feeding quietly in one corner of its territory when an intruder enters. Becoming aware of what is happening it ceases to search for food, and approaching the intruder, at first swimming slowly but gradually increasing its pace, it finally rises and attacks with wings and beak, and drives its rival back again beyond the boundary. Thereupon its attitude undergoes a remarkable change; ceasing to attack, but remaining standing for a few moments as if still keeping guard, it betrays no further interest in the bird with which a few seconds previously it was fighting furiously. On one occasion I watched a trespasser settle upon a conspicuous clump of rushes situated near the boundary. The owner, who was at the moment some distance away, approached in the usual manner, and, having driven off the trespasser, returned immediately to the clump, where it remained erect and motionless.
A feature which marks all the fighting, and which we cannot afford to disregard, is the conative aspect of the behaviour of the owner of the territory. The bird attacks with apparent deliberation as if it were striving to attain some definite end. I recollect an incident which was interesting from this point of view. A pair of Reed-Buntings were disturbed by a Weasel which had approached their nest containing young. Both birds betrayed symptoms of excitement; as the Weasel threaded its way amongst the rushes, so they fluttered from clump to clump or clung to the stems, uttering
