|
October 2002. Palau asked about the invasiveness of pigeons and their impact on health in the Pacific and elsewhere. Are pigeons pests?
In the Regional Strategy for Invasive Species in the Pacific coordinated by SPREP, there is no reference to Pigeons as “significant invasive species”.
Dick Watling’s 2001 edition of A guide to the Birds of Fiji and Western Polynesia has the following to say about Pigeons:
Feral Pigeon: Distribution “[Pigeons are] now well established in many of the larger towns of the region, it rarely moves into agricultural areas and has not reverted to the truly wild state by colonising island or sea cliffs. Occasionally taken to smaller islands where it may become temporarily established. In American Samoa, apparently not permanently established.”
Under Remarks and Similar Species it is stated: “A relatively recent addition in the ornithological literature from the region but not a recent introduction for it was certainly present in Fiji soon after the turn of the 20th century. There is evidence that it may have first arrived with missionaries as early as the 1840’s. Although well established, it is doubtful if most of the populations are truly feral, they being free-flying pets in most cases.”
Spotted Dove: Under Remarks and Similar Species it is stated: An introduced bird, the spotted Dove was first recorded as being established in 1923. It is now a very common species in all man-modified habitats. In his opening remarks regarding introduced predators or competitors Dick Watlings states: It has become commonplace to blame the mynahs, bulbuls and other introduced birds for ‘driving the native birds into the bush’. For the most part this is wrong – yes, the range of the mynahs and bulbuls is increasing but they will never live in undisturbed forest. As we cut down the forest so they move into the resultant farmland and open habitats, while the endemic birds retreat with the forest.
It was pointed out that the IUCN Guidelines for the Prevention of Biodiversity Loss caused by Alien Invasive Species, as approved by the 51st Meeting of the IUCN Council, Gland, Switzerland, Feb. 2000 (SCC Invasive Species Specialist Group – Species Survival Commission), defines ALIEN INVASIVE SPECIES as:
An alien species which becomes established in natural or semi-natural ecosystems or habitat, is an agent of change, and threatens native biological diversity.
As to the second part of the question: are pigeons pests?, Palau had this to say in answer:
Based on experience living in Honolulu for 5 years, pigeons are pests. A quick look at the Internet and some other references supports this:
- they can carry and spread avian and human diseases
- they are also nuisances and pests in their own right: they are messy and dirty, reproduce in large numbers, and become established as self-sustaining populations in urban/populated areas – “rats with feathers”.
In the IUCN publication on 100 worst alien invasive species a reference to avian malaria, which has contributed to the extinction of at least 10 native bird species in Hawai’i and threatens many more. Pigeons are susceptible to avian malaria, which the IUCN publication reports was introduced to Hawai’i in exotic birds. On this basis, it would seem that pigeons are a risky proposition. Palau was advised “to go back to basics”. The Glossary of Phytosanitary Terms, ISPM No 5, which gives the definition of ‘pest’ as Any species, strain or biotype of plant, animal or pathogenic agent injurious to plants or plant products. Pigeons are very good at eating seeds that have just been sown, damage seedlings after emergence as well as many other activities that make them a pest when they get into stored food (plant products).
Later, it was reported that 30 pigeons had been destroyed, and the owners (not the pigeons, presumably) had been very cooperative. It would seem that attempts to eradicate pigeons from Palau will be successful.
|
