Support for the Adirondack Cooperative Loon Program’s Annual Loon Census has continued to grow on a yearly basis. The reports received from our observers contribute to and expand our knowledge regarding the locations of summering loons in the Adirondack Park. We are very grateful for all of their efforts!

Chart #1 illustrates the total number of census observers and reports received each year from 2001-2006, with over five hundred observers participating in the 2006 Census.

The number of lakes observed included in the Census from 2001-2006 has ranged from 129 to 221 (Graph #1).  The number of Census lakes where loons have been observed has ranged from 102 to 158, and the number of lakes where no loons have been observed has varied from 27 to 70.

Graph #2 indicates a slight decreasing trend from 2001-2006 in the percent of lakes with loon chicks, with the lowest values in 2005 (23%). The data also illustrates a slight increasing trend in the percent of lakes without loons from 2001-2006. However, there is a year-to-year fluctuation in the number of lakes with and without loons, which is not unusual for such a long-lived species. For example, the high amount of rainfall experienced early in 2006 flooded many loon nests, leading to the lower numbers of loon chicks.

Through the efforts of our Census observers, the Loon Program will be able to determine whether this variation is an actual population trend of concern, or a normal fluctuation in the Adirondack loon population. Anecdotally, and based on the preliminary analysis of the Loon Census results, it appears that the Adirondack loon population has almost doubled since the NYS DEC’s last survey in the 1980’s. The Census results will be analyzed in more depth this winter to better evaluate trends in the Adirondack loon population over time.

The graph below illustrates that the proportion of adult and young loons on the lakes has remained relatively constant during the six years of the Census (Graph # 3). The majority (~85%) of the birds surveyed have been adult loons. Approximately ~14% have been chicks, and ~2% were immature loons. The Census is conducted in mid-summer, when the chicks are generally young. Thus, it is expected that there would be fewer immature loons observed on the lakes than there would be if the survey was conducted later in the summer.