Active amphibian population management during the current filling operation
Quarry Life Award 2018 Final report
1. Contestant profile . Contestant name: Kristin Geisler u. Dominik Heinz
. Contestant occupation: Biologists for nature conservation
. University / Organisation Naturschutzbund (NABU) Landesverband Hessen e.V.
. Number of people in your team: 15
2. Project overview Title: Active amphibian population management during the current filling operation Contest: (Research/Community) Research Quarry name: Malapertus, Germany
1/3
Abstract
Since 2015 Heidelberger Sand und Kies and the Naturschutzbund (NABU) Landesverband Hessen e.V. are cooperating on the implementation of a biodiversity management system in the Malapertus quarry. The main objective is the collaborate planning and implementation of the renaturation as well as the nature conservation guidance during filling operation. The success of this cooperation can already be shown by a large number of accomplished nature conservation and species protection activities in the quarry. Positive effects for the company result in nature conservation consulting and an up-to-date and solid basis of collected data. Both can be used to compose risk analysis to avoid potential environmental damage. The data collection and knowledge can be valuable for the company for public relations and to prevent concerns of authorities and public.
Part of the cooperation is the relocation of the two endangered species natterjack toad (Epidalea calamita) and midwife toad (Alytes obstetricans) as required in the final operation plan (Abschlussbetriebsplan). These two species are particularly and strictly protected in the Federal Nature Conservation Act (Bundesnaturschutzgesetzt) and the Habitats Directive (FFH-Richtlinie). The populations of those two species in Malapertus are of national importance due to their high number of individuals. In collaboration with volunteer NABU members more than 20.000 amphibians have been relocated since the beginning of the resettlement activities in 2016. The animals were relocated from the filling areas to replacement habitats in the renaturation area inside the quarry. The results about the pros and cons or successes and failures of the used relocation methods should serve as a guideline for similar projects in the future.
2/12
Final report 1 Introduction Dynamic habitats, such as constantly changing floodplains, became rare in intensively used cultural landscapes. Therefore, they have a high value for biodiversity. Many species rely on these locations and likewise became rare in Germany and Europe. The two target species in the project natterjack toad (Epidalea calamita) and midwife toad (Alytes obstetricans) especially depend on raw soils and temporary ponds. Quarries with steady mining activity provide structural diversity in a small area and therefore they supply secondary habitats. Due to different impacts as natural succession, changing land use or recultivation, these habitats often lose their suitability factors and characteristics. A specific biodiversity management is of high value for the conservation of biotopes and species. In 2015 a cooperation agreement between Heidelberger Sand und Kies GmbH and the Naturschutzbund Deutschland (NABU) Landesverband Hessen e.V. was signed. The aim is implementing a biodiversity management for the Malapertus quarry in Wetzlar, which benefits the company as well as nature conservation. As part of this cooperation, a large-scale relocation of two protected species natterjack toad and midwife toad took place. Both were relocated from filling areas into previously selected and optimized habitats. The projects objective is to preserve the current high population level of the two species over the entire period of the filling process and beyond. The following final report intense to highlight the achievements for nature conservation and the company as part of the cooperation. Furthermore, experiences and efficiency of the relocation methods are compared and evaluated.
1.1 Investigated species All investigated species are amphibians. They must be relocated before recultivation because of their protection status (s. Table 1) and the extended mortality rate during the filling operation. 1.1.1 Natterjack toad (Epidalea calamita) The natterjack toad is a typical pioneer species which inhabits newly created ponds with burrowing raw soils and hiding places in the surrounding area. In Hessen it occurs almost exclusively in operated or abandoned mining areas (POLIVKA et al., 2014). It inhabits heaps and pit walls, if they are not shaded the entire day (NIEKISCH 1982). Typical reproduction water bodies are shallow, sun-exposed and vegetation-free small ponds such as water-filled wagon tracks, puddles and wet farmland (SANDER 1996, LAUFER & SOWIG 2007, MÖLLER & STEINBORN 1981). As daytime hiding places stones, boards, plastic films, roofing felt, construction waste and similar structures are used. For hibernation, the toad digs in or uses frost-free areas in loose stone heaps or boulders (SINSCH 2009). The reproduction period of the natterjack toad extends from April to July. Usually the males start with mating sounds at dawn, in some cases during daytime. The mating sound activity an intensity depends on weather conditions. After rainfall more animals are calling than during dry periods. Is a long-lasting dryness followed by rainfall, the calling activity is significantly higher (NIEKISCH 1982). 1.1.2 Midwife toad (Alytes obstetricans) Midwife toads prefer low-vegetation, sun-exposed terrestrial habitats in heaps, stone dumps, mining areas, and storm damaged forest areas that have multiple daytime hiding places with holes and loose rocks (FELDMANN 1981). In Germany, it is nowadays found mainly in habitats that are currently or had been heavily influenced by humans (FRITZ & SCHWARZE 2007). They need winter habitats with deep soils or sufficiently deep gap systems in the substrate close to the summer habitats (GROSSENBACHER & ZUMBACH 2003). Almost all types of water bodies are used as spawning waters. Preference is given to sunny, quiet and slow-flowing streams (FRITZ & SCHWARZE 2007). Midwife toads migrate only over short distances, so that the spawning waters are close to their terrestrial habitat. Usually, adult animals do not stay further than 30 m from the water. Longer distance migrations are rare (FELDMANN 1981). The reproduction phase extends from March to August (MERTENS 1947). At dawn, the animals begin to call with a short note. Calls are occasionally heard during the daytime. The call activity depends on the weather (HEINZMANN 1970). The midwife toad is the only European amphibian that practices brood care. During mating the male wraps the eggs around its hind legs and carries them until the larvae hatch. The males search for hiding places with ideal humidity for the larval development (GLANDT 2010). After three to six weeks the larvae are released into water (ARNOLD & BURTON 1979).
