A large white swan of North America. It feeds on aquatic plants in shallow water and breeds along wetlands and lakes.
Adults have white plumage and a long neck; the bill is black without a yellow patch.
Counting Trumpeter Swans together can hide how age classes contribute to population growth. An integrated analysis of the reintroduced south-central Ontario population used 2006–2019 data and estimated apparent annual survival at 0.84 for adults and 0.80 for juveniles. The model combined relative counts, productivity and resightings of marked birds.
Age also mattered for entry into breeding: the transition probability was 0.07 for a three-year-old subadult female and 0.53 for a nonbreeding female aged four or older. Mean population growth was 1.16, with no trend in growth rate during the study; adult survival had the strongest influence on change.
An extinction-risk assessment has not been added yet.
In the south-central Ontario reintroduced population, apparent survival was estimated at 0.84 for adults and 0.80 for juveniles during 2006–2019. Adult survival most strongly influenced population growth, and age affected the transition to breeding. Tracking age structure supports management of reintroduced swans.