Can comparing life histories help conserve carnivores?

Abstract

The demographic relationship between life-history variation and environment may form a foundation for developing conservation strategy. We predicted that grouping 52 North American carnivore species based on life-history modules (reproductive output and reproductive chronology) would highlight differences in adaptations to particular environments. We tested whether differences among life histories related to particular environments classified according to primary productivity and seasonality into a 2 × 2 table. We found that bet-hedgers (e.g., bears, martens, fishers) have evolved life history adaptations to unpredictable environments, marine carnivores (e.g., seals) have evolved highly competitive abilities, and other terrestrial carnivores show adaptations to high reproduction (e.g., neotropical felids and procyonids) or survival (e.g., foxes and skunks). For example, 'reproducers' lived in environments with low seasonality and high primary productivity and were characterized by high reproductive output (long gestation, large neonates and small litters), short chronology of reproductive events (early age at maturity and short life), small home ranges and high population density. Conservation measures to promote carnivore populations should differ relative to the type of life history, emphasizing adult survival for bet-hedgers and survivors, and juvenile survival for reproducers and competitors. © 2002 The Zoological Society of London.