Yellowstone has many well-known and iconic
animals such as bison, once down to only 20 or 30 in number, but now numerous
and easy to find roaming in herds across the open grasslands. Wolves, another iconic species, have been
reintroduced to Yellowstone, but are not easy to see.
For avian fauna in Yellowstone
there are probably no iconic species that one would look for in the Park
that could not be found elsewhere. For me however the Trumpeter Swan was one
species I was hoping to see in the Park as a small permanent population lives
there year round. The local birds are joined over winter by some migrating
birds coming down from Alaska and Canada, however as we were there in early
Fall we would only have a chance of seeing the resident birds.
The Trumpeter Swan was almost wiped out
from the lower 48 States by the early 1900’s and severely reduced in the
remainder of its range in northwest Canada and Alaska by hunting for food and
feathers, (its large flight feathers made high quality quills apparently), habitat
destruction and lead shot has poisoned many young swans. With protection and
careful management the species has now made a recovery in its core range however
the resident population in Yellowstone has been in decline for a number of
years now.
The Trumpeter Swan (Cygnus
buccinator) is only found in North America though it is closely related to
the Whooper Swan found in Eurasia – some authorities regard them as the same
species. It is the heaviest bird native to North America and, on average, the
largest living waterfowl species. An all white plumaged swan, the Trumpeter may
be confused in the field with the similar but smaller Tundra Swan.
We found Trumpeter Swans by luck when a
road closure forced us to go the long way round to visit Old Faithful. The road took
us along a section of the Yellowstone River at the northern end of the Hayden
Valley where the river widens and flattens into a slow shallow course before
its dramatic plunge through the spectacular Yellowstone Grand Canyon.
Yellowstone River, Hayden Valley, Yellowstone National Park, a great wildlife viewing area. |
First fall on Yellowstone River downstream from Hayden Valley in Yellowstone Canyon. |
As usual we were alerted to the
presence of some wildlife of interest by a large crowd gathered beside the road
along the riverbank, including at least a dozen photographers, some with very
long lenses on tripods. It was not until we stopped, got out of the car and
walked over to the top of the river bank and looked down that we discovered the
wildlife species of interest, in this case, two adult Trumpeter Swans feeding
on aquatic vegetation right beside the river bank.
Just a few of the large lenses focused on a pair of Trumpeter Swans. |
To frame these two large swans the long
lens contingent were forced to station themselves well back however with my
shorter (420mm) lens I positioned myself closer. I was soon joined by at least
six other photographers gathered close beside me and was surprised to hear the
large bursts of shots they were firing off for two such large slow moving
birds. To capture action shots, for example birds in flight, I sometimes use
the Continuous Shooting mode, which I generally have selected and
control with the shutter button for single shots or bursts as needed. For me
this situation demanded careful attention to detail and capture of shots here
and there when appropriate and not rapid firing with large numbers of images
captured.
Two adult Trumpeter Swans on Yellowstone River. The shallow section of river in the Hayden Valley provided good habitat with aquatic vegetation to browse. |
Adult Trumpeter Swan, note the straight bill and the black facial skin tapering to a V at the eye. The duck was feeding on tit bits disturbed by the Swan. |
The adult swans were active pulling up
waterweed from the bed of the river and eating, stirring up mud and other
matter as they foraged. A few ducks were scavenging close by for tit
bits stirred up by the much larger swans. Feeding associations among birds such
as this are quite common.
To my surprise three ducks were huddled
together sound asleep beside the bank with a large number of tourists and
photographers standing directly above them and birds feeding nearby. Clearly
these ducks felt safe in Yellowstone.
Sleeping ducks. |
After capturing a few shots of the
adult birds feeding I noticed four more swans about 100 metres downstream. A
quick scan with the binoculars showed them to be three juvenile Trumpeter Swans
and what looked like one white adult. The four commenced to swim upstream
towards us in close formation.
Four Trumpeter Swans making their way in V formation upstream. The three grey birds are juveniles, the white one does not have an all black bill? |
Before the juveniles arrived the two
adults lost interest in feeding and moved off to commence some preening, giving
the opportunity to capture a few shots of one with its wings spread while
flapping to arrange and settle preened wing feathers.
The two adults were preening when this one began to flap its wings. |
I guess vigorous flapping of the wings shakes out any dirt and loose feathers and helps to arrange and settle the wing feathers. |
The Trumpeter Swan is the largest waterfowl, adult wingspan exceeds 2 metres. |
As the juveniles approached I noticed
that the white bird was also juvenile as it had a largely pink bill and not
a fully black bill. A later check of field guides showed this was a rare white
juvenile which are only found in the Yellowstone birds.
I suspect the four young birds were
siblings belonging to the two adults. All four young were banded.
The young ones arrived below us and
commenced feeding where the adults had recently left off. As with many young,
they fed close together even though there was plenty of space and food for all
and the inevitable squabbles broke out with some feather biting and so on.
Three of the four juveniles feeding close together. |
The rare white juvenile is letting the typical grey juvenile know it is too close. |
There has been a lot of research on
Trumpeter Swans in Yellowstone to try and work out why the resident population
has been declining since the early 1960’s. Anyone interested in this subject
can find links to papers on the topic in Wikipedia; just enter Trumpeter Swan
in the Wikipedia search box.
All four juveniles were banded, this is H53. |
I hope H53 and his/her siblings enjoy a
long and productive life in Yellowstone and that there will always be a
resident population of Trumpeter Swans there for future visitors to see and
enjoy as we did in the Fall of 2014.