EURING Newsletter - Volume 2, December 1998

EURING PROJECTS

THE EURING SWALLOW PROJECT IN FINLAND

By Pertti Saurola

RINGING CENTRE, FINNISH MUSEUM OF NATURAL HISTORY, ZOOLOGICAL MUSEUM, P.O.BOX 17, FIN-00014 HELSINKI, FINLAND (Email: pertti.saurola@helsinki.fi)

Finnish ringers are being very active within the swallow project, and their interest has also been stimulated through two different articles. A first one (Saurola, P. 1997. Haarapääsky, EURINGin projektilaji 1997-2001, Linnut 2: 36-41) has been meant to motivate Finnish ringers to take part in the EURING Swallow Project. The Finnish Swallow population, like some other local populations in Europe, has in fact been declining during the last decades. In total, 64,617 Swallows were ringed in Finland during 1913-1996, mostly in the southern part of the country. Since 1968, the annual total of nestlings and full-grown birds ringed varied from 209 to 955 and from 85 to 3,782, respectively. Of the ringed swallows, 215 have been found dead and 473 retrapped; in addition, 34 swallows ringed abroad have been reported from Finland. These recoveries indicate that the Finnish Swallows follow the eastern flyway trough Europe to their main wintering area in the eastern part of southern Africa. In contrast, very little can be said about survival, breeding, natal dispersal and pre?migratory strategies of the Finnish Swallows. Thus, there are very good national and international reasons to join the EURING Swallow Project.

After the first pilot year of the EURING project, when over 10,000 birds were ringed in Finland, a second paper (Saurola, P. 1998. Pääskyjen perässä kattotuoleilta ruovikkoon. Linnut 2: 18-24) has offered a full report on the activities in 1997, encouraging the ringers to join the project in 1998. In total, 2,921 nestlings, 328 breeding adults and 7,596 full-grown birds roosting in reed-beds were ringed in 1997. All these figures were new annual records, for nestlings three times and for full-grown birds two times higher than the previous ones. The number of ringings was distributed unevenly across the country: 32% of the nestlings and 68% of all full-grown birds were ringed in one 100x100 km square (67:3) of the Finnish National Grid. In 1997, 3 breeding study areas were set up; in total, 374 nest records cards were filled, but very many of them included data from one visit (ringing of nestlings) only; 25 adults ringed in previous years were recaptured at the nest.

Ringing of swallows roosting in reed-beds in July-September was attempted at 9 sites in southern Finland. However, three of them were very good roosting sites in previous years, but in 1997 the numbers were very small. Further, at one site ringing was forbidden by a landowner fed-up with the Natura 2000 - program. In Tuusulanjarvi, 7 hybrids between the Barn Swallow and House Martin, Delichon urbica, were found, i.e. one out of 465 young swallows was a hybrid! In total 28 such hybrids have been reported from Finland, 10 of them in 1997. Altogether 85 Swallows ringed as nestlings in the last summer were retrapped in three reed-beds (Tuusulanjarvi, Pyhajarvi and Lusinselka).

These data give some information (although heavily biased by the clumped distribution of ringings) on the pre-migratory movements of young Swallows. The average increase of the body mass of roosting Swallows was 0.04 g/d in first-year birds and 0,07 g/d in older birds. A preliminary analysis suggested that the variation of the body mass was clearly dependent on the weather (cfr. Ormerod 1989).

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