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,
Seed dormancy an environmental signal detector for germination. For example, legume (Fabaceae) seeds become permeable after the thin-walled cells of lens (water-gap structure). Following disrupted pulls apart to allow water entry into the seed.Other water gap structures include carpellary micropyle, bixoid chalazal plug, imbibition lid and the suberised ‘stopper’. In nature, the seed coats of physically dormant seeds are thought to become water permeable over time through repeated heating and cooling over many months-years in the soil seedbank. For example, the high and fluctuating temperatures during the dry season in northern Australia promote dormancy break in impermeable seeds of "Stylosanthes humilis" and