How to tell a Trumpeter from a Tundra Swan

by Gary Swant

I had just spent 20 minutes watching a group of 11 Tundra Swans when a person called and asked if I had seen the Trumpeter Swans in the same pond.  I asked when they had seen them.  It was just a few minutes before I was watching the same white swans, which were not Trumpeter but Tundra Swans.  They are hard to tell apart without some experience and studying their field marks. 

This got me to thinking that I should write an article on how to identify Tundra verses Trumpeter Swans.

First of all, most people can identify large white water birds as swans, not Snow Geese or Ross’s Geese.  After that it gets a little difficult.  I even have to spend a little time, once in a while, and check the field guide to make sure that my first impression is correct.  I been known to get the ID wrong as well.

Let’s begin with the Trumpeter Swan.  Trumpeters were so rare a few decades ago that the joke was, “If it has a red band around its neck it’s a Trumpeter, if not, it’s a Tundra.”  Fortunately, Trumpeter Swans have rebounded in the last 50 years and it is not unusual to see them today.  I remember my first sighting.  I hiked several miles into a remote lake in Yellowstone Park and was thrilled with finding four Trumpeter Swans, two adults and two signets.  Most of last December I was seeing twenty-seven of them sitting on the ice and swimming in a small pool of ice-free water in a local pond.  On the Christmas Bird Count conducted at Warm Springs WMA on January 1, 2021, we counted 21 Trumpeters.  There are always a few that winter at the Lee Metcalf WMA at Stevensville as well.

The call of the Trumpeter is very diagnostic and as their name suggest they sound like a trumpet being blown.  Tundra Swans produce more of a whistling sound, thus the older name Whistling Swan.

Physical traits are a little more difficult than their calls.  I first look at the head.  If the top of the head and bill are in a continuous slope it is a Trumpeter.  If you get a frontal view the base of the bill is pointed at the center.  Additionally, the side of the bill from the eye to the lower mandible is a straight line.  Overall, Trumpeters are larger with an 80 inch wingspan, compared to a 66 inch wingspan in the Tundra.  Trumpeters weigh 23 pounds verses 14.4 in the Tundra.  Size is often difficult to ascertain, especially through binoculars or a spotting scope.  However, it is a good way to separate the two species in a mixed species flock.  Looking at the side profile the Trumpeter has an evenly round back when the wings are folded and the Tundra has a more peaked back.   

The bill of the Tundra ends abruptly at the base and the head is rounded, so that the bill and head do not form a continuous smooth line.  The base of the bill has a rounder border rather than the pointed center of the Trumpeter.  Often, Tundra Swans show a lot of yellow on the bill.  Trumpeters tend only to have limited yellow on the lower mandible, and never on the upper portion of the bill near the base.

This may all sound like a lot to keep track of.  If you look at both species over time you will get an innate sense for these two species, and identification will come easily and quickly.  I hope this has helped.  

One final note on identification that you can use that is behavioral rather than a physical trait.  Trumpeters winter in the Clark Fork and Bitterroot Drainages of Montana.  Tundra generally do not.  Tundra migrate through in large numbers in April and May and again in October and November.  Tundra numbers can be quite large with several hundred to a thousand or more.  Trumpeter are never found in large numbers.  Having said all of that, there will always be that individual bird that is the exception.  So this winter if you see a flock of 20 to 30 white swans take the time to look at every individual.  There just might be a Tundra among those Trumpeters that didn’t migrate south.    

Now go to the field and separate these two species.  If you do you’ll feel good about your birding skills and build your confidence.