Bird ringing is one of the most popular methods for studying wild birds. Each trapped bird is marked with an individually numbered ring and later recovery or observation of the individual gives important information about their movements and migration. Given proper amount of data we can have a more detailed picture about the migration patterns, behaviour, roosting and wintering sites of the local breeding populations.
The standardised, annually repeated bird ringing in the same location and under the same circumstances is one of the best methods for following population changes. Collected data point out the specifics of the population (e.g. survival probability, reproductive success) that are necessary to discover the reasons behind population changes. Increase or decrease of bird populations are usually the results of habitat changes indicated by mostly human activities, therefore long data-series of ringing can contribute to reveal serious environmental problems.
The history of ringing wild birds for gaining knowledge began in 1899, Denmark. Hungary was the 3rd country in the world to launch bird ringing for scientific purposes in 1908. Ringing activity in the area of Lake Fehér was initiated by Dr. Péter Beretzk in 1939. In the location of the Roller Visitor Centre ringing of reed passerines has been running since 1996 in the frame of Lake Fehér Ornithology Camp (FOT). The camp takes part in 2 ringing programmes annually: CES and Actio Hungarica.
The aim of Constant Effort Sites (CES) ringing scheme is to monitor the breeding population of songbirds in the area. For this purpose ringing has to be elaborated the same way every year: with a standardised method and sample size in the breeding period. The program has been launched by the British Trust for Ornithology (BTO) in 1983, currently involving almost 20 countries of 2 continents in the research programme. Hungary – including Ornithology Camp of Lake Fehér – joined the program in 2004.
Actio Hungarica (AH) is the system of ringing stations in Hungary founded with the formation of MME BirdLife Hungary in 1974 following the example of Actio Baltica research programme in Poland. Standardised ringing of migratory songbirds is running continuously in the period of summer and autumn on these ringing stations. Also the organized mist netting and standard biometric data collection of passerines started with the establishment of AH camps in Hungary. Currently 8 AH camps are operated in Hungary, Ornithology Camp at Lake Fehér cooperates in the program since 2003.
Ringing season on Lake Fehér Ornithology Camp starts in mid-April when the mist nets are installed on their standard location. This is followed by a week of spring ringing camp where birds are caught on their return from the wintering sites and important data are collected.
Reed passerines start their breeding in the second half of April, therefore ringing continues according to the CES protocol until early July. During the 2 months period there are only 9 occasions – regularly weekend mornings – when ringing activities take place. The small number of occasions ensures that the birds are minimally disturbed in the incubating and chick feeding.
CES ends in early July but migration monitoring work continues in the station following the AH protocol. Accordingly – in accordance with weather conditions – mist nets are operated in the mornings and evenings. During summer, ringers work in one-week shifts on the station where their work is supported by students, thesis writers and volunteer ringing assistants. Continuous ringing is running at least until the end of August, with the help of volunteer professionals however we try to continue the research work in autumn as well.