Mooty, J.L. and P.S. Perry. 1985. Common loon numbers in northcentral Minnesota. Final report by the Nongame Wildlife Program, Minnesota Department of Natural Resources. 11 pp.
Common loons were counted from fixed-wing aircraft on 116 lakes in two north-central Minnesota counties in 1985. The unadjusted estimate of the total loon population (N +/- 95% CI) for the 1,179 lakes in these counties was 1675 +/- 358, or 3.88 loons/100 ha of water. Comparison of air and ground counts from 77 lakes in 1986 indicated that 69% of the adults and 45% of the chicks were seen from the air. The adjusted population estimate is 2,609 +/- 564 loons. The adjusted density estimate is 6.69 loons/100 ha.