HIBERNATION IN BIRDS
W. L. McAtee, 1947, Amer. Midland. Nat., 38, p. 191 (old records on torpidity). E. C. Jaeger, 1949, Condor, 51, p. 105 (poor-will).
SNAKESKINS IN BIRDS' NESTS
A. L. Rand, 1953, Nat. Hist. Miscl. (Chicago), No. 125 (snakeskins in nests).
CO-OPERATION BY BIRDS
A. L. Rand, 1954, Fieldiana-Zool. (Chicago), Vol. 36, pp. 10, 12 (co-operation, various species).
WATCHDOGS AT THE NEST
R. E. Moreau, 1942, Ibis, p. 240 (in Africa). D. R. Dickey and A. J. van Rossem, 1938, Publ. Field Mus. Nat. Hist., Zool. Ser., Vol. 23, p. 360 (in El Salvador).
BIRD GUIDES TO HONEY
H. Friedmann, 1954, Nat. Geog. Mag., Vol. 105, p. 551 (honey-guides).