Pest Birds & Associated Hygiene Problems

Bird watching is a sport and recreational activity involving more than 10 million people and as such, it is hardly surprising that birds are the subject of a number of Federal and State laws, and generate such wide public opinion and support.

The most commonly encountered pest birds are swallows, gulls, pigeons, starlings and sparrows. Swallows and gulls are the only two of these pest birds protected by Federal and State laws, and technicians trying to control pigeons, starlings and sparrows may come up against strict state and/or local regulations.

Public opinion is usually strongly against any control measures involving killing when toxins are used, since there exists the possibility of affecting nontarget birds and animals with the poison. Also, any control or repelling measures which conjure images of injury or inhumane treatment may also be expected to evoke such a negative public reaction.

HEALTH HAZARDS AND DISEASES OF BIRDS. There are more than 40 known viruses and 60 transmittable diseases directly attributed to birds and their droppings. Let's review some of these in more detail and look at the examples of diseases known to have been contracted by humans from birds.

Histoplasmosis. Pigeon droppings carry spores of the systemic fungal disease called histoplasmosis, which can be contracted by breathing dusty pigeon droppings or soil contaminated by pigeon and/or starling droppings. Pigeons are known to transmit pigeon ornithosis, encephalitis, Newcastle disease, cryptococcosis, salmonella food poisoning, and other diseases.

Pest management professionals who are performing site cleanup to remove bird droppings and nesting material are particularly vulnerable to these diseases and should take great care to wear adequate protective clothing. Chemical pretreatments of sites should also be conducted to kill bacteria and viruses. The spores of histoplasmosis are inhaled typically when dried or when old roosts have been disturbed, as occurs during cleanings carried out prior to bird control applications.

Cryptococcosis. Another fungal disease found primarily in pigeon droppings is cryptococcosis. More than 80% of established pigeon roosts have been found to contain this organism. When the dried droppings are inhaled, a respiratory disease usually occurs commencing with a lung infection which then spreads to the rest of the body, especially the nervous system.

Psittacosis. On December 16, 1987, a local California newspaper reported that a window cleaner with 30 years' experience had 40% of his lung tissue destroyed after inhaling the bacteria psittacosis. The victim in this case was a fit, 55-year-old man who awoke one morning unable to breathe.

The bacteria that causes psittacosis is found in the droppings of pigeons, parrots and other birds and can be inhaled by breathing the air introduced by air conditioning systems which carry the organism from a bird roost. Pigeons most frequently roost on and around air conditioning systems on roofs of city buildings, domestic houses and other structures, which leads to the transmittal of this bacteria.

PERSONAL PROTECTION IS ESSENTIAL. The most susceptible to these diseases are people who breathe the air in buildings which have old and established bird roosts. While on-site, technicians are continuously exposed to the air containing these microorganisms which have a proven likelihood of infection.

Apart from wearing appropriate protective clothing, chemicals are now available to combat the disease and odor problems associated with bird infestations, and these should be an essential prerequisite to any bird or bat exclusion project.

The problem of accumulated or residual bird droppings located in voids which cannot be reached with extraction equipment can, in fact, be solved simply by "digesting" the droppings with enzymes.

Digest-It, a new chemical introduced in late 1996 by Hot Foot America, contains a mixture of three enzymes which are activated by the addition of water. The chemical is sprayed onto bird or bat droppings and is designed to digest the feces while also neutralizing odors. This may also be a solution to the problem of drains and downspouts blocked by an accumulation of bird droppings. The product also digests other solids such as grease and can be applied using the spray equipment typically carried by pest control technicians on their routes. To protect PCOs against bacteria and viruses, a sterilizing solution with odor neutralizer should be sprayed onto the droppings to the point of saturation.