Page:Popular Science Monthly Volume 48.djvu/509

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EFFECT OF DROUGHT UPON ANIMAL LIFE.
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instance of the effects of the drought was to be seen in a small stream known as Pond Run. This is fed by scattered springs; is a stream of perhaps an average depth of six inches and a width of two or three feet. Sudden dashes of rain swell the volume of waters, but this accession is as rapidly run off. In ordinary summers the volume is reduced to considerably below the estimated average measurements, but the stream has not before been known to be absolutely dry throughout its course. For a period of five weeks the water from the springs along its valley were insufficient to give it running water, and in many cases there was no perceptible moisture at the fountain heads. As the water gradually disappeared, that portion of the stream's fauna dependent wholly upon moisture, as fish, turtles, and batrachians, collected in the pools, particularly those beneath bridges, and there by overcrowding soon poisoned the water to which no fresh supply was being added. It might be asked why these animals, except the fish, did not seek other and healthier localities, but the reason is plain. Everywhere about them was an arid region exposed to a tropical temperature into which they did not dare to venture. Again, while lingering in the pest holes into which they had gathered, they had gradually undermined their strength and were too weak to travel when, if ever, it occurred to them to do so.

And now back to the meadows. The last general migratory movement was to the tide-water flats, and here, of course, the moisture and vegetation were unaffected, and I have never seen so crowded a condition as that in which were many of the streams that were never quite dry at even the lowest stage of the tide. The carnivorous fishes waxed fat, for there was an available minnow ever in front of every pike, perch, and bass; and the grasshoppers driven to the creek banks, where alone there was green herbage, were continually leaping into the stream, and were snapped up before they could reach the opposite shore. There was here, however, not such an accession of batrachian life, frogs in particular, as might have been expected, and I failed to notice any undue number of the mud minnow (Umbra limi). This fact led me to make a few examinations of the parched or semi-desiccated areas. I found in two locations, that I had never before known to become dry, that frogs, of three species, and the mud minnow had buried themselves where there still remained moisture, but with a crust of dry earth above it. These frogs and fish were like hibernating animals when exhumed—i. e., soundly asleep, rather than dead, and all slowly revived when placed in clear, cool water. I estimated that they had been in their cramped quarters for at least three weeks. Two weeks later, I hunted for others but failed to find them; but the day after the first prolonged rain I found the mud minnows in their usual abundance