TDK conference 2009

In Hungary more than half of the total area is involved in cultivation, and thus farmland is a quite important habitat for a great amount of species. In the last quarter of the 20th century the populations of many farmland birds declined across north and west Europe, suggesting that this trend will be present in central European countries, including Hungary, with entering the EU. Since the entering in 2004, our economy is also directed by the Common Agricultural Policy (CAP), which can be regarded as a new threat to the stable Hungarian farmland populations. The aim of my study was to get more information about the habitat preferences of five farmland birds using their distributions. However, densities may be misleading as indicator of habitat qualities (e.g. refuge effect), hence, I measured the duration of song-flight of the Skylark (Alauda arvensis). Song flight is a reliable advertisement of male fitness, and males with bigger fitness can hold better territories. This is a new approach in qualifying crops in farmland.

Bird censuses were conducted applying the line transect method on the Heves Environmentally Sensitive Area (ESA) from April to May, four times together in 2008. The distribution of the five species- Quail (Coturnix coturnix), Skylark, Yellow Wagtail (Motacilla flava), Common Stonechat (Saxicola torquatus) and Corn Bunting (Emberiza calandra) was species-specific across crop types, with the Quail showing similar densities in all fields (wheat, set-aside, oil-seed rape, maize, semi-natural pasture, alfalfa, sun-flower), while the Stonechat and Corn Bunting showed significant preferences for the oil-seed rape and set-aside. The Skylark and the Yellow Wagtail marginally preferred the oil-seed rape. Measuring the duration of song flights was conducted in April and June 2009 in Heves ESA and near Szombathely in June in three types of land (semi-natural pasture, wheat, oil-seed rape). In Heves ESA, in April I found the highest durations on oil-seed rape based on the median, in June the wheat was the first when oil-seed rape was the last considering length of song flights.

Based on my results i think that song flight performance depends on the region (Heves, Szombathely), the timing of the study (April, June) and the maximum and minimum height of vegetation. Song flight as a new method seems to be effective in qualifying crops on farmland, since it showed detectable spatial and temporal variation. Preferences measured from densities and duration of song flight in Heves ESA were similar for example in the case of oil-seed rape. To summarize, measuring the duration of song flight is an effective way to qualify crops in culivated agricultural areas. Further, I hypothetised that the diversity of crops in the Heves ESA, and the relatively low level of management intensity are responsible for the richness of birdlife in crops.