AVJNF: Søholt Storskov, amphibian survey

Study Extent

Ponds and lakes of Søholt Storskov, see Description.

Sampling

All already known and potential ponds suitable for breeding of amphibians were identified based on the best vectorised maps from the National Survey and Cadastre of Denmark, the official registrations of protected nature, aerial photographs from 2019, terrain height model from 2018 with 0.4 m resolution and walking in the area. The total of 88 ponds and 3 large lakes were surveyed during 11 days in the period from March 11th to June 27th, 2020. Each locality was surveyed once for early breeding amphibians one of these days: the 11th, 14th, 19th or 27th of March 2020. The localities where amphibians were found in March or those considered as potential breeding ponds were visited 1-3 times more both in April, May and June. On the 8th of May there was listened and light spotted for amphibians at day and night. At the last visit on the 26th and 27th of June a total of 69 ponds were surveyed for tadpoles/larvae by sweeping a dip net 10-15 times 2-3 m through the vegetation in each pond. In addition, there was visually searched and listened for frogs in the area around the ponds. The survey method was based on the Technical instruction A17 for the Danish monitoring program NOVANA (Søgaard et al., 2018). The hydrophone listening for Common spadefoot toad (Pelobates fuscus) was omitted because its occurrence in the area was highly unlikely. In addition to the NOVANA protocol, egg clutches of the so-called brown frogs (Rana arvalis, R. dalmatina and R. temporaria) were counted for estimation of population sizes. Common grass snake (Natrix natrix) was registered too, since it is the main predator on amphibians. Reference: Søgaard, B., Adrados, L., C. & Fog, K. 2018: Overvågning af padder. Teknisk anvisning til ekstensiv overvågning. TA A17, Version 2. Aarhus Universitet. DCE – Nationalt center for Miljø og Energi. 17 pp.

Quality Control

N/A

Method steps

1. N/A

Amphibia, Natrix natrix

1. Amphibia
   common name: Amphibians rank: class
2. Natrix natrix
   common name: Common grass snake rank: species

Denmark, Lolland, Søholt Storskov