In general, those investment diversities are the results of interactions of many biological traits to meet embryo and nestling development under the predation pressure and interspecies competition.

• 总之，如此不同的投资差异是在捕食压力和种间竞争作用下以及亲鸟为满足鸟卵胚胎和雏鸟迅速生长发育的必要条件下，各种生物学特征协调的结果。