3/12
1.1.3 Further species Other occurring amphibian species are common newt (Lissotriton vulgaris), alpine newt (Ichthyosaura alpestris), fire salamander (Salamandra salamandra), common toad (Bufo bufo), common frog (Rana temporina) and green frog (Pelophylax esculentus/ridibundus). Following only the two occurring newt species are considered in more detail, since the other species only occur in a small number of individuals at Malapertus. Common newts inhabit a variety of water types and terrestrial habitats. Preferred water bodies are vegetation- rich with sufficient hiding places. The reproduction phase of the common newts extends from February/March to July. Thereafter they stay in terrestrial habitats until the hibernation from October/November to February/March (BLAB 1986). Alpine newts inhabit a variety of different small waterbodies. Preferred are ponds and puddles. The reproduction phase extends from February/March to June. Thereafter they remain in terrestrial habitats in humid day hiding places until the hibernation from October/November to February/March (BLAB 1986). Outside the migratory phases at the beginning and at the end of the reproduction phases, only slight migratory activity can be observed in both species (FELDMANN 1981).
Table 1. Protection status of the four investigated species (MT midwife toad, NT natterjack toad, CN common newt, AP alpine newt, FFH Fauna-Flora-Habitat (Habitats Directive), BNatSchG Bundesnaturschutzgesetzt (Federal Nature Conservation Act), BfN responsiblity for the species according to the Bundesamt für Naturschutz Germany (Verantwortungsarten))
FFH-appendix IV Rote Liste Rote Liste (FFH-Anhang IV) BNatSchG IUCN Red List Deutschland Hessen BfN MT strictly protected specially and strictly Least concern endangered critically none (streng geschützt) protected (besonders endangered und streng geschützt) NT strictly protected specially and strictly Least concern near threatened endangered high (streng geschützt) protected (besonders (declining) und streng geschützt) CN not listed specially protected Least concern Least concern Least concern none (besonders geschützt) AN not listed specially protected Least concern Least concern Least concern high (besonders geschützt)
2 Methods 2.1 Investigation area Until 2010 in Malapertus limestone was mined. In 2012 the area was taken over by Heidelberger Sand und Kies, who started recultivation and renaturation. The quarry is 93 ha in size. As part of the renaturation one third of the area was reserved for nature and species conservation. The other two thirds of the area will be used for forest and agriculture in the course of recultivation. Currently the filling process takes place in the recultivation area. 2.2 Optimizing habitats To provide suitable habitats for resettled animals, replacement ponds outside the filling area were created in collaboration with Heidelberger Sand und Kies employees. In the area of conservation in the quarry temporary water bodies with a maximum water depth of 40 cm for the natterjack toad, and permanent waterbodies with a maximum water depth of 1 m for the midwife toad were created. To prevent the ponds of drying out a pump was installed and used in dry periods. In addition, some areas were optimized as terrestrial and winter habitats. Rock piles with coarse stones (15-500 mm) were installed to serve as winter habitats and at the same time as day-hiding places. Moreover, the topsoil layer of some areas has been removed to prevent the overgrowing by bushes and shrubs. There are also slopes which have been cleared of vegetation. To prevent a returning migration of resettled animals, a one-side passable amphibian fence was set up with an angle of about 45° in direction of the conservation area. This fence allows migration into the conservation area but prevents a migration back into the filling areas. An amphibian fence out of mesh foil by the manufacturer Schwegler was used. When setting up the fence it is important to secure the downside against infiltration. This was done by putting sand on the lower part of the fence.
4/12
2.3 Relocation of animals Relocation of amphibians from scheduled filling areas was accomplished in cooperation with 13 volunteer NABU members. To catch the highest possible amount of amphibians and to prevent animal losses, relocation was only done during suitable weather conditions. The identification of species and age status (adult, sub-adult, juvenile, larvae) was done for every relocated animal. Adults (ad) are mature animals which participate in reproduction. Sub-adults (sad) are juveniles that have passed one hibernation but are not yet mature. Juveniles (juv) are young animals that have not yet hibernated. Larvae (lv) are juveniles who have not yet completed the metamorphosis. The sex only was recorded if a clear determination in the field was feasible. There has not been done any sex differentiation of natterjack toads. The sex differentiation of midwife toads has only been done if the toad was carrying eggs.
