Long-term persistence of amphibian populations in a restored wetland complex
Published source details
Petranka J.W., Harp E.M., Holbrook C.T. & Hamel J.A. (2007) Long-term persistence of amphibian populations in a restored wetland complex. Biological Conservation, 138, 371-380
Published source details Petranka J.W., Harp E.M., Holbrook C.T. & Hamel J.A. (2007) Long-term persistence of amphibian populations in a restored wetland complex. Biological Conservation, 138, 371-380
This study is summarised as evidence for the following.
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Create ponds for amphibians
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.