Background information and definitions
Many ponds have been lost as land has been converted for agriculture or development, and with the intensification of agriculture, for example. Creation of additional breeding habitat may help to replace some of that lost and therefore help to maintain and increase amphibian populations. Different pond types can be created and some may be beneficial to certain species but not to others. Also new ponds may promote establishment of non-target species, such as the American bullfrog Lithobates catesbeianus or predatory fish, which can compromise the aims of the project.
Evidence from studies that monitored colonization of created ponds by amphibians in general is combined. Studies that targeted specific species have been separated into separate sections. Some of the targeted species may have colonized ponds monitored in the general amphibian section and vice versa. Study ‘ponds’ and ‘pools’ have been referred to as ‘ponds’ within this section.
There is additional literature that shows that 40–75% of garden ponds are used as breeding sites by amphibians (Beebee 1979, 1984; Banks et al. 1986). Common species were found to have colonized naturally, rather than been introduced, in 47–77% of cases (Banks et al. 1986). There is also some literature describing the presence of amphibians in urban stormwater ponds and Sustainable Urban Drainage systems designed to intercept and process pollutants and storm water (Bray et al. 2001; Powell et al. 2001; Scher et al. 2005; Simon et al. 2009; O’Brien 2015).
See also: 'Create ponds for frogs', 'Create ponds for toads', 'Create ponds for natterjack toads', 'Create ponds for green toads', 'Create ponds for salamanders (including newts)' and 'Create ponds for great crested newts'.
Studies investigating the creation of wetlands are discussed in ‘Create wetlands’.
Banks B. & Laverick G. (1986) Garden ponds as amphibian breeding sites in a conurbation in the north east of England (Sunderland, Tyne & Wear). Herpetological Journal, 1, 44–50.
Beebee T.J.C. (1979) Habitats of the British amphibians (2): suburban parks and gardens. Biological Conservation, 15, 241–257.
Beebee, T. (1984) Successes and failures of amphibians in garden ponds. The Herpetological Society Bulletin, 9, 21–24
Bray R. (2001) Environmental monitoring of sustainable drainage at Hopwood Park motorway service area M42 junction 2. Proceedings of the Proceedings of the 1st national conference SUDS. Coventry University.
O’Brien, C.D. (2010) Sustainable drainage system (SuDS) ponds in Inverness and the favourable conservation status of amphibians. MSc Thesis. University of Bath.
Powell A., Biggs J., Williams P., Whitfield M., Logan P. & Fox G. (2001) Biodiversity benefits from SUDS – results and recommendations. Proceedings of the Proceedings of the 1st national conference SUDS. Coventry University.
Scher O. & Thiery A. (2005) Odonata, Amphibia and environmental characteristics in motorway retention ponds. Hydrobiologica, 551, 237–251.
Simon J.A., Snodgrass J.W., Casey R.E. & Sparling D.W. (2009) Spatial correlates of amphibian use of constructed wetlands in an urban landscape. Landscape Ecology, 24, 361–373.
Supporting evidence from individual studies
A small, replicated before-and-after study in 1965–1986 of three created ponds in Missouri, USA (Sexton & Phillips 1986) found that stable amphibian populations were established in all ponds. Between 10 and 12 amphibian species colonized the ponds, some within 11 days of construction. However, fish invaded two of the ponds after nine and 16 years. Only two of 11 amphibian species remained after the invasion of six fish species in one pond. In the other pond, amphibian species did not appear to be significantly affected during the year after invasion by two fish species. The three ponds were created in 1965–70. Eggs of spotted salamanders Ambystoma maculatum, wood frogs Rana sylvatica and ringed salamander Ambystoma annulatum were translocated to two of the ponds in 1965–1980. Ponds were monitored using drift-fencing with pitfall traps until 1986.
