Hi Glenn,
I think on the first, I'd either crop to include a bit more sky, or none at all.
On the second, I'd have leveled it - and if I'd been photographing the birds, I'd be quietly cursing
thankyou dave for the advice
The others show some action, but I think the focusing missed on the last one especially.
The last might be improved if you have the reflection of Jack's head in the foreground too.
However, in general, your cropping/composition isn't too bad.
I think the third is my favourite, and if you PP, trying to recover some detail on the shadow side of Jack would be worth doing.
Cheers,