Great Spots

of recent days an enormous amount of aggressive behaviour between 2/3 Great Spotted Woodpeckers in the ash wood on Waters's Edge bordering Barton Broads--two birds drumming often in the same old ash--I have watched them on three mornings constantly chasing and falling out---both birds attempt to use the same more noisy branch in the large ash displacing each other frequently---when a third bird arrived there was pandemonium with much more noisy calling and aggressive flights and chases around tree trunks---when I eventually got some shots of the two it suddenly dawned on me that both were in fact females!---strangely I had assumed that males do most of the drumming but consulting BWP I see it states that both sexes drum and use this as an aggressive defence of territory and nest holes----I did not see the third bird well enough to see if it was a lucky male!----