Colony Kronberg / Ts. (Germany)

2004 was a remarkable year for Common Swifts in Central Europe. Although Common Swifts normally raise only one brood each year, in this colony eleven pairs re-started egg laying after July 15th, having raised their first broods successfully. On August 10th there were second brood chicks in five nests. The other parent birds had already left their nests to migrate to Africa.

Two chicks in nest 12 on August 9th, 2004. One later died. Photo: Erich Kaiser
 

On September 8th there were fledglings in four nests: two in nest 20 weighing 26 grams and 31 grams, one in nest 19 who weighted 38 grams, and one in nest 3 weighing 37 grams, where the second chick was found lying dead beside the nest. Two more fledglings in nest 25 were in good shape. By this time the parent birds were as far as was ascertainable, no longer present, so as a precaution the chicks from nests 2, 19 and 20 were removed for hand rearing.

On September 10th the young bird from nest 19 was released after it demonstrated vigorously it wanted to fly. Likewise, the two young in nest 25 fledged, evidence showing just one out of eleven second broods succeeding without any help from man. But the single young bird from nest 19 probably could have survived and flown off by itself, without the additional food or assistance it received from human beings.

The young from nest 19 before fledging: The feathers of the wings are 17 cm long. A perfectly grown young second-brood Swift!  Photo: Erich Kaiser
 

There were also reports from other colonies in 2004 of second broods, for example from Holger Rappenecker, in whose colony four out of ten pairs started a second brood (from Tim Mattern in „birdnet.de“).

Bringing nest material. Photo: Erich Kaiser
 

Feeding. Photo: Erich Kaiser
 

Feeding. Photo: Erich Kaiser
 

Photographs like these can only be taken when the breeding birds feel completely secure in their nest.

Reports

Papers written about this colony:

Kaiser, Erich (1984): Neue Erkenntnisse über das Ausfliegen junger Mauersegler (Apus apus). Die Vogelwelt 105:146-152, APUSlist No. 0064

Kaiser, Erich (1992): Populationsdynamik einer Mauersegler- (Apus apus) Kolonie unter besonderer Berücksichtigung der Nichtbrüter. Die Vogelwelt 113:71-81, APUSlist No. 0064   

Kaiser, Erich (1993): Schutzmöglichkleiten für Mauersegler. Vogel und Umwelt 07:307-312, APUSlist No. 0070

Kaiser, Erich (1997): Sexual recognition of Common Swifts. British Birds 090:167-174, APUSlist No. 0200

Kaiser, Erich (2004): Gehäuftes Auftreten von Zweitbruten beim Mauersegler Apus apus. Die Vogelwelt (in print)

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