2.3.1 Resettlement methods 2.3.1.1 Artificial refuge inspection The natural hiding places of the investigated species cannot be inspected selectively without huge effort. Artificial refuges (AR) serve as daytime hiding places, which can be inspected manually. As ARs, conveyor belt slices with a size of approx. 60 x 100 cm were used. 30 ARs have been spread out evenly in the filling area. It was ensured that they were not placed on vegetation or large stones and that the edges offer an entrance for amphibians. The frequent inspections took place from April to August. After inspection, the ARs were returned to their origin location to sustain vegetation density and soil moisture factors. A night temperature above +8°C and sufficient soil moisture are ideal weather conditions for AR inspections. The inspections usually have been done by two persons. 2.3.1.2 Nightly catching campaign Nightly catching campaigns took place during the main activity time of the amphibians (April to June) for 4 hours from dusk onwards. Active amphibians were caught out of the filling areas by hand. The campaigns were done by five to eleven people with hand or headlamps. A minimum temperature of +8°C was set as a requirement. The animals were sorted by species and placed in catch containers. Natterjack Toads were transported separately because of excretion of an irritating skin secret. Midwife toads were transported in containers with lids, because they are able to jump out of the bins. It is important to use dry containers for transporting egg carrying midwife toads, because the egg shells may burst if they get in touch with moisture. In this case the larvae could perish in the containers. Newts have been transported in containers with lids, because they are able to climb out of the bins. 2.3.1.3 Amphibian catching fence Amphibian fences with bucket traps were set up close to ponds to catch the migrating animals. It was used a fence of mesh foil from Schwegler. To install the fence a track of 2 m with flat surface and without large stones was prepared, to ensure the sealing of the fence to the ground. The fence was installed uprightly and its lower side was secured against infiltration with a layer of sand. Along the fence 8 lockable catching buckets (paint buckets with lid) were buried. All bucket bottoms were provided with approximately 50 holes <3 mm in diameter to allow water to drain but no animals to escape through the holes. Wet sponges were placed in the buckets to help trapped amphibians not to dehydrate. During long periods of drought, the buckets kept closed to reduce the risk of dehydration of caught animals. Rain showers instead provide for ideal conditions for the use of the fence.
2.3.2 Public relations To offer the opportunity to get to know the value of quarries as a biodiversity hotspot, a field trip with 25 master students from the University of Gießen took place.
5/12
3 Results 3.1 Habitat improvement in the conservation area In preparation of the resettlement substitutional amphibian habitats were established. a) To optimise the terrestrial habitats some areas were cleared of shading vegetation and parts of the top soil were removed. A total area of about 1.000m² terrestrial habitats was created. b) To optimise the reproduction habitats 15 waterbodies in the conservation area were created. Due to the long-lasting drought in 2018, all of the ponds would have fallen dry in the early summer. By using the provided pump four ponds were supplied with water during the hole reproduction phase. In all of these ponds a successful reproduction took place.
3.2 Catching results From April to August 2018 a total of 8.693 amphibians (4.744 ad, 418 sad, 3.315 juv, 216 lv) were relocated from the filling area to the newly created habitats by using the three applied catching methods. 3.2.1 Artificial refuge (AR) inspection Over the 33 AR inspections (total expenditure of time: 39h) 2.344 amphibians in total were caught. Thereof 400 midwife toads (28 ad, 3 sad, 369 juv), 1.407 natterjack toads (65 ad, 12 sad, 1.330 juv), 7 common toads (1 ad, 7 juv), 464 common newts (253 ad, 8 sad, 203 juv) and 66 alpine newts (12 ad, 1 sad, 53 juv). 3.2.2 Nightly catching campaigns Over the 8 nightly catching campaigns (total expenditure of time: 154h) 3.812 amphibians in total were caught. Thereof 281 midwife toads (281 ad), 1.239 natterjack toads (932 ad, 307 sad), 38 common toads (35 ad, 3 sad), 1.787 common newts (1.770 ad, 17 sad), 460 alpine newts (444 ad, 16 sad) and 5 fire salamanders (5 ad). 3.2.3 Amphibian catching fence Over the 32 bucket traps inspections of the amphibian fence (total expenditure of time: 69h) 2.539 amphibians in total were caught. Thereof 431 midwife toads (64 ad, 154 juv, 213 lv), 663 natterjack toads (110 ad, 49 sad, 504 juv), 14 common toads (6 ad, 8 juv), 1.352 common newts (702 ad, 2 sad, 648 juv), 74 alpine newts (34 ad, 40 juv) und 5 fire salamanders (2 ad, 3 lv). During the project period there were nine dead amphibians found alongside the fence.
4 Discussion 4.1 Successful biodiversity management through cooperation of mining companies and nature conservation associations Due to their structural diversity mining sites provide plenty of high value secondary habitats with high relevance for nature conservation (PELLKOFER et al., 2010, SINSCH 1988, TRAUTNER & BRUNS 1988, TRÄNKLE et al., 2003). A specific management with little effort can highly increase the potential for biodiversity on Quarry sites (BEIßWENGER et al., 2002, WILLIGALLA & ACKERMANN 2016).
4.1.1 Experiences of the cooperation between Heidelberger Sand und Kies and NABU Hessen In 2015 Heidelberger Sand und Kies GmbH and NABU Landesverband Hessen signed a cooperation agreement for the implementation of a biodiversity management at the Malapertus quarry in Wetzlar for the following ten years. The main objectives of the cooperation are a) the collaborate planning and implementation of the renaturation as well as b) the nature conservation guidance during the current filling operation. HeidelbergCement set up a group guideline to promote biodiversity (RADEMACHER et al. 2010). It defines principles for dialogue, data monitoring, habitat creation and its maintenance. These principles are part of the collaboration. In our opinion for the the long-term success of the cooperation, the following aspects are important: a) regular (quarterly) workshop meetings with a balanced number and consistent participants of the company and the nature conservation organisation, b) close contact between the local employees and nature conservation organisation and c) possibilities for long-term development.
