The Cuckoo Cuculus canorus has a foul popularity due to its behavior of laying its eggs on the nests of different birds, who then increase their younger. However in south-west Europe there’s a hen that kicks out the sitting tenants and takes over the nest altogether. The White-rumped Swift Apus caffer, a tropical African breeding species, was solely found breeding in Europe within the Sixties. This was in southern Spain, close to the city of Zahara de los Atunes in Cádiz Province, on the northern shore of the Strait of Gibraltar. On the time the hen was confused with the Little Swift Apus affinis, the same species, additionally with a white rump. The confusion was comprehensible. Little Swifts breed in Tangier, just some kilometres on the opposite facet of the Strait so it will have been logical to count on these to have made the quick sea crossing into Europe.
The White-rumped Swift, alternatively, had a sub-Saharan distribution so no one suspected it to have made the leap throughout the Sahara. If its arrival was shrouded and mysterious, its nesting behaviour is actually a cloak and dagger affair. White-rumped Swifts arrive in April and hunt down Crimson-rumped Swallows Cecropis daurica. They’ve additionally arrived from tropical African wintering grounds and, by that point, are busy repairing previous nests. These are mud constructions, simply identifiable by an extended entrance tunnel, which can be positioned on the roofs of culverts, below bridges and related constructions. The swifts arrive, search the swallows out, discover their nests and evict the tenants! They then settle of their newly acquired residence, lay their eggs and lift their brood. How are you going to inform if a Crimson-rumped Swallow’s nest has been taken over? Simple. The swifts line the doorway with white feathers – it’s the clear signal that that is now property of White-rumped Swifts and it could even be a manner of displaying a possible mate that this little bit of actual property has an proprietor.
The inhabitants of White-rumped Swifts has expanded slowly, in numbers and geography, some now breeding as far north as Extremadura in central Spain, however the stronghold stays the Strait of Gibraltar. Current estimates recommend that the inhabitants could also be of the order of 200 pairs. That’s the whole European inhabitants, tucked away in south-western Iberia.
What triggered this enlargement from Africa? I’ve a hunch that it was the Crimson-rumped Swallows themselves. Howard Irby, writing on the finish of the nineteenth Century mentioned that the Crimson-rumped Swallow had been recorded from Malaga and Valencia. In different phrases, it was a uncommon hen. These days, Crimson-rumped Swallows are ample and widespread breeding birds so there should have been an arrival and enlargement in the course of the twentieth Century. The swifts would have adopted. They had been first detected within the Sixties however who is aware of how lengthy that they had been there earlier than that?
What of the Little Swift? Curiously, in addition they breed in Iberia at present. They had been first detected in Malaga in 1981 and within the Strait of Gibraltar space in 1983 and are slowly spreading northwards. The inhabitants is small, maybe not more than 200 or so pairs, and the primary focus is, once more, in Cadiz Province, SW Spain. They breed in colonies, usually near human habitation.
I’m fortunate to reside shut to those two gems and in part of Europe that boasts no fewer than 5 breeding species of swift!
