A walk in the bush

My first images I am posting for critique.
I took my D50 for a walk yesterday and took quite a few photos. Here are some I'd like you to review and comment on ways I can improve them.
Here they are:
This is the full frame of the first one.
This is my favourite one.
Some more of the pics are at my gallery at http://www.mybugbear.net/D50-pics/
I don't think any of these are fantastic shots but they are my attempts at nature photography. I'd really like to eventually get a macro lens or even a zoom with a macro to put on my D50.
Thanks for helping me.
Alistair
I took my D50 for a walk yesterday and took quite a few photos. Here are some I'd like you to review and comment on ways I can improve them.
Here they are:

This is my favourite one.
Some more of the pics are at my gallery at http://www.mybugbear.net/D50-pics/
I don't think any of these are fantastic shots but they are my attempts at nature photography. I'd really like to eventually get a macro lens or even a zoom with a macro to put on my D50.
Thanks for helping me.
Alistair