Estimates of Lethal Equivalents and the Cost of Inbreeding in Mammals


Research output: Contribution to journalArticlepeer-review


Abstract: The costs of inbreeding in natural populations of mammals are unknown despite their theoretical importance in genetic and sociobiological models and practical applications in conservation biology. A major cost of inbreeding is the reduced survival of inbred young. We estimate this cost from the regression of juvenile survival on the inbreeding coefficient using pedigrees of 40 captive mammalian populations belonging to 38 species. The number of lethal equivalents ranged from –1.4 to 30.3, with a mean of 4.6 and a median of 3.1. There was no significant difference between populations founded with wild‐caught individuals, a mixture of wild‐caught and captive‐born individuals, and individuals of unknown origin. The average cost of a parent‐offspring or full sibling mating was 0.33, that is, mortality was 33% higher in offspring of such matings than in offspring of unrelated parents. This is likely to be an underestimate.

Original languageEnglish
Pages (from-to)185-193
Number of pages9
JournalConservation Biology
Issue number2
StatePublished - Jun 1988
Externally publishedYes

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Ecology
  • Nature and Landscape Conservation


Dive into the research topics of 'Estimates of Lethal Equivalents and the Cost of Inbreeding in Mammals'. Together they form a unique fingerprint.

Cite this