17 March 2014

Occurrence of Swans at Carter Lake

Trumpeter Swan Occurrence at Carter Lake in Recent Years
Julian Date 2003 2013 2014
1 - - - - 18
2 - - 3 - -
3 - - - - 19
4 - - 3 - -
5 - - - - 16
7 - - 3 - -
9 - - - - 22
11 - - - - 11
13 - - 3 16
19 - - - - 28
20 - - 3 15
23 - - - - 30
28 - - - - 26
29 - - - - 23
34 - - 3 3
36 6 - - - -
39 4 - - - -
40 - - 3 - -
43 - - - - 29
44 - - - - 24
47 5 - - - -
49 - - - - 28
51 - - - - 26
52 - - - - 25
54 5 2 - -
57 - - - - 21
61 - - 2 - -
62 - - - - 22
65 - - 8 - -
68 - - - - 32

Carter Lake has been a unique site in the past few weeks as a place to enjoy swans. The numbers present and the ease of being able to observe them day-to-day was unique.

Most notably indicated were Trumpeter Swans, which included adults and family groups. The first record of occurrence was January 1st, indicating the possibility that the birds were present in during the last couple of days in December 2013. These birds were not present during waterfowl surveys on the 18th and 28th of the month.

Especially appreciated during their presence was a photographic spread in the Omaha World-Herald, done by Mark Davis in his usual fine style of photography. At this time, attention was being given to a bird with a marker on its wing. It was number 387, and was tagged in Minnesota, as previously reported.

During the winter, special attention was given to denoting the waterfowl present when weather conditions were particularly cold. Frigid conditions, several times, meant a dearth of open-water. When temperatures were especially sub-zero, the area of open water was less than the extent of a football field.

The number of swans present has varied, especially as a result of the time when the fowl survey was done at the lake. On the last date of record for the season, 32 Trumpeter Swans were present in the morning, with documentary photographs that indicate their relative extent. They had moved westward on the lake, from just south of the boat dock, to where water being pumped from the Missouri River, provided an open-water condition. That evening, another Omaha area bird watcher, counted 27 during his evening visit.

Basis for Calculation Overall Value
1250 bird-use days x $10 per day $12,500
Birder valuation: 5 x 68 x $5 1,700
Estimation of minimal economic value: $14,200

Trumpeter Swans were present on at least 68 dates in early 2014, correlating with a minimum of 1250 bird-use days. Each day of occurrence has a value, not only to the birds, but also as an economic value associated with visits by swan enthusiasts. The intrinsic value of a swan can't be found in any book of finance, but there is obviously one, so for consideration purposes, it is designated as $10.00. Then there is the value to area birders to see a swan. On some dates there were numerous people present enjoying the view, especially after they were reported by the media. This extent can be approximated at five people per day for 68 days, and about $5.00 per person.

Tundra Swan Occurrence
Julian Date 2013 2014
3 - -1
9 - -1
11- - 1
19 - -1
20- -1
23- -1
28- -1
29- -1
43- -1
49- -1
51- -1
52- -1
57- -1
62 - -1
65 1- -
68 - -1

Obviously, these swans present provided an economic value exceeding about $15,000.

Also, how much "buzz" was generated for this species, because of the photospread in the local newspaper, and comments and bird interest generated online.

One point of tragedy, provided by a poster on NEbirds, a dead juvenile Trumpeter Swan occurred on the south side of the lake. This would be Carter Lake City. The carcass was seen but no details were given to indicate the reason for its demise, other than it occurred on February 15th.

Tundra Swan

Records for this littler swan have a lesser extent of occurrence. Then one was seen in March, 2006. The most prevalent details are about one of these swans which decided to spend the past winter at Carter Lake. It was a lesser fowl associated with the larger Trumpeter Swans. One of these birds was reported from January 3 to March 9, 2014, based upon an evaluation of all of the records associated with waterfowl surveys at Carter Lake.

Trumpeter Swans at Carter Lake, February 9, 2014

A special thanks to local birders that have posted their observations online so they were available for consideration in this analysis.