BWP states '52 stomachs from throughout the year contained 24% wild fruit and seeds' so it would seem that many seeds go down the hatch. BWP goes on to state that in Southern Britain, yew (Taxus baccata) is the most popular fruit. There's no mention of regurgitation.
Whilst on the subject of mistle thrushes. A few weeks back I was watching a pair outside my bedroom window which were feeding on the berries of an Irish yew, and twice I saw one bird regurgitate the seed which dropped to the ground. I had always thought that the seeds of berries, hips, fruits etc... went through a birds digestive system and were passed in their droppings. Is there anything documented about this, or what have others witnessed? I would be interested to hear.
Today I watched a Mistle Thrush flying for a couple of minutes around a woodland in full song. BWP states they sing "exceptioanlly from ground and not infrequently in flight" . First time I've seen it in 35 years birding, (other than jumping from one perch to a nearby second). Anybody else come across this?