A replicated before-and-after study in 1984–1987 of nine created ponds on a new golf course near Aarhus, Denmark (Skriver 1988) found that breeding populations of common frogs Rana temporaria were established in six ponds and common newts Triturus vulgaris in four ponds. Common toads Bufo bufo were also heard calling in one pond from 1986. Common frogs had colonized eight of the new ponds by 1987, with 14–117 egg masses found in six of the ponds. Common newts were first recorded breeding in four ponds in 1987. After the development of a golf course in 1984, nine ponds were created over four years.Study and other actions tested
A review in 1991 of amphibian translocation programmes in the USA (Reinert 1991) found that four of five amphibian translocations to created ponds resulted in established breeding populations. In one study in Missouri, breeding populations of spotted salamanders Ambystoma maculatum and wood frogs Rana sylvatica established from translocated eggs in one created pond and ringed salamanders Ambystoma annulatum but not wood frogs established in a second created pond. In a study in New Jersey, a breeding population of tiger salamanders Ambystoma tigrinum established at a created pond, with returning adults and 18–25 egg masses recorded within four years. In Missouri, eggs of spotted salamanders, wood frogs and ringed salamander were translocated to two created ponds in 1965–1980. Both ponds were monitored until 1986. In New Jersey, 1,000 tiger salamander eggs were translocated 20 km to a created pond (0.2 ha) each year in 1982–1985.Study and other actions tested
A before-and-after study in 1990–1992 of a man-made pond within woodland on the constructed Danube Island, Austria (Chovanec 1994) found that at least six amphibian species reproduced in the pond within the first two years. In the year of completion, three species reproduced successfully: green toad Bufo viridis, European tree frog Hyla arborea and marsh frog Rana ridibunda. A further three species reproduced in the pond over the next two years: European fire-bellied toad Bombina bombina, common toad Bufo bufo and agile frog Rana dalmatina. Two smooth newts Triturus vulgaris were also recorded. The 2 ha pond was sealed with a layer of clay and was completed in 1990. The slope, shore and planting scheme were created to attract amphibians and dragonflies and to discourage human disturbance. Amphibians were monitored during 30 visits in March-October by visual surveys and hand-netting.Study and other actions tested
A replicated before-and-after study in 1977–1996 of 13 created ponds on chalkland in England, UK (Beebee 1997) found that five amphibian species colonized ponds. Six of 13 new ponds were occupied by common frogs Rana temporaria (46%) and three (23%) by common toads Bufo bufo, which constituted 67% and 75% of their total 1996 distributions (total ponds: 26). Great crested newts Triturus cristatus colonized only one new pond, smooth newts Triturus vulgaris colonized four (only 40% of distribution) and palmate newts Triturus helveticus did not colonize created ponds. Thirteen ponds had been created since 1977, within a 150 km2 area. Ponds were surveyed in spring 1995 or 1996 for species presence by egg counts, torchlight surveys, netting and newt trapping.Study and other actions tested
A replicated before-and-after study of projects in 1986–1997 that created and restored 3,446 ponds for amphibians in Denmark (Fog 1997) found that pond management maintained and increased populations. The national population of European tree frog Hyla arborea doubled. A total of 387 (42%) created ponds were naturally colonized by rare species and 38 colonized by captive-bred animals. Alpine newt Triturus alpestris was the most efficient colonizer (72% of new ponds). Approximately 2,000 ponds were created or restored for rare species, over half of which were for the European tree frog. A questionnaire was sent to all those responsible for pond projects across Denmark to obtain data. Over half of the projects created new ponds. For a pond to be defined as ‘colonized’ a species had to be present but not breeding.Study and other actions tested
A randomized, replicated before-and-after study in 1994 of 133 ponds created for amphibians in the Netherlands (Stumpel & van der Voet 1998) found that 80% contained amphibians and 68% breeding amphibians. A total of nine species were recorded and each pond supported up to five reproducing species. Amphibians were found in ponds of all ages (> 50% presence in ponds of 1–7 years); however, presence was higher in older ponds. Amphibian presence was affected by pond characteristics such as surrounding topography, vegetation cover and electrical conductivity of the water. A random, stratified sample of 133 of 1,691 created ponds was taken across a number of provinces. Amphibians (eggs, larvae, juveniles and adults) were sampled in spring and autumn using netting and visual observation. Sixteen pond characteristics were recorded.Study and other actions tested