6/12
4.1.2 Added value of cooperation for the company A successful cooperation of mineral extraction companies and nature conservation organisations opens up a large number of positive effects beyond the promotion of biodiversity on the quarry sites. Nature conservation-specific consulting: In case of new mining activities or changes of temporarily non used land, a risk analysis can be provided by the nature conservation organisation (TRÄNKLE & RÖHL 2001). A potential risk of environmental damage or disadvantages for nature and species can thus be considerably reduced by early planning. If necessary an ecological construction supervision can be supplied (ROLLER et al. 2014, BEIßWENGER et al. 2002). Joint action offers multiple opportunities for employee training and raising awareness. Trusted exchange: A consistent group of participants allows to exchange sensitive data. As part of the cooperation, communication rules can be defined. Security: A signed access authorization with safety instructions and disclaimer (Haftungsausschluss) can be made. Collection and analysis of scientific data: A continuous monitoring provides an enormous amount of data, which has high scientific and social relevance. For the company a good data base and argumentation by experts has high value. Especially to approve mining permissions or in public relations the data can be used to support the operational intentions (ROLLER et al. 2014). Positive public perception: The company can generate a positive perception of authorities and the community through cooperation (ROLLER et al. 2014). For example, negatively influenced residents can receive positive experiences through guided tours (TRÄNKLE & RÖHL 2001).
4.2 Active amphibian population management in Malapertus In the experts report (Artschutzrechtliches Fachgutachten) as part of the final operation plan (Abschlussbetriebsplan) for the Malapertus quarry a conflict to § 44 Abs. 1 BNatSchG (Tötungsverbot, Störungsverbot, Zerstörung von Fortpflanzungs- und Ruhestätten) was determined for the two strictly protected amphibian species natterjack and midwife toad due to the filling operations. To reduce the risk of killing for a preferably large number of individuals, the experts report recommends a relocation of those two species by artificial refuges (AR) and amphibian fences. The relocation measures should be continued until no animal of these species will be captured any more (KORDGES 2015). In a highly suitable habitat like the Malapertus this goal is very unlikely to achieve. Animal losses cannot be completely excluded. The objective should be to sustain stable metapopulations. 4.2.1 General criticism of species resettlement Resettlements in content of nature conservation measures should be seen critically, because success is questionable. According to § 45 (7) BNatSchG relocations can only be approved, if there is no reasonable alternative and the conservation status of the population does not downgrade as a result of the resettlement. The requirements for a successful relocation are very complex and cannot be assessed entirely in advance. This includes the incorrect estimation of population size, lack of habitat requirements in the relocation habitat and competition or isolation problems (SCHULTE & VEITH 2014). Relocations can only be implemented with enormous personnel and time effort. Scientifically seen, it must be criticized that there are just a few research results of successful relocations, which would justify this method as an effective conservation measure. A long term study in the relocation area is necessary to verify the success of relocation. It can be assumed that failures generally are not reported, because of fears of legal consequences. Especially in case of strictly protected species which required official permission by authority (SCHULTE & VEITH 2014). 4.2.2 Reason for relocation in Malapertus The reason for a relocation in Malapertus is the lack of preferable alternatives. The filling process affects two third of the quarry. It leads to a total loss of current habitats and the extinction of populations in that area. In case of the natterjack toad, Germany has a high responsibility due to the classification by the Bundesamt für Naturschutz (STEINICKE et al. 2002). The number of 400-500 adult individuals of the two target species estimated in the expert report, determines the importance in comparison with other known populations in Hessen (KORDGES 2015). This has been supported during the ongoing relocation by a significantly higher number of caught animals.
7/12
An essential requirement for relocation is the presence of suitable habitats. A crucial importance is a timely preparation of artificial habitats because they have to be proved for their functionality. In case of creation of spawning ponds, it must be ensured that they provide the species specific requirements like water availability. Due to the wide range of literature on habitat requirements for the studied species, the research focus of this final report is the efficiency evaluation and the comparison of the three applied relocation methods.
4.3 Method comparison 4.3.1 Method-independent influencing factors Weather: Amphibians are poikilotherm animals. Therefore, the activity is reduced during too low and too high temperatures. They are also highly dependent on sufficient moisture due to the risk of dehydration. During extreme heat, amphibians usually use deeper hiding places in the ground. Availability of spawning ponds: If long periods of drought lead to an absence of temporary ponds, which are preferred by natterjack toads, no persisting water bodies were used for reproduction (GREMLICA & NEUGEBAUER 2014). In this case, the amount of present adults is significantly lower. Season: Due to preferred weather conditions and different length of reproduction phases, the occurrence in the spawning ponds is species specific. The relocation numbers show significantly earlier decreases of different species during the year. In case of no observed animals it is important not to assume that the area is free of those species. There might be no captured amphibians because of the difference of their life cycles. Terrain: The structure of terrain has a high impact on the methods efficiency. Catching is much more difficult in vegetation-rich areas than on raw soils. Animals on steep walls and slopes cannot be caught and not be relocated. In shallow ponds the catching rate is significantly higher than in deeper ponds because of less escape possibilities. Experiences: Especially in case of hand-catching animals at night as well as in the AR inspection, there is a clear increase in catching success among experienced personnel (SCHLÜPMANN & KUPFER 2009). Due to their good camouflage animals are often only found by experienced crew members.
