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  • Author: Agnieszka Ożarowska x
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Agnieszka Ożarowska and Reuven Yosef

A comparison of the Emlen funnel and Busse's flat cage for orientation studies

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 in the daytime. He, and Nowakowski and Malecka (1999), proved that birds tested in daylight and at night displayed similar distributions of their preferred directions. This study also supports their findings. Zehtindijev et al. (2003) found that results in the Emlen funnel 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 one 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 U-test of angular dispersion) both during the day and 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 during 10 minutes of testing) that was higher for Busse's flat cage in daytime tests.

Open access

Katarzyna Stêpniewska and Agnieszka Ożarowska

Abstract

Stêpniewska K., O¿arowska A. 2012. The Eurasian Reed Warbler (Acrocephalus scirpaceus) breeding in Egypt - a new evidence? Ring 34: 45-50.

To date, the documented breeding range of the Eurasian Reed Warbler in Egypt is limited to the Nile Delta. In March and September 2001 two females with brood patches were caught in the Wadi El Rayan Protected Area (30°19’E, 29°12’N) in the Western Desert of Egypt. These records, if accepted, might shift the southern border of the breeding range of Reed Warblers in Egypt west of the Nile Delta. The two individuals were the only records of breeding Reed Warblers in Wadi El Rayan, suggesting that the breeding population is small. It is possible that the population has been established recently because artificial lakes were created in Wadi El Rayan in 1973. The studies during the breeding season are essential to determine if such probable breeders demonstrate a new, but permanent breeding population or only ephemeral incidents, as well as to collect the data on the number, breeding biology and biometrical characteristics of such local populations at the southern limit of the world breeding range of the Reed Warbler.

Open access

Pavel Zehtindjiev, Mihaela Ilieva, Agnieszka Ożarowska and Przemysław Busse

Directional behaviour of the Sedge Warbler (Acrocephalus schoenobaenus) studied in two types of orientation cages during autumn migration - a case study

Migratory directions of Sedge Warblers tested in the Emlen funnel and Busse's flat cage during autumn migration in the Balkan region were studied. Some methodological aspects of orientation data analysis were discussed as well. According to orientation data at least two populations of the Sedge Warbler migrate in NE Bulgaria: one in SW direction via Greece, crossing the Mediterranean Sea to Libya, and then Central Africa and second one through Turkey, (Cyprus?) and the Middle East to the eastern parts of winter quarters (SE direction). This pattern is clear when a calculation method that assumes reverse and axial behaviour of birds (i.e. reversing vectors from northern sectors) is applied. Nature of "reverse migration" is still not well recognised and seems to be very interesting for further studies.