The following information comes from Balance©,
a semiannual publication of Crane Pest Control for its commercial
and industrial clients and special regulatory agencies.
A CITY-FULL OF PIGEONS
One of the trickiest and most unpleasant
assignments for the pest control industry involves the feral
(wild) pigeon, Columbia livia. Most of us, from our
childhood years, learn to appreciate birds. But the fact remains
that the feral pigeon, a wild breed of winged vertebrate, is so
prolific within our intimate environment and poses so strong a
potential for disease that it is legally classified as a
"pest animal", much as is the rat or common mouse.
Fortunately there is no other bird species
that approaches the pigeon in terms of public health problems.
Among the diseases it carries or transmits are forms of
ornithoses, encephalitis, Newcastle disease, histoplasmosis,
cryptococcus, toxoplasmosis and salmonella food poisoning. These
birds are a real threat, not only to humans but to other bird
life, frequently causing epidemics that destroy large flocks of
various game and other protected species of birds. The various
arthropods living on the birds, called ectoparasites, include
fleas, ticks and mites. It is not uncommon to find these various
"bugs" infesting buildings after wandering out of
pigeon nests.
These pigeons are a serious urban problem
in the United States for a variety of reasons. They have the
theoretical capability of living up to 30 years. The stress of
"city life"-what with natural predators, disease and an
occasional automobile-reduces their lifespan to about
three-and-one-half years.
Pigeon behavior is fairly predictable and
straightforward. They seek food and shelter, prefer to
"loaf" during the day in a sunny spot and require a
safe nest from both the elements and predators for their young.
Unfortunately our buildings offer an infinite variety of suitable
harborages, and our free handouts of food-either intentionally or
otherwise-support their needs.
In California their control is
realistically a somewhat selfish endeavor, i.e., each property
owner protects his or her own turf with localized methods of
pigeon control. In other states control measures include the
direct destruction of the birds using various avicides. In
California we stress trapping or physically repelling them.
Physical methods of protecting structures
include the use of wires, netting, building-out ledges or placing
porcupine-like prongs along narrow surfaces. Gooey paste applied
along ledges is another form of "physical" deterrent.
An interesting and somewhat controversial repellent is the use of
grain treated with the chemical 4-aminopyridine (brand name
"Avitrol"). The ingestion of this product causes the
pigeons to emit an "alarm" reaction to the flock,
resulting effectively in their vacating the area. Because there
is an approximate 3% mortality rate in this method, several
cities in California have enacted local ordinances to prohibit
its use.
Since this pest bird has been around for so
many years, it has been subject to numerous attempts to dissuade
it. Various forms of statuary such as owls, snakes and other
predators can be seen ornamenting rooftops in a vain attempt to
repel the birds. All sorts of electronic gadgets, flashing lights
and even timed explosions of gunpowder have been brought to bear
with varied but always short-term results.
Ideally, control calls for a
community-wide, cooperative effort including a degree of human
self-discipline. If we had begun with a small representative
population and had prohibited feeding, the normal dynamics of
nature would probably suffice to keep their populations down to
relative acceptable levels. If we treated them with the same
basic respect-and distance-as we do squirrels and raccoons, they
would retain nature's built-in fear that would further discourage
their intimacy within our living space. Barring that kind of
enlightened community interest, the feral pigeon will be sharing
our roofs and window sills for the foreseeable future.
For more information you can contact us at 1(800) 592-7777 or
You may also email us at CraneInfo@CranePestControl.com
The contents of this webpage are proprietary to Crane Pest Control, Copyright 1997. All rights reserved.