That's the churring of the nightjar.
Hall Caine.

CHURR
Churr, v. t.

Defn: To utter by churring.

CHURRUS
Chur"rus, n. Etym: [Hind. charas.]

Defn: A powerfully narcotic and intoxicating gum resin which exudes from the flower heads, seeds, etc., of Indian hemp.

CHURRWORM
Churr"worm`, n. Etym: [AS. cyrran, cerran, to turn.] (Zoöl.)

Defn: An insect that turns about nimbly; the mole cricket; — called also fan cricket. Johnson.

CHUSE
Chuse, v. t.

Defn: See Choose. [Obs.]

CHUTE
Chute, n. Etym: [F. chute, prop. a fall.]