What can the breeding bird population reveal about a biotope? A lot! Do we see rather demanding bird species or “common birds” that can settle just about anywhere? The breeding bird population can provide information about the condition of a habitat. Birds are also easy to study because they are rather sedentary – plus, there are many birdwatchers and therefore lots of data that is readily available.
Before we collected any data, ideal values were set for Berlin’s green spaces first: which bird species would have to settle in what numbers? A distinction was made between indicator species – demanding birds that only settle under certain conditions – and ubiquitous species that can survive anywhere. The second step was to determine the actual number of birds. Then, the number of breeding birds and their species diversity were matched with the habitats in which they occur.
There are areas that are classified as especially valuable, based on their location, conditions and vegetation, such as wet meadows or river floodplains. If species expected in a certain area are absent or scarce, further research is needed to identify why the bird population is so small and what measures can be taken to improve their living conditions.
The result is clear: the number of “common birds” is increasing, while “Red List” species are becoming more and more rare. Potentially valuable breeding areas such as the Tegeler See or Wannsee have fallen short of expectations.