The Rock Pigeon (Columba livia) in Ibiza and Formentera

31 July 2024

NOVA FALCONS, AN ENVIRONMENTAL COMPANY SPECIALISING IN BIRD AND PEST CONTROL..

The feral pigeon (Columba livia), also known as the domestic pigeon, is a bird belonging to the Columbidae family that is widely distributed throughout the world. Its presence is often linked to human activity, constituting a public health problem in urban environments if its population is not properly controlled. At least 10 subspecies of rock pigeon have been described. And although the rock pigeon is also called the domestic pigeon, domestic pigeons, which can vary greatly in size and colour, are the direct descendant of the rock pigeon.

Therefore, and to put it more clearly: if we go to a cliff where there are pigeons, we will probably see a ‘pure’ rock pigeon (so to speak); on the other hand, if we go to the square of any town or village where there are pigeons, we will see the straight descendants of the rock pigeon, the domestic pigeon, which, although it differs somewhat in appearance from the rock pigeon, does not differ enough to be separated into a different species.

Broadly speaking, the rock pigeon weighs between 230 and 380 grams, with a wingspan of between 60 and 70 cm. There is a slight sexual dimorphism in the colouring of the neck. In both sexes, the neck is green and purple with a striking metallic lustre; however, in the female this iridescence in neck colours is less, and is rather limited to the sides of the neck. In addition, females have a less voluminous and darker breast.

Pigeons breed all year round, although their breeding peaks in spring and summer. Their clutches usually consist of two white eggs. Incubation of the eggs lasts 18 days and development, once hatched, takes about 30 days. Breeding is carried out by both parents, who are able to produce so-called ‘pigeon milk’, which is a nutritious fluid produced in the crop of both sexes. The life expectancy of a rock pigeon is usually about 5 years.

Accumulation of pigeons in a semi-urban area, coming from an uncontrolled pigeon loft in the vicinity of Jesus, Eivissa.

Naturally, a pigeon feeds on seeds, berries and insects; however, in human environments such as cities, they have learned to feed on food scraps from people, which they forage on the ground, terrace tables, parks, rubbish... or even given to them by some people.

This large amount of available food, together with the lack of predators and their ‘naturalisation’ in the urban environment, has led to this species of bird being considered a pest, due to its adverse effects on public health in the urban centres where it is installed.

Pigeons: a public health problem.

Pigeons in Ibiza and Formentera, as elsewhere, can become a public health problem when their populations are not controlled and they become a pest, due to (among other factors) the large number of parasites and pathogens that they can contain and in turn spread (thus acting as vectors of pathogens and diseases).

Contact with their droppings can lead to histoplasmosis, cryptococcosis and psittacosis. On the other hand, frequent contact with populations not subject to veterinary controls, or an environment where there is often a mixture of pigeon faeces and feathers, can lead to a characteristic pneumonia, commonly called ‘pigeon fancier's lung’.

Pigeons sunning themselves on a building in the port area of Ibiza early in the morning.

They also pose a risk as carriers of diseases and other pathogens that can affect other birds, such as avian influenza, smallpox, Salmonella, coccidia and Trichomonas. Another complication they can generate in people are problems such as allergies, as well as being carriers of ticks, fleas, mites and other ectoparasites.

On the other hand, the damage they cause with their droppings and nest building must also be taken into account. This damage often ends up affecting the historical heritage of the cities in which they are present. This damage to heritage often affects both the aesthetics of monuments, due to the colonisation of pigeons and their droppings, and the dissolution of part of the building materials of this historical heritage. Pigeon droppings have an acid pH, which causes the rocks with which much of our heritage was built (limestone rocks) to gradually dissolve.

Pigeon control

At Nova Falcons, we have all the equipment, experience and resources necessary for pigeon control in Ibiza and Formentera. Pigeon control must be carried out (if it is to be lasting and effective), taking into account the environment, the seriousness of the problem, the objective sought and the objective causes that generate it.

The measures to be implemented to control the pigeon population in an urban environment such as the city of Ibiza, for example, must take into account aspects such as:

Nesting points.
Food sources.
Population censuses in order to know the pest situation and to control its evolution in an objective way.
Interaction of the population with individuals.
Other aspects associated with its proliferation, development and adverse effects on public health.n large part of our heritage (limestone rocks) is gradually dissolving.

One of our technicians from the Environmental Health area (Nova Control), checking a non-invasive trap for pigeons.

With this in mind, measures should be considered that will best help to prevent the pigeon population from increasing further and to reduce the existing pest to the desired levels. Some of the useful measures to control the pigeon population could be:

Cultural measures: public awareness campaigns to prevent citizens from contributing to their proliferation.
Organisational-structural measures: eradication/deprivation of nesting sites.
Corrective measures: passive capture by means of cage traps, intensive capture by means of net cannons or implementation of Biological Control by means of falconry (biological control by means of birds of prey). Although this last measure is not applicable in all environments and will always require a prior study that considers its effectiveness and viability, taking into account the characteristics of the environment and the size of the pest.

One of our falcons with a freshly caught pigeon.