Methods of fieldwork at SEEN ringing stations

Institutions that are SEEN members collect scientific data mainly by means of catching and ringing of birds at field stations, that are active continuously 2 months each spring and autumn seasons at minimum. At some stations also standardised migration counts of passing and resting birds during the day and moon-watch observations of nocturnal bird migration are conducted.

We use special ornithological mist-nets and/or the Heligoland-type traps to catch birds. Methods of proper removing birds out of the nets, transportation, storing and handling are given in detail in SEEN “Bird Station Manual”. Caught individuals are identified to species (if possible to subspecies as well), age/sex is determined (when possible) and the individual is ringed. Then standard set of measurements including: wing-length, wing-formula, tail-length, fat score and weight is taken. If a caught individual is in active moult, a short note of the process advancement is made. Night migrants are tested in the Busse’s cage for their directional preferences (10 minutes’ test).

Apart from this standard procedure some additional measurements/observations, like muscle-score, detailed moult description with a use of the moult-cards, morphological description, tarsus-length, feather-length of the third outermost primary measurements etc., are taken for some species/at some stations.
We use three different kinds of notebooks for data collection:

1. ringing notebook  - ringing data and biometrical measurements are noted
2. orientation tests’ notebook – results of the tests in the Busse’s orientation cage and weather conditions during the test are noted
3. moult cards’ notebook – description of moult stage/advancement is noted