Heterothermy, the ability of some animals to lower their metabolism and body temperature, is traditionally seen as an effective adaptation to predictable seasonal bottlenecks of unproductive cold periods. A new review suggests that the use of heterothermy may have been used as a response to acute emergency situations in animals that colonized Madagascar.
Land mammals from Africa may have colonized Madagascar by rafting on drifting vegetation, and heterothermy may have facilitated survival on rafts and after colonization. Furthermore, delayed childbirth and prolonged sperm storage would have allowed females to reach the island with unborn offspring and to establish a founder population. Indeed, all recent taxa of land mammals found on Madagascar or their close relatives include representatives that use heterothermy.
"Our article uses the colonization of Madagascar as an example, although the concept is true for any colonization event. Torpor is incredibly useful when it comes to surviving periods without, or only limited access to, food and water, such as during a raft on the ocean or a journey to unhospitable landscapes," said Dr. Julia Nowack, lead author of the Mammal Review article.