Premium
Uinta Ground Squirrel Demography: Is Body Mass a Better Categorical Variable Than Age?
Author(s) -
Sauer John R.,
Slade Norman A.
Publication year - 1987
Publication title -
ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.144
H-Index - 294
eISSN - 1939-9170
pISSN - 0012-9658
DOI - 10.2307/1938469
Subject(s) - fecundity , demography , population , litter , ecology , biology , categorical variable , mathematics , statistics , sociology
We compared the relative impact of age and body mass on fecundity and survival in a population of Uinta ground squirrels, and modeled the population using body—mass classes as stage categories of Lefkovitch stage transition matrices. Body mass was a better predictor of survival than was age, and was nearly as good a predictor of litter size. Mass—based stage transition matrices provided results similar to age—based transition matrices, but also indicated that larger and subsequently more fecund young were a consequence of a population reduction. We believe that mass—based analysis of ground squirrel populations is a viable alternative to traditional age—based analyses. Body mass is easy to measure in small—mammal populations and is linked to a variety of life—history characteristics.