Study

Long-term management of a natterjack toad (Bufo calamita) population in southern Britain

  • Published source details Banks B., Beebee T.J.C. & Denton J.S. (1993) Long-term management of a natterjack toad (Bufo calamita) population in southern Britain. Amphibia-Reptilia, 14, 155-168

Actions

This study is summarised as evidence for the following.

Action Category

Clear vegetation

Action Link
Amphibian Conservation

Control invasive plants

Action Link
Amphibian Conservation

Add lime to water bodies to reduce acidification

Action Link
Amphibian Conservation

Deepen, de-silt or re-profile ponds

Action Link
Amphibian Conservation

Create ponds for natterjack toads

Action Link
Amphibian Conservation

Head-start amphibians for release

Action Link
Amphibian Conservation
  1. Clear vegetation

    A before-and-after study in 1972–1991 of heathland in Hampshire, UK (Banks, Beebee & Denton 1993) found that vegetation clearance resulted in increased occupancy by natterjack toads Bufo calamita (see also Buckley & Beebee 2004). At least six toads, including four juveniles, took up residence and established home ranges at the site within a year of vegetation clearance. However, within two years rank vegetation covered 90% of the ground and no toads remained in the area. Scrub was cleared from 40 ha by cutting and uprooting and bracken was treated with herbicide over 12 ha. Toads were monitored once every 10 days in March and August each year.

     

  2. Control invasive plants

    A before-and-after study in 1972–1991 of ponds on heathland in Hampshire, England, UK (Banks, Beebee & Denton 1993) found that pond restoration and creation with swamp stonecrop Crassula helmsii control, vegetation clearance, liming and captive-rearing and releasing toadlets resulted in a three-fold increase in natterjack toad Bufo calamita populations. Spawn string counts, which relate to the female breeding population, increased from 15 to 43. Swamp stonecrop was eliminated from two of six new ponds it invaded and controlled in two others. Nine small ponds (< 1,000 m2) were created and four restored by excavation. Swamp stonecrop was pulled up and treated with herbicide. In addition, one pond was treated with limestone (1983–1989), scrub was cleared by cutting and uprooting (40 ha) and bracken was treated with herbicide (12 ha). Captive-reared toadlets were released in 1975 (8,800), 1979, 1980 and 1981 (1,000 each). Each year, toads were monitored every 10 days in March and August.

     

  3. Add lime to water bodies to reduce acidification

    A before-and-after study in 1983–1989 of a heathland pond in Hampshire, UK (Banks et al 1983) found that adding limestone temporarily increased breeding by natterjack toads Bufo calamita. The pond was used for breeding more frequently while it was being limed (1–9 vs. 0–3 spawn strings), but tadpole mortality was high and metamorphic success low and toads abandoned the pond before liming ceased. A naturally acid pond (735 m2) had 25 kg of powdered limestone added annually in April (1983–1989). Toads were monitored before, during and after the intervention, once every 10 days in March and August each year.

     

     

  4. Deepen, de-silt or re-profile ponds

    A before-and-after study in 1972–1991 of ponds on heathland in Hampshire, UK (Banks, Beebee & Denton 1993) found that pond restoration by deepening, along with other interventions, tripled a natterjack toad Bufo calamita population. Spawn string counts (female population) increased from 15 to 43, with a maximum number of 48 in 1989 (see also Buckley & Beebee 2004). Nine small ponds (< 1,000 m2) were created and four restored by excavation to generate shallow, temporary ponds with gradually shelved margins. Scrub was cleared from 40 ha by cutting and uprooting, bracken was treated with herbicide over 12 ha and swamp stonecrop Crassula helmsii, which invaded six new ponds, was pulled up and treated with herbicide. Captive-reared toadlets raised from spawn were released in 1975 (8,800), 1979, 1980 and 1981 (1,000 each). Limestone was added to one naturally acid pond (735 m2) annually in April 1983–1989. Toads were monitored annually, once every 10 days in March and August.

     

    (Summarised by: Rebecca K Smith)

  5. Create ponds for natterjack toads

    A before-and-after study in 1972–1991 on heathland in Hampshire, England, UK (Banks, Beebee & Denton 1993) found that pond creation, along with other interventions resulted in a three-fold increase in a natterjack toad Bufo calamita population (see also Buckley & Beebee 2004). Egg string counts (female population) increased from 15 to 43, with a maximum number of 48 in 1989. Ponds tended to be used for breeding within a year of construction. Nine small ponds (< 1,000 m2) were created and four restored by excavation. Scrub, bracken and swamp stonecrop Crassula helmsii were controlled. Captive-reared toadlets raised from eggs were released in 1975 (8,800), 1979, 1980 and 1981 (1000 each). Limestone was added to one naturally acid pond (735 m2) in April 1983–1989. Toads were monitored annually, once every 10 days in March and August.

     

  6. Head-start amphibians for release

    A before-and-after study in 1972–1991 of natterjack toads Bufo calamita on heathland in Hampshire, UK (Banks, Beebee & Denton 1993) found that captive-rearing and releasing toadlets, along with aquatic and terrestrial habitat management, tripled the population (see also Buckley & Beebee 2004). Egg string counts, i.e. the female population increased from 15 to 43, with a maximum 48 in 1989. Captive-reared toadlets raised from eggs were released in 1975 (8,800), 1979, 1980 and 1981 (1,000/year). Nine small ponds were created (< 1,000 m2) and four restored by excavation. In addition, scrub, bracken and swamp stonecrop Crassula helmsii were removed and limestone was added to one acidic pond annually in 1983–1989. Toads were monitored each 10 days in March and August each year.

     

Output references

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