Any change in the Methodology of field studies on bird Migration? A comparison of methods used in 1994-2003 and a Quarter Century earlier
The holistic approach to the study of bird migration observed in the past decades and the huge advancement in technology should be seen in the numbers and types of methods used in field studies for this phenomenon. To check this assumption, we compared field methods used in the studies on bird migration published in international journals in 1994-2003 (N = 570 papers) and in 1967-1976 (N = 394 papers). We noted an increase in the mean number of methods per a single paper (from 1.49 in the former of these decades to 1.98 in the latter) and a change in the frequency of each method. In recent years, methods such as satellite telemetry, DNA or isotope proportions analyses have been developed. An increase in the mean number of methods as well as changes of the most frequently used methods were more apparent in journals indexed on the ISI Master Journal List in 2003 than in other current journals, where the methods were often found to be similar to those applied a quarter century earlier, which surprised us.