The research behind a mainland conservation flock

In a September 1989 paper, Dirk van Vuren and Philip Hedrick treated Santa Cruz Island sheep as a case study in conserving genetic resources from feral livestock. Their report records the capture of 18 lambs to establish a mainland population. Eighteen is a historical founding group, not a count of sheep alive today.

The authors described several ways that an isolated livestock population might retain valuable variation: visible traits, reproductive or survival characteristics, rare alleles and the circumstances of its ancestry and isolation. Their abstract reports evidence of potentially valuable traits in the Santa Cruz sheep. It does not establish that every present-day descendant carries every proposed adaptation.

The paper also recognized a difficult conservation boundary. Retaining livestock genetic resources must not undermine protection of native biodiversity threatened by feral animals. Moving a founding group into managed care offered a way to conserve a livestock lineage while addressing island ecological damage. That dual purpose remains central to understanding this breed’s preservation history.