BRITISH WARBLERS
No. 3 territory and a considerable distance from the footpath. The male at times was excitable, showing it in the usual manner, but the principal feature was his conflicts with the owner of No. 3 territory, the attacks coming first from one and then from the other. On one occasion both birds were hopping about the ground within a few feet of one another, and when one retired the other did likewise. Upon examination I found the outer part of the nest formed. The next morning both sexes showed signs of excitement, flapping their wings in the usual way; the nest had been added to, but neither bird approached it while I was present. On April 28th the female was constructing a nest in an entirely different part of the territory, and an examination of the first one revealed the fact that nothing had been added thereto since the previous day. The second nest was situated within a few feet of the footpath. Throughout the morning of April 29th the female was busy building, and considerable excitement was shown by both sexes. After this date nothing unusual occurred until May 7th; there were then five eggs in the nest, and soon after my arrival the male pursued the female and together they fluttered about the ground, coition probably taking place. A third bird now entered the territory and followed the female, who was excitable and kept flapping her wings. The male forthwith flew at this new arrival and appeared to drive it away, but later it returned, when again it seemed to be attacked by the male. At this time I thought that the intruder was the female from No. 1 territory; that it was a female I had little doubt. On May 8th this third bird again appeared, when the male, instead of attacking, followed it flapping his wings in the usual manner; this action on his part confirmed my opinion that the intruder was a female. Upon the male thus following her she retired, but presently returned and commenced to search for food close to the first female. The latter bird seemed to resent her presence and consequently flew at her, upon which she again retired. In the evening the second female was again present. On the
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