The tundra swan (Cygnus columbianus) and trumpeter swan (Cygnus buccinator) are two North American waterbirds that look very similar to the untrained eye. These two heavyweights of the bird world can be seen foraging and sometimes breeding on shallow fresh and estuarine water bodies across much of the northwest, midwest, and northeast of the United States.
Many birdwatchers struggle to tell these two birds apart, so what should you look out for to make a positive identification?
Tundra swans are the most common North American swans. They differ from the trumpeter swan by being smaller and usually having a yellow spot just in front of their eyes. This yellow spot isn’t always visible, but it is a useful marker to look out for.
Apart from the physical differences, trumpeter swans and tundra swans also differ in their calls and breeding distributions. Both tundra and trumpeter swans are migratory waterfowl, but trumpeter swans are also resident in some states and can be seen at any time of the year. Any swan (other than an introduced mute swan) seen during the summer months is likely to be a trumpeter since tundra swans are only present in the winter months.
Read on to learn everything you need to know to tell the differences between these birds easily out in the field.
To add another layer of confusion, tundra swans are often split into two subspecies.
The primary difference is in the color of the bill, with Bewick's swans having a lot more yellow coloring visible, with tundra swans generally having a mostly black bill, with slight spotting of yellow - which sometimes isn't even visible.
Both tundra and trumpeter swans are enormous birds, but the trumpeter swan is the larger of the two. In fact, trumpeter swans are the heaviest waterbirds in North America! Of course, the size difference is most apparent when the two species are seen together.
A pair of trumpeter swans
Tundra swans are the most common swans in North America. As of 2015, there were estimated to be over 170,000 individuals in the United States. These birds are only present in the non-breeding seasonal, however.
The trumpeter swan population is estimated at around 50,000 individuals. While this is not a very large population, the birds are widespread and increasing in number. The picture wasn’t always this positive, however. The hunting of trumpeter swans, as well as the beaver and muskrats that maintain their breeding habitat, resulted in a population crash that left fewer than 100 survivors.
Captive breeding programs and the rehabilitation of wetland habitats have brought the trumpeter swan back from the brink of extinction, and today their conservation status is ‘Least Concern’.
Tundra Swan (Whistling Swan) in flight
The eyes and bill are probably the most reliable place to look when distinguishing between tundra and trumpeter swans. Keep reading to learn exactly what to look out for when identifying these similar species.
Both tundra and trumpeter swans have black eyes, but the eyes of the tundra swan stand out more from the black facial skin. Trumpeter swans’ eyes appear to be contained within the black ‘mask’ created by the bill. Another key difference between the species can be seen in the black facial skin between the eye and the base of the bill.
Most tundra swans have a yellow spot immediately in front of the eye that contrasts with the black bill. This feature isn’t always visible, however. The trumpeter swan has a more subtle reddish or pinkish edge to the bill.
Another key feature to look out for is the angle in the line between the eyes of the swan. In the tundra swan, the boundary of the black bill and white forehead create a rounded line. In the trumpeter swan, this line between the eyes is pointed when viewed from the front.
The trumpeter swan bill is also longer than that of the tundra swan and follows the same angle as the forehead. This creates a fairly straight line between the crown and the tip of the bill. In the tundra swan, the forehead is more rounded and pronounced.
Close up of a Trumpeter Swan
Close up of a Tundra Swan
Apart from their black legs, eyes, and bills, both trumpeter and tundra swans show all-white plumage. The feathers on the head and neck of both species can become stained reddish-brown from feeding in iron-rich mud, however.
Both tundra and trumpeter swans have black legs and feet. The tundra swan has a notably shorter and thicker neck but this feature is most reliable when the birds are seen side by side.
Neither tundra nor trumpeter swans sing, but both species make distinctive calls. Tundra and trumpeter swans have very different calls, and this is a great way to tell the species apart when you can’t get a good look at them.
The trumpeter swan has a loud, bugle-like call that fits perfectly with the bird's name! This call has a low pitch and can be heard from a great distance. The call of the tundra swan is higher in pitch and more whistle-like than the trumpeter swan. Tundra swan calls often consist of two or more notes.
Close up of a Bewick's Swan (Tundra Swan Subspecies)
The trumpeter swan tends to take a long ‘runup’ to pick up lift and momentum before taking flight. They do this both on land or water, but can also take off directly when necessary. Tundra swans have a slightly faster wingbeat than their larger relatives.
Tundra swans are non-breeding migrants to the United States (not counting Alaska where they breed) while trumpeter swans do breed in some states and are even present year-round in certain areas. Read on for a breakdown of where these two species are most likely to be seen.
There are two isolated overwintering populations of tundra swans in the United States. The western population is centered around Washington, Oregon, and California, while the smaller eastern population overwinters from New Jersey to South Carolina. Tundra swans do turn up at widespread localities as far south as Louisiana, however.
While both swan species migrate to the USA, trumpeter swans are also resident and medium distance migrants within the United States. They occur year-round in some areas of the North West. In the mid-west, these birds breed in the great lakes region and overwinter further south.
Trumpeter Swan swimming in Yellowstone River
Trumpeter swans have been recorded to live up to 29 years in the wild and 32 years in captivity. This is similar but slightly longer than the oldest recorded tundra swan of 27 years. Most individuals do not live anywhere near this long, and trumpeter swans in Canada have been estimated to live just 3 or 4 years on average.
Females of both tundra and trumpeter swans look much the same as their male counterparts and are equally challenging to distinguish between in the field. The males of each species are larger than the females on average, however.
A small flock of Whistling Swans (Tundra Swans) in flight
The juveniles of both swan species are a brownish-gray color overall, but tundra swans tend to be a lighter shade. Tundra swans also tend to molt into their adult plumage earlier than trumpeters. This can result in juvenile trumpeters with mixed gray and white plumage while trumpeter swans of the same age remain all gray.
The bills of both juvenile trumpeter and tundra swans have a pinkish center when seen from the side. Tundra swans may also have a whitish spot on the base of the bill which can be helpful when distinguishing between the two species.
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