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The effects of prorating risk in the development of life‐tables
Author(s) -
Odum R. Andrew,
Smith Brandie R.
Publication year - 2001
Publication title -
zoo biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.5
H-Index - 54
eISSN - 1098-2361
pISSN - 0733-3188
DOI - 10.1002/zoo.1028
Subject(s) - biology , fecundity , population , demography , leslie matrix , sociology
This study used computer models to investigate two different strategies for assessing risk in the development of age‐based life‐tables from studbook data sets. One methodology is similar to that currently employed in American Zoo and Aquarium Association population management, which prorates animals at risk within age‐classes. The other follows the method used in human life‐tables that assumes animals are at risk for the entire age‐class. This study concludes that prorating risk may invalidate population growth projections by significantly and unequally over‐estimating fecundity and mortality rates. This effect is most pronounced in species that have distinct breeding seasons (birth pulse populations), seasonal mortality, and small data sets. Recommendations include using a non‐prorated methodology, tabulating life‐tables using only completely known age‐class data, and combining population parameters for emigrations, releases, and deaths for population growth projections. Zoo Biol 20:279–291, 2001. © 2001 Wiley‐Liss, Inc.