We have compiled a summary of Focus on Feeders results going back several years.
Understanding the Results
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 are summarized for selected species in three ways, each giving us a slightly different picture of changes in winter feeder activity:
- numbers of birds per participant (pdf)
- rank order of abundance (pdf)
- frequency (proportion of participants reporting each species) (pdf)
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: 2012, 2011, 2010, 2009, 2008, 2007, 2006, 2005, 2004, 2003