138 TRANSACTIONS-PERTHSHIRE SOCIETY OF NATURAL SCIENCE. 
estuaries, and scatter over the upland fields, where they pair, and 
make scratchings in the ground; several of these are often made 
before the actual site is fixed upon, and lined with a few straws for 
the reception of the eggs. Large flocks of Gulls also come inland 
and follow the plough, filling the newly turned furrow, to feed upon 
the worms and grubs exposed to view, and there is a continual 
circling of glistening wings as each bird presses forward in turn, to 
take the foremost place, in the long white line behind the ploughman’s 
back. A party of Rooks is often present to share the rich banquet 
so opportunely provided at this time of the year, their glossy black 
coats contrasting strongly with the pure white and gray plumage of 
the Gulls. There is a marked difference in the behaviour of the two 
species of birds—the Gulls, especially the Black-headed variety 
(Lams ridihundus), are very noisy, squalling and scolding each other 
in the air, while the Rooks feed quietly, as they walk deliberately 
along the furrow, without uttering a sound. 
High overhead we hear the cry of the Curlews, as they fly onward 
to the moors, from the ooze and mud-flats of the sea-shore, where they 
have spent the winter, and perhaps a small flock of Oystercatchers or 
a pair of Redshanks hail in as they hurry past to their breeding 
grounds. Many birds are now choosing their mates, and terrible 
battles are often fought before this matter of all importance is settled. 
By the end of March a few young Thrushes and Blackbirds are 
out of their shells, nests of Redbreasts, Hedge-Sparrows, and Wrens 
are finished; Ringdoves are sitting on their platforms of dead twigs, 
and Dippers in their domed nests in the river bank, while woodland, 
copse, and fields, are ringing with the musical notes of the birds. 
Foreign migrants are now on the wing, and delicate birds from 
the palm-groves of Africa and the orange-gardens of Southern Europe 
are continually dropping into our woods and shrubberies, some per¬ 
haps returning to the very bush where their last year’s nest is hanging 
in tatters on the branches. 
Filled with an intense and longing desire which they can neither 
resist nor control, myriads of these feathered pilgrims gather together 
at this time of the year in southern climes, and watch and wait till at 
a change of the wind, at the rising of the moon, or at some sign of 
which we know nothing, they suddenly rise in great swarms into the 
air and start with outstretched necks and swiftly-beating pinions to 
compass a flight of thousands of miles over desert and ocean, through 
light and darkness and storm, to their nesting haunts. Flock after 
flock rush on in rapid succession, and all through April and part ot 
May there is a continuous stream of aerial travellers steering their way 
with unerring precision to their several goals: some choose the haunts 
of men, where they are more or less known and observed, others 
