Your link has a space in it. So its invalid.

The page should be at
www.earlham.ac.uk/sites/default/files/images/articles/Keeping
Colombia%20megadiverse/colombian-trees.jpg

SOME browers handle invalid links (with spaces) by adding in the %20
seamlessly.

So its broken site, written by someone who's using a browser that's fixing
their error in realtime. So they don't see there mistake.