These Tree Swallows have been feeding their chicks in their cavity nests for some time, however the chicks are now big enough to be sticking their heads out and so can be seen.
Both parents have a full-time job. They spend most of their time flying around the immediate neighbourhood of their nest catching aerial insects.
An winged insect is delivered to the yawning gape of a chick by the mother.
And the father delivers a different insect.