[ANIMAL PEOPLE is the leading independent newspaper providing

original investigative coverage of animal protection worldwide,

founded in 1992. Our readership of 30,000-plus includes the

decision-makers at more than 10,000 animal protection organizations.

We have no alignment or affiliation with any other entity. $24/year;

for free sample, send address.]

 

 

 

 

[Guest guest]

Merritt Clifton wrote:

 

> In the case of cats, population growth appears to occur in

> half-lives: about half of all kittens die before weaning, half of

> all weaned cats do not live long enough to reproduce, half of all

> who bear litters will never bear another, half of all who bear a

> litter in any given year will not survive to breed next year.

 

Most interesting. While I was aware of the final results (more or less),

this is the first time I am hearing of the " half-lives " - explains a lot.

 

S. Chinny Krishna

[Guest Guest]

Just saw a show on wild cats in one city (Los Angeles) wherein an organization claimed to be effective against cat overpopulation because they were neutering 80-100 cats a day out of an estimated 1 million wild cats in the city and stated that they would eventually reach all wild cats.... By anybody's numbers, its impossible... Trying to use conservative numbers, I figured a population of 1 million cats would increase by 2700 cats a day, so the population explosion there would continue, with them hardly making a dent... Obviously, this is an attempt by animal activists to say that there is no need to euthanize, which seems ludicrous to me.