We have recently had a “Hate pigeon week”.   

Some weeks ago, pigeons were cruelly massacred with air rifles at the instigation of the Balzan Local Council. Balzan mayor Ian Spiteri is reported to have stated that pigeon population control is necessary because “the birds are pests which carry disease and are a risk to people’s health”. By way of justification he cited an anecdote, a close relative’s ‘severe respiratory problem’ caused by canaries – not pigeons.  The mayor was also  quoted  as  mentioning    residents who complained that they were suffering from respiratory problems “proven” to be caused  by pigeon, these included ‘parasite bites’. 

The facts are these: Feral urban pigeons do not pose a risk to people’s health. The likelihood of ill-health from urban feral pigeons is so low as to be virtually non-existent. In order to justify the shooting of pigeons, Mayor Spiteri trawled the internet and drew up a bogus list of awesome diseases which, he claimed, are transmitted by pigeons (“Health is a priority – Mayor”. 15 July). In so doing the mayor went wildly beyond exaggeration and the information he passed on to this newspaper was both misleading and invalid – as such it was pure scaremongering. More obfuscation was shed on the issue by Dr Mario Spiteri (23 July) who spoke vaguely  about an  illness which cows get from pigeons (which does not seem to be the case) and of cases where people were ‘directly infected by pigeons’ … without specifying.

As Natalino Fenech aptly pointed out (“Pigeon culling is just a show put on by local councils” – Ornithologist Natalino Fenech, 14 July): “If one wants to scare people by posting stuff from the internet about which diseases can be contracted from pigeons, anyone can play that game.” 

Here is the truth about Mayor Spiteri’s list of diseases:  

Histoplasmosis (caver's disease, Ohio valley disease, reticuloendotheliosis) is not spread by pigeons. The causative agent (Histoplasma capsuatum) occurs widely, mostly in soil, regardless of the presence of pigeons. It is often found in bird and bat droppings and may only present a hazard during major clearing operations. Normal activity such as street sweeping does not result in sufficient exposure.

Candida yeasts are found everywhere. Candidiasis is commonly present in the intestinal tracts of healthy humans as well as all domestic animals. Candida infections occur typically as thrush in sick babies. Pigeons are not involved in its transmission. 

Cryptococcosis is a rare disease. Spores of cryptococcosis (C neoformans) occur in soil and decaying vegetation throughout the world. Dust that contains bird droppings are sources of C. neoformans and pigeon coops can contain cryptococcus. Healthy people do not become infected even at high levels of exposure – it is a risk factor only in people with a compromised immune system. Eighty-five per cent of cases of cryptococcosis worldwide occur in people who  suffer from AIDS and they do not catch it from street pigeons. 

Salmonella infection is a very common cause of food poisoning and a disease of concern in every country. It is not caused by pigeons, but by eating infected foodstuffs. Much the same applies to E. coli which the mayor included in his list.

Saint Louis encephalitis is mostly of concern in the USA, where only few cases (generally under 10) are seen every year. Eradication of pigeons is not considered to be of any use in its prevention because other bird species, not pigeons, are carriers of the virus, especially house finches and sparrows. Much the same applies to West Nile Virus infection – pigeons are remarkably poor transmitters of the virus (if at all).

There are three diseases which are specifically associated with birds. The first is psittacosis (ornithosis, parrot fever) which mainly affects parrots and parrot-like birds (cockatoos, parakeets etc) but may also affect other birds, such as pigeons. It is an exceedingly rare disease with less than one human case identified each year in the USA. The second is ‘bird fancier’s lung’ (allergic pulmonary alveolitis, hypersensitivity pneumonitis). It is of an allergic nature and caused by persistent long-term exposure to bird feather dust or ‘bloom’ in enclosed spaces. Those at risk from these two diseases include bird owners, pet shop employees and veterinarians – neither of these diseases are likely to be caused by urban pigeons. The third is avian influenza (bird flu, H5N1, H7N2, H7, H5N2 etc., flu). This illness is transmitted primarily from domestic ducks and geese and migratory birds. So far there is no evidence that pigeons can get infected with avian influenza and spread it. The likelihood of humans contracting bird flu from  feral pigeon is virtually nil.

Diseases possibly transmitted by exposure to birds may occur after heavy exposure as, for instance when a bird loft is cleaned. Street cleaning activities do not result in high exposures. Diseases caused by birds, when they occur, are mostly occupational diseases due to repeated close contact as might occur in bird breeders or pet shop owners.

There is no dispute that pigeon droppings are unsightly in urban pockets where the pigeon population is dense and this is reason enough for pigeon population reduction by humane means. On the other hand, it is wrong and abusive to justify cruel methods of culling by issuing exaggerated and technically incorrect statements on non-existent health hazards from feral pigeons. This is bare-faced scaremongering.

Indiscriminate killing of pigeons does not work and shooting them is both cruel and futile as it can also create a health hazard; a decomposing dead bird is a greater health hazard than a live one. In any case, shooting pigeons without local food reduction makes little difference. The shot birds are quickly replaced by breeding of the survivors or by pigeons that migrate from neighbouring areas.

There are kinder and more effective ways to control pigeon populations such as provision of pigeon dovecotes where pigeons are encouraged to roost and have their eggs removed and replaced with dummy eggs. Anti-roosting systems such as anti-roosting spikes have also proved effective. Some people, especially the old, derive satisfaction form feeding friendly pigeons; providing (extra-urban) designated feeding areas away from affected areas has also reduced the problem.

Since deliberate and persistent feeding of pigeons is the root cause of the problem, the simplest solution is public education that aims to reduce available food.

 

George Debono

Sliema