site.btaInsect Eaters Among Most Vulnerable Bird Species in Bulgaria - Report

Insect-eating birds are among the most vulnerable bird species in Bulgaria, with their populations declining at a faster rate than those of grain eaters. This is one of the conclusions in a report on the state of widespread bird species in Bulgaria in the 2005-2022 period that was officially presented at an online event. 

Yordan Hristov of the Bulgarian Society for the Protection of Birds (BSPB), which organizes the annual monitoring of widespread bird species in Bulgaria as part of the National Biodiversity Monitoring System, explained that insect-eating birds are a good indicator of the state of the environment as they feel changes in it the most. Their declining numbers indicate worsening of the environment they inhabit, and the situation is similar in many European countries. This downward trend reflects agricultural intensification, the expert added.

Compared to the first monitoring in 2005, bird populations on farmland shrank by 37% , ranking at the most vulnerable in 2022.

Hristov also said that among insect-eating species, the most drastic decline was observed in the populations of the lark and the shrike, by over 50% compared to 2005. A similar but slower downward trend was seen in the populations of the grain-eating true finches and buntings.  

The BSPB analysis is based on 245 sites across the country which were counted in at least three years between 2005 and 2022. At 122, the count sites were at a nine-year high in 2022, but Hristov said more sites need to be included in the monitoring, meaning more volunteers need to take part from various regions of Bulgaria. 

Assessing the status of 80 bird species based on the 2022 monitoring, the environmental organization found that 26% of them declined, 20% increased, 19% showed stable trends, and 35% could not be assessed.

Hristov specified that the most significant declines were observed in the populations of the swallow, the martin, the calandra lark, the quail, and the house sparrow, the latter shrinking by 50% when in previous years its population was stable. The population of the red-backed shrike decreased by 57% and of the cuckoo, by 50%.

The most significant increases were observed in the populations of the wood pigeon, the pheasant, the common whitethroat, the nightingale, and the chiffchaff.

Among the stable populations are those of the dove, the hawfinch, and the Eurasian blackcap.

Among the species whose population trends could not be assessed were the blue tit and the crested lark, Hristov said.

The monitoring was carried out within a project for implementation of the common bird species monitoring scheme. The project has a duration of three years (2020-2022) and is funded by the Enterprise for Management of Environmental Protection Activities (EMEPA) with support by the Executive Environment Agency.