Reproductive Strategies and Their Relevance to Vertebrate Conservation.

Declines in global biodiversity have prompted conservation biologists not only to document the scale and causes of the problem but also to seek remedies that might mitigate the parlous state of many wild animal populations. While some corrective measures, such as reducing pollution, floods, droughts, and forest fires, necessarily require actions that operate at national or international levels, the conservation of threatened, but locally important, species can only be achieved if the biology of the target species is understood in detail. Wild species of all types have evolved mechanisms, or strategies, that optimize reproductive success in order to ensure their continued survival. Some of those evolved strategies are unexpected and surprising, as well as being difficult to replicate in scenarios such as breeding programs, where the prime objective is often to support dwindling or small populations. For example, natural breeding may be highly seasonal in some species and dependent on daylight/dark cycles, while in others, cues such as food availability and the occurrence of floods or droughts may be more important modulators of survival. Some reptilian species have evolved mechanisms that influence the sex ratios of succeeding generations by influencing the temperature at which embryonic development occurs, while some fish species have the ability to change gender if, for example, a breeding male is lost from a population.The purposes of this article are twofold: first, to highlight the diversity of reproductive strategies among vertebrates and, second, to examine the importance, feasibility, or, indeed, difficulties involved in applying assisted breeding technologies.