Black Bear

[Tiger the Lion]

Love natural history pieces. Some thoughts below:

Curled in this narrow space
she aches from the bite of winter.
She has grown narrow and bones
protrude at her hips and shoulders. Not sure about the 2 uses of "narrow" in such close proximity. You may be able to sub "hollow" in either instance. Might maintain the sonics and meaning.

Small inert forms tuck beneath her pelt, "Pelt" almost always refers to skin/fur from an already dead animal. Was this intentional? If not, fur,hair, coat - all work.
their slumber soothed by diaphanous ghosts
 that hover above the space where
 denizens await the rebirth of earth.

The trill of a robin, a rustle of deer, not sure about "a rustle" here. -- the rustle? a rustling? I'm not sure.
the run off of melting snow down green hills.
Inertia still aches in her ribs.
Shivering dormancy she emerges into spring - "emerges into" doesn't work. By simple definition you are saying "comes out of into" Lots of ways to fix this. I'm sure you'll find one.
where there is room to breathe.

Enjoyed this one. Good luck with it!
Paul