The five sets of photos below show life in the rookery (a term applied to any colony of breeding animals). All photos taken over two days in December 2011 at Donna Nook, Lincolnshire.
Click on the first image of each set for a larger picture that you can then view as a slideshow.

This first set show general views, as seen from the viewing area.

The set below show an unsuccessful attempt to free a female seal (cow) from a fishing rope caught around its neck. The way this is usually done is to isolate the seal, throw a weighted net over it, then get volunteer wardens to sit on the animal, covering it's head with a sack to prevent it from becoming too stressed.
This is a highly dangerous manoeuvre, which is aborted if there is any danger to the volunteers. In this case, the cow escaped from the net and was joined by other seals, so the wardens retreated.
There was no further opportunity to help this seal.

A small number of seals do die while in the rookery. If they are too close to the viewing area they are removed before they begin to rot. Adults are taken by a JCB driven by an MoD contractor, based a few hundred yards along the coast. The corpse is taken out of sight, and further out towards the tideline where it will either be washed out to sea, or eaten by scavengers.

The set below shows a bull seal hoping to mate with the cow, who is trying to explain that she is washing her hair!

For more photos and information on the breeding colony at Donna Nook, Lincolnshire, click here

However, the females give in eventually!
The gestation period is 11.5 months, including a three-month delay in the implantation of the fertilised egg to allow the cow to come ashore to give birth at the appropriate time of the year.