I don't know for sure or anything but this is how I think it works...
... When Abe losses a bird they just do what they do but stay within sight of Abe. If Abe get to a place where he can chant freely (no orbs or bad guys) and his birds can move freely, he can chant and get his birds back one by one...
... this idear is bassed on logical thinking, the way things tend to be on Oddworld and the Shrykull portals. As you would probly know with the Shrykull portals Abe chants, the Mudukons jump through then the birds fly out and into Abe (while he is canting). with this new info this can now be interprayed (spelling) into meaning Abe now has a lot more life... thus he can burn it off in one go becoming the Shrykull and killing everything...
... This has got me thinking... You know how Abe has a blue polsaiting (spelling) ring when he gets the Shrykull power? and you know how Abe has blue skin? Well what if Mudukon skin blueness indicates there highest posible life amount (bird amount) for a Mudukon. Therefor the blue polsating ring could be a higher skin blueness that is so high that it glows. This would explain why blue skin is highly regarded in Mudukon culture. And that could be therefor why Abe is so important.