I’ve photographed a variety of songbirds, wading birds and raptors throwing pellets but yesterday was the first time I’ve been able to document a wren of any species exhibiting the behavior.
Relative size apparently makes no difference when birds are competing for nesting cavities. In this case the Northern Flickers are twelve times larger than the house wren (130 g vs 11 g).
The Williamson’s Sapsuckers I photographed earlier this summer had a routine while they were feeding their chicks and I presume it went on all day long. And often a feisty pair of wrens made that routine more complicated.