I discovered this nest today, stumbled upon it without realising, and recognised it immediately as the nest or 'bedroom' of lesser spotted teenager bird. Many characteristics shared with teenager birds worldwide, but this particular nest made more obvious by loud calling (shouting) of female, or mother, lesser spotted bird upon discovery. Much fuss and botheration between teenager and mother resulting in nest reformation into what can only be described as a 'tidy' condition. Barely natural environment for lesser spotted teenager bird, but its okay, don't worry, well known to return nest to more natural environment as soon as mother's back is turned.
