Busy Tree Bees

I was quite surprised to see up to 7 Tree Bumblebees (Bombus hypnorum) busy on the Wall Cotoneaster (C. horizontalis) outside the kitchen window yesterday, despite the persistent rain. They were coming and going all the time so there's clearly a nest nearby. The only other species noted braving the weather were a couple of Early Bumblebees (B. pratorum). Today's weather is much more extreme, with gales as well as driving rain, so it will be interesting to see how hardy these newcomers really are!...