Local variation in Rana termporaria egg and clutch size: Adaptations to pond drying?

Egg and clutch size variation among populations of common frogs (Rana temporaria) were studied in 14 ponds in Sweden. Also two secondary indices, clutch mass and allocation tactics (egg size3/clutch size) were studied. For all four characters there was a pond-wise correlation between the values across the two study years. All characters differed among ponds and all but allocation tactics differed between years. At least part of this variation must be environmental. The ponds were classified as permanent or temporary. The latter dried completely in some years, killing all tadpoles. Pond type affected all characters except egg size. Thus, clutches in shallow ponds were smaller, lighter and, correcting for clutch mass, had larger eggs (from the allocation tactics index). I suggest that this variation may he adaptive.