Justification of Red List Category
This species is listed as Least Concern on the basis of evidence indicating that the its range and population are increasing and may have been recovering over the last two decades at least. Although it has a very small range and probably a small to moderately small population, it is showing positive trends, it is not restricted to 10 locations or less and its population comprises more than one sub-population, all of which probably exceed 1,000 individuals, and is not severely fragmented, thus it no longer approaches the thresholds for Vulnerable under any of the IUCN criteria.
In 2007, the species was estimated by SEO (Sociedad Española de Ornitología/BirdLife in Spain) to number 5,000-20,000 individuals, roughly equivalent to 3,300-13,000 mature individuals.
The species's population is suspected to have recovered over at least the last 20 years (BirdLife International 2010), with evidence for this coming from increases in population estimates and the extent and quality of suitable habitat.
This species occurs on Tenerife (more than 2,000 individuals (Martín and Lorenzo 2001), particularly at Anaga and Teno), La Palma (more than 3,000 birds (Martín and Lorenzo 2001) in a restricted area of the north-east), La Gomera (over 1,000 in Garajonay National Park with some birds outside the park) and El Hierro (where it occupies the whole of Golfo and Sabinosa) in the Canary Islands, Spain. It may formerly have occurred on Gran Canaria, as bones similar to those of a laurel pigeon have been found and there is a possible sight record from the late 19th century. It was common in the past, but disappeared from many areas owing to clearance of laurel forest in the islands. More recently the rate of laurel forest clearance has been slowed or stopped. Population estimates for the species are 1,160-1,315 birds in 1980, 6,000 individuals in 2001, and 5,000-20,000 most recently. Whether these figures reveal genuine population increases is unclear, but the area of occupied territory appears to be expanding and despite several potential threats the population is at least stable, probably increasing.
It occurs in dense laurel forest in mountainous areas, especially in ravines; also in heath of Myrica faya and Erica arborea, and sometimes in rather open areas, e.g. cultivation. It spends the hottest part of the day in deep shade. It feeds mainly on fruit but also takes grain and occasionally buds, leaves and shoots. It will gather in large concentrations on fruiting trees, plucking berries from the tree but also feeding on the ground. Breeding occurs in January-September. It makes some altitudinal movements to take advantage of ripe cereals and fruit at lower elevations in late summer.
Historical declines resulted from intensive exploitation of laurel forests. The extent of forest loss has slowed, although fragmentation has continued in some areas as forests are exploited for poles and tool handles. A small amount of illegal hunting occurs at drinking sites. As it is a tree-nesting species, predation by introduced mammals including rats is of less significance than for C. junoniae but it remains a potential threat, the impact of which has not been fully assessed (Hernández et al. 1999). Grazing pressure from sheep is leading to habitat degradation on La Gomera and at El Hierro. Forest fires also pose a moderate threat to its habitat (BirdLife International 2010). Recreational activities cause some disturbance in the breeding season. The species is potentially threatened by outbreaks of Newcastle Disease and Tuberculosis (BirdLife International 2010).
Conservation Actions Underway
A European action plan was published in 1996. The majority of areas inhabited by this species are now protected under regional or national law (BirdLife International 2010). Hunting has only been a residual threat since hunting-free zones (coinciding with reserves) were implemented. The restoration of pine forest and thermophile forest is still pending full implementation. As part of a LIFE project (2005-2008), work has been carried out to eradicate exotic plant species, plant native species, raise public awareness and increase knowledge of the survival of different native species present in thermophilous forests. Tenerife has undertaken a major effort in eradicating Monterey pine and replanting with native species. Also in Tenerife, Canarian pine tree plantations are partly cleared (thinned) which makes them more suitable for the species. Some islands have rat control plans in place (BirdLife International 2010).
36 cm. Large dark grey pigeon. Mainly dark grey with blacker flight feathers and paler grey tail with dark terminal band, hindneck with green and pink gloss and reddish tinge to breast. Red bill and yellow eye. Similar: Only likely to be confused with White-tailed Laurel Pigeon C. junoniae or dark Feral Pigeon.Voice: Guttural mournful cooing. Hints: Look for birds flying low and fast over laurel forest.
Text account compilers
Bird, J., Capper, D., O'Brien, A., Peet, N. & Taylor, J.
BirdLife International (2020) Species factsheet: Columba bollii. Downloaded from http://www.birdlife.org on 29/01/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 29/01/2020.