There could be many causes for their disappearance. If there was a predator in the area or another Trumpeter Swan family, your swan family could have been chased or the mother removed the family from the area for safety. Trumpeter Swans are extremely large birds and will chase other Trumpeter Swans as well as Mute and Tundra Swans, geese, ducks and other waterfowl. The larger Trumpeters can inadvertently or intentionally kill other swans and waterfowl just because of their large size.

As far as the geese, Trumpeter Swans will chase and may even kill the geese so they are not likely the cause of the Trumpeter family from leaving.

If there is a problem with a food source (not enough to sustain the cygnets as they eat twice the amount of Sub aquatic vegetation (SAV) than an adult Mute Swan), the parent may have had to move them to another area for feeding purposes.

Fireworks, gunfire, disturbance from boats, wave runners, jet skis, etc., can also upset the family and force the family to move on.

We are not sure where you are located, but many states have been aggressively killing the Mute Swans to open up wetland areas to establish Trumpeter Swans. Trumpeter Swan eggs and young have been collected prior to and after hatching to establish flocks in other areas. The purpose of this establishment of Trumpeter Swan flocks into various areas by state and federal wildlife officials is to increase the numbers so that Trumpeters can be used for Trophy Waterfowl Hunting purposes. This is how the state and federal wildlife officials will make money for their budgets in the near future. This money making venture has cost and continues to cost thousands of Mute Swans their lives. Eventually, Trumpeter Swans will lose their lives through hunting to make a buck for wildlife agencies. We certainly hope this is not the case for your swan family, but it something that the public needs to be aware. Hopefully, your family will return soon. The Regal Swan