Sunday, 25 November 2012

Swifts nesting in House Martin nests

Ulrich Tigges sent us an article in French which was particularly relevant for when one gets into discussions about nest-box sizes. We thought it worthy of a wider audience, so Jake has translated it. 

Summarised from a paper by Willy Raitière and Patricia Audureau

On July 05, 2008, while we were surveying the town of Bouin in search of urban breeding birds, as part of the Atlas of Breeding Birds in Brittany, we found two active colonies of House Martins Delichon urbica. One of them had about 10 nests located under the roof of a house in the main street. When counting nests of this colony, we noticed that one of them had very dark primaries visible over the edge of the nest. On closer inspection, we concluded that it was a Common Swift brooding in a House Martin's nest, which was very cramped.

The back of the Swift protrudes from the martin's nest (Boin - Vendee, July 2008). W. Raitière

White faces of 2 chicks are just visible
Aware of the unusual nature of this discovery, Willy decided to go back to the site a week later to verify that it was not just a Swift using the martin's nest for roosting. Upon arrival on the morning of 13 July, he noted that the dark primary feathers were no longer visible; instead, he could make out the head of a young swift, clearly not ready to fledge, as the primaries had still not fully emerged from the sheath. Shortly afterwards, an adult Swift arrived with food, just managing to enter the nest. Thus, a pair of Common Swifts raised a brood of at least two young in a House Martin's nest.

Similar occurrences were recorded at Anton during the nineties (Deliry, pers comm); near Loches in the 1950s, and at and Brétigny-sur-Orge in the early 2000s (Voisin, pers comm); and in the 8th arrondissement of Paris in 2007 (Detalle, pers comm). Beyond our borders, similar cases have also been noted in Moira, County Antrim, Northern Ireland in 2007, Markgröningen, northwest of Stuttgart in Germany in 1987 (Wendt, 1988) and more recently in Mengeringhausen in Hesse in the center of Germany in 2007 and 2008 (Bergmann, 2008). Moreover, in the Handbuch der Vögel Mitteleuropas (1980), the authors note that in river valleys that do not have trees, Swifts have used the nests of both House Martins and, more rarely, Sand Martins Riparia riparia.

References

Glutz von Blotzheim U. N., Bauer K. M., 1980. Handbuch der Vögel Mitteleuropas. Akademische Verlagsgesellschaft, Wiesbaden, vol. IX : 686p.
Wendt E., 1988. Mauersegler (Apus apus) brütet im Mehlschwalbennest. Ornithologische Jahreshefte für Baden- Württemberg, 04 : 72
Bergmann H.-E., 2008. Mauerseglerbrut im Mehlschwalbennest. Der Falke, 11-08
Raitière, W., & Audureau, P. 2010. Un couple de martinets noirs Apus apus nichant dans un nid d'hirondelle de fenêtre Delichon urbica. Ar Vran, 21(2): 19-20

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