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Historia poblacional, variabilidad genética y crecimiento de la cornamenta de los carneros de las Montañas Rocosas
Author(s) -
FitzSimmons Nancy N.,
Buskirk Steven W.,
Smith Michael H.
Publication year - 1995
Publication title -
conservation biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.2
H-Index - 222
eISSN - 1523-1739
pISSN - 0888-8892
DOI - 10.1046/j.1523-1739.1995.9020314.x
Subject(s) - ovis canadensis , biology , french horn , ovis , loss of heterozygosity , population , zoology , genetic variability , ecology , bovidae , allele , demography , genetics , genotype , psychology , pedagogy , sociology , gene
Bighorn sheep ( Ovis canadensis ) are restricted in distribution and numbers relative to presettlement conditions. Some populations have alledgedly suffered losses of fitness resulting from small, insular populations and a breeding system that reduces effective population size. Large horns in rams, which confer breeding superiority, are absent from some populations, and this absence may result in part from loss of genetic variability. We investigated the relationship among allozyme variability, population history, and horn growth in bighorn sheep from the Rocky Mountains. Heterozygosity was higher for bighorn sheep than has been reported for Dall sheep ( O. dalli ). Heterozygosity and allelic variability were marginally related to effective population size for the proceeding 15 years. Horn growth was significantly higher in more heterozygous than in less heterozygous rams for years 6, 7, and 8 of life. By the end of year 8, more heterozygous rams had 13% higher horn volumes than less heterozygous rams. Most hunting of bighorn sheep involves selective removal of large‐horned rams, which we hypothesize may reduce genetic variability of these populations and contribute to losses in fitness.