Research team:
Coordinator´s
Researcher´s:
Mgr. Ivan Mikuláš
Ing. Lada Jakubíková
Use of actual data about the nesting occurrence of birds in the Czech Republic as an indicator of landscape units fragmentation (ACTIVITY 3)
The main goal of ACTIVITY 3 is the creation of a database of current nesting occurrence of all bird species living in the Czech Republic. The database of the collected data will serve for evaluation of changes in distribution of all bird species in model types of landscape within the Czech Republic.
Research state:
Mapping in a network of squares is generally used to monitor long-term changes in the species diversity of organisms and their numbers in large territories. The first category in which it was used is that of birds. Breeding bird atlases are today natural sources of accurate information about the distribution and population of birds at the level of regions, states, and even continents. As the mapping is repeated after 10-15 years, it is possible to follow the trends in the distribution and population of individual bird species. They often reflect changes caused as a rule by various human activities. On the one hand, outputs from breeding bird atlases are helpful in the formulation of bird protection principles and their application; on the other hand, changes in the distribution and population of birds indicate the state of their habitat and it is then possible to take effective steps to stabilise its optimum state.
The success of mapping rests on cooperation among many volunteers, experienced bird enthusiasts who do not hesitate to spend many hours in the field without recompense. It is thanks to them that we can gather reliable information about the current distribution of birds during three or four years mapping operations. In the Czech Republic the state of the breeding birds has been mapped three times: in 1973-77, 1985-89, and 2001-2003.
Project aims
- to collect information on the distribution of all bird species breeding in the Czech Republic,
- to compare the ascertained numbers with the past numbers, in particular with the previous atlases,
- to use selected indicative bird species to detect the fragmentation in different types of habitat with a potential for rectification of undesirable anthropogenic changes.
Applied methodology
In the current mapping of the breeding bird distribution in the Czech Republic we used the generally known KFME network (11.2 x 12 km), and for some purposes each base square was divided into 4x4 smaller squares (2.8 x 3.0 km). The mapping takes place in the base squares aiming to confirm the nesting of as many species as possible.
During the mapping the task was to visit all the biotopes aiming to find as many bird species nesting there. First we visited the most represented biotopes (fields, forests, villages, ponds), then the rarer ones (sandpits, marshlands, alluvial plains…).
Unlike the previous periods, the principal instrument for saving all the data related to the current mapping of the nesting distribution of birds in the Czech Republic is the online database ‘atlas.birds.cz’. Apart from entering the data it is possible to view the current maps of the distribution of individual bird species and to find on an interactive map how many bird species have been counted until now in the individual squares and the number of hours spent in each year of the project. If the cursor is moved over the squares we identify the logged-in mappers whom we can contact by email if needed. Squares with a lack of data were processed by mappers financed from the project funds.
The main output is a database of the current nesting occupation of all bird species within the network of base squares (11.2 x 12 km) and in model areas in the network of small squares (2.8 x 3.0 km). The results are comparable with data from past mappings. Data on the landscape elements can be linked to the timeline of the nesting occupation of the model bird species. A comparison between the nesting distribution maps and the bird species with specific demands can reveal problems with fragmentation of different habitat types at the level of the Czech Republic.
Results
The project output is an extensive data file with detailed information about the current nesting occupation of all bird species in the territory of the Czech Republic in 2015 and 2016. As it is freely accessible on the web portal ‘atlas.birds.cz’ it is serving the competent government and self-government authorities. There are hard data on the nesting occupation of all the species and their up-to-date distribution maps. The project results facilitate significantly the use of the National Nature Conservation Database maintained by a state-controlled organisation, the Nature Conservation Agency of the Czech Republic. The project results have been presented in scientific journals, conferences and seminars for the lay and scientific community.
