Rare Bird - possibly

I was out the other day and taking pictures of chicks at watermead park. As is often the case all the water birds gravitated towards me hoping to be fed.

1/320 @ 6.3, iso 400, 200mm

When I took this not particularly good pic of a chic, I knew there was an adult on the edges and planned to crop her out at home. When I looked at her on the computer there was something that made me think it might not be a Mallard hybrid and I planned to go back a few days later to see if I could get some better pictures of her.

1/640 @ 6.3, iso 400, 400mm

In the mean time, her offspring seemed to get very tired from charging around after tidbits and curled up to sleep in the middle of the pool.

1/100 @ 6.3, iso 400, 400mm

The return visit was successful and she swam towards me as soon as I arrived.

1/100 @ 6.3, iso 400, 400mm

 So I had plenty of time to get more detailed photos of her.

1/125 @ 6.3, iso 400, 400mm

I cant be totally certain, perhaps someone will tell me if I am right. But looking at the pale cheeks, brown cap and dark bill with a pink tip makes me think it is a Red Crested Pochard. A bird that is very rare this far north.

1/800 @ 6.3, iso 400, 400mm

By way of an easily identified bird, here is the Heron that is nesting by a weir not 2 metres  from the footbridge.

All taken on a Canon EOS 7d and EF 100 - 400mm L series lens