SAVl'S WARBLER
and Marsh Warbler, and the two Whitethroats are severally very closely allied, but by no means adopt a similar method of expressing their emotion. Therefore the identity of expression of the Grasshopper and Savi's Warbler is the more interesting. Both sexes are very excitable at this period, the male sings persistently, and while doing so seems to be watching the movements of the female. She runs about, mouse-like, amongst the thick masses of dead reed, and the male espying her climbs or nutters down the reed upon the top of which he was singing and pursues her, running in and out amongst the reeds, at one moment spreading his wings and napping them up and down and then expanding his tail like a fan, and at another following her in a stately way carrying his head erect, or yet again creeping after her with his head lowered, threading his way in and out of the stems. The tail when expanded may be either raised or lowered, and a dead leaf of the reed is often searched for, picked up, and carried in the wake of the female. In this way the male pursues her around his territory, eventually returning to the reed which forms his headquarters, up which he climbs, and then again commences his peculiar song. When on the ground both sexes are able to run with considerable speed, but sometimes they move by hopping. Like the Grasshopper Warbler they have the peculiar habit of walking along a horizontal reed, and the male does so even when with wings and tail outspread he is pursuing his mate. The behaviour of the female during this period is unusually interesting, for she not only sings but also pursues the male, and even opens and closes her wings when close beside him.
The nest, which is rather deep and solidly constructed, is placed at the base of the reed stems and is composed of the interwoven leaves of the common reed.
The song is similar in type to that of the Grasshopper Warbler, but far more musical, and in a way resembles the tinkling of numerous tiny bells. The bird produces the notes with its bill widely opened. At the commencement there is a
5
