Research team:
Coordinator
Researcher:
Ing. Milič Solský, Ph.D.
Database completion, mapping, prediction and confirming of critical sections for amphibians on roads (ACTIVITY 7)
Amphibians are among the most endangered groups of vertebrates. The biggest loss of amphibians happens at unprotected sections of roads with high traffic intensity. Those roads cross over their migrating routes (critical sections). The aim of this project is to create complex Czech Republic database of up to date critical sections. Other critical spots will be predicted with modern modeling tools and verified on sites.
Research state:
Amphibians count among the most endangered classes of vertebrates. They are threatened by degradation and fragmentation of their biotopes (populations), changes in the landscape, including the transport infrastructure. Transport constructions endanger amphibians (and other animals) with traffic – disturbance, pollution and road accidents involving animals. Most deaths of amphibians occur on unmarked road sections with heavy traffic, which intersect their migration routes.
As part of the project we carried out several specific tasks whose results should help increase the effectiveness of the protection of amphibians in relation to the construction of roads and traffic on them. Output from these activities are the indicators described below.
Updated database of road sections with mortality of amphibians. In this activity we brought up to date the database of road sections where deaths of amphibians occur. The source of data was a database maintained by the Nature Conservation Agency of the Czech Republic (NCA CR) containing more than 500 such sections to which we added new or existing collision places where amphibians are killed. Thy were divided into risky ones with annual mortality on the order of tens or hundreds of individuals and critical ones (hundreds to thousands of individuals killed during spring migrations). In total we added over 110 sections. The source of this information was data obtained from the Czech Nature Protection Association and other non-profit organisations and entities engaged professionally in the protection of amphibians (in particular, NaturaServis s.r.o.). Some of the data were gathered through research as part of this project. Knowledge of sections where amphibians are endangered by traffic, including quantification of the degree of the risk and selection of sections with the highest risk (risky and critical sections), will allow us to plan measures (construction or alteration of culverts) in the most risky places and decrease the degree of mortality of amphibians.
Prediction of places where amphibians are threatened by traffic. As part of this activity we predicted places where amphibians’ migration routes cross transport constructions. For this purpose we carried out a multi-criterion analysis of the relevant environmental characteristics (e.g. distance to a reproduction biotope), information on the incidence of amphibians, information on traffic density, friction maps and climatic characteristics. The output is a map of the potential risky and critical places. In this method the input layer is a map of the friction surface that measures the resistance of the individual biotopes as it is being overcome. A point of intersection of a migration route was identified as a risky section. In this was we recorded 1,091 risky sections. In a similar way we predicted the risky sections (risky sections with potentially highest mortality on the order of thousands of individuals). We predicted 22 risky sections situated largely on lower-category roads with lighter traffic. These sections with confirmed high mortality should be protected, like the sections identified during the previous activity, by permanent barriers and appropriate migration structures.
Analysis of the causes of amphibians’ mortality on roads. The aim of this activity as to identify factors responsible for higher amphibians’ mortality on roads. In cooperation with NCA CR we selected for subsequent field research and analyses 24 sections, in particular critical (with high mortality of amphibians on the order of hundreds to thousands of individuals). Then we chose control sections. These were localities with no major mortality of amphibians and similar spatial arrangement in the vicinity of roads with the same traffic density close to mapped risky and critical sections. During the field research of all these sections we recorded their environmental characteristics, such as distance of a reproduction biotope from a road, presence of linear structures suitable for migration of amphibians, and existence and functionality of road structures usable to overcome them (typically pipe and frame culverts). Using generalised linear models we compared the properties of the control and critical sections. The factors most responsible for the mortality of amphibians on roads include distance to a reproduction biotope (the closer it is to a road the higher risk of mortality) and the number and functionality of migration objects. In a number of cases the culverts are not functioning (damaged, blocked), and cannot serve their function. Another output from this part of the activity is a catalogue of critical sections with their locations, detailed descriptions, photo documentation, map outputs, and proposed measures aiming to reduce amphibians’ mortality.
Photogallery:
