nuts

Description

Squirrel data set (nuts) from Zuur, Hilbe, and Ieno (2013). As originally reported by Flaherty et al (2012), researchers recorded information about squirrel behavior and forest attributes across various plots in Scotland's Abernathy Forest. The study focused on the following variables. response cones number of cones stripped by red squirrels per plot predictor sntrees standardized number of trees per plot sheight standardized mean tree height per plot scover standardized percentage of canopy cover per plot The stripped cone count was only taken when the mean diameter of trees was under 0.6m (dbh).

Usage

data(nuts)

Format

A data frame with 52 observations on the following 5 variables.

cones

total fish counted per site

ntrees

mean water depth per site

dbh

adjusted area of site

height

total fish counted per site

cover

mean water depth per site

sntrees

standardized mean water depth per site

sheight

standardized total fish counted per site

scover

standardized mean water depth per site

Details

nuts is saved as a data frame. Count models use ntrees as response variable. Counts start at 3

Source

Zuur, Hilbe, Ieno (2013), A Beginner's Guide to GLM and GLMM using R,

References

Hilbe, Joseph M (2014), Modeling Count Data, Cambridge University Press Zuur, Hilbe, Ieno (2013), A Beginner's Guide to GLM and GLMM using R, Highlands. Flaherty, S et al (2012), "The impact of forest stand structure on red squirrels habitat use", Forestry 85:437-444.

Examples

data(nuts)
nut <- subset(nuts, dbh<.6)
summary(PO <- glm(cones ~ sntrees + sheight + scover, family=quasipoisson, data=nut))