It's a simple question that I can't really find the answer to.
Page 49 of the core book talks about other party members helping a roll with the usual +1 to +3 bonus, similar to other Free League games. Party members helping with a roll lose their own actions that 'round'.
Page 211 of the core book talks about the Delver rolling Agility to see how many zones the group can cover before encountering a hazard. Important note: No other party members are rolling anything at all until a hazard is met (or they come across something important that might warrant it). So there's nothing in principle stopping other members of the party from offering Help on those Delve rolls.
So I don't see anything preventing this at all. It *appears* like the rest of the group can Help to offer up to a +3 bonus as long as they can justify it, which shouldn't be difficult.
Likewise, same goes for bird-boy getting Help from other party members for Blight scanning, though this one might be much harder to justify unless someone can explain how they are softly singing to the bird or something before it flies off, lol.
I can't see anything at all in the book that states that Help cannot be offered on either of these. Am I mistaken?