woodpecker | R Documentation |
Number of juvenile and adult Acorn Woodpeckers and survival in the Water Canyon, New Mexico population, reconstructed from Stacey and Taper (1992).
woodpecker
A data frame with 18 rows and 4 columns
rate
Adult or juvenile stage
year
Year
start
Total number of starting individuals
surv
Number surviving to spring
Stacey, P.B., and M. Taper. 1992. Environmental 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.
Kendall
and varEst
woodpecker
x <- subset(woodpecker, rate == "adult")
plot(x$year, x$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
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