There is a pair Herring Gulls that have been a around since the beginning of the breeding season which has nested on our neighbours flat roof. (Actually there are hundreds of pairs all nesting on roofs in the area. Each pair has their own roof and they come year after year.) The male from the neighbours roof is really friendly and so nosy, he sits on our shed hours every day watching. What I have noticed though is his nostrils - I can see right through one side and out the other and his beak is continually dripping through these holes. What is the pupose of this dripping?
http://www.mywildlifefriendlygarden....gull%20(6).jpg