Aestivation also aestivate. Although relatively uncommon, a small number of mammals aestivate. Animal physiologist Kathrin Dausmann of Philipps University of Marburg, Germany, and coworkers presented evidence in a 2004 edition of "Nature" that the Malagasy fat-tailed dwarf lemur hibernates or aestivates in a small tree hole for seven months of the year. According to the Oakland Zoo in California, East African hedgehogs are thought to aestivate during the dry season. Aestivation Aestivation or æstivation (from , summer, but also spelled estivation in American English) is a state of animal dormancy, similar to hibernation, characterized by inactivity and a lowered metabolic rate,
History of the San Fernando Valley the location of human settlements in the San Fernando Valley was constrained by two forces: the necessity of avoiding winter floods and need for year-round water sources to sustain communities through the dry summer and fall months. In winter, torrential downpours over the western-draining watershed of the San Gabriel Mountains entered the northeast Valley through Big Tujunga Canyon, Little Tujunga Canyon, and Pacoima Canyon. These waters spread over the Valley floor in a series of braided washes that was seven miles wide as late as the 1890s, periodically cutting new channels and reusing old ones, before sinking into the gravelly