No abstract

Formella M., Busse P. 2002. Directional preferences of the Reed Warbler (Acrocephalus scirpaceus) and the Sedge Warbler (A. schoenobaenus) on autumn migration at Lake Dru¿no (N Poland). Ring 24, 2: 15-29.In 2000, during the whole autumn migration period, Reed Warblers (212 indiv.) and Sedge Warblers (205 indiv.) were tested with Busses method (Busse 1995) for directional behaviour at Lake Dru¿no ringing site. Distributions of scratches, reflecting cage activity of an individual, were tested for uniformity and more than 97% showed directional behaviour of tested birds. The data were elaborated using non-standard method for evaluation of circular data proposed by Busse and Trociñska (1999) that allows to show multi-modal distributions.Results show that as much as around 55% of obtained headings point at directions reversed in relation to the normal direction of autumn migration. They suggest that pronounced number of individuals show axial behaviour in the cage. Causes of this phenomenon are still vague and it was decided that directional behaviour will be discussed after reversing northward headings by the doubling the angle method (adding 180°). Then main directions of headings were set as WSW, SSW and SE. They were confronted with available ringing recovery data and quite high (10-12°difference) or even very high (WSW beam of migration of Reed Warblers 5°difference) accordance was found. Using, for the comparison, the same method to the Lesser Whitethroat (Sylvia curruca) data published elsewhere, an excellent agreement between cage data and ringing recoveries at the level 2°only was found. This can be treated as a check of the field and evaluation methods used for basic data presented in the paper. The heading pattern changed in the course of autumn migration and in subsequent periods different headings dominated. The most clear it was for the Reed Warbler data. However, this problem still needs further analyses.

The general migration pattern of passerines can be estimated using a variety of methods. A number of partial analyses based on ringing data, usually limited to a few species, have been published. A very few continent-scale presentations have been offered, as extremely long periods of ringing activity are necessary for passerines. This is especially true for areas where the recovery rate is very low, including vast areas of north-eastern and eastern Europe and the Middle East/Africa. Similarly, radar and moon-watching studies are of limited value for drawing migration patterns within wider areas. Radar studies require good coverage by the radar systems, while weather radar distribution density and the level of evaluation are very uneven. Modern logger and satellite tracking are more applicable to non-passerines, and as yet enable detailed study only of limited numbers of individuals, and not population studies. At the end of the 20th century, a very simple tool was introduced for field studies on the preferred headings of individual birds caught for ringing, i.e. the use of flat orientation cages. This method was introduced as a standard within the SEEN (SE European Bird Migration Network) in 1995. This study presents a preliminary large-scale evaluation of the data collected within this project. The database used contains more than 43,000 orientation tests performed at 45 ringing sites. The area covered stretches from the northern part of western Russia to southern Egypt and from Italy and Poland to Siberia and Armenia. Eight streams of migration are identified within this area, creating a fairly complicated pattern of avian movements.

Zehtindjiev P., Ilieva M., O¿arowska A., Busse P. 2003. Directional behaviour of the Sedge Warbler (Acrocephalus schoenobaenus) studied in two types of orientation cages during autumn migration a case study. Ring 25, 1-2: 53-63.Migratory directions of Sedge Warblers tested in the Emlen funnel and Busses 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.

A new research project near Jericho in the Jordan Valley (Palestine) was launched on 10 September 2013, work continued until October 23rd 2013. Standard ornithological work and bird ringing work was conducted using mist nets situated in an oasis type habitat of Wadi Qelt surrounded by palm plantations. The field methods followed the SEEN (SE European Bird Migration Network) standards that include apart from ringing of captured birds, also several measurements (wing length, tail length, wing formula) and scores (fat load and body mass), as well as the studies on the directional preferences of migrants using round, flat orientation cages. Ornithological research was enhanced by parasitological studies analysing migratory birds (hosts) - helminths relations during migration period of the former. This was a part of complex studies covering the Middle East and north African ringing sites. Altogether 481 individuals of birds representing 59 species were ringed and about 50 were retrapped. The most interesting was relatively high share of Masked and Red-backed shrikes as well as good number of birds of local species as Dead Sea Sparrows and introduced Indian Silverbills.