Date: April 10, 2018
Source: Lund University
In a unique study, researchers at Lund University in Sweden have mapped the origins of migratory birds. They used the results to investigate and discover major differences in the immune systems of sedentary and migratory birds. The researchers conclude that migratory species benefit from leaving tropical areas when it is time to raise their young -- as moving away from diseases in the tropics enables them to survive with a less costly immune system.
Analysing the genealogy of over 1300 song bird species, passerines, enabled the researchers to establish that both sedentary birds, which do not leave northern Europe in the winter, and migratory birds, which breed in Europe but spend the winter close to the equator, originate from Africa.
The researchers then went on to study the immune system in three different groups: sedentary birds in tropical Africa, European sedentary birds, and migratory birds. Their findings show that African sedentary birds have a more varied and extensive immune system than that of both European sedentary birds and migratory birds.