Swan and Trumpeter swan

Swan noun - Stately heavy-bodied aquatic bird with very long neck and usually white plumage as adult.

Trumpeter swan and swan are semantically related. In some cases you can replace phrase "Trumpeter swan" with "Swan", this terms are similar.

Trumpeter swan noun - Large pure white wild swan of western North America having a sonorous cry.

Swan and trumpeter swan are semantically related. You can use "Swan" instead a noun phrase "Trumpeter swan".