A replicated, site comparison study of 78 constructed farm ponds in England, UK (Baker & Halliday 1999) found that amphibian colonization of constructed and existing ponds was similar, although species composition differed. Amphibians were found in 65% of constructed and 71% of existing ponds, or 26% and 39% respectively once ponds with frogspawn introductions had been removed (16 new; 3 existing). Numbers of species in each type were also similar (3–4). Common toad Bufo bufo was found significantly more frequently (40 vs 22%) and great crested newt Triturus cristatus (9 vs 20%) and smooth newt Triturus vulgaris (23 vs 39%) less frequently in constructed ponds. Common frogs Rana temporaria and toads were found significantly more frequently, smooth newts less and great crested newts were never found with fish. Constructed ponds were significantly larger (1,704 vs 409 m2) and had higher proportions of fish (54 vs 20%) and waterfowl (46 vs 14%) than existing ponds. Egg, torch and dip-netting surveys were undertaken at 78 new and 49 existing ponds over 3,000 km2. Habitat data were also collected.Study and other actions tested
A replicated before-and-after study in 1996–1997 of 37 created ponds in forest, farmland, grassland and residential areas in Latah County, Idaho, USA (Monello & Wright 1999) found that up to seven species of amphibians were present. Three species were present within 24–33 of the ponds and four within 3–4 ponds. The proportion of ponds used for breeding varied with species (Pacific tree frog Hyla regilla: 54%; Columbia spotted frog Rana luteiventris: 35%; eastern long-toed salamander Ambystomam acrodactylum columbianum: 62%; American bullfrog Rana catesbeiana: 5%; roughskin newt Taricha granulosa: 8%). Western toad Bufo boreas and blotched tiger salamander Ambystoma tigrinum melanostictum reproduced in a single pond. Ponds (25–860 m2) that had been created by excavation and damming areas of high water runoff were surveyed 12–20 times in March-August. Surveys comprised visual encounter searches of the shore, egg searches, dip-netting and call surveys at four locations around ponds. Four to eight funnel or minnow traps were also set for a minimum of 14 days in February-April.Study and other actions tested
A before-and-after study in 1998 of constructed ponds and the restructured shoreline of the constructed Danube Island, Austria (Chovanec et al. 2000) found that in the first year, nine of 12 species found on the island colonized and bred in most of the nine inshore water bodies (see also Chovanec, Schiemer, Waidbacher & Spolwind 2002). There was a significantly higher number of species and number of successfully breeding species at those inshore sites compared to water bodies connected to the Danube River. Up to eight species bred in one pond. Colonization was more likely in ponds closer to older ponds. All but two of the other water bodies provided summer habitat for some species. The 21 km shoreline, which was straight with steep embankments, was restructured by creating shallow water areas, gravel banks, small permanent backwaters and temporary waters. Thirteen newly-created inshore zones and existing artificial water bodies (created 1989–1997) and one natural water body were monitored for amphibian colonization. Monitoring was undertaken during 20–32 visits (day and night) in February-October 1998 by visual surveys, audio strip transects and hand-netting.Study and other actions tested
A before-and-after site comparison study in 1979–1991 of three created ponds in a Carolina bay wetland in South Carolina, USA (Pechmann et al. 2001) found that the permanent created ponds supported a significantly different amphibian community structure compared to the seasonal wetlands they were replacing. Four to 13 frog and toad and two salamander species were recorded in created ponds, with three other salamanders seen rarely. Juveniles of 10 frog and toad and two salamander species metamorphosized and left the ponds. The original wetland had breeding populations of 7–15 frog and toad and 4–5 salamander species. Few frog and toad colonists had been recorded at the original wetland. Mean size at metamorphosis was significantly smaller for two species of frogs and greater for two salamander species at created ponds compared to a reference site. In 1983, three ponds (200 m2, <1 m deep) were created (and lined) on the edge of the original wetland. Amphibians were monitored in the original wetland, created ponds and a reference wetland. Drift-fencing with pitfall traps, minnow traps, dip-netting and seine netting was used.Study and other actions tested
