Definition of "whimpering"

And my sea-birds made a great confusion in the awful calm, filling it with flashing pinions and plaintive whimperings, and settling into the shape of a dome all formed of beating wings, in which I on my ship and the tridentiferous god of the sea were enclosed, face to face.

1912, Prospero [pseudonym; Frederick Rolfe], Caliban [pseudonym; Harry Pirie-Gordon], “The Thirteenth Papyrus”, in The Weird of the Wanderer: Being the Papyrus Records of Some Incidents in One of the Previous Lives of Mr. Nicholas Crabbe, London: William Rider & Son, Limited, […], page 128