. The ecology and life history of the common frog (Rana temporaria temporaria). Rana temporaria. GENERAL LIFE HISTORY OF THE TADPOLES 39 rather exceptional event, although they were quite close together. Moorhens did not attack the spawn, but few tadpoles survived and, on 1st May, none could be found in the open pond. Some were, however, found in a small pool alongside a drain leading under the road. After three weeks, drought began to isolate this pool from the pond and, on 14th May, it only measured about 20 x 24 cm and, on 21st May, the MG. 400 300 200 100 •P<DOL -sPAWfli siIte -^ 10 20
. The ecology and life history of the common frog (Rana temporaria temporaria). Rana temporaria. GENERAL LIFE HISTORY OF THE TADPOLES 39 rather exceptional event, although they were quite close together. Moorhens did not attack the spawn, but few tadpoles survived and, on 1st May, none could be found in the open pond. Some were, however, found in a small pool alongside a drain leading under the road. After three weeks, drought began to isolate this pool from the pond and, on 14th May, it only measured about 20 x 24 cm and, on 21st May, the MG. 400 300 200 100 •P<DOL -sPAWfli siIte -^ 10 20 30 APRIL 10 20 SO MAY. O 20 SO MAY Fig. 14. Bentley Heath Village Pond, 1949 {left) A study of a doomed population in a pool that was drying up. Growth was good at first, and the decline set in under very crowded conditions. Fig. 15. Green Street Pond, 1947 (right) Another study of a doomed population. The tadpoles in the marsh were in very small volumes of water, but not very crowded, and fared well until the end. water was on the point of complete evaporation. The graph shows the changes in weight of a tadpole population at the limit of possible living conditions, brought about by entirely natural causes in a natural environment. It shows that until the conditions had become obviously desperate the tadpoles grew well. Green Street Pond 1947 (Fig. 15). Here the frogs laid about fifty clumps of spawn in a bay opening out of the marsh bordering the main pond, behind a bank. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Savage, Ronald Maxwell. New York, Hafner Pub. Co.
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Keywords: ., bookcentury1900, bookcollectionbiodiv, booksubjectranatemporaria
