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El Papel del Tamaño del Parche, Enfermedades y Movimientos en la Rápida Extinción del Borrego Cimarrón
Author(s) -
Singer Francis J.,
Zeigenfuss Linda C.,
Spicer Leslie
Publication year - 2001
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 - 10.1111/j.1523-1739.2001.99488.x
Subject(s) - ovis canadensis , biological dispersal , epizootic , population size , population , biology , persistence (discontinuity) , extinction (optical mineralogy) , habitat , ecology , range (aeronautics) , home range , local extinction , zoology , demography , paleontology , virus , materials science , geotechnical engineering , virology , sociology , engineering , composite material
The controversy ( Berger 1990, 1999; Wehausen 1999) over rapid extinction in bighorn sheep ( Ovis canadensis ) has focused on population size alone as a correlate to persistence time. We report on the persistence and population performance of 24 translocated populations of bighorn sheep. Persistence in these sheep was strongly correlated with larger patch sizes, greater distance to domestic sheep, higher population growth rates, and migratory movements, as well as to larger population sizes. Persistence was also positively correlated with larger average home‐range size ( p = 0.058, n = 10 translocated populations) and home‐range size of rams ( p = 0.087, n = 8 translocated populations). Greater home‐range size and dispersal rates of bighorn sheep were positively correlated to larger patches. We conclude that patch size and thus habitat carrying capacity, not population size per se, is the primary correlate to both population performance and persistence. Because habitat carrying capacity defines the upper limit to population size, clearly the amount of suitable habitat in a patch is ultimately linked to population size. Larger populations (250+ animals) were more likely to recover rapidly to their pre‐epizootic survey number following an epizootic ( p = 0.019), although the proportion of the population dying in the epizootic also influenced the probability of recovery ( p = 0.001). Expensive management efforts to restore or increase bighorn sheep populations should focus on large habitat patches located ≥23 km from domestic sheep, and less effort should be expended on populations in isolated, small patches of habitat.