Wyoming Landscapes - The Desert Life Zone

The rains drizzle into the desert basin; the water collects itself and courses around greasewood mounds and out across the alkali flats. At one point along the pour, the level surges, rises above a lip, and spills into the ancient meander of an oxbow bend. In the pool that night, a boisterous aggregation of Great Basin Spadefoots assembles ... A week passes and the pond has shriveled to a puddle and its demise is at hand. The tadpoles, a teaming and heaving riotous mob, now stir in a batter that is more flour than water ... click here for the full excerpt

The rains drizzle into the desert basin; the water collects itself and courses around greasewood mounds and out across the alkali flats. At one point along the pour, the level surges, rises above a lip, and spills into the ancient meander of an oxbow bend. In the pool that night, a boisterous aggregation of Great Basin Spadefoots assembles. Males clasping females, they shed their gametes and then disperse. Abandoned and left behind, the reproductive efforts of the affair now rest quietly, cradled amongst the submerged vegetation.

By mid morning, the trickle feeding the oxbow subsides and dies, leaving the severed pool isolated and alone. A fertilized egg, encased within a gelatinous capsule, divides into a pair of cells, then four, then more; these multiplying cells form a ball (the blastomere) that surround and consume the nourishing yolk. Later, in the afternoon, the ball puckers, forms a neural groove where a backbone will lie, and then elongates by developing head and tail. Gill emerged; muscle twitched; heart fluttered; blood flowed.

The day evaporates into night and the embryo hatches from its jelly case. A tadpole now, it lingers still clinging to the old nursery and waits for its body to acclimate to the new environment. With youthful zeal, it outgrows the attraction, swims an inch or two, then stutters and stalls. Like a feather, drifting and wafting in descent, it settles to the bottom and lies exhausted from the effort.

A week passes and the pond has shriveled to a puddle and its demise is at hand. The tadpoles, a teaming and heaving riotous mob, now stir in a batter that is more flour than water. Those that were unable to complete metamorphosis are denied even a futile attempt at escape; they dry into chips and are entombed within the mud. The newly transformed (or mostly so) begin their exodus. Some take immediate (but alas temporary) refuge in deeper hoof shaped troughs left by mammals having previously visited the scene. Some seek (sadly still, short-lived) shelter from the drying sun by hiding under blistered and curling plates of mud. Still others drag across the land, leaving a desperate, streaking trail out of the mire, their corpus soon eaten by beetle and ant.

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