viernes, 7 de abril de 2017

Pallid Swifts - at last?

 Pallid Swift (Apus pallidus)

The widespread resident swift on most of the Canary Islands is the Plain Swift (Apus unicolor), although it is suspected that part of the population departs for Africa in winter. The islands of Tenerife, Gran Canaria, Lanzarote, Fuerteventura and El Hierro additionally have breeding populations of Pallid Swift (Apus pallidus), which seem to be restricted to certain parts of those islands.

In the case of La Palma, any swift species seen on the island, other than the Plain Swift (A. unicolor), can be assumed to be a migrant, until further information is available.

 Pallid Swift (Apus pallidus)

Followers of this blog might recall my previous sightings of Alpine Swift (Tachymarptis melba) on the island...no identification problems with that bird!

However, I find many other swifts difficult. There are records of Common Swifts (Apus apus) for all the Canary Islands, including La Palma, but in most cases these passage migrants probably go unnoticed. To be honest, I have made little effort to find them.

Pallid Swift (Apus pallidus)

The Pallid Swift (Apus pallidus) is a different story, and I have been on the lookout for this bird on La Palma in recent years: it is classed as a summer visitor to all the Canaries, and even breeds on some of the islands, as mentioned above. So why no evidence on La Palma?

Despite being a little early in the year for a "summer visitor", I am pretty convinced that the three images in this post show Pallid Swifts, or at least the discernible fieldmarks seem to point in that direction: white throat patch, contrast in colour between the outer primaries and the rest of the wing, larger size compared to Plain Swift and less fluttering flight-action, pale, scaly appearance of plumage, bulky body, etc.

Could this be the Pallid Swift - at last?

Second opinions would be most welcome.

1. Second opinions from two knowledgable Canary Island observers, who are both familiar with the breeding colony of Pallid Swifts on Tenerife, have informed me that, in their opinion, the above images do not show Pallid Swifts (A. pallidus), but possibly Common Swifts (A. apus). 

So, I will accept their verdict and keep searching!

2. I have even received a second opinion from a Swedish bird illustrator, who is considered an authority on swifts in Northern Europe. He also says my birds are not Pallid Swifts (A. pallidus), and actually thinks they could be Plain Swifts (A. unicolor).

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