4.3.2 Cost benefit ratio The two passive methods form the experts report, (AR inspection, amphibian catching fences) and the active (nightly catching campaign) relocation methods will be compared in terms of their costs and manpower requirement, their efficiency and individual influencing factors and risks. All following predictions on different method efficiencies have to be seen as relative conclusions. They are only proportional to the number of caught animals in Malapertus 2018. To make general valid statements there should be a comparison to scientifically proven population sizes. Because there has not been done any capture-recapture- studies in Malapertus there is no data available. Table 2. Comparison of catching efficiency according to species and age status1 (MT midwife toad, NT natterjack toad, CN common newt, AN alpine newt, ad adult, juv juvenile, AR AR inspection, night nightly catching campaign, fence amphibian catching fence)
MT NT CN AN
ad juv ad juv ad juv ad juv AR 8% 71% 6% 73% 9% 24% 2% 24% night 75% 0% 84% 0% 65% 0% 91% 0% fence 17% 29% 10% 27% 26% 76% 7% 76% 1The age stages sub-adult and larva were excluded from the comparison. A significant number of sub-adults could only be found for the natterjack toad and therefore cannot be compared to the other species. The midwife toad tadpoles trapped by the amphibian fence were a direct consequence of a pump failure, were the catching buckets were accidently flooded. That result does not correspond to the purpose of the method, so the larva was excluded to prevent a wrong species-specific result.
8/12
4.3.2.1 Artificial refuge (AR) Material costs: The costs of materials and installation in a quarry are low. In case of existing used conveyor belts the materials are free of charge. The method works best on rough surfaces and soils without vegetation. If a removal of topsoil is necessary to eliminate disturbing vegetation, additional costs may appear. Personnel effort: Spreading of the ARs requires no special experience and is low in terms of time. The huge temporal flexibility for the inspections is an advantage and is not comparable to any other passive capture method (KORDGES 2009). Efficiency: The species-independent time efficiency was 60 animals/h (total catch/attended time). Regarding the total number of caught animals, the AR inspection provided 27% of relocated animals and represents the lowest amount. It can be assumed that an increase of animal numbers could be achieved by enhancing the inspection rate. Comparing the different age stages, the method proved to be very effective for the relocation of juvenile animals (59%). In particular, the two toad species show a species-specific capture efficiency (s.Table 2).
Young animals particularly depended on near-pond hiding places (KORDGES 2009). Especially for freshly metamorphosed midwife toads ARs proved to be suitable, which were located directly on shallow water zones. Natterjack toad juveniles occur much earlier in the year. During the course of summer, they also can be found under ARs in larger distance from the spawning waters. This corresponds to the results of the study by SINSCH (1997), who describes a random spread out of juvenile natterjack toads after leaving the spawning ponds. An AR comparing study by MÜHLBAUER et al. (2015) has shown the preferences for rapidly warming AR by juveniles of European green toads (Bufo viridis) as a comparable pioneer species like the natterjack toad. Due to their relatively lower fitness they are more dependent on thermoregulatory behaviour than adult animals and therefore prefer particularly warm hiding places. Influencing factors and risks: Major factors influencing the capture efficiency are soil structure and vegetation. The inspections difficulty can be raised by both factors. In addition, dense vegetation leads to a clear degradation in habitat quality and less animal occurrence (KORDGES 2009). Ants like to settle below ARs. The settlement of Ants results in almost 100% avoidance by amphibians (MÜHLBAUER et al. 2015). Furthermore, the choice of material is important. Various studies recommend the advantage of rapidly heating materials such as rubber compared to wooden-ARs (MÜHLBAUER et al. 2015, KORDGES 2009, SCHLÜPMANN & KUPFER 2009). With this methodology, the risks of animal losses can be excluded because of the lack of a trap effect. At high juvenile densities, increased caution is required when uncovering and turning back ARs to avoid squashing animals.
4.3.2.2 Nightly catching campaigns Material costs: The material costs for catching containers and lamps are low. There are no costs for installation. Personnel effort: Personnel effort is not flexible in terms of time and the number of required people is high. For catching amphibians which prefer to disperse on driveways a team of at least 5 people is recommended. Efficiency: The species-independent time efficiency was 25 animals/h. The nightly catching campaigns provided 44% of the total number of relocated animals. The catching at night is the method with the largest number of resettled animals. It is not mentioned in the experts report even if it is the most efficient method. It is barely described in other publications about methods of field herpetology and not implemented in amphibian monitoring (SCHLÜPMANN & KUPFER 2009). At the time of the nightly catching campaigns, no reproduction had taken place yet. Accordingly, no juveniles could be caught. Without regarding the species-specific differences adult animals could be relocated significantly more effective at night (73%). This can be explained by the main activity phase of amphibians during night time. In conclusion only about a quarter of the migratory mature animals were caught by the other two conventional methods. The nightly catching campaigns proved to be the method of choice for midwife toads, as the species has only a limited temporal dependence to ponds (SCHLÜPMANN & KUPFER 2009). It is almost not possible to catch female midwife toads with passive catching methods, because of their small activity ranges due to their particular breeding biology (KORDGES 2003). Within nightly catching campaigns several midwife toads could be relocated during mating.
9/12
Influencing factors and risks: The biggest influence on the efficiency of the nightly catching campaigns is the personnel factor (number of people, experience). The risk of animal losses is to be rated very low by proper retaining in the catching containers (s. 2.3.1.2) and cautious movement in the quarry.
