Of special interest was a blackbird roost, in an area of bamboo study plots, with an estimated 800,000 individuals. The composition of the group using this roosting area was made by carefully observing the smaller groups of birds as
they came into the roosting area, determining the composition of these groups and then arriving at a total by counting the number of groups that came in to roost. It was a carefully made estimation, not just a guess.
Author: Julian L. Dusi
Volume Number: 10 Year Published: 1962
Issue Number: 4
Page Number: 47
Link to article: http://birdlife.aosbirds.org/1962/Vol 10 No. 4_1962_47-48.pdf
Link to the full issue of BirdLife: http://birdlife.aosbirds.org/1962/Vol 10 No. 4_1962.pdf