Understanding a major global divergence in tropical life history strategies

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Life history attributes such as rates of birth, death, growth, and development typically are related in predictable ways that support distinct, but successful, life styles. Typically, birth rate and adult longevity are negatively correlated and development time and life-time survival are positively correlated. Slow development and low fecundity are thought to be essential to a life history that includes long maximum life spans and are thought to have their effects through improving the health and survival of offspring. However, tropical birds of Asia appear to violate this pattern, being similarly long-lived to the birds of the New World tropics, but having higher fecundity and development rate. Therefore, low fecundity and slow development may not be necessary for high offspring quality and long life. This study will use extensive and detailed comparative surveys, complemented with some field experimentation, to examine possible environmental causes of the higher fecundity and faster development of 25-30 bird species in Sabah, Malaysia. Additionally, the work will examine the extent to which fecundity and development rate determine offspring immune function and thereby determine adult longevity. This work will provide new insight into the roles of development rate and fecundity in the ability to fight pathogens through immune function and of the influence of this and other indicators of offspring quality on longevity. It also will improve understanding of the environmental causes of variation in rates of birth, death, and development and their interrelationships. These rates greatly influence the vulnerability of populations to environmental change and can significantly aide our ability to sustain biodiversity in North America, as well as world-wide. Finally, this work includes substantial scientific training of many undergraduate and graduate students, including members of groups currently underrepresented in science.