The gentle rains of winter prepare the way for the year’s greatest burst of activity. By March, spring flowers are blooming and birds are starting to nest. Snakes begin to come out of hibernation. April and May see the apex of spring activity, as insects swarm around the flowering plants, and birds take advantage of this proliferation of food to raise their young. The desert now is yellow with the blossoms of paloverde, mesquite, acacia, and brittlebush. But April also marks the beginning of a drought that intensifies through May and June, making these last 2 months the year’s parching crucible in which reproductive ability is tested. If winter rains have been meager, the heat and drought of May and June can kill all the young of many birds. Some birds, such as Gambel’s quail, may not even attempt to nest in a dry year. Conditions may be so harsh at this season that some mammals, such as the pocket mouse, close up shop completely, sleeping the days away underground. Relief comes with the rains of July and August. Now the summer annuals spring magically from the ground, perennials put forth new leaves, and saguaros do all their growing for the year. This summer burst of plant growth is accompanied by a new hatching of insects, which allows a few more birds to nest, and along with the new vegetation supports a larger pyramid of animal life generally. Among the new animals that reappear are toads, which now emerge from their long sleep in the soil to mate and lay eggs in the pools formed by summer rains. When the last torrential rain of August or September falls, a new dip in the yearly cycle of activity begins. This one is not so deep, not so trying, as the drought of early summer, but it too is a time of relative quiet. Roundtail squirrels go underground to sleep until cooler weather comes. Now the migrating birds slip through, hardly noticed among the mesquites and paloverdes. Butterflies lay their eggs, in preparation for a new generation beyond the winter. Signaling the last phase in the yearly cycle, wet canyons turn yellow and brown as cottonwoods, willows, and sycamores present a pale version of the spectacular foliage displays seen in the East.