Then as Dazzler suggested might happen... I managed to split it! I have to add the birch I was using seemed to have quite an irregular grain which didn't help.
Everyone must of done that at some stage, dont be discouraged, try again
If the birch was on the floor (eg a fallen one that was there more than a few months) it might of gone spalty, was it sort of mottled inside with dark veins and soft bits like the inside of a crunchie bar? Irregular grain can be a pain but then most wood has it
Just one of those things. Woodwork (in most any form) is really a developed series of procedures and processes that find effective ways to deal with and minimise that fact. It is possible to split off those side pieces, but unless your log has ruler-straight even grain, chances are one side or the other will run off and take the bowl section with it LOL Its happened to me lots of times thats why I rip them now.Keep trying though!
A coping saw wouldnt help much, but a bow saw would be OK to do the rough form. I use a big beautiful old disston rip saw, and basically just remove the 2 pieces either side of where the handle (of a ladle) is going to be, just a very basic squre box formm which is then refined with axe and knife. Do the curves where the handle meets the kuksa bowl with a narrow bladed knife, it will travel smoothly around the radius