ULRICH TIGGES:

The Phenology of the Common Swift Apus apus in Eurasia and the Problem of Defining the Duration of their Stay

This paper is dedicated to the first phenologist, the author of the Book Jeremiah (Jeremiah 8.7).

(Printed 2007 in Podoces. Republished with permission.)

ISSN 1438-2261

More arrival data: http://www.commonswift.org/arrival.html

Original paper: http://www.wesca.net/Podoces/Podoces2.2/Podoces 2_2_ Phenology of Common Swift.pdf