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Monitoring Finnish Owls 1982-1996: methods and results

Informally Refereed
Download (PDF 226 KB): https://research.fs.usda.gov/download/treesearch/15532.pdf

Abstract

In 1982, the Raptor Grid, a nation-wide program for monitoring birds of prey was started by the Finnish Ringing Centre. Voluntary banders were asked to select a 10 x 10 km study plot and find annually all active nests or at least occupied territories of birds of prey from their study plot (annual total averaged 120). Since 1986, additional information was collected with the Raptor Questionnaire. In 1996, more than 30,000 potential nest sites of owls were checked. The maximum annual number of nests were: e.g., Tengmalm's Owl 2,265, Ural Owl 901, Long-eared Owl 578, Tawny Owl 548, and Eagle Owl 537 nests. During the program, populations remained stable, although the annual fluctuations were extensive. International cooperation is needed to monitor nomadic species.

Parent Publication

Citation

Saurola, Pertti. 1997. Monitoring Finnish Owls 1982-1996: methods and results. In: Duncan, James R.; Johnson, David H.; Nicholls, Thomas H., eds. Biology and conservation of owls of the Northern Hemisphere: 2nd International symposium. Gen. Tech. Rep. NC-190. St. Paul, MN: U.S. Dept. of Agriculture, Forest Service, North Central Forest Experiment Station. 363-380.