SCIBERRAS, J. & SCIBERRAS, A (2012) Wild pigeons and doves of the Maltese Islands. The Malta Independent, June 11th pg 9.

The majority of the locals believe that hardly any birds exist in the Maltese islands; except for sparrows and pigeons. In reality this is not the case, because just over 450 species of birds have been recorded in Malta, 52 of which often nest, while others visit irregularly.
Jeffrey Sciberras and Arnold Sciberras write

The number of wild pigeons and doves species (collectively known as Columbids) found locally is sufficient enough to make someone appreciate the rich biodiversity that our country sustains.

Most people, when thinking of the word ‘pigeon’, envisage city pigeons – unfortunately also sometimes referred to as 'rats of the sky’ or ‘rats with wings’– or think about the domestic pigeon breed known as Homer or homing pigeons. When it comes to the word ‘dove’, people immediately think of the migratory Turtle Dove which is prized game for hunters. This generic thought holds some truth, but certainly does not refer to all the species of doves and pigeons we encounter on the Maltese Islands. In fact, seven species of pigeons and doves occur in the wild on the Maltese Islands. In nomenclature, wild pigeons in Maltese are called ‘Tudun’, while domestic pigeons are called ‘Ħamiem’. The word ‘Tudun’ also specifically refers to the European Wood Pigeon. Three species of migratory and local wild pigeons occur here, including the largest species, which is the European Wood pigeon, Columba polumbus; the Rock Dove, Columba livia from which all the domestic races have derived, such as the Feral Pigeon, Columba livia (domest.) and the Stock Dove, Columba oenas, which is similar in appearance to Feral Pigeons, but has shorter black wing bars and eyes that are completely black, lacking the orange iris . The European Wood pigeon and the Stock dove are two migratory species which are both scarce and rare visitors, which have never been documented to breed on the Maltese Islands. In contrast, the Rock Dove frequently breeds in local cliffs, and unlike the other two species, it is a resident species. Unfortunately, it has become very rare to see pure-breed wild Rock Doves in Malta. This is due to the fact that this species has been domesticated for a long time (more than 5000 years) and many varieties and breeds have artificially evolved from it. Feral Pigeons are likely to be descendants of primitive domestic pigeons which escaped, managed to survive in the wild, and interbred with wild Rock Doves. 

Feral Pigeons are distinguished from domestic breeds simply because, despite the multitude of colours, their morphology (not plumage) is almost identical to wild Rock Doves. Due to an explosive growth from Feral Pigeons, the species has become an exceedingly common bird on a global scale, but the pure wild race, at least in Europe, is quite rare and has a limited distribution along the cliffs of Northern Europe. In 2001, one of the authors (AS) made an attempt to breed the wild Rock Dove. While the breeding inside Għammieri was successful, reintroductions in the wild seemed difficult because Feral Pigeons have to be eliminated first, and Pure Rock Doves often fall target to Hunters.

Doves are morphologically smaller than Pigeons. Four species visit the Maltese Islands. The largest species is the Eurasian Collared Dove, Streptopelia decaocto, which until recently was considered as a rare visitor but is now an established breeding bird. This species has been extending its range all over Europe and hence it started to arrive here in large numbers and eventually started breeding here. It first established itself as a breeding bird at Għajn Żejtuna; but eventually it started spreading in various localities such as Addolorata Cemetery, Buskett, Lija, Attard, Pietá, Fawwara and even in Comino and Gozo. Given chance, this species will spread all over the islands within a few years because in addition to being a prolific species, migratory individuals have tendencies to join resident flocks. The second largest species is the European Turtle Dove, Streptopelia turtur, which migrates in large numbers but is very rarely granted a chance to nest, even though many attempts have been reported over the years. The third largest and rarest species is the Laughing (or Palm) Dove, Streptopelia senegalensis. Another dove found on the Maltese Islands is the Barbary Dove, Streptopelia risoria (domest.). It is debatable whether this species is a domesticated breed descendant from the African Collared Dove Streptopelia risoria roseogrisea, or a totally different species. This species has bred in the wild via escaped individuals and sometimes hybridises with the Eurasian Collared Dove.

