274 
OipSERVATIONS ON BIRDS. 
The least observation and attention would convince men, that 
these birds neither injure the goatherd nor the grazier, but are 
perfectly harmless, and" subsist alone, being night birds, on night 
insects, such as scarahcei, and phalcence j and through the month 
of July mostly on the scarahceus solstitialis, which in many 
districts abounds at that season. Those that we have opened, 
have always had their craws stuffed with large night moths and 
their eggs, and pieces of chaffers : nor does it any wise appear 
how they can, weak and unarmed as they seem, inflict any harm 
upon kine, unless they possess the powers of animal magnetism, 
and can affect them by fluttering over them. 
A fern owl, this evening (August 27) showed off in a very un- 
usual and entertaining manner, by hawking round and round the 
circumference of my great spreading oak for twenty times fol- 
lowing, keeping mostly close to the grass, but occasionally 
glancing up amidst the boughs of the tree. This amusing bird ^ 
was then in pursuit of a brood of some particular phalsena be- 
longing to the oak, of which there are several sorts ; and ex- 
hibited on the occasion a command of wing superior, I think, to 
that of the swallow itself. 
When a person approaches the haunt of fern-owls in an even- 
ing, they continue flying round the head of the obtruder ; and 
by striking their wings together above their backs, in the manner 
that the pigeons called smiters are known to do, make a smart 
snap : perhaps at that time they are jealous for their young ; and 
their noise and gesture are intended by way of menace. 
Fern-owls have attachment to oaks, no doubt on account of 
food; for the next evening we saw one again several times 
among the boughs of the same tree ; but it did not skim round 
its stem over the grass, as on the evening before. In May these 
birds find the scarabceus melolontha on the oak ; and the scarabceus 
solstitialis at midsummer. These peculiar birds can only be 
watched and observed for two hours in the twenty-four: and 
then in a dubious twilight an hour after sun-set and an hour 
before sun-rise. 
On this day (July 14, 1789) a woman brought me two eggs of 
a fern-owl or eve-jar r, which she found on the verge of the 
Hanger, to the left of the hermitage, under a beechen shrub. 
This person, who lives just at the foot of the Hanger, seems well 
acquainted with these nocturnal swallows, and says she has often 
found their eggs near that place, and that they lay only two at 
