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,
Dormancy is dormancy imposed by the external environment. "Correlated inhibition" is a kind of physiological dormancy maintained by agents or conditions originating within the plant, but not within the dormant tissue itself. "Rest" (winter dormancy) is a kind of physiological dormancy maintained by agents or conditions within the organ itself. However, physiological subdivisions of dormancy do not coincide with the morphological dormancy found in white spruce ("Picea glauca") and other conifers (Owens et al. 1977). Physiological dormancy often includes early stages of bud-scale initiation before measurable shoot elongation or before flushing. It may also include late leaf initiation after shoot elongation