High Plains Swan Population Continues to Thrive

The number of Trumpeter Swans in the high plains flock continues to thrive.

Results of the 2010 autumn survey indicated a population of 524 swans, which is a "record-high count," but only one more bird than in 2009.

"There was an increase in the number of breeding pairs and birds in groups," according to the survey report. "The number of non-breeding pairs decreased by 16, but the number of broods and average brood size remained relatively unchanged."

The total population has shown a steady increase in the past few years, according to survey results:

1995: 214

2000: 321

2005: 358

2006: 427

2007: 398

2008: 429

2009: 523

2010: 524

Notably, the population has more than doubled in 15 years.

There were 174 cygnets noted during the 2010 survey, which compares to 171 in 2009. The total number of broods was 65 in 2010, and 63 in 2009.

The survey report indicates there were 65 pairs with cygnets in 2010 (60 in 2009) and 56 pairs without cygnets this past season (72 in 2009).

"The increase in total birds could be credited not only to the number of reproductively active pairs, but also wetland habitat quality," the survey report says.

The aerial survey was done from August 30 to September 1, and on September 8. The area surveyed has been similar in the past few years, and does not extend beyond the eastern boundary of Cherry county.

Survey results are available in a report by Shilo Comeau, of the Fish and Wildlife Service, out of Martin, SD, and Mark Vrtiska, of the Nebraska Game and Parks Commission.

Considering the Survey Report

The 2010 report of the autumn survey of Trumpeter Swans, is a slight variation on the 2009 report.

The introduction is the same text. The only items changed in the methods section were the dates for the survey, and temperatures.

The results section conformed to the changes as a result of the survey.

Figure 1 - a map of the region - is the same. Figure 2 was slightly modified by including an additional year of results.

The boiler-plate presentation of the results continues with Table 1 and Figure 3. There were no substantive changes in the Habitat Conditions section.

Once again on Page 5, was an aerial photograph of a sandhill's wetland, showing the mosaic of habitat, with three swans and a Great Blue Heron within the view.

The caption for the 2009 report said: "Picture taken from the airplane during the survey, ..." The same picture with the exact same caption were used in the 2010 report.

Obviously this is misleading since the exact same picture could not have been taken two years in a row. A slight change in the caption text could have indicated that the picture was from a previous year's survey, but this was not done.

Another item mentioned in the survey reports for 2010 and 2009, is "Habitat availability in the Sandhills is currently being modeled using data collected from previous surveys, and this should give managers an idea if there is enough habitat available for this flock to persist at the current objectives."

Since the exact same text has been issued for two years, will this same statement be given next year? There is no information available to indicate what is involved with this habitat modeling effort.

The value of this report is its presentation of the number of swans, but the report could be so much more than another rendition of what has already been presented. Conditions for Trumpeter Swans of the High Plains Flock change every year, and this years report did not indicate anything new in this regard.

Habitat Management

Nothing was said in the survey report for 2009 and 2010 regarding the potential for habitat management to provide additional habitat for breeding swans and their young.

One point of consideration is the potential for restoring a Grant County lakebed to its former condition.

The Sandhills Task Force has an application on file to the Nebraska Environmental Trust to recreate historic hydrological conditions at Egan Lake. The landowners are supportive.

If the site, which is not currently a lake, is no longer pumped to remove water, but which could have a greater extent and variety of wetland habitats, might provide an additional nesting site for a pair of swans, as well as other wetland birds.

There may be other similar opportunities for lake restoration within the sandhills, which is the core habitat of the High Plains Flock. There is no known evaluation which has focused on the potential to increase habitat among the hills' dunes.

Habitat restoration could be a key element to ensure a healthy population of the Trumpeter Swan, as well as other birdlife of the region's lakes and marshes.