Nest box cameras
Nest box camera observations produced similar findings to the droppings method. The most frequently seen bird roosting in camera-nest boxes was the Blue Tit, accounting for almost two-thirds of records, with the Great Tit accounting for nearly a quarter. An absence of roosting birds was the next most frequent record, registering 5% of observations.
The camera approach was beneficial, however, in that numbers of roosting birds could be examined. Blue and Great Tits almost invariably slept alone, averaging 1.2 and 1.0 individuals per box each night, respectively. Sample sizes of other species were relatively small, so broader conclusions about how many of these normally roost together are difficult to make. However, again, Wrens topped the list with numbers scrumming down for the night reaching double figures.
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