This could behavior could be the result of several issues.

1. This is a young bird, under three years of age and has not yet reached mating age. Typically, finding a mate can occur between 2-3 years of age.

2. Your area may not have a sufficient number of Trumpeter Swans from which to choose an available mate.

There could be several reasons for the low numbers. US Wildlife Services and various other states and their wildlife entities are harvesting Trumpeter Swans from Alaska, incubating the eggs and then releasing the captive raised birds into areas they do not belong in order to increase their numbers for Trophy Waterfowl hunting purposes. This is why the Mute Swans are being killed so that wildlife officials can open habitats to place the Trumpeter Swans. Wildlife officials deny this, but they allowed hunting of the Trumpeters by Native Americans in Minnesota last year. Immediately, hunters began asking state and federal wildlife biologists if the numbers were adequate to open hunting to the general public. All of the Mute Swan killings and introduction of the Trumpeters has been at the cost of the taxpayers to support less than 1% of the population (hunters) so wildlife coffers can be maintained and/or enhanced.

Additionally, it is a known fact (admitted by Canadian wildlife authorities that released Trumpeters in Canada will not go south due to the hunting of waterfowl in the area so they are beginning to stay in Canada. Apparently, the birds are smart enough to avoid the guns. Your swan may have flown near this hunting area and is staying in your habitat to avoid the guns. Finally, this introduction program and the killing of the Mute Swans ( again at taxpayer expense) has been less than stellar. It has costs tens of thousands of Mute Swan lives and untold Trumpeters. Wildlife officials admit that introduced captive raised Trumpeters in Yosemite had to be fed supplementally because they could not find enough food on their own, and their numbers dwindled once federal and state wildlife officials stopped the supplemental feeding. So, as you can see, your swan could possibly be a captive raised swan that was released to find a mate, it's own habitat and food and now is staying in what it believes is a safe habitat. All at the cost of raising state and federal budgets in the false name of conservation. The Regal Swan