Snow Geese Scouts

Many Blackfoot residents have noticed the unusually high numbers of Snow Geese (along with swans and ducks) in the watershed this year, and that they have been staying around longer than in other years.  We’ve thought it likely that they were piling up here where there has been at least a little open water and fields, waiting for things to thaw to the north.  Now we are seeing big flocks leaving the watershed, heading north over the Bob Marshall.   And a biologist in California has some really cool transmitter data showing not only that a lot of the geese that winter in California have been passing through here, but that some of them seem to scout out conditions in the north while they wait!  Chris Nicolai of the U.S. Fish and Wildlife Service put radio transmitters on 39 geese in the Central Valley and has been following them via satellites as they’ve migrated north.

Radio telemetry locations of Snow Geese migrating out of California’s Central Valley in spring 2018

The map above shows that most of them have come through Montana and spent weeks in the Great Falls area before moving to Canada recently.  And at least one goose made two trips up to Alberta and back to Benton Lakes in Montana this spring!  We don’t know if these birds have some way of communicating with the rest that conditions are not right to continue migration or if these are just overeager individuals that can’t help checking things out.  But it does seem that most of the flocks have some way of knowing when to move.  And the warmer, drier weather that has accelerated our snowmelt and started to open up the lakes has put them back on course.  The map below shows that some of these geese came right through the Blackfoot on their way north:

Locations of Snow Geese in Montana this spring as they migrated north to Canada.

 

You can track these Snow Geese directly by going to https://www.movebank.org/node/36241 and searching for Wintering California Geese.  Or you may be able to see a big flock overhead if you are out and about in the Blackfoot today!

Swans in the Blackfoot: Trumpeters or Tundras?

Tundra Swans flying over Wigeon Marsh near Ovando on April 1.

This time of year, as well as in the fall, I have to take a close look at–or listen to–any swans I see, to know which species I’m observing. While we are now fortunate enough to have a fairly robust summer population of Trumpeter Swans in the middle and upper Blackfoot, we also have migrating Tundra Swans that pass through on their way to nesting grounds in the Alaskan and Canadian Arctic.  These “cousins” to our Trumpeter Swans can be difficult to tell from trumpeters, even by expert observers!

The Sibley Guide website has a lot of good information on distinguishing the two, as does the Trumpeter Swan Society . Trumpeters are larger than Tundra Swans, although it’s difficult to see that unless they are side by side.  Trumpeters have long, straight bills, usually with a strip of orange on the lower part.  Tundra Swans have rounder heads with shorter, more concave bills.  Tundras typically have yellow spots on the black “lores” near their eyes, but they can also have orange strips!  As you can see from the photo below, they can be difficult to identify unless you can clearly see them side by side.

Adult Trumpeter Swan (left) and adult Tundra Swan (right) showing larger size difference of Trumpeter and different bill shape. Toronto on 17 December 2017. Photo by Jean Iron, used with permission.

The sounds the two species make are very distinct, however, and this is the easiest way to tell them apart if you are lucky enough to hear them. Tundra Swans were formerly called Whistling Swans, and they definitely have a different call than the low tone of the trumpeters.  You can hear the sounds of Trumpeter Swans here and compare them to the higher pitched “whistle” of the Tundra Swans here.

Mute Swans, an exotic species from Europe, have become established in some parts of the eastern U.S. and Midwest, but fortunately have not made it to Montana, as they are aggressive competitors with our native swan species and can damage ecosystem functions.  I had a scare last week as we were driving home from Oregon and saw a golf course near Spokane with Mute Swans in several of the ponds!  On closer inspection they turned out to be decoys, probably placed there to scare off geese and ducks, but they also gave a fright to this swan observer.

With many bodies of water still frozen in western Montana, people are seeing lots of swans and Snow Geese filling up the few open ponds and fields.  It’s a wonderful time to be out and about, hearing the cries of the wild flocks as they wing their way north or settle down for some important rest and refueling on their long journeys.  The wetlands of our watershed provide vital habitat for so many species throughout the year.  And it’s just as exciting to know that some of the swans will stay right here in the Blackfoot to raise their young this coming summer!