First time I’ve heard this iconic and declining bird. Listen for the machine gun fire of drips and drops. Also the ‘whee-whee-wheeee’ wheezy call. There are a few warblers in the background which might confuse things.
The habitat you can see is coppiced birch trees with a few maturing sessile oaks in the background. Birch trees can be cut right down to the base on a cycle of between 7-12 years or so and they will grow back vigorously. This creates the dense vegetation that the naturally elusive – to the eyes – nightingale depends on to breed. Blean also holds one of England’s few colonies of heath fritillary butterfly which will benefit from the sunlight reaped by coppicing.