280 
OBSEEVATIONS ON BIllDS. 
willow wrens which he assures us he has discovered. Ever since the 
publication of his History of Selborne I have used my utmost 
endeavours to discover his three birds^ but hitherto without success. I 
have frequently shot the bird which " haunts only the tops of trees, 
and makes a sibilous noise/' even in the very act of uttering that 
sibilous note, but it always proved to be the common willow wren or 
his chifF-chaff. In short, I never could discover more than one species, 
unless my greater pettychaps, sylvia hortensis of Latham, is his greatest 
willow wren. — Markwick. 
FERN-OWL, OR GOAT-SUCKER. 
The country people have a notion that the fern-owl, or churn-owl, 
or eve-jarr, which they also call a puckeridge, is very injurious to 
weanling calves, by inflicting as it strikes at them, the fatal distemper 
known to coAV-leeches by the name of puckeridge. Thus does this 
harmless ill-fated bird fall under a double imputation which it by no 
means deserves — in Italy, of sucking the teats of goats, whence it is 
called cap7'imulgus; and with us, of communicating a deadly disorder 
to cattle. But the truth of the matter is, the malady above mentioned 
is occasioned by the cestrus hovis, a dipterous insect, which lays its 
eggs along the chines of kine, where the maggots, when hatched, eat 
their way through the hide of the beast into the flesh, and grow to a 
very large size. I have just talked with a man who says he has more 
than once stripped calves who have died of the puckeridge ; that the 
ail or complaint lay along the chine, where the flesh was much swelled, 
and filled with purulent matter. Once I myself saw a large rough 
maggot of this sort squeezed out of the back of a cow. 
These maggots in Essex are called wornils. 
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 ; and through the month of July mostly on 
the scaraboeus solstitialis, which in many districts abounds at that 
season. Those that we have opened, have always had their craws 
stufibd with large night moths and their eggs, and pieces of chaff'ers : 
nor does it anywise appear how they can, weak and unarmed as thej^ 
seem, inflict any harm upon kine, unless they possess the powers of 
animal magnetism and can afi'ect them by fluttering over them. 
A fern-owl, this evening (August 27) showed off" in a very unusual 
and entertaining manner, by hawking round and round the circum- 
ference of my great spreading oak for twenty times following, 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 belonging to the oak, of which there are 
several sorts ; and exhibited 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 evening, 
they continue flying round the head of the obtruder ; and by striking 
their wings together above their backs^ in the manner that the pigeons 
