As part of the LIFE project floodplain amphibians, NABU Lower Saxony is currently creating six new breeding ponds for rare amphibians at the edge of the nature conservation area Ilker Bruch within the city of Wolfsburg. They will primarily serve the tree frog as breeding ponds. This rare amphibian has its most important occurrence in the catchment of the river Aller at the Ilker Bruch and the surrounding areas. This population needs safeguarding and strengthening, explains project leader Dr. Markus Richter from NABU Lower Saxony. The local branch of NABU Wolfsburg and the City of Wolfsburg have provided these areas for the conservation action.
A further aim of this activity is the creation of a suitable habitat for the fire-bellied toad. “Together with other water bodies, which we want to create in the autumn of this year, they should create the conditions for a reintroduction” explains Dr. Richter. The fire-bellied toad used to have numerous occurrences along the river Aller, but has been extinct for a few decades. The area Ilker Bruch and its surroundings offer ideal conditions for the reintroduction, if a sufficient number of new ponds is created. A decision about the actual reintroduction will only be made once it is established, that the water bodies meet the needs of the species, explains Richter further.
NABU operations manager Joachim Neumann had to deal with much more practical questions. A specialised company from the region had already been commissioned in late summer to do the earthwork. The ongoing higher levels of rainfall during the whole of the second half of the year made the execution of the work impossible. Again and again the start of the earthworks had to be rescheduled. “The dry weather of the recent days caused the water levels to drop, so that an attempt to deliver the work was undertaken.” Up to now everything is going well. I think we’ll manage” says Neumann with confidence.
Photo: Earthwork for amphibians in Wolfsburg (Photo credit: Joachim Neumann)
In at least three project areas the digger was supposed to come in this autumn to create new ponds for the fire-bellied toad and the tree frog. But the unusually high levels of rain of the last months enforced inactivity. Already in May, various areas had a large proportion of the surface under water. The strong rainfalls had turned the meadows into water bodies. Further rainfall did not allow the areas to dry out over the summer. In Lüchow, in the floodplain of the river Elbe, the highest amount of rainfall for 35 years has been recorded for June. The areas earmarked for action are currently so soaked, that the required removal of soil is impossible. It is currently unclear, if this activity can be carried out at all this year.
Photo: Flooded area near the river Schunter (M. Richter)
Within the context of the NABU project LIFE floodplain amphibians the first 889 reared fire-bellied toads could be released in the project area Lower Saxony River Elbe Valley. The release happened in the area Grosser/ Kleiner See in the parish of Am Neuhaus, Luneburg district. 10 breeding ponds were created here last year for the fire-bellied toad and three existing ponds were restored. At least twenty further ponds are to follow. In addition, an extensive grazing programme for the water bodies and the surrounding area is being established, the water level of the grasslands is being raised. This will create a large-scale and highly suitable habitat for fire-bellied toads in the coming years. The project team anticipates that one of the strongest populations of the fire-bellied toad in Lower Saxony will establish at this site.
As there are hardly any fire-bellied toads present in the area Grosser/ Kleiner See, it was necessary to enhance the existing population with bred animals. The breeding of the fire-bellied toads was undertaken by Amphi International at the breeding station at Neu Darchau. There are plans to release toads bred in this way for a further two years. After that the population should be sufficiently strengthened to be self-sustaining and able to grow. The administration for the Biosphere Reserve Lower Saxony River Elbe Valley are also involved in this project as a partner. Within the project, further releases are planned along the river Elbe as well as in the catchment of the river Aller. The aim is to restore the original distribution area of the fire-bellied toad in Lower Saxony.
Photo: One of the agricultural tenants of the land releases fire-bellied toads, Florian Bibelriether (Amphi International)
In the Elbe valley in the area of the parish of Amt Neuhaus the first fencing work started at the beginning of March. Approximately 4 km (2.5 miles) of fence enable the fencing off of 46 hectares of grassland. This allows the transition from mowing and aftermath grazing to a permanent extensive grazing regime. At the end of 2017, the creation of new ponds for the fire-bellied toad will follow on these fenced-off areas. By establishing an extensive grazing regime the banks of the water bodies are due to improve their habitat conditions, e.g. keeping the banks free of willows.
Preparations started towards the end of the summer to select sites for the reintroduction of the fire-bellied toad. For the area NABU 6 several sites are planned for the reintroduction. Currently it is investigated, where exactly the best conditions for a permanent establishment of the fire-bellied toad are. Many site visits were conducted and maps and aerial photography were analysed. For the reintroduction to be successful, all required components of the habitat need to be present (or have to be created). The lack of sufficient water dynamics along the river Aller is a problem. Following the management of the River Aller with weirs and barrages, the water levels of the river and in the floodplain are currently fairly constant. The fire-bellied toad needs a high level of water dynamics with flooding in spring and shallow waters drying out in late summer. These conditions only exist in a few places. The situation along the river Oker within the boundaries of the City of Brunswig is more favourable. The floodplain is regularly flooded. It is expected that it is possible to create breeding ponds with sufficient water dynamics. The decision on the implementation of the reintroduction is made not before the newly created ponds prove to be suitable.
