Because seasonality in tropical habitats is controlled primarily by variations in rainfall rather than variations in temperature, it is frequently less predictable in timing, and spatially more patchy than seasonality in temperate habitats. This constrains the ways in which tropical species can adapt to seasonally adverse conditions, and in particular, may give greater importance to migratory behaviour as a component of seasonal adaptation.

Australian pierid and nymphalid butterflies illustrate these points. The species studied are present as adults during the dry season. Some undergo a reproductive diapause while others breed continuously. Major seasonal shifts in geographic distribution are a conspicuous feature of their biology, except in species whose reproduction is cued directly by rainfall, or are restricted to less seasonal microhabitats. Reproductive diapause is often associated with aggregation and with non-melanic polyphenism. Reasons for spending the dry season as an adult may include the fact that adult food remains available through the dry season even though larval resources disappear, and an improved capacity for opportunistic dispersal before breeding begins. The use of direct rainfall cues to control diapause may exclude non-migratory species from subtropical or temperate regions.