Amphibian catch cross
Terrestrial fishing equipment is referred to as amphibian fishing crosses, which are mainly used to detect migrating amphibians in the context of field herpetological investigations (mapping), for example to clarify migration directions. Amphibian crosses are also used to record amphibians in their land habitats.
The use of amphibian catch crosses is now standard for amphibian protection in the context of route-finding processes in road construction, including for planning amphibian passages .
Working principle
An amphibian trapping cross consists of cross-shaped barrier fences made of various materials with a wing length between 5 and 10 m. At the crossing point, a catching vessel (qualitative / quantitative recording) or four catching vessels (additional recording of the direction of migration) are embedded in the ground, in which the amphibians moving in the room catch themselves. Since some amphibian species (such as newts ) climb well, protection against climbing over is often attached to the safety fences.
effectiveness
The use of amphibian crosses is currently the most effective method for detecting animals in land habitats. However, the effectiveness of the crosshairs should not be overestimated, as only a fraction of the migrating animals even come into the catchment area of a crosshair. Furthermore, the animals do not always run right along the barrier fence until they fall into the buckets, as is often assumed, but occasionally run around the entire facility. The escape rate of the animals from the buckets is also generally very high and depends on the depth of the buckets used. With the frequently used cleaning buckets (approx. 30 cm deep), the escape rate for all frogs (Raniden and Hyliden) is more than 80%. Similar values are achieved by pigs. The number of frogs and newts caught is only increased significantly with buckets more than 45 cm deep and with their own climbing protection. For toads and similarly sedate amphibians, cleaning buckets are usually sufficient.
Since the aim of the usual investigations is to detect all occurring species (or all strictly protected species), the use of deep buckets is a prerequisite for obtaining reliable results. Cleaning buckets and the like are then not sufficient. The fence material also limits the effectiveness of the traps. Newts of any age can climb up the fabric material and thus overcome the trap. Smooth plastic tarpaulins are only climbed by very young animals. Despite all the problems, the creation of amphibious crosses is the only reliable way to say something about the land use of amphibians.
Catch spectrum
In addition to the target species (amphibians), small mammals are often caught in the trapping vessels , which, unlike amphibians, usually die within a very short time in the trapping vessel. In order to keep the mortality rate in small mammals low, sticks are often placed in the trapping vessels, which enable small mammals to leave the trapping bucket. In addition to mice, shrews and voles, young hares and rabbits, young birds, hedgehogs, ground beetles and others are also regularly found as unwanted by-catches.
Legal basis
In Germany, there are strict legal limits to the targeted use of amphibious crosses. Since the target group of amphibians is "specially protected" or "strictly protected" species according to the BNatSchG and BArtSchV , an exemption must be obtained from the responsible nature conservation authority before using amphibian fishing crosses.
Individual evidence
- ↑ Federal Ministry of Transport, Building and Housing (Ed.): Leaflet on amphibian protection on roads ( MAmS for short ), Bonn 2000 (PDF; 1.5 MB) .
Web link
- Catch Cross ( Memento from March 10, 2007 in the Internet Archive )