Poor Benjamin Barton, a man who was both central to the development of the natural sciences in the U.S. and a man seemingly torn between a million different projects. His "fragment," part 1 of what ultimately was just one part, is mostly an annotated list of the birds of the Philadelphia area. But the second half of his appendix to the fragment, a short essay on the utility of birds, became one of the most influential pieces of pro-bird protection writing at the time. I've embedded a late 19th century edition below (please scroll down)
Barton states at the outset that some birds deserve protection "if not by the LAWS, by at least the GOOD-SENSE of the nation." Smaller birds, in particular, feed largely on insects. Adding the fact that they "contribute much to our pleasure by the melody of their notes," the balance of good far outweighs the bad. He goes on to identify several species of special note. These include the phoebe/pewee, the bluebird, woodpeckers, the house wren, the ibis, and the vulture. The passage on the house wren is particularly elaborate and was the section most often cited by later writers.
As a devourer of pernicious insects, one of the most useful birds with which I am acquainted, is the House-Wren....This little bird seems peculiarly fond of the society of man, and it must be confessed, that it is often protected by his interested care. From observing the usefulness of this bird in destroying insects, it has long been a custom, in many parts of our country, to fix a small box at the end of a long pole in gardens, about houses, etc. as a place for it to build in. In these boxes they build and hatch their young. When the young are hatched, the parent birds feed them with a variety of different insects, particularly such as are injurious in gardens.Like the purple martin, the house wren had already been recognized as a useful garden bird and homes were built by colonists to attract it. Barton continues (with a scene inspired by Bradley)
One of my friends was at the trouble to observe the number of times that a pair of these birds came from their box, and returned with insects for their young. He found that they did this from forty to sixty times in an hour; and in one particular hour the birds carried food to their young, seventy-one times. In this business, they were engaged the greater part of the day; say twelve hours. Taking the medium, therefore, of fifty times an hour, it appeared that a single pair of these birds took from the cabbage, salad, beans, peas, and other vegetables in the garden, at least six hundred insects in the course of one day. This calculation proceeds upon the supposition, that the two birds took each only a single insect each time. But it is highly probable they often took several at a time.[A little extrapolation (8400 insects over the course of two weeks) and the house wren pair far outdoes the 3360 caterpillars attributed to the famous pair of house sparrows]
The fact just related is well calculated to show the importance of attending to the preservation of some of our native birds. The esculent vegetables of a whole garden may, perhaps, be preserved from the depredations of different species of insects by ten or fifteen pair of these small birds: and independently of this essential service, they are an extremely agreeable companion to man: for their note is pleasing. A gentleman, in the neighbourhood of Philadelphia, thinks he has already reaped much advantage from the services of these Wrens. About his fruit-trees, he has placed a number of boxes for their nests. In these boxes, they very readily breed, and feed themselves and their young with the insects, which are so destructive to the various kinds of fruit-trees, and other vegetables.Given the territoriality of the house wren, it is unlikely that Barton's 10-15 pairs in a single garden would ever come to pass (unless it was a very large garden). Nevertheless, we have in Barton a clear statement of the value of protecting these birds. (Note that later writers would be less enthusiastic about house wrens, given their tendency (like house sparrows) to drive other useful birds away).
Barton's book itself may not have been widely available but it was quickly excerpted in periodicals, including The Monthly Magazine, and American Review (1800) and The Scots Magazine (1801). It was also used in agricultural texts like William Cobbett's (1804) An epitome of Mr. Forsythe's Treatise on the Culture and Management of Fruit Trees as an authoritative statement on birds' usefulness. For the use of the wren passage in particular, see The New Family Receipt Book (1810).