Help on error (Error: could not find function "kernelUD")

Hello,

I am working through examples of generating Home Range using the
adehabitatHR package. Everything is going fine until I load the code for the
kernelUD function, it looks like this;

data(puechabonsp)
kud <- kernelUD(puechabonsp$relocs[,1], h="href")
kud

I then get an error of;     Error: could not find function "kernelUD"

Any thoughts on what I am doing wrong to get this error, should that
function be built into the package?

Thanks!

Angela (aka very new to R)