swallows {circular} | R Documentation |
Orientation of juvenile barn swallows
Description
The _swallows_ dataset has 114 rows and 2 columns. The observations are the headings of juvenile barn swallows (_Hirundo rustica_) tested in orientation cages (Emlen funnels) during autumn migration under simulated overcast conditions.
Usage
data(swallows)
Format
A data frame with 114 observations on the following 2 variables.
treatment
a factor with levels
control
(control group: local magnetic field) andshifted
(shifted magnetic field, magnetic North = geographical West)heading
a numeric vector: modal heading of each bird
Source
Giunchi, D., and Baldaccini N. E. (2004) Orientation of juvenile barn swallows (Hirundo rustica) tested in Emlen funnels during autumn migration. Behav. Ecol. Sociobiol. (56):124-131.
Examples
data(swallows)
swallows <- split(swallows$heading, swallows$treatment)
swallows <- lapply(swallows, function(x) circular(x, units='degrees', template='geographics'))
plot(swallows[[1]])
points(swallows[[2]], col=2)
legend('topright', legend=c('control', 'shifted'), pch=c(19,19), col=c(1,2))
[Package circular version 0.5-0 Index]