A continuation of a before-and-after study (Chovanec et al. 2000) of nine created inshore zones and ponds and restructured shoreline of the constructed Danube Island, Austria (Chovanec et al. 2002) found that in the first two years, 10 of 12 species found on the island colonized and bred in most of the inshore water bodies. Eight species were recorded in the first year and an additional two were found in the second year. Common toad Bufo bufo disappeared in the second year. Green toad Bufo viridis was found at six sites in 1998 but due to successional processes in 1999 it was only found at three sites. Numbers of species and breeding species remained higher at inshore sites compared to those connected to the Danube River. Monitoring was undertaken during 20–32 visits in 1998 and 16–39 visits in 1999 by visual surveys, audio strip transects and hand-netting.Study and other actions tested
A replicated before-and-after study in 1998–2000 of created and restored ponds in 12 natural parks in mountain and plains areas in the Lombardy District, Italy (Gentilli, Scali, Barbieri & Bernini 2002) found that pond creation and restoration increased amphibian populations and resulted in colonization by new species within two years. Populations increased at six sites (average: 1.5 species; range 1–4). Between one and seven species colonized ponds at each site (average: 1.7 species). Numbers of egg clumps increased in the second year. Ponds were created or restored and were lined with clay or PVC if necessary. Other habitat management was also undertaken at some sites including increasing dead wood, excavating tributary canals and removing fish.Study and other actions tested
A review of 15 seasonal pond creation projects in New England, USA (Lichko & Calhoun 2003) found that one of the two projects that specifically monitored amphibian eggs, larvae, juveniles and adults was considered successful, the other was not. Overall, amphibians were monitored in 12 of the projects, with 6 monitoring indicator species such as the wood frog Rana sylvatica or spotted salamander Ambystoma maculatum. Programmes created ponds to provide amphibian habitat. Eight translocated amphibian eggs or adults to ponds.Study and other actions tested
A replicated, site comparison study in 1996–2002 of 10 constructed ponds within a wetland restoration area in North Carolina, USA (Petranka, Kennedy & Murray 2003) found that created ponds were rapidly colonized by amphibians and contained significantly more breeding species than natural ponds (4 vs 3/pond; see also Petranka, Murray & Kennedy 2003, Petranka & Holbrook 2006). Overall, seven species bred in created ponds within the first year and 10 species in 2002. Species richness reached equilibrium within two years. A total of 10 species bred in natural ponds. One species was only recorded in one natural pond. Six species occupied constructed ponds significantly more frequently than natural ponds (33–99 vs 0–78%). Occupancy of pond types by the other four species did not differ significantly (0–99 vs 9–93%). Ten ponds were created in 1995–1996 (average 480 m2). Restoration in 1996–2002 also included restoring original channels, filling ditches, removing fill and planting native trees. Ten natural ponds were surveyed for comparison. Ponds were surveyed using dip-netting and open-bottomed samplers each 1–3 weeks in January-August each year.Study and other actions tested
In a continuation of a study in North Carolina, USA (Petranka, Kennedy & Murray 2003), a replicated, site comparison study (Petranka, Murray & Kennedy 2003) found that breeding populations of wood frogs Rana sylvatica and spotted salamanders Ambystoma maculatum increased from 1997–1998 following pond construction (see also (Petranka & Holbrook 2006). Numbers then decreased to pre-construction levels in 2002, due to drought and ranavirus. Wood frogs reproduced within 71% and spotted salamanders within 59% of created ponds in the first year. From 1996–2002 juvenile productivity was significantly higher in created than natural ponds for spotted salamanders (47 vs 24%), but similar for wood frogs (34 vs 26%). Juvenile productivity and survival tended to decrease in both types of ponds over time. Numbers of eggs tended to be higher in ponds located where breeding sites existed prior to construction. Egg mass counts were undertaken every 1–3 weeks during the breeding season in 1996–2002.Study and other actions tested