The working group of the LIFE project Floodplain Amphibians met in Neu Darchau at the River Elbe. The first new ponds created for the fire-bellied toad were visited. The working group, consisting of relevant District Councils, representatives of the federal Lower Saxony Agency for Hydrology, Coastal and Nature Protection, local groups of NABU and other nature conservation organisations and amphibian experts meets regularly. This ensures an extensive knowledge exchange within the project and that all measures are carried out at a high quality technical level. This time the meeting took place in Neu Darchau within the area of the Biosphere Reserve River Elbe in Lower Saxony. Project lead Dr Markus Richter (NABU Lower Saxony), Rebecca Heiligtag (Biosphere Reserve Administration) and Ute Thiergärtner as well as Florian Bibelriether (Amphi International ApS) presented the latest state of play of the project. After that, the working group visited the first creation measures for the fire-bellied toads on site. Within the area of “Großer und Kleiner See” (Large and Small Lake) in the Parish of Neuhaus the project has created ten new ponds and restored three existing ones. In addition, small and large ditches were blocked causing water-filled ditches and shallow floodings complementing the offer of different types of water bodies. Florian Bibelriether explained: “The fire-bellied toad needs different types of waterbodies throughout the year. All habitat requirements of this species can only be met if different types of waterbodies are on offer.”
Photo: Florian Bibelriether of Amphi International ApS (right hand side) explains the building measures (Marion Müller, NABU Lower Saxony)
...presentation of the NABU Project LIFE floodplain amphibians
The German-Polish conference “Amphibians and Reptiles – distribution, protection and perspectives on development”, will take place on 22 September 2017 at the Brandenburg Academy, at Criewen Castle at the river Oder. The project LIFE floodplain amphibians is represented. Florian Bibelriether from Amphi International, who delivers the project together with NABU Lower Saxony and the Biosphere Reserve administration for the Lower Saxony River Elbe Valley, will present the protection measures for the fire-bellied toad, the tree frog and the great crested newt under the title “Protecting amphibians in the north east of Lower Saxony”. The Brandenburg Academy in cooperation with BUND Brandenburg is the conference organiser. Speakers from Germany and Poland will present and discuss measures necessary for the protection of amphibians and reptiles in Germany and Poland as well as taking stock of the current situation in various areas. The conference is targeting River Ecologists, Biologists, Landscape Planners, Land Managers and Researchers as well as representatives from administrations and everybody else who is interested. The draft conference programme as well as further information is available at www.brandenburgische-akademie.de
The investigation into the genetics of the Lower Saxony fire-bellied toad has started. Project partner Amphi International ApS took samples from over 100 toads in spring and summer, predominantly from the floodplains of the River Elbe within the parish of Neuhaus. Analysis of the samples will be done by the working group of Prof Dr Tiedemann from the Institute for Biochemistry and Biology at Potsdam University. This working group has substantial experience in the genetics of the fire-bellied toad in northern Germany. This investigation will determine which populations of fire-bellied toads are most suitable for the planned reintroductions to other locations. The use of individuals for reintroductions which are not genetically native to the area has to be avoided. On the other side, a high genetic diversity is helpful for the long-term survival of the new populations to be established. More samples from the river Elbe floodplain will be taken next spring. This means final results will be available in 2017.
A small population of tree frogs lives along the river Schunter, a small river within the City of Brunswig. Several new ponds had been created along the river as part of a large-scale restoration project. However, the tree frog has only populated a small number of these ponds. Measures as part of the LIFE Floodplain Amphibians project are now going to help the tree frogs. Several ponds -nearly completely overgrown by trees and shrubs - have been cleared. This will let more sunshine through to the water surface. Tree frog tadpoles only develop successfully in warm water. The bottom level of several ponds was raised. These ponds had so far been filled with water permanently. During flooding events fish entered the ponds and prevented the reproduction of the tree frog. The redesigned ponds should now regularly dry out in the summer. This will prevent the permanent presence of fish and other predators feeding on tree frog spawn and tadpoles. Several shallow ponds, which previously dried out too early, were deepened. Finally, two new ponds were created. In total there are now 14 ponds with suitable conditions for tree frog reproduction. The measures were conducted in close collaboration and active support from the local nature conservation group FUN in the Brunswig suburb of Hondelage. FUN established grazing by cattle and water buffalos on meadows along the river Schunter. These will now manage the ponds and ensure that they will not overgrow again.
Photos: Excavator working on the Schunter, Dr Markus Richter
Tree Frog: Frank Körner
The first practical measures as part of the LIFE Floodplain Amphibians project have started by commissioning a local building company with the works. This will shortly create 10 new breeding ponds and restore three existing ponds for fire-bellied toads in the River Elbe floodplain in the parish of Neuhaus. One further larger pond will be redesigned to meet the requirements of the fire-bellied toad. The ponds will serve as feeding and breeding habitats. In addition, smaller and larger ditches in the surrounding area will be blocked. This will re-wet the whole area. Shallow floodings will form in spring that will warm up quickly. This is a preferred habitat for fire-bellied toads migrating from their overwintering habitats.