Changing your blog picture is simple, and you can change it to anything you like...
First, you need to save your chosen picture onto your computer; I used the online bird guide on the RSPBs website for my peregrine. I saved by single right clicking on the image and selecting "save picture as", then chosing a folder on my computer to save it into.
Picture; peregrine
On your RSPB personal profile blog page click onto "edit profile"... over your picture you can then select "change avatar". Select the option "upload and avatar" then click to "browse". Find and select your chosen saved picture, then click "upload and use image".
Awesome!