More than fifty bird species were counted in 637 squares (94%), and more than 75 species in 548 squares (81%) and more than 100 species in 295 squares (44%). On average, 94 bird species were counted in 2014-16. All the data are readily accessible on the portal ‘atlas.birds.cz’. Apart from this, there are methodical instructions and several current map outputs, namely occupancy of the squares by mappers, nesting incidence of individual bird species, number of species in the squares, numbers of mappers, nesting population of the individual bird species, number of species in the squares, and numbers of hours in the squares.
The changes in the distribution of a number of bird species indicate fragmentation of landscape elements resulting from human activities. A negative impact of the changes on the wetland biotopes is evident for example in the black-necked grebe. In 2014-16 it was recorded in only 6.6% of the squares, while in the period 1973-77 it was 36%, 1985-89 it was 35% and in 2011-03 in 23% squares. The total numbers in the Czech Republic in 1985-89 were estimated at 2,500-5,000 pairs and in 2001-03 only at 300-600 pairs, which means a reduction by another almost 90% (this is equal to losses of around 5-7% per annum). The current mapping has revealed a continuous dwindling of the population. The root causes of the decreases in our country are patently a low nutrition offer caused by competition from intensive fish farming, liquidation of littoral growths, and then a marked decrease in the population of the black-headed gull (1973-77: 39%, 1985-89: 53%, 2001-03: 46% and 2014-16: 22%), in whose colonies this species likes to nest. The trend is similar for most species of waders (common sandpiper, black-tailed godwit, Eurasian curlew). The decrease in the population of these species is linked to liquidation of meadows, farmland improvement, landscape drainage, and liquidation of shallow pond edges.
In other species the changes resulted in an increase in population: greylag goose (1973-77: 4%, 1985-89: 8%, 2001-03: 16% and 2014-16: 22%), goosander (1973-77: 0.3%, 1985-89: 1%, 2001-03: 3% and 2014-16: 15%), sea eagle (1973-77: 0%, 1985-89: 3%, 2001-03: 13% a 2014-16: 26%), and common crane (1973-77: 0%, 1985-89: 1%, 2001-03: 6% and 2014-16: 14%).
Reductions in the habitable surface and population decreases are evident in a number of cultivated land birds, which incontestable signals a negative impact of human activities. A prime example is the barn owl (1973-77: 58%, 1985-89: 50%, 2001-03: 38% and 2014-16: 13%). The main causes of the reductions are landscape changes stemming from intensification of agriculture, use of pesticides, and increase in and acceleration of road transport. The little owl is another species whose population is rapidly dwindling and it has disappeared from most towns and villages and is largely found in urban housing estates. Since the last mapping at the beginning of the millennium a further reduction a further decline in the territorial distribution and population (distribution in the Czech Republic: 1973-77: 72%, 1985-89: 68%, 2001-03: 27% and 2014-16: 5%). The crested lark has clearly left the farming land and complete dependency on urban biotopes ranks it at present among the outright synanthropic species. The occupation in the squares (1973-77: 56%, 1985-89: 44%, 2001-03: 19% and 2014-16: 5%) and the population are ceaselessly dwindling. The occupation of the common partridge since the middle of the last century was certainly caused by thoughtless amalgamation of farming lands, introduction of extensive monocultures, liquidation of scattered greenery, and the use of pesticides. The distribution in the squares has been constantly decreasing over the last three decades - 1973-77: 92%, 1985-89: 84%, 2001-03: 78%, and 2014-16: 39%.
Fragmentation in the forest habitat is clearly indicated by forest birds, specifically the wood grouse (1973-77: 11%, 1985-89: 7%, 2001-03: 5% and 2014-16: 1%) and the black grouse (1973-77: 22%, 1985-89: 15%, 2001-03: 10% and 2014-16: 5%). Other forest species, such as the common wood pigeon and the stock dove, profit from these changes.
The changes in the distribution a population of the bird species in the Czech Republic can certainly be used as an indicator of the fragmentation of landscape elements by human activities. On the one hand, outputs from the nesting distribution help to formulate the bird protection principles and their application, and on the other hand the changes in the distribution a population of birds indicate the state of their habitat and it is then possible to take effective steps to stabilise its optimum state.
Photogallery
