Common Bird Monitoring Scheme in Bulgaria

Bulgaria was identified as a priority country for the common bird monitoring scheme by an international monitoring workshop in Prague in 2002. Establishing such a scheme in Bulgaria would extend the geographical coverage of the monitoring significantly into southeast Europe. Bulgaria is a pre-accession country and has the highest species richness in Europe. Given accession in 2007, the timing of the project would allow pre-accession data to be collected.

At the beginning of 2004 the Bulgarian Society for the Protection of Birds (BSPB), with the financial and methodological support from the Royal Society for the Protection of Bird (RSPB), started a pilot common bird monitoring scheme. The project aims at establishing a national widespread breeding bird monitoring scheme based on the UK Breeding Bird Survey model and incorporating the experience from other European countries. The major objective of the scheme is to monitor population trends of widespread birds in Bulgaria in order to assist policy and decision makers on conservation issues in the country.

Survey methods of the Bulgarian CBM scheme closely follow that of the Breeding Birds Survey in the UK. Survey plots are 1×1 km, semi-randomly selected within 10×10 km UTM squares, transect line counts in three distance bands.

In the pilot year (2004) 74 observers from 14 towns and villages took part in the scheme (Figure 1). The total number of covered squares in this pilot year was 75 – one of the observers covered two squares.

Figure 1. Distribution of the surveyed plots in 2004
(10×10 km UTM squares with at least one covered 1×1 km square)

Despite the relatively satisfactory number of volunteers, not all parts of the country are covered, especially in NW and Central Bulgaria.

In total 139 birds species were recorded during the first year of the scheme. 26 prime habitat types out of 42 were covered across the country.
The most numerous species were:

1 Sturnus vulgaris 12 Parus major
2 Alauda arvensis 13 Fringilla coelbs
3 Hirundo rustica 14 Pica pica
4 Delichon urbica 15 Passer montanus
5 Passer domesticus 16 Galerida cristata
6 Miliaria calandra 17 Columba livia forma domestica
7 Turdus merula 18 Streptopelia turtur
8 Luscinia megarhynchos 19 Cuculus canorus
9 Lanius collurio 20 Motacilla flava
10 Oriolus oriolus 21 Emberiza melanocephala
11 Garrulus glandarius 22 Merops apiaster

The preliminary results from the second year for the Bulgarian scheme are also quite positive. Over 130 observers from 24 towns and villages across Bulgaria covered their squares. 90% of the volunteers who took part in the scheme in 2004 covered their squares in 2005 as well. The distribution of the sample squares is much more even throughout the country (Figure 2) in comparison with 2004.

Figure 2. Distribution of the surveyed plots in 2005

The main challenges for BSPB in the future are to keep the current rate of the recruitment of observers and to increase the knowledge of young and inexperienced volunteers about bird identification.

Svetoslav Spasov
BSPB Monitoring Officer