Individual study: Combatting adult invasive American bullfrog Lithobates catesbeianus.
Louette G, Devisscher S & Adriaens T (2014) Combatting adult invasive American bullfrog Lithobates catesbeianus. . European Journal of Wildlife Research, 60, 703-706
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
American bullfrog control: Direct removal of juveniles
A replicated study in 2010 and 2011 across three sites in Belgium (Louette et al. 2014) found catchability of bullfrog tadpoles in small shallow ponds using one double fyke net for 24 h to be reasonably consistent at approximately 6%. Bullfrog populations were investigated in ten permanently wet, small, shallow fish ponds (average surface area 1,500 m2; max depth 150 cm), across three sites. In six water bodies (Hoogstraten and Arendonk), bullfrog tadpole population density was estimated. In these ponds, a number of double fyke nets were set (parallel and two meters out from the shore) for 24 h, covering all sides of the water body. A minimum of three catch efforts of equal magnitude were performed. After every catch effort, all captured individuals were removed from the population. To determine the accuracy of these population size estimates, calibration using seine netting was performed in two ponds.
American bullfrog control: Direct removal of adults
One replicated study in 2012 and 2013 in Balen, northeast Belgium (Louette et al. 2014) found catchability of adult bullfrog in small shallow ponds using one double fyke net for 24 h to be reasonably consistent at approximately 0.7%. Catchability of adult American bullfrogs was investigated using mark-recapture at the peak of reproduction. Adult bullfrogs were sampled during 16 separate capture occasions. At each sampling occasion in 2012, ten ponds were randomly sampled, and six ponds at each capture occasion in 2013. For every subsequent sampling occasion, a new randomisation of sampled ponds was made. Each time, one double fyke net was placed 2m out and parallel to the shore of the longest side of the pond for 24 h. Every two days, fyke nets were alternated between the opposite banks of the ponds under investigation. Individuals were marked with an injection of pigment under the skin, and released in the centre of the pond.