Pigeons and doves are generally weary of humans but a few, including those mentioned, have adapted to live near humans and found urban life more suitable. The European Wood Pigeon and the Collared Dove withstand urban life, but the major cities around the world, are dominated by Feral Pigeons. Can anyone imagine cities without this bird? If it weren’t for mankind, this race would not have existed. Humans managed to raise wild Rock Doves in captivity. When the species became tame, by artificial selection, several breeds and plumages emerged, none of which ever existed before. The purposes of domestic breeds are several, namely as sources of food, such as the Broiler, for competition and sport such as the Homer, and for exhibitions such as fantails, Pooters, Dwarfs, and so on. Feral pigeons obtained the various plumages from domestic breeds, but regained the morphological characteristics of the original ancestors from wild Rock Doves. This species was one of several which also assisted the renowned naturalist Charles Darwin to formulate his theory regarding evolution.

Many people assume that feral pigeons bring nothing but diseases, and these are considered to be a treat to architectural features, statues and buildings. It is true that their urban settings mean that they are not tidy and that their acidic faeces dissolves carbonic structures and to many bird breeders, naturalists and so on, the feral race is seen as a common species without any ecological value whatsoever. On the other hand to those interested in the classification of biodiversity, this race is a clear example of evolution. It is true that when a species evolves, it constantly changes to adapt to its environmental surroundings. The feral pigeon is not only a mix of coloured plumages which decipher nothing, but an array of forms, some of which persisted to exist and continued from one generation to another, in order to become distinct. This means that certain plumages have become standardised, and in some cases reached dominancy. From observations made by the authors, seven consistent varieties have been identified. Locally, the consistent varieties evolved in areas where the species is abundant, such as Valletta, Floriana, Ta' Xbiex, Msida, Ħamrun, Comino and Victoria (Gozo).So far no records or documents exist to show that these varieties are taxonomically recognized, except for the fact that feral pigeons can easily interbreed with wild Rock Doves . It is likely that certain varieties within time can become endemic. This has happened in places around the globe where species have become isolated. The varieties are morphologically pure, but not necessarily genetically pure as they can be interbred with other forms. Although it was noted that birds of opposite sexes are mostly attracted to similar plumages.

The so called ‘varieties’ are the following: nomenclature for such varieties is often colloquially used for describing individual birds in domestic breeds:

• The Blue Bar is the closest plumage to the original, which clearly belongs to the Nominate Rock Dove. The colour is bluish-grey, with two black bands on each side of a wing. Generally, the bands of the feral pigeon are thinner and not often as consistent as those of the Rock Dove. The tail is grey and black-tipped. The neck feathers are shiny with purple and green iridescence. The rump is white. Those very similar to the original are rare.
• The Blue Checkered is similar but is uniformly-dotted on black and on the wing. Common.
• The Dark variety is black from head to the wing-edge, but its rump and tail are similar to that of the original. Common.
• The Red Bar is like the Blue Bar, but whitish-grey while the neck and chest are brownish-red, with red bands of similar shape to those of the Blue Bar. Scarce.
• The Red Checkered is similar to the Blue Checkered but instead of having grey and black, they have a brownish-red pattern. Frequent.
• The Brown variety is similar in pattern to the Dark variety, but with shades of reddish- brown. All of the brown colored varieties have brown veins on their feathers.

The rest of the forms that exist are intermediate between the mentioned consistent varieties, without any uniform pattern. Albinistic and melanistic forms occur. Albinistic flocks of pigeons are restricted to public gardens and farms. Melanistic pigeons are rare on the whole. Very rare forms sometimes seen are the Bronze, which is a likely descendant of the brown variety, and the Bluish-Red Bars are likely to be a cross between the Blue Bars and the Red Bars. Certain individuals are similar to any variety, but have odd characteristics such as white primary feathers, or irregularly placed white feathers on any part of their body, and these are referred to as Pied pigeons. With time, feral pigeon varieties outside Malta have become distinct subspecies. One example is Columba livia atlantis, which is found in Northern European countries along the Atlantic. Another example is found in England, at Trafalgar Square, where the entire population of feral pigeons evolved into the Dark Variety.

In recent years, some cities around the world started to implement measures to reduce the feral population of pigeons. This has become a necessity, in order to control the spread of disease, reduce genetic pollution with the original wild stock, and to prevent further damage to historical architecture. But at least it should be done in a humane or natural manner, such as reintroducing birds of prey that feed on feral pigeons. However, to some people the loss of feral pigeons from towns and cities is a big loss since it has become synonymous with urban infrastructures and societies.