abd (version 0.2-8)

BrookTrout: Salmon Survival in the Presence of Brook Trout

Description

Total numbers of salmon released (salmon.released) and surviving (salmon.surviving) in 12 streams, 6 with brook trout present and 6 with brook trout absent. The proportion of salmon surviving (proportion.surviving) is given for each stream.

Format

BrookTrout is a data frame with 12 observations on the following 4 variables. BrookTrout2 is a different summary of the same study and gives survival rates for chinook in different years.

trout

a factor with levels absent and present indicating whether brook trout are absent or present in the stream

salmon.released

a numeric vector of the total number of salmon released

salmon.surviving

a numeric vector of the number of salmon surviving

proportion.surviving

a numeric vector of the proportion of salmon surviving

Source

Levin, P.S., S. Achord, B.E. Fiest, and R.W. Zabel. 2002. Non-indigenous brook trout and the demise of Pacific salmon: a forgotten threat? Proceedings of the Royal Society of London, Series B, Biological Sciences 269: 1663-1670.

Examples

str(BrookTrout)
str(BrookTrout2)

bwplot(proportion.surviving ~ trout, BrookTrout)

aggregate(proportion.surviving ~ trout, BrookTrout, FUN = favstats)
summary(proportion.surviving ~ trout, BrookTrout, fun = favstats)