We had just sat down to blueberry pancakes yesterday morning when we saw a male bluebird sitting in the maple tree outside our kitchen door. This was the first bluebird we’ve seen around our home, and so we examined his brilliant blue coat and blush breast through binoculars. Twice he swooped down to get a bug—bluebirds are prodigious insect eaters—until finally flying away.
House sparrows are the bluebird’s enemy. The house sparrows (actually some kind of a finch) were brought from England, possibly to control insects. Introducing a species to solve a particular problem never seems to work. The mongoose was brought to Hawaii in the late 1800s to take care of rats on sugar plantations, but almost never the twain shall meet: rats are nocturnal, and the mongooses are out mostly in the day. So instead of rats, the mongoose preys on native Hawaiian birds and their eggs. The house sparrows may eat some bugs, but their preferred diet is bird seed and discarded people food (they thrive around humans).
As we’ve seen in our own garden, house sparrows claim a home and hang onto it throughout the winter until they start producing several clutches of babies. One birdhouse, erected by a previous owner, has been a sparrow home at least as long as we’ve lived here. A new birdhouse we put up a couple of years ago didn’t suit at first, because we left off a perch (specifically to discourage the sparrows). Now they have decided to make due, and simply grip onto the entrance hole.
House sparrows squeeze out native birds, like the eastern bluebird, destroying their nests, eggs, and sometimes killing the adult birds. We want to convince our bluebird to take up residence, but that will require a drastic reduction in our house sparrow population. How to achieve this without directly harming them will be our challenge.