Saturday, 26 April 2014

Quest for the wild canary 10: Other non-passerines

Laurel Pigeon
Of the remaining non-passerines to be covered, the most important are the pigeons. Six species breed on the islands, of which two are endemic. We managed to see the two endemic pigeons, Laurel Pigeon Columba junoniae and Bolle’s Pigeon C.bolii, on La Gomera, after some searching in the laurasilva forest.
Eurasian Collared Dove is a recent colonist of the islands (along with much of the rest of the world including North America), but we missed out on an even more recent colonist on Fuerteventura, the African Laughing Dove Streptopelia senegalensis. Laughing Doves have bred for some years, but the population is still very small and appears to be fading away instead of becoming established. The other two breeding pigeons are the feral pigeon C.livia, and the European Turtle Dove S.turtur.

Bolle's Pigeon
The two endemic pigeons both seem to derive from separate colonisations of the islands by the very widespread European Wood Pigeon C.palumbus. They both feed on fruits of various laurasilva trees such as Azores Laurel Laurus azoricus and Small-Leaved Holly Ilex canariensis. In addition leaves and seeds of other plants make up the diet, which may also include terrestrial crops on occasion.
Small-Leaved Holly
The main ecological separation between Bolle’s and Laurel pigeons is in their nesting behaviour – Laurel Pigeons nest on the ground on rocky areas while Bolle’s Pigeons are tree nesters. Ground nesting is unusual in pigeons and probably reflects that the Laurel pigeons’ ancestors colonised the islands much earlier, before the arrival of any terrestrial (and especially mammalian) predators.  They also nest at different times of the year – the breeding season for both is extended but the Laurel Pigeon nests mainly April – July whereas Bolles Pigeon nests earlier in the year. Populations of both are actually increasing following heavy losses but are still very small – Laurel Pigeon has been assessed at around 5,000 adults on the various islands and is Near Threatened, whereas Bolle’s Pigeon is commoner at possibly up to 20,000 individuals and is classed as Least Concern. Main ongoing threats are habitat destruction and alteration, some illegal shooting, and nest losses from predators, especially Black Rat.  
Habitat of Laurel and Bolle's Pigeons
They are actually very hard to see, especially in fog-shrouded forest – they tend to sit quietly in trees and then shoot quickly across to the other side of a valley where they disappear into the trees. The best way to see them is to wait at a good point overlooking suitable habitat and wait for them to fly across the valley. This time we got good views of both species in flight and even a perched Laurel Pigeon, although it was too far away to photograph.

Very similar in flight to pigeons are the sandgrouse. We had views on two days of Black-bellied Sandgrouse Pterocles orientalis in flight. On the ground they are practically invisible unless you see them land, but in flight they are very fast and direct flyers.

Pallid Swift
Also seen, in flight naturally, were two species of swift. Pallid Swift Apus pallidus is fairly widespread on the mainland, but Plain Swift A.unicolor is a near-endemic to Macaronesia (a few were recently discovered breeding in Morocco). Given the name, and the fact that both Pallid Swift and Common Swift Apus apus also breed on the islands, identification is quite a problem, but we were too early in the year for Common Swift and Pallid Swifts have a distinctive white throat. Plain Swifts are partial residents – the numbers decrease over winter and presumably winter somewhere in Africa, but some remain year round. The others are summer migrants. Plain Swifts are classed as Least Concern by the IUCN. They breed at higher elevations than the other species and nest on the walls of ravines, sometimes in loose colonies.

Great Spotted Woodpecker (UK)
We got good views at a picnic site on Tenerife of the local race of Great Spotted Woodpecker, Dendrocopus major canariensis. These are very similar to the nominate race which occurs in the UK, and are probably one of the most significant native nest predators of the smaller woodland birds.

Monk Parakeet at nest
Not native to the islands, but looking to become part of the native fauna, are two parrot species. The Rose-Ringed Parakeet Psittacula krameri and the Monk Parakeet Myiopsitta monachus both breed around a now-defunct zoo on Fuerteventura and we saw both species easily. The Monk Parakeets were sharing their nest site in the top of a palm tree with a pair of Sacred Ibis (also a feral breeding species). Monk Parakeets are unusual for parrots in that they construct elaborate nests instead of simply using holes in trees.

Finally, one of the most vivid birds to be seen in Europe was seen several times by the path behind our hotel on Fuerteventura. The Hoopoe Upupa epops is a bird that often feeds on the ground around olive groves and orchards, and has figured in European and Middle Eastern folklore from earliest times.

(hoopoe image is mine, rest from Wikipedia)

No comments:

Post a Comment