Oak & Nuthatch !

My local patch Ashenbank Woods has been providing me with some good woodland photographic opportunities as well as enhancing my knowledge and understanding of  woodland natural history.
I thought I would write a more in depth report on the Nuthatch nest site

I made an effort to learn a few calls from the woodland birds that  I might come across, the call of the Nuthatch was one of those, nothing special about that,  its quite an easy call to recognise, but it makes locating the Nuthatch a lot easier.

I have been trying for sometime to get a decent photograph of a Nuthatch, without much success, my luck  may have changed as I have stumbled across an active nesting sight, so if all goes well for the Nuthatches, the opportunity to study their nesting activities and the chance to get some photographs will be very welcome.

So this  is the Oak tree, the Nuthatches are nesting in what looks like an Oak Burl, approximately ten metre above the ground, indicated by the white star in the photograph

This is a close up of the Oak burl and the entrance to the nesting burrow, it looks like the bark has been chipped away all around the entrance, the actual entrance hole looks quite small, Nuthatches are known to reduce the size of entrance holes by plastering around the hole with mud, the optimum being about three centimetres .

I found this line drawing of various Nuthatch nesting burrows to give an idea of what's going on inside.

I first came across this site on 1st April , two birds were coming to the nest site, very difficult to tell which bird was male or female, I believe the only way to tell is the underwing colouring, which in the male is slightly darker orange , the female is lighter and more uniform, I have found this not to be very helpful in the field. The photograph below does show a slightly darker brick red to the underwing, so could this be the male ?

Possible male Nuthatch ( darker brick red underwing )

Both birds were seen arriving at the nest site with bark flakes in their beaks, which they quickly deposited within the burrow before quickly exiting. see photographs below and the diagram above.

It seems that the depth of the burrow can be controlled by the depth of the bark flake level, ensuring the optimum level is obtained, the eggs are laid in a shallow depression within the bark flakes.

Possible female nuthatch ( paler underwing blending into breast)

So it appears that three days later April 3rd, both birds are still bringing in bark flakes for the interior of the burrow. It will be difficult to know whether eggs have been laid if it gets that far, I suppose seeing the  parent birds bringing food to the burrow will indicate successful hatching. I will be keeping a watchful eye as I pass through on my daily walk through the woodland, a further report to follow as things hopefully progress.