“Nest building has begun”

B. writes:

Last Saturday, Feb 21, John C. called me to say he had just seen a pair of dippers bringing nesting material to the nest site under the bridge in Bluebird Park. I checked on Sunday and found nothing in 30 min of watching. But Monday morning saw a dipper appear from upstream and enter the cavity.

Also a pair has been seen carrying nesting material to one of the nest boxes under the bridge. I saw it yesterday (Tues, Feb 24) carrying a large gob of moss. I thought this was very early for nesting, but checked my field notes and it is the same date as in 2013. The breeding season has begun.