4.3.2.3 Amphibian catching fence Material costs: The material costs of the used fence are 400 €/100 m plus the costs of the bucket traps. The costs were classified as high. There may be additional costs for the terrain modelling and sand as a protection for infiltration of the fence. The installation is time-consuming and quite complex for unexperienced users (KÖBELE et al. 2017). Personnel effort: The personnel effort for installation is high and determined by reproduction phases. The control of catching fences is flexible due to the manual opening of the bucket traps. Each opening requires one additional visit at the side (SCHLÜPMANN & KUPFER 2009). Open buckets have to be checked necessarily once a day to avoid losses of animals. This leads to a high requirement of time. In areas with a high vegetation growth rate, maintenance at the fence may be necessary during the summer months. Efficiency: The species-independent time efficiency was 37 animals/h. The fence provided 29% of the total number of relocated animals. Especially for juveniles of the two newt species the fence showed to be very effective. Three quarter of them were relocated with this method. In case of the low natterjack toad catching rates, it needs to be mentioned that the time when the first cohort with a high number of individuals left the water body, the bucket traps were not operational due to the pump defect and the increased water level. Furthermore, the fence primarily serves to catch the migrating midwife toads into the ponds. So the position of the fence was determined by their winter habitat areas and therefore was less suitable for the location of the reproduction zones within shallow waters. Regarding adult individuals, only in case of common newts a relatively large proportion (26%) could be relocated by the amphibian fence (s.Table 2). There might be two explanations for this species-specific catching success: The enormous population size in the quarry and the distinctive escape behavior in the water (GREMLICA & NEUGEBAUER 2014). Therefore, there was only a comparatively small percentage of the common newts, that could be caught during the nightly catching campaign. In Comparison, attracting natterjack toads could be almost completely caught out of the shallow water zones.
Alpine newts have a shorter water abidance due to their shorter reproduction phase (BLAB 1986) The main migration of adult animals back to terrestrial habitats occurs earlier when no catching fence controls had taken place. Influencing factors and risks: Until the mid-1990s, amphibian fences were considered as an almost error- free method so they were commonly used. Meanwhile, there is a variety of studies that significantly revise this assessment. A whole series of influencing factors can reduce the catching efficiency (SCHLÜPMANN & KUPFER 2009). The highest possible catching performance only is given, if the fence is correctly set up to prevent the infiltration by crawling under and climbing over (especially by newt species (KÖBELE et al. 2017)). In addition, the trapping method of using a buried bucket can be inefficient for strong-jumping amphibians. In Malapertus, this only applies to midwife toads. By a total of 64 adult midwife toads caught, there were also found 33 spawn clutches in buckets without any midwife toads. Therefor there must have been a high rate of adults which have dropped the egg clutches and escaped out of the traps afterwards. Competed to all methods the amphibian fences involved the highest risk of animal mortality. The trap method exposes the caught animals to an increased risk of dehydration and predation. The survival of animals highly depends on the weather and can be positively influenced by wet sponges in the bucket traps (KORDGES 2003). This is just possible up to a certain maximum day temperature. In four cases the use of wet sponges leads to an unexpected laying of spawn from natterjack toads in the catching buckets. By trapping juveniles there is also a drowning risk for the metamorphlings in case of water-filled catching buckets after rain events. This risk can be reduced by sponges which act as a “life raft”. Predation can be reduced by covering the open buckets with rubber mats. However, they only provide very inadequate protection for raccoons (Procyon lotor). There also can be a predation of juvenile amphibians by possible bycatch like shrews or ground beetles. The risk of bycatch of other maybe stress-proned or protected species should also be considered.
10/12
4.4 Summary of advantages and disadvantages The catching efficiency of all three applied methods strongly depends on weather and terrain (s. 4.3.1). Differences in material costs, personnel effort, species-specific efficiency, individual influencing factors and risks are shown in Table 3.
Table 3. Summary of advantages and disadvantages of the three relocation methods AR inspections nightly catching campaigns amphibian catching fence
+ low material costs + low material costs + partially flexible in time + low installation effort + no installation effort + no influence of personnel + flexible in time + low risk of animal losses experience + low personnel effort + efficient for catching adults + efficient for catching juveniles + efficient for catching (newts) advantages advantages juveniles (toads)
- in case of high juvenile - high personnel effort - high material costs densities increased risk of - high temporally dependence on - complex installation animal losses during main activity phases - need of maintenance uncovering ARs - risk of bycatch and animal losses - risk of spawning in the bucket traps - risk of climbing over disadvantages disadvantages - escape of strong-jumping species
5 Conclusion Management: Biodiversity management is a key element in preserving and increasing biodiversity in quarries. The successful cooperation of companies with nature conservation associations provides access to specialists support in planning and implementation of nature conservation measures as well as the analysis and prevention of potential environmental damage through the mining operation. Winners of such cooperation are both, nature and the company. Relocation: The relocation methods used in the project provided good results. Due to the diversity of influencing factors, no general recommendation for a specific relocation method can be given. Nevertheless, the pros and cons presented in this report can be used as decision guideline. Due to the large variety of species characteristics, the target species has to be considered to define the suitable method. Generally, in the case of a relocation, the combination of several catching methods are recommended. The results for the mentioned species are transferable to species with a similar biology, in particular the “pioneer species” among frogs and toads, but also to the generalists among the newts and salamanders.