A replicated, site comparison study of 22 paired pond sites in 1999–2000 in New South Wales, Australia (Hazell et al. 2004) found that constructed farm dams had similar amphibian species diversity to natural ponds. Both ponds types supported an average of five species and an overall total of 11–12 species. Only one species, the striped marsh frog Limnodynastes peronii, showed a different trend, occurring in only six dams compared to 14 natural ponds. Farm ponds (>10 years old) were paired with natural ponds (1–3 km away) with similar stock access and landscape features. Surveys were undertaken on two nights/site in spring and summer 1999–2000. Pond pairs were surveyed on the same night by call counts (50 m transect). Four observation surveys were also undertaken along transects (5 x 2 m) within different microhabitats at each site.Study and other actions tested
A replicated, site comparison study in 2000–2001 of 30 created ponds within agricultural landscapes in southeastern Minnesota, USA (Knutson et al. 2004) found that nine amphibian species reproduced in created ponds. Blue-spotted salamander Ambystoma laterale only reproduced in one of the natural ponds. Ponds surrounded by crops had similar species richness and reproductive success as natural ponds surrounded by non-grazed pasture. Ponds used for watering livestock tended to have lower amphibian reproductive success, compared to those with no livestock. Species richness was highest in small ponds without fish. Amphibian reproductive success was highest in ponds with less emergent vegetation and no fish. Thirty created and 10 natural ponds were randomly selected. The 30 created ponds were classified based on adjacent land use: crops, grazed and non-grazed grassland. Other habitat characteristics were recorded. Amphibians were monitored in April-August 2000–2001 by direct observations and larval dip-netting surveys.Study and other actions tested
A replicated before-and-after study in 1987–2003 of 22 created ponds in a grassland and woodland nature reserve in Limberg, the Netherlands (van Buggenum 2004) found that the majority of ponds were colonized by two to five amphibian species. Common frog Rana temporaria showed a peak in the number of colonized ponds after five years. By 2003, a total of 5,200 egg masses were recorded. Smooth newt Triturus vulgaris also colonized rapidly and continued to increase. Common toad Bufo bufo and edible frog Rana klepton esculenta took longer to colonize and maintained small populations. Calling males of the European tree frog ranged from 3–15 over 11 years. From 1987, 22 ponds (20–66 m2) were created for amphibians in the 2 km2 reserve. Ponds were monitored in 1988–2003.Study and other actions tested
A replicated site-comparison study in 2000–2003 of eight created ponds in restored peatland near Québec, Canada (Mazerolle et al. 2006) found that within a year three of four species found in natural ponds were breeding in the created ponds. Wood frogs Rana sylvatica and green frogs Rana clamitans melanota were present in 60–88% of created ponds each year. Numbers were 1–5 times greater than in natural ponds for green frogs (tadpoles: 23 vs 2; frogs: 5 vs 1/100 trap nights) and wood frog tadpoles (127 vs 1). Numbers of wood frog adults to juveniles were similar (1 vs 1). Leopard frogs Rana pipiens were not found and American toads Bufo americanus only found in created ponds. In 2000, tadpole numbers were lower in the four ponds stocked with plants compared to those left to recolonize naturally; however, numbers were similar in 2001–2002. Amphibians were surveyed using minnow traps set for 1–3 consecutive nights/month in May-August, 2000–2003 (24–192 trap nights/pond/year). Vegetation, invertebrates and pH were also monitored. For comparison 10–12 ponds in each of three natural (mined) peatlands were also sampled in 1999 and 2000.Study and other actions tested
In a continuation of a study in North Carolina, USA (Petranka, Kennedy, Murray 2003, Petranka, Murray & Kennedy 2003), a replicated site comparison study (Petranka & Holbrook 2006) found that wood frogs stopped using and spotted salamanders reduced their use of constructed ponds for breeding following the introduction of fish. Egg mass numbers decreased by 97% for wood frogs and 69% for spotted salamander the year after fish introduction. Adults appeared to rapidly recolonize if fish disappeared. Where egg masses were deposited, salamander tadpoles were absent from five of six ponds with fish, compared to just one of nine ponds without fish. Hatchling survival decreased by 96% in ponds with fish relative to fish-free ponds. Fish were introduced five to seven years after construction.Study and other actions tested
