SEEN - SE European Bird Migration Network
Emlen funnel cage and Busse`s flat cage - comparison of two methods used in orientation studies
Agnieszka Ożarowska(1), Reuven Yosef(2)
1) Bird Migration Research Station, University of Gdańsk, Przebendowo, 84-210 Choczewo, Poland
2) International Birding and Research Centre in Eilat, P.O. Box 774, Eilat 88000, Israel

The Emlen funnel cage was introduced in 1966. Since then it has been used in numerous studies on bird orientation. In 1995, Busse proposed another technique in the form of flat, round cylindrical cage. Busse also tested nocturnal migrants during the daytime. He, and Nowakowski and Malecka (1999), proved that birds tested at day and night displayed similar distributions in their preferred directions. This study also supports their findings. Zehtindijev et al. (2003) found that results in the Emlen funnel cage and Busse's flat cage were coherent, despite the tests were performed in different conditions (night-day) and in different years. This study is the first that compares results of the same individuals tested in the two types of orientation cages during the day (N = 75) and night (N= 17). Results of both methods did not differ (Watson-Williams test of mean angles; Mann-Whitney test of angular dispersion) both during the day as well as at night. Multiheading bird behaviour is common in both types of cages and seems to be a normal feature of orientation data. The only difference was found in bird activity (i.e., number of scratches etc. during 10 minutes of the test) that was higher in the Busse’s flat cage in daytime tests.
Created by Pronetix 2006