Acknowledgement A large number of people contributed to the great success of this project. We want to thank the employees of Heidelberger Sand und Kies, especially Jürgen Popp, Ulrich Schnarre and Sascha Schönberger for their dedicated support and the successful cooperation for a common goal. Furthermore, we thank the many volunteers, in particular Inga Hundertmark, Katharina Damm, Theresa Sewer, Hannah Gallathe, Kirsten Schellenberg, Frauke Freise, Hiltrud Mai, Hartmut Mai, Jan Sachse, Frank Rudolph, Günther Ott, Klaus Weinberg and Bernhard Feth, who have actively supported us many nights during our "Toad Hunt".
11/12
To be kept and filled in at the end of your report Project tags (select all appropriate): This will be use to classify your project in the project archive (that is also available online)
Project focus: Habitat: ☐Beyond quarry borders ☒Artificial / cultivated land ☒Biodiversity management ☐Cave ☒Cooperation programmes ☐Coastal ☐Connecting with local communities ☐Grassland ☐Education and Raising awareness ☐Human settlement ☐Invasive species ☐Open areas of rocky grounds ☐Landscape management ☐Recreational areas ☐Pollination ☒Sandy and rocky habitat ☐Rehabilitation & habitat research ☐Screes ☐Scientific research ☐Shrub & groves ☐Soil management ☐Soil ☒Species research ☐Wander biotopes ☐Student class project ☐Water bodies (flowing, standing) ☐Urban ecology ☒Wetland ☐Water management ☐Woodland
Flora: ☐Trees & shrubs Stakeholders: ☐Ferns ☐Authorities ☐Flowering plants ☐Local community ☐Fungi ☒NGOs ☐Mosses and liverworts ☐Schools ☐Universities Fauna: ☒Amphibians ☐Birds ☐Insects ☐Fish ☐Mammals ☐Reptiles ☐Other invertebrates ☐Other insects ☐Other species
12/12
References
AGAR & FENA (2010): Rote Liste der Amphibien und Reptilien Hessens (Reptilia et Amphibia), 6. Fassung, Stand 1.11.2010. - Hessisches Ministerium für Umwelt, Energie, Landwirtschaft und Verbraucherschutz (Hrsg.), Arbeitsgemeinschaft Amphibien- und Reptilienschutz in Hessen e. V. und Hessen-Forst Servicestelle Forsteinrichtung und Naturschutz, Fachbereich Naturschutz (Bearb.); Wiesbaden, 84 S. IUCN 2018. The IUCN Red List of Threatened Species. Version 2018-1.
13/12
MÖLLER, S. & STEINBORN, G. (1981): 10. Die Kreuzkröte – Bufo calamita LAURENTI, 1768. In FELDMANN, R. (Hrsg.): Die Amphibien und Reptilien Westfalens. – Abhandlungen aus dem Landesmuseum für Naturkunde zu Münster in Westfalen 43: 83-88. MÜHLBAUER, M., ZAHN, A., KÖBELE, C. & SEDLMEIER, H. (2015): Manche mögen’s heiß: Verstecke und Lebensräume junger Wechselkröten (Bufotes viridis). – Zeitschrift für Feldherpetologie 22: 191-210. NIEKISCH, M (1982): Beitrag zur Biologie und Schutz der Kreuzkröte (Bufo calamita Laur.). - Decheniania 135, 88-103. PELLKOFER, B., SPÄTH, J. & ZAHN, A. (2010): Kreuz- und Wechselkröte (Bufo calamita und B. viridis) im Unteren Isartal – Bestandssituation und Artenhilfsprogramm. - Zeitschrift für Feldherpetologie 17: 61–76. POLIVKA, R., J.-M. LAPP, C. HEUCK, S. EWERS, B. T. HILL, S. STÜBLING & M. KORN (2014): Untersuchung 2013/14 zur Verbreitung der spätlaichenden Amphibien (Gelbbauchunke, Wechselkröte, Kreuzkröte, Knoblauchkröte, Geburtshelferkröte) in den Naturräumlichen Haupteinheiten D18, D41, D44, D47, D53 und D55 in Hessen. - Gutachten im Auftrag von Hessen-Forst FENA, Bioplan Marburg, Marburg, PGNU Frankfurt a. M., BFF, Linden, 86 S. + Anhang. RADEMACHER, M., TRÄNKLE, U., HÜBNER, F., OFFENWANGER, H. & KAUFMANN, S. (2010): Förderung der biologischen Vielfalt in den Abbaustätten von HeidelbergCement. 2. Auflage. HeidelbergCement AG (Hrsg.). ROLLER, G., HIETEL, E., EBERLEIN, A. & SCHARDT, S. (2014): Umwelthaftung bei Biodiversitätsschäden – Anwendungsorientierter Leitfaden für die Steine- und Erdenindustrie. - FH Bingen, 52 S. SANDER, U (1996): Kreuzkröte - Bufo calamita (Laurenti, 1768). In: BITZ A., K. FISCHER, L. SIMON, R. THIELE & M. VEITH (Hrsg.): Die Amphibien und Reptilien in Rheinland-Pfalz. Band 1, 199-216. - Gesellschaft für Naturschutz und Ornithologie Rheinland-Pfalz e.V. (GNOR), Landau. SCHLÜPMANN, M. & KUPFER, A. (2009): Methoden der Feldherpetologie – eine Übersicht. – Zeitschrift für Feldherpetologie, Supplement 15: 7-84. SCHULTE, U. & VEITH, M. (2014): Kann man Reptilien-Populationen erfolgreich umsiedeln? Eine populationsbiologische Betrachtung. – Zeitschrift für Feldherpetologie 21: 291-235. SINSCH, U (1988): Auskiesungen als Sekundärhabitate für bedrohte Amphibien und Reptilien. - Salamandra 24: 2/3 161-174. SINSCH, U. (1997): Postmetamorphic dispersal an recruitment on first breeders in a Bufo calamita metapopulation. – Oecologia 