Fig. 2. (A) Water retention curves for soil from Notaden nichollsi (dune and swale) and Neobatrachus aquilonius (claypan and swale) burrows. Each line represents a curve for a soil sample collected at a different excavation point within each site. (B) Relationship between soil gravimetric water content and water potential (Decagon Dewpoint PotentiaMeter) for dune, swale and claypan soil. Data are for soil samples taken at intervals from the soil surface down to the depth of the burrowed frog, during excavations in 2004. Grey symbols in B are beyond the resolution of the Decagon analyser and are between 0 and -100 kPa.