woodpecker {popbio} | R Documentation |
Number of juvenile and adult Acorn Woodpeckers and survival in the Water Canyon, New Mexico population, reconstructed from Stacey and Taper (1992).
data(woodpecker)
A data frame with 18 observations on the following 4 variables.
rate
year
start
surv
Stacey, P.B., and M. Taper. 1992. Environmentl variation and the persistence of small populations. Ecological Applications 2: 18-29.
Akcakaya, H. R. 2002. Estimating the variance of survival rates and fecundities. Animal Conservation 5: 333-336.
Kendall, B. E. 1998. Estimating the magnitude of environmental stochasticity in survivorship data. Ecological Applications 8(1): 184-193.
data(woodpecker) woodpecker with(subset(woodpecker, rate=='adult'), plot(year, start, type='o', pch=16, ylab="Number of adults", xlab="Year", main="Acorn Woodpeckers in Water Canyon")) ##stage-specific survival rate x<-aggregate(list(Nstart=woodpecker$start, Nsurv=woodpecker$surv), list(stage=woodpecker$rate), sum) x$survival<-x[,3]/x[,2] x