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Mute Swan Surveys

Every 3 years, DEC conducts a mid-summer Mute Swan Survey to assess the population status of this non-native, invasive species. Efforts are coordinated with other Atlantic Flyway states to help evaluate the need for and success of management efforts. Although many people enjoy viewing mute swans, wildlife agencies are concerned that the growing number of swans will result in adverse impacts to other wildlife and their habitats, and create new conflicts with human interests.

DEC normally conducts the tri-annual mute swan survey without much volunteer assistance; however, to ensure as complete a count as possible, DEC invited ornithologists, birders, and others to contribute to the 2008 survey by reporting counts of swans from any area of New York State. We are pleased that a number of individuals and clubs did submit counts of mute swans during the survey period, and those data were included in the results reported below.

2008 Mute Swan Survey Results

A total of 2,624 mute swans were counted in New York during the 2008 mid-summer survey. This total included 2,311 adult birds and 313 cygnets (106 broods, 2.95 cygnets per brood). Nearly 80% (2,099) of the total count came from Long Island, where one or more swans were found at more than 80 different locations. Approximately 13% (335) of the total count came from the Hudson Valley region, although none were reported north of Columbia or Greene counties. The other 7% (190) came from western and central New York, with the vast majority found in bays along the south shore of Lake Ontario and at Black River Bay and Perch River Wildlife Management Area. Detailed counts for specific locations are available upon request.

The 2008 swan counts were considerably higher than in 2005, but were similar to results from 2002. Survey coverage was not as complete in 2005 as in other years, and we suspect that this accounts for much of the variation in counts between the three surveys. Over the long term, the mute swan population in New York has increased significantly since the 1980s, as indicated by the tri-annual surveys (see below) and the recently completed New York State Breeding Bird Atlas.

Thanks to all who contributed to this survey, especially the non-DEC folks who helped make this another good example of cooperative citizen science.

Table 1. Number of mute swans counted during the 2008 mid-summer survey in New York.
Region No. of Adults No. of Broods No. of Cygnets Total No. of Swans Cygnets/Brood
Long Island 1,843 86 256 2,099 2.98
Hudson Valley/Eastern NY 307 9 28 335 3.11
Great Lakes/Western NY 161 11 29 190 2.64
New York State Totals 2,311 106 313 2,624 2.95
Table 2. Number of mute swans counted during tri-annual mid-summer surveys in New York 1.
Year No. of Adults No. of Broods No. of Cygnets Total No. of Swans Cygnets/Brood
19861 1,609 62 206 1,815 3.32
1989 1,748 58 157 1,905 2.71
1993 1,823 79 246 2,069 3.11
1996 1,421 n/a 2 223 1,644 2.71
1999 2,206 79 223 2,429 2.82
2002 2,520 102 328 2,848 3.22
2005 1,879 97 267 2,146 2.75
2008 2,311 106 313 2,624 2.95

1 The first survey (1986) was completed entirely by aircraft and was limited to the Hudson River and Long Island coastal areas. Coverage was expanded in 1989 and subsequent years to include additional inland areas wherever mute swans were known to occur.

2 Total number of broods was not accurately determined in 1996, so the calculation of cygnets/brood was based on 52 known broods with a total of 140 cygnets.

Mute Swan Population Trends
Figure 1. Number of mute swans counted during tri-annual mid-summer surveys in New York (see Table 2 for additional information).