“Does age-related mortality explain the life history strategies of tropical and temperate songbirds?”

The history tries to elaborate on reasons why species numbers differ from that of the offspring. For example, in the history of the evolution of tropical songbirds, they seem to develop at the same rate as those of the temperate type. However, they develop wings faster. The growth patterns have been influenced by the feeding of the offspring by the parent and the presence of predators.

Research shows that temperate species have a faster growth rate during the early stages. However, On the other hand, in tropical species, during the later stages of life, faster growth occurs, making them acquire almost the same body mass as those of temperate species in the equal timeline (Martin, 2015). These findings have helped us understand the growth of wings of both temperate and tropical species of songbirds. The tropical species develop longer wings than those of temperate species, despite the temperate ones being the first to develop wings. This has reduced the death rate among tropical species after the nestling period, enabling adequate provision for their offspring. On the other hand, temperate species face difficulty evading predators due to shorter wings and hence experience a high death rate making it difficult to provide for their offspring. 

Reference

Martin, T. E. (2015). Age-related mortality explains the life history strategies of tropical and temperate songbirds. Science, 349(6251), 966-970.