Seasonal fluctuations in animal population dynamics are among the most fundamental attributes of life on Earth. A long recognized but poorly understood example is the dramatic seasonal fluctuation in the abundance of malaria vectors in the semi-arid savannah and Sahel regions of Africa. In these regions, the vector mosquitoes largely disappear during a prolonged 3- to 8-month dry season, when lack of rain causes the aquatic larval habitats to disappear. As a result, malaria transmission plummets. When the rains return, the mosquito vectors rapidly reappear, leading to a resurgence of malaria transmission. How the vector populations are able to persist through the prolonged dry season and rapidly rebound with the onset of rains is referred to as the ‘dry-season malaria paradox’, and has remained an enduring mystery of malariology for nearly 100 years. Writing in Nature Ecology & Evolution, Faiman et al.1 help to resolve this mystery by using an innovative isotopic labelling strategy: they demonstrate that at least approximately 20% of the local population of the malaria vector Anopheles coluzzi in the West African Sahel survive the dry season locally by undergoing summer dormancy, known as aestivation.
Source: Ecology - nature.com
