|
Past Results
In 1988, after more than 20 years of conducting the Cardinal-Titmouse Survey, the Conservation Department at Mass Audubon expanded the survey to a report on the activity of all winter feeder birds. Participants were asked to report the highest number of every bird species seen during the count weekend in early February.
Checklists were published in newspapers across Massachusetts to encourage participation, and the effort succeeded spectacularly. Department staff received thousands of responses, and summary reports were published in summer issues of Sanctuary magazine. So many responses were received that the capacity of the staff to analyze the information was overwhelmed, and after several years the project went into hibernation. In 1997, Focus on Feeders re-emerged and has been operating continuously to the present day.
 | White-breasted Nuthatch and House Finch.
Photo by Bruce de Graaf. |
In an effort to provide our friends and participants with more of the data they've been helping Mass Audubon compile, for the first time we present the summary results comprising the past 20 years of feeder watching. The database will be updated every year.
In a project of this sort it is not possible to simply ascribe changes in reported feeder activity to changes in bird abundance. A variety of factors must be accounted for, including weather immediately before and during the count period, as well as changes in the number and distribution of participants. Nevertheless, the results can portray long-term trends, and they have depicted expansion of species from the south, such as Red-bellied Woodpecker and Carolina Wren.
Results for the years are summarized for selected species in three ways, each giving us a slightly different picture of changes in winter feeder activity: 1) absolute number and numbers of birds per participant; 2) rank order of abundance; and 3) frequency, or proportion of participants reporting each species. Rank order and frequency records are relative measures that don't depend on differences in counting among participants. They are less precise measures of abundance, however, and change in rank order for a species is often dependent on the abundance of other species. For simplicity we are displaying the results for only the top 28 species ranked based on the results of the 2007 survey.
Some interesting patterns include the decline in rank of European Starling and House Finch since the late 1980's and the episodic change in relative abundance of Common Redpoll and Pine Siskin—and not always in synchrony.
In general, the most frequently cited species are also the most abundant, with the exception of European Starling and House Sparrow, reflecting their higher abundance in more developed areas and general absence from more rural areas of Massachusetts. It is perhaps not surprising that Black-capped Chickadee, although not the most abundant feeder visitor is the most commonly observed species at feeders—almost every feeder has a visiting Chickadee. Downy Woodpeckers are also commonly observed, even if they are not very abundant.
View Past Results: 2009, 2008, 2007, 2006, 2005, 2004, 2003
|
