And sometimes, the distance given on signs increases while you get nearer ;-)

Btw, I looked at the UK Highway Code (I wanted to know whether I misbehaved when I cycled in UK before reading it).
I found zebra crossings, pelicane crossings and toucan crossings.
Ok, I (think I) understand how they work.
I am wondering about the names. Zebra crossing (German: Zebrastreifen) is obvious - the black and white stripes.
But I do not see the connection to a toucan or a pelicane. How did these crossings come to their (unusual?) names?