A small replicated study in 1998–2007 of two constructed temporary ponds along a new highway bypass in New Hampshire, USA (Merrow 2007) found that during the first two years, a relatively diverse community of amphibians used the ponds. Spotted salamanders Ambystoma maculatum were found in one of the two ponds. In existing ponds, spotted salamander breeding was similar in the six years before and two years after highway construction (14–73 vs 28–77 egg masses/pond). However, the highway had not yet opened for traffic. Created ponds were designed to mimic existing ponds and a 60 m upland buffer was preserved around each. Egg mass counts were undertaken.Study and other actions tested
A replicated site comparison study in 1996–2006 of 10 constructed ponds within a wetland restoration site in North Carolina, USA (Petranka et al. 2007) found that amphibian species richness in constructed ponds was significantly higher than natural ponds until fish were introduced. There was an average of four species in constructed ponds compared to three in natural ponds in 1996–2002, but in 2003–2006 the number in created ponds had decreased to three. The wood frog Lithobates sylvaticus population increased rapidly in created ponds between 1998 (400 egg masses) and 2000 (1,750). It then declined rapidly in 2000–2002 (to 600) and at a slower rate until 2006 (to 200) due to ranavirus, pond drying and fish invasions. Spotted salamander Ambystoma maculatum fluctuated less, tending to increase from 1997 (891 egg masses) to 2005 (2,931). Populations in natural ponds were more stable (50–300 egg masses). Despite reproductive failures, success in a few ponds allowed populations to persist at high levels. Ten ponds created in 1995–1996 as part of the wetland restoration were compared to 10 natural ponds. Monitoring was undertaken every 1–3 weeks in February-August and less frequently from September-January. Egg mass counts, dip-netting and larval sampling was undertaken and presence of fish and ranavirus recorded.Study and other actions tested
A replicated before-and-after study in 1992–1994 of 22 constructed ponds within two clearcut areas of the Monongahela National Forest, West Virginia, USA (Barry, Pauley & Maerz 2008) found that 11 ponds in the first year and 14 in the second were used by breeding amphibians. Of the 14 ponds used, 43% were used by more than one species for breeding. Ponds supporting three species were significantly deeper and tended to have higher nitrate concentrations than those supporting fewer. Species included American toad Bufo americanus, wood frog Rana sylvatica, mountain chorus frog Pseudacris brachyphona and Cope's grey tree frog Hyla chrysoscelis. Allegheny mountain dusky salamander Desmognathus ochrophaeus and spring salamander Gyrinophilus porphyriticus were present but not breeding. Ponds up to 28 m2 and 37 cm deep were constructed randomly along an abandoned logging road six months after timber harvest. Monitoring was undertaken monthly in April-September 1993–1994. Dip-netting and funnel traps were used along drift-fences around each pond.Study and other actions tested
A site comparison study in 1999–2001 of created ponds, lakes and streams on golf courses in Georgia and South Carolina, USA (Scott, Metts & Whitfield Gibbons 2008) found that numbers of amphibian species in created seasonal water bodies were more similar to natural water bodies than created permanent water bodies. Created seasonal water bodies supported 18 species (at least four were breeding), compared to 11 in created permanent water bodies and 24 in natural seasonal water bodies. The number of fish species was 15–16 in created and 10 in natural water bodies. Three amphibian species made up 99% of captures on golf courses with only permanent water bodies and 64% on those that had permanent and seasonal wetlands. Five golf courses from four to over 25 years old were selected. Three had permanent and two also had seasonal water bodies. Eleven natural seasonal wetlands were also sampled. Monitoring was over four days/three nights at two monthly intervals using minnow and hoop-net traps, dip-netting and visual surveys. Drift-fencing (50 m) with pitfall traps was installed at seasonal water bodies for one year.Study and other actions tested
