beavers {stats}R Documentation

Body Temperature Series of Two Beavers

Description

Reynolds (1994) describes a small part of a study of the long-term temperature dynamics of beaver Castor canadensis in north-central Wisconsin. Body temperature was measured by telemetry every 10 minutes for four females, but data from a one period of less than a day for each of two animals is used there.

Usage

data(beavers)

Format

The beaver1 data frame has 114 rows and 4 columns on body temperature measurements at 10 minute intervals.

The beaver2 data frame has 100 rows and 4 columns on body temperature measurements at 10 minute intervals.

The variables are as follows:

day
Day of observation (in days since the beginning of 1990), December 12–13 (beaver1) and November 3–4 (beaver2).
time
Time of observation, in the form 0330 for 3:30am
temp
Measured body temperature in degrees Celsius.
activ
Indicator of activity outside the retreat.

Note

The observation at 22:20 is missing in beaver1.

Source

P. S. Reynolds (1994) Time-series analyses of beaver body temperatures. Chapter 11 of Lange, N., Ryan, L., Billard, L., Brillinger, D., Conquest, L. and Greenhouse, J. eds (1994) Case Studies in Biometry. New York: John Wiley and Sons.

Examples

data(beavers)

(yl <- range(beaver1$temp, beaver2$temp))

beaver.plot <- function(bdat, ...) {
  nam <- deparse(substitute(bdat))  
  attach(bdat)
  # Hours since start of day:
  hours <- time %/% 100 + 24*(day - day[1]) + (time %% 100)/60
  plot (hours, temp, type = "l", ...,
        main = paste(nam, "body temperature"))
  abline(h = 37.5, col = "gray", lty = 2)
  is.act <- activ == 1
  points(hours[is.act], temp[is.act], col = 2, cex = .8)
}
op <- par(mfrow = c(2,1), mar = c(3,3,4,2), mgp = .9* 2:0)
 beaver.plot(beaver1, ylim = yl)
 beaver.plot(beaver2, ylim = yl)
par(op)

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