I have a 2 day old blue tit nestling. I have been feeding him mince beef every hour ( he won't take it any sooner) and he has been thriving. BUT tonight iv noticed his abdomen is looking VERY black??? With a sort of yellow bit in it... I hatched him from an egg as my neighbour destroyed his nest. By mistake of course. Anyway it was irreparable and the only whole egg was still warm! I set my radiator to 38 degrees and 48 hours later he was pipping! Al be honest I did not expect it to even work! But he's here!! His belly was a little black at hatching but I'm sure it's not ment to be as bad as it is.... I can't find any info on this anywhere so this is our last plea for help...
I'd be inclined to check www.helpwildlife.co.uk and see if there is a rescue centre nearby (not a vet).
Unicum arbustum haud alit duos erithacos
(One bush does not shelter two Robins)
Zenodotus (3rd Century B.C.)