Quick question about English transitive verbs w/o objects

[Das Baron]

Is there a name or technical term for the way English treats transitive verbs like "to feed", whereby they usually take an object ("The bird feeds its young"), but when it takes no object it's understood as having an unstated reflexive object ("The bird feeds"; i.e. "The bird feeds itself")?

[linguoboy]

Is there a name or technical term for the way English treats transitive verbs like "to feed", whereby they usually take an object ("The bird feeds its young"), but when it takes no object it's understood as having an unstated reflexive object ("The bird feeds"; i.e. "The bird feeds itself")?

"ambitransitive"

[KathTheDragon]

More specifically, ergative verb.

[Yng]

Not quite sure this works as ergative. When a bird 'feeds', it doesn't follow that it is 'being fed' - it could be eating food it found itself. When a glass breaks, it is broken.

I would say 'feed' transitive and 'feed' intransitive are actually different senses without a transparent connection like 'break' (trans) and 'break' (intrans). Perhaps you could interpret it as having an unstated reflexive object, but that's not how I intuitively interpret it and I can't think off the top of my head of any other examples.

[Curlyjimsam]

Beth Levin in her book English verb classes and alternations calls this the "understood reflexive object alternation". This PDF has a good summary of the various alternations Levin discusses: there are other meanings which can arises when an object is omitted too, depending on the verb in question - so The bird eats does not mean "the bird eats itself" but "the bird eats something unspecified" (unspecified object alternation).