Hawthorn Hill Of Birds And Patterns Two years ago, I lamented the absence of bluebirds up here on the hill. As well, the equally disappointing absence of the several pairs of tree swallows that habitually took up residence in the two nest boxes adjacent to our larger vegetable garden. Both species have chosen to summer elsewhere again. However, my faith in what nature writer Hal Borland has characterized as nature’s enduring patterns has not waned. Frankly, I have more confidence…