112: 42-47. SINSCH, U. (2009): Bufo calamita – Kreuzkröte. In: GROSSENBACHER, K. (Hrsg.): Handbuch der Reptilien und Amphibien Europas. – Band 5/II, Froschlurche (Anura) II (Hylidae, Bufonidae). - AULA-Verlag, Wiebelsheim. SSYMANK, A. (1994): Neue Anforderung im europäischen Naturschutz. Das Schutzgebietssystem Natura 2000 und die FFH-Richtlinie der EU. Natur und Landschaft 69 (9): 395-406. STEINICKE, H., HENLE, K. & GRUTTKE, H. (2002): Bewertung der Verantwortlichkeit Deutschlands für die Erhaltung von Amphibien- und Reptilienarten. – Bundesamt für Naturschutz (Hrsg.), Bonn – Bad Godesberg. TRÄNKLE, U. & RÖHL, M. (2001): Naturschutz und Zementindustrie – Projektteil 1: Auswertung einer Umfrage. - Verlag Bau + Technik, Düsseldorf. TRÄNKLE, U., OFFENWANGER, H., RÖHL, M., HÜBNER, F. & POSCHLOD, P. (2003): Naturschutz und Zementindustrie – Projektteil 2: Literaturstudie. - Verlag Bau + Technik, Düsseldorf. TRAUTNER, J. & BRUNS, D. (1988): Tierökologische Grundlagen zur Entwicklung von Steinbrüchen. – Studie der Bürogemeinschaft Landschaftsökologie + Planung i.A. Akademie für Naturschutz und Landschaftsplanung, Ber. ANL 12: 205-228. WILLIGALLA, C. & ACKERMANN, J. (2016): Artenhilfskonzept 2015 Kreuzkröte (Bufo calamita) in Hessen. Endbericht, überarbeitete Fassung im Auftrag von Hessen-Forst FENA, Willigalla – Ökologische Gutachten, Mainz, 40 S. + Anhang.
14/12
Appendix 1 – Map of the Malapertus quarry in Wetzlar
Figure 1. Outline map of the Malapertus quarry in Wetzlar, Germany.
15/12
Appendix 2 – Data and tables
Table 1. Cost benefit ratio of used relocating methods (AR artificial refuge inspections, night nightly catching campaigns, fence amphibian catching fence, MT midwife toad, NT natterjack toad, CN common newt, AN alpine newt, time efficiency total catch/attended time) AR night fence personal effort low high low material costs low - free low high costs low - free free low - free installation time effort low no effort high in the field difficulty level simple none complex time effort medium high medium inspections flexibility high low low MT 10 2 3 NT 36 8 10 CN 12 12 20 time AN 2 3 1 efficiency total 2018 60 25 37 total adults 2018 9 23 37 total juveniles 2018 50 0 20
Table 2. Total number of relocated animals acording to the used methods (AR artificial refuge inspections, night nightly catching campaigns, fence amphibian catching fence, ad adult, sad sub-adult, juv juvenile, lv larvae, MT midwife toad, NT natterjack toad, CT common toad, CN common newt, AN alpine newt, FS fire salamander) AR night fence total number of inspections 33 8 32 time effort (h) 39 154 69 total number of relocated amphibians 2018 2344 3810 2539 ad 359 3467 918 total number sad 24 343 51 according to age status juv 1961 0 1354 lv 0 0 216 MT 400 281 431 NT 1407 1239 663 total number CT 7 38 14 according to species CN 464 1787 1352 AP 66 460 74 FS 0 5 5
16/12
Appendix 3 - Pictures
Figure 1. Adult natterjack toad (Epidalea calamita) Figure 2. Midwife toad (Alytes obstetricans) male releasing the larvae in the water
Figure 3. Creation of replacement ponds in the Figure 4. Clearing the slopes of bushes and shrubs to conservation area prevent shading terrestrial habitats
Figure 5 Setting up a one-side passable amphibian fence Figure 6. Refilling of ponds used by natterjack toads into direction of the conservation area (Epidalea calamita) and midwife toads (Alytes obstetricans) for reproduction during drought
17/12
Figure 7. Inspection of artificial refuges (AR) in the filling Figure 8. Four of the occurring amphibian species below area an artificial refuge, including juveniles of the midwife toad (Alytes obstetricans), the natterjack toad (Epidalea calamita) and the common newts (Lissotriton vulgaris), as well as adult common newts and an adult alpine newt (Ichthyosaura alpestris)
Figure 9. Transport containers for the nightly catching Figure 10. Observed mating of midwife toads (Alytes campaigns to transport species separated and to prevent obstetricans) during a nightly catching campaign escape
Figure 11. Setting up an amphibian fence in the filling area Figure 12. Trapping bucket at the amphibian fence with to catch amphibians migrating to the ponds rubber mats for shading and to prevent predation
18/12
Figure 13. Trapping Bucket with wet sponges after a Figure 14. Joint artificial refuge (AR) inspection during a nightly catching campaign with common newts field trip with students of the University of Gießen (Lissotriton vulgaris) and juvenile natterjack toads (Epidalea calamita) and midwife toads (Alytes obstetricans)
19/12