Does Hibernation Slow the “Pace of Life” in Dwarf Lemurs (Cheirogaleus spp.)?

The classic mammalian life history continuum polarizes small-bodied species that live fast and die young from larger-bodied species with longer life spans and reduced adult mortality rates. Hibernating mammals, however, deviate from this pattern and tend to have short gestations, accelerated early infant growth in preparation for hibernation, retardation of growth and development in association with hibernation, and delayed achievement of full adult size and first reproduction. This pattern has never been systematically tested in hibernating primates. We examine body mass, growth trajectories, dental development, and reproductive status of dwarf lemurs (genus Cheirogaleus ), the only obligate hibernators among primates, to determine whether life histories in these small-bodied strepsirrhines vary in accord with expectations based on the use of energy-saving strategies. We show that this pattern does indeed hold for primates. Unlike similarly sized nonhibernating strepsirrhines such as bush babies (genus Galago ), wild dwarf lemurs display short gestation and lactation periods, rapid early (pre-hibernation) growth and development followed by retardation of growth and dental development during hibernation, delayed attainment of adult size, and delayed first reproduction. We conclude that hibernation constrains the degree to which dwarf lemurs can experience life in the fast lane. Cheirogaleus have life history profiles that are neither fast nor slow but a combination of both.