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Providing evidence to improve practice

Individual study: Demography and movement in a relocated population of Oregon spotted frogs (Rana pretiosa): influence of season and gender

Published source details

Chelgren N.D., Pearl C.A., Adams M.J. & Bowerman J. (2008) Demography and movement in a relocated population of Oregon spotted frogs (Rana pretiosa): influence of season and gender. Copeia, 2008, 742-751


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Create ponds for frogs Amphibian Conservation

A replicated study in 2001–2004 in four created ponds within a wetland in Oregon, USA (Chelgren et al. 2008) found that survival of translocated Oregon spotted frogs Rana pretiosa increased with increasing pond age. Nine ponds were created in 2001–2004 using explosives (0.01–0.07 ha; 2 m deep). In spring 2001, nine spotted frog egg masses and in June–September 2001, 41 frogs were translocated to the four largest ponds from a site 2.5 km away. Frogs were tagged.

 

Translocate frogs Amphibian Conservation

A study in 2001–2004 of created ponds within a wetland in Oregon, USA (Chelgren et al. 2008) found that survival was lower for Oregon spotted frogs Rana pretiosa translocated as adults compared to those translocated as eggs. Frogs had a significantly lower survival rate during the first year after translocation, compared to the following three years (e.g. large frogs: 28–44% vs 48–74%) and non-relocated frogs. Annual survival rate was significantly higher for large frogs (>53 mm; 48–74%) compared to small frogs (40–53 mm; 5–39%). Survival increased with increasing pond age. Nine ponds were created in 2001–2004 using explosives (0.01–0.07 ha; 2 m deep). In spring 2001, nine spotted frog egg masses and in June–September 2001, 41 marked frogs were translocated to the four largest ponds, from a site 2.5 km away.