How the Harlequin Got His Spots

What could be more straightforward (and more beautiful) than
an adult male Harlequin Duck? True, but have you ever stopped
to think about how a male Harlequin gets its stunning good
looks? To answer that question, Utah birders Keith Evans and
Paul Higgins did something disarmingly simple: During the
course of several months, they studied an immature male
Harlequin Duck of known identity. Their observations led
them to a detailed understanding of how a male Harlequin
acquires its complex and exquisite plumage.
Victoria, British Columbia. October 2009.
Photo by © Glenn Bartley.
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B I R D I N G • M AY 2 0 1 2
Although not the focus of this article, the demise
of the Utah Harlequin Ducks elicited strong feelings from many birders. Join the discussion here:
blog.aba.org/2012/05/shooting-rarities.html
Keith Evans
Ogden, Utah • [email protected]
Studying Molts and Plumages
in Histrionicus histrionicus
tah hotline alert! Living in a large western state
offers many advantages to the birder. But it can
often mean a five-hour drive to chase a rare bird.
Thus, when a Harlequin Duck sighting was reported on
the Utah rare bird alert in late September of 2011, my
first question was: “Where?” I soon learned that a juvenile Harlequin Duck was being observed along the
causeway crossing the Great Salt Lake to Antelope Island State Park, in Davis County. My excitement intensified, as the causeway is only a 20-minute drive from
my house. The next morning, I began the seven-mile
trip across the causeway, eagerly scanning the numerous ducks bobbing in the choppy water.
I took a quick look in my “big Sibley” to establish a
search image. Every birder knows the distinctive pattern of a male Harlequin in breeding plumage, but the
sighting was of a juvenile. I was just beyond the six-mile
point when I spotted a brownish duck with white spots
on its face. With a spotting scope, I could easily see the
large bill of a bird about the size of a nearby Northern
Shoveler, so I knew this sighting was of a Surf Scoter.
The Surf Scoter is an uncommon visitor to Utah and,
under ordinary circumstances, a “good” bird. Today,
though, I was mildly disappointed at the sighting.
Within 15 minutes, I had sighted another possible
Harlequin. This duck was about the size of a nearby
Ruddy Duck, chunkier in build, and with a small bill.
Bingo! I had found my target bird. I set up the scope for
a better look and was enjoying the clear view when another motorist stopped and asked if I had seen the reported Harlequin Duck. It was fun to point toward the
bird and not repeat those words we have all heard way
too often: “It was just here, in plain sight.”
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HARLEQUIN DUCK
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The story gets better. Over the next few days,
the bird moved in close and took up residence
along a rocky shoreline near a bridge. The bird
would be an easy find for many birders and
other visitors to Antelope Island State Park.
Things got better yet. Two more “femaleplumage” Harlequin Ducks joined the first one.
The original bird was subtly different from the
other two, so we nicknamed it “Harley One.” The
three Harleys became a regular subject of conversation among the region’s birders. The ducks became gratifyingly tame, and would swim toward
the causeway to rest and preen on nearby rocks
even when birders were standing on the bridge
and talking.
First-winter Molt Sequence
in a Harlequin Duck
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By mid-October, about 22 days after our first
sighting, Harley One was showing two white
spots on his newly developing wing (tertial)
feathers. Another flurry of reports let everyone
know there was at least one male among the
three Harlequins on the north side of the causeway near the first bridge. Harley One was indeed
a young male and progressing through its firstwinter (preformative) molt. Paul Higgins, a
friