The Science of Trap-Neuter-Release by Merritt Clifton

[Guest guest]

The Science of Trap-Neuter-Release by Merritt Clifton

Presented to the Asia for Animals Conference, Hong Kong, September 3, 2003

 

 

On August 1, the city governor of Bangkok, Thailand,

ordered the eviction of street dogs from the central historical

district.

 

" Our city is not Calcutta, " the governor said.

 

The governor almost certainly did not understand that his

order, if enforced, would make Bangkok more like Calcutta.

 

What the governor said, yet did not know he said, was that

instead of street dogs he wanted Bangkok to have more rats, crows,

gulls, pigeons, feral cats, feral pigs, and monkeys running

amok--as occurs in Calcutta, where more than a century of poisoning

and electrocuting street dogs opened urban habitat up to them.

 

Compassionate Crusaders Trust founder Debasis Chakrabarti,

here in the audience, ended those abuses in Calcutta. The People

for Animals ABC street dog sterilization program that Debasis founded

in Calcutta has now made a good start toward controlling the problems

associated with street dogs by vaccinating and sterilizing them, and

treating them for mange.

 

Meanwhile, Calcutta and every other city that ever tried to

kill street dogs, including in the U.S., now has to deal with rats,

crows, gulls, pigeons, feral cats, and sometimes feral pigs and

monkeys, or raccoons, who occupy the same ecological niche as

monkeys in North America.

 

Each of these species is much harder to control.

 

All of these species are present in urban habitat anyway,

but in relatively low numbers. Their populations explode only when

dogs are not present to control them, partly by predation and

harassment, but mostly by consuming much of the available food.

 

So long as edible refuse remains abundant, the absence of

dogs will allow other urban wildlife to breed up to the carrying

capacity of the habitat, at equivalent biomass. That means ratios

of approximately one monkey or raccoon for each dog who has been

removed, or three cats, or anywhere from several dozen to several

hundred rats, gulls, crows, or pigeons.

 

So long as the habitat provides adequate food and cover for

animals, we will have whatever animals have evolved to survive in

the available niches--and I must mention that no one, not even the

Pied Piper, has yet found a way to rat-proof a city.

 

We cannot choose to not have animals as our neighbors,

because without them there would be habitat voids, and nature abhors

a void.

 

What we can choose is what kind of animals will become our

most visible neighbors.

 

Instead of learning to live with one easily tamed and

befriended species whose habits are well understood and whose

diseases are readily controlled and cured, the governor of Bangkok

said he wanted his city to be at much greater risk from leptospirosis

and bubonic plague, which are transmitted mainly by rat parasites.

 

He said he wanted Bangkok to be at much greater risk from

influenza and other corona viruses, transmitted mainly by birds,

with pigs as an intermediary for spreading mutated forms to humans.

 

He said wanted Bangkok to be at greater risk from the 90 or

more viruses, endemic among monkeys, which can severely infect

humans from a bite.

 

He also said he wanted Bangkok to have more poisonous snakes,

who in the absence of street dogs would do much more rat-catching.

 

That's what the governor of Bangkok said, between the

lines--but I don't think he meant it.

 

What he meant was that he wants a clean and healthy city.

What he did not understand is how to get there.

 

One option is to develop municipal sanitation so effective

that there is no longer any food for urban wildlife. That has worked

up to a point in much of the U.S., Europe, Singapore, Japan, and

here in Hong Kong--but only up to a point.

 

Even though the food waste remaining accessible to animals in

all of these places is insufficient to support many street dogs and

pigs, all of these places still have abundant feral cats, rats,

crows, and gulls. Hong Kong and parts of Japan also have nuisance

monkeys.

 

At best, the urban wildlife population can be reduced by

limiting the food supply. Realistically, it cannot be eliminated.

 

Another option is to try to kill all of the species that

become problematic. This simply does not work, because killing each

animal opens habitat to others, and even if you could kill all of

the birds and mammals, you would only leave more food available to

insects.

 

Cockroaches have already survived the Devonian extinction,

the Permian extinction and the extinction of the dinosaurs, as well

as the H-bomb testing at Bikini Atoll, so if you want to see the

real-life evolution of " The Cockroach That Ate Cincinnati, " just try

total extermination of all animal life.

 

The third option is learning to live with urban wildlife, by

replacing alienated, fearful, and dangerous animals with animals we

understand, who understand us.

 

This is what ABC is all about, as it is called in India, or

TNR, as it is called in the U.S. and Europe.

 

The idea of either ABC or TNR is to vaccinate and sterilize

at least 70% of the population of street dogs and feral cats, who

are the urban wildlife whose habits are most compatible with those of

humans, so as to maintain disease-free, stable or gradually

diminishing numbers of these animals in the available habitat niches.

 

In some places, as in much of the U.S., the object is to

allow native species who reproduce much more slowly, and are also

relatively non-problematic, to gradually reclaim habitat from which

they were extirpated decades ago by human development.

 

In most of Asia, however, the goal is to keep some highly

problematic and dangerous native species from occupying cities in

greater abundance, while minimizing the problems associated with

street dogs and feral cats.

 

The easiest way to reduce dog and cat problems is to replace

a short-lived and ever-reproducing population with a much more stable

population of animals who are living beyond their difficult

" teenaged " years and becoming assimilated into households as domestic

pets, while continuing to occupy their ecological niche.

 

Fortuitously, 70% is the effective threshold percentage of

animals of any species who must be vaccinated to prevent the spread

of most contagious diseases, including rabies, and also the

threshold percentage of dogs and cats who must be sterilized to

achieve population stability, with incremental population reduction

occurring as the percentage of sterilized animals increases.

 

70% is not the target for both vaccination and sterilization

by happy accident.

 

Sterilization is in effect surgically " vaccinating " animals

against reproduction. The goal is to reduce the vulnerability of the

potential host population to the condition, by reducing the

possibility of transmission to odds so slim that the condition cannot

replicate itself more rapidly than it dies out.

 

Many of the delegates to this conference have verified

through their own experience that 70% or somewhere close to it is the

magic number, among them Christine and Jeremy Townend of Help In

Suffering in Jaipur, India; Chinny Krishna of the Blue Cross of

India; and Pradeep Kumar Nath of the Visakha SPCA in

Visakhapatnam, India.

 

In the U.S., the numbers of dogs killed by animal shelters

began falling fast after the percentage of owned pet dogs who were

sterilized reached 67%, in the late 1980s.

 

The numbers of cats killed by U.S. animal control agencies

began a rapid drop after 1991, when the percentage of pet cats who

were sterilized reached about 85%, which equaled about 60% of the

estimated total U.S. cat population, including ferals.

 

Since then, the advent of neuter/return to control feral cat

numbers and increasing human acceptance of responsibility for outdoor

cats has blurred the distinction between pets and ferals. Of the

estimated 73 million " pet " cats in the U.S. now, 10 to 15 million

may in truth be fed ferals, who a decade ago would not have been

called " pets. "

 

During the past 10 years the number of cats who have been

sterilized by U.S. veterinarians each year has been approximately

double the number of pet cats assimilated into households, which

indicates that the U.S. feral cat population today is probably no

more than half what it was in 1991.

 

This is the same kind of transition that ABC or TNR programs

are already demonstrably accomplishing in Asia.

 

One strong indication of success, although often read

completely upside down and backward, is that the incidence of

dog-bite is remaining high in India and rapidly rising in China,

even though the incidence of rabies has been very sharply reduced in

both nations.

 

Free-roaming street dogs relatively seldom bite people,

unless they are rabid, because they are used to the constant

presence of strangers, and soon learn that any threatening behavior

toward humans can be fatal. Instead, they tend to run from any

menacing human approach.

 

Pet dogs, on the other hand, become highly protective of

the humans they regard as fellow pack members, and also protect the

humans' property. Instead of running from a perceived threat, they

bite. Thus as more Indian dogs are treated as pets, they respond as

pets--and thus in India, where most dogs still run free, and in the

U.S., where most dogs are confined in yards or houses, the ratio of

humans to dog bites each year that require medical treatment is

identical, at 62 to 1.

 

Further, 70% of the bites requiring treatment in India are

verifiably committed by pets, according to one recent study. This

also parallels the U.S. experience.

 

Obviously we need to reduce the incidence of pet dogs biting,

but this is a sociological and behavioral problem, which has

established solutions in the form of appropriate education of both

dogs and humans, and is not to be confused with the issues

pertaining to ABC or TNR.

 

There will always be those who think killing animals is

cheaper than sterilizing animals, and therefore more appropriate for

developing nations, including much of Asia--even though killing

animals is demonstrably ineffective in doing anything other than

providing patronage employment of dogcatchers.

 

Some of the people who continue to advocate killing animals

will point to the huge numbers of animals killed by U.S. animal

control agencies throughout most of the 20th century, increasing

every year from 1895, when records were first kept, until circa

1970, when the U.S. was killing 115 dogs and cats per year per 1,000

human residents.

 

It must be pointed out that the focus of the U.S. animal care

and control strategy on exterminating homeless dogs and cats was an

enormous and very costly failure, costing us close to $2 billion a

year.

 

In truth, the U.S. really began to control our dog and cat

populations effectively only after gradually abandoning almost a

century of concerted effort to kill them, and turning instead to

high-volume dog and cat sterilization.

 

Since 1970 the U.S. has reduced population control killing of

dogs and cats by 87%, with a 75% drop since 1985.

 

What developing nations cannot afford is to spend as long as

we did making the same mistakes we did, before doing what has

finally begun to bring success.

 

Thank you.

 

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 9,500 animal protection organizations.

We have no alignment or affiliation with any other entity.]

--

--

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.]

--

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.]