Life Tables and the Leslie Matrix
Life Table Construction
Barnacle Life Table (Connell 1970)
Average # offspring per original individual
Tc =cohort generation time =mean time between birth of individual and its offspring
Tc=3.928/1.282=3.1
The intrinsic rate of increase ( r ) is approximated by lnR0/Tc =0.08
Yes! This is the r found in dN/dt=rN.
The intrinsic rate of increase is simply a population average and fails to provide precise age-specific influences on population size.
The Leslie Matrix provides Age-based Estimates.
Only females count in a Leslie Matrix
You need Px=probability that a female of age x at time t will live until time t+1
You need the mean # of female offspring produced by females of age x. This number (mx) is obtained from a one-sex life table.
Multiply P0 by the mean # of female offspring produced by age x females to obtain the net fecundity (fx), which = the number of those offspring that survive to age 1.
Building a matrix M
Cohort life table of female gray squirrels from(Charlesworth 1994)
The Leslie Matrix! For Charlesworth (1994) M=
A more easily multiplied Leslie Matrix from Begon et al. (1996)
The state vector=the # individuals in each age class (nx) at t1.
Multiply Matrix * Vector to get age distribution at time t2 (Begon et al. 1996)
Email: Albert.Meier@wku.edu
Home Page: http://bioweb.wku.edu/faculty/ameier
Other information: This slide show constitutes Lecture 1 of 500 for Ecology 315.