A replicated before-and-after, site comparison study of 450 existing ponds, 208 of which were created and 22 restored in six protected areas in Estonia (Rannap, Lõhmus & Briggs 2009) found that amphibian species richness was higher in created and restored ponds than unmanaged ponds within three years (3 vs 2 species/pond). There was an increase in proportion of ponds occupied by the declining common spadefoot toad Pelobates fuscus (2 to 15%) and great crested newt Triturus cristatus (24 to 71%) and by the other five species present (15–58% to 41–82%). Breeding also occured in an increasing number of pond clusters each year for great crested newts (39% to 92%) and spadefoot toads (30% to 81%). In autumn 2005–2007, ponds were created and restored in 27 clusters. Six clusters (46 ponds) were designed for great crested newts, two (31 ponds) for spadefoot toads and 19 (153 ponds) for both. Depths, sizes, slopes and shapes varied. Restoration included clearing vegetation, extracting mud, levelling banks, pond drying and ditch blocking (to eliminate fish). Before management, 405 ponds were surveyed. After restoration in 2006–2008, each pond was visited for 10 minutes of visual counts and dip-netting.Study and other actions tested
A replicated before-and-after study in 2007 of 17 created ponds in a coastal forest in Gironde, France (Berroneau, Miaud & Bernaud 2010) found that eight of 13 amphibian species known in the area colonized the ponds. A number of new species for the region were also recorded including the common midwife toad Alytes obstetricans. Between one and five species colonized each pond, with ponds in the dune or forest fringe having more species that those further inside the forest (≥ 4 vs 2 species). Green frogs Pelophylax sp. were found in all 13 ponds that contained water. The other seven species were found in one to eight ponds. Seventeen ponds were created in the 1970s within a 10 km2 area of forest and dunes. Some dried in summer. Call and visual surveys were undertaken in March 2007.Study and other actions tested
A review of pond creation projects for amphibians in Poland and Denmark (Briggs 2010) found that targeted species colonized ponds. Following the creation of three permanent and four temporary ponds in 1997 in Bialowieza, conservation species such as the European tree frog Hyla arborea, common spadefoot toad Pelobates fuscus and great crested newt Triturus cristatus successfully colonized the ponds. Temporary ponds were more successful for reproduction. Both fire-bellied toads Bombina bombina and European tree frogs colonized and reproduced in temporary, but not permanent ponds created for them (n = 10) in Wigry National Park. For details of the pond creation and restoration project in Denmark see (Briggs 2003).Study and other actions tested
A replicated before-and-after site comparison study in 1999–2003 of eight ponds constructed to replace those lost during highway construction in western France (Lesbarreres et al. 2010) found that five of six species observed in the original ponds colonized created ponds within three years. Successful reproduction was observed for four of those species. Species richness did not differ significantly between the original (3.3 species/pond) and constructed ponds (3.6) by 2003. Diversity scores showed a similar pattern (original: 1.9; 2003: 1.8). Recovery differed between species and ponds. There was a significant increase in population size of agile frog Rana dalmatina and European toad Bufo bufo, and in the proportion of ponds occupied by them. Common midwife toad Alytes obstetricans disappeared from the area in 2001. Ponds were built with similar physical characteristics and within 80–120 m of destroyed original ponds. In January-July 1999–2003, ponds were surveyed up to three times per week and daily during the breeding season. Call and visual transect sampling and dip-netting was undertaken at night.Study and other actions tested
A small replicated site comparison study in 2006–2008 of two created temporary ponds in Spain (Ruhí et al. 2012) found that created ponds had similar or higher amphibian species diversity compared to natural local ponds. The constructed pond in the ‘high diversity’ area had similar adult but higher larval species richness compared to natural ponds (adults: 9 vs 7–8; larvae: 6–8 vs 4). The constructed pond in the ‘low diversity’ area had higher species richness than natural ponds (adults: 4 vs 2; larvae: 3–4 vs 2). Numbers of adult natterjack toads Bufo calamita entering the created pond was higher in the ‘high diversity’ area, but the number of post-metamorphic individuals leaving was higher at the ‘low diversity’ site. Ponds less than 0.5 ha and 1 m deep were created in 2006 on arable land. Amphibians were monitored in March-June using drift-fencing with pitfalls surrounding each pond. Larvae were sampled monthly using dip-netting. Five natural wetlands/ponds within 3 km of each constructed pond were sampled in 2006 using dip-netting and transect surveys at night.Study and other actions tested