Solving Loon Mysteries

Loon productivity survey 2007 findings

2007 was the second year of a study designed to measure how well loon chicks fare on Maine 's inland waters. As a complement to the loon count, volunteers monitored a lake or part of a lake for loon activity from as early as ice out through the end of the summer.

Volunteers kept track of when a pair of loons established their territory, when they nested, how many chicks they hatched, and how many chicks made it to six weeks of age or roughly adult size.

For our 2007 Productivity Survey, 28 volunteers participated on 22 lakes across the state, following a total of 35 loon pairs through the summer. Five of those pairs acted like territorial pairs but never nested. The remaining 30 pairs nested but only 16 hatched chicks that were subsequently observed. Of the 29 chicks that initially hatched, 22 survived to six weeks of age or until late August, which is quite remarkable.

What does this mean for the future of Maine 's loons? Our sample size is still quite small so strong conclusions can't be drawn just yet. Looking at the number of chicks that survived per territorial pair shows our finding (0.63) is higher than what is thought to be “average” loon productivity (0.50). But our sample is biased toward loon territories that produce chicks since it's hard to recruit people to volunteer for an unproductive part of a lake where loons may not nest regularly or successfully. Having a broader sample of loon nesting territories may bring our numbers down and be more representative of how well loons actually do on Maine 's lakes.

With the critical pieces of information our monitors supply, we can begin to build a database of loon productivity for the state. This type of information has been collected in New Hampshire for more than 20 years, and by BioDiversity Research Institute in limited areas in Maine for the last decade.

A big thank you goes out to everyone who participated in this year's survey. The productivity study will continue in 2008, so look for more information on this growing study in future issues of Habitat.

In the meantime, if you are interested in participating in the productivity study for 2008, please e-mail sgallo@maineaudubon.org or call 781-6180 ext. 216.