Table 1 Definitions and notation used in this study
NeEffective population size per generation
NbEffective number of breeders in one time period
Embedded ImageAn estimate of Nb or Ne based on genetic data
Embedded ImageAn estimate of Nb adjusted to account for bias due to age structure
NTTotal number of individuals age 1 and older alive at any given time
NATotal number of adults (individuals with age ≥α) alive at any given time
N1Total number of offspring produced per time period that survive to age 1
xAge (units can be days, weeks, months, or years)
sxProbability of surviving from age x to age x + 1
lxCumulative probability of surviving to age x (Embedded Image with s0 = l1 = 1)
bxMean number of offspring in one time period produced by a parent of age x
ωMaximum age
αAge at maturity (first age with bx > 0)a
ALAdult life span = ωα + 1
GenGeneration length (mean age of parents of a newborn cohort)
CVfCoefficient of variation of bx for adult life span (using only ages with bx > 0)b
HMeanHarmonic mean
SASSIndividuals of the same age and sex
  • a This follows the definition used by Waples et al. (2013), who adopted a simple rule to deal with a large number of diverse data sets. When sufficient data are available, a more precise estimate would be age at which 50% are mature or weighted age at first maturity.

  • b When bx varied between sexes, CVf was computed over data for both sexes, after standardizing bx to values that produce a population of constant size.