GRASSHOPPER-WARBLER
apparently on the point of pairing. The male was excitedly following the female, singing at intervals, and at times bowing slightly; but this is the only evidence I have that two broods may be reared in the same season, while on the other hand the general behaviour of the males, when the young are fully fledged, is very different to this, for they sing for about a fortnight, that is to say, during the latter part of June and the beginning of July, then become restless and wander away from their breeding quarters. During these last days of June, if the weather is warm, their song can be heard to advantage in the evening and on through the night, rising and falling as the head is inclined first this way and then that. It is surprising how the song will penetrate, for it can be heard without difficulty a quarter of a mile away. It often happens, too, at this time of year, that the only other sounds in the night-time are the "churring" of the Nightjar, the craking of the Landrail, and the hissing of the young Brown Owls, sounds which are well in keeping and only tend to emphasise the stillness of the night.
Although their song is so peculiar, yet there are a few notes in the song of the Tree-Pipit and Wren for which they may easily be mistaken, and often when listening at daybreak for these Warblers I have been completely deceived by these few notes, which, at a distance, with the remainder of the song lost, are barely distinguishable from those of the Wren or Tree-Pipit. The range of call-notes they use seems to be small; the usual one is something like that of the Robin or Blackcap, a "tic tac tac" and this note seems to be used principally when alarmed. The note which the female uses to call the male, or to put the young at their ease, is usually a single "tic" on the other hand, this single "tic" quickly and loudly uttered may also be one of alarm; it seems, therefore, that it depends more on the manner in which the note is given than on the actual note itself. There is no difference in the note of the two sexes.
Climatic conditions seem to influence them to a certain
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