I've written this poem, but I need an honest critique.

It starts at dusk, most every night
When stars come out and moon is bright
I feel my skin grow thin and tight
And in my bones I sense great might.

It hurts a bit, but very brief
Great happiness replaces grief
As my fur breaks my feeble skin
And out I come with placid grin.

Upon the ground I place my paws
As I admire my sharp claws
And such great force I feel in my jaws
My teeth as strong and sharp as saws.

My ears the silent woods can cleave
The tiniest sounds I can perceive
My eyes are keen and very sharp
They cut into the deepest dark.

My fur is brown and cream below
My tail tip black as soaring crow
By twilight night, it seems to glow
In the soft gleam of moonlit snow.

And how I run and leap and bound!
I sprint with speed and cover ground
And chase my prey to gobble meat
And howl with joy from high rock seat.

In cool, clean stream I wash my fur
I cleanse my coat of dirt and bur
And groom it neat to look real nice
And clean my teeth by chewing ice.

When tired, I curl up in my den
Asleep to the sound of chirping wren
Warm and cosy, alone and free
No shadow of sorrow, only glee.

At home in land of rock and tree
I'm happy, joyful, calm and free
A lone young wolf so full of life
So far from human stress and strife.

It is quite like a second birth
Into a body of greater girth
I wish to live here every day
Where wood is green and sky is grey.

This is the way that it should be
A lone wolf in the woods, you see
This is the wish most dear to me
A tranquil life at peace and free.