Why there is no negative correlation between egg size and number in the Common Pochard?

Abstract

Trade-off between offspring size and number belongs to the most discussed concepts in the life history theory. Our data of the Common Pochard (Aythya ferina) indicate that females which had laid clutches containing many big eggs lost a much larger amount of energy invested and, moreover, produced hatchlings of relatively lower body mass if compared with females having few small eggs.

Keywords

• egg size number trade off
• energy allocation
• breeding attempt
• birds