A new study from Lund University in Sweden increases knowledge of how boundaries and barriers are maintained between different species in the animal world. According to theory, crosses between two species, known as hybrids, may not survive encounters with natural predators to the same degree as their parents. Now, researchers at the Department of Biology in Lund show that reality confirms this theory.
Hybrids between the closely related fish species of roach and bream fall prey to fish-eating cormorants to a far greater extent than their parents. This has been proven in a field study. According to the researchers, this is probably due to the hybrids’ inability to fully exploit the properties which make their parent species difficult for predators to catch: speed and body shape.
— source alphagalileo.org 2017-08-17