Orientation of juvenile barn swallows
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.
data(swallows)
A data frame with 114 observations on the following 2 variables.
treatmenta factor with levels control (control
group: local magnetic field) and
shifted (shifted magnetic field, magnetic North =
geographical West)
headinga numeric vector: modal heading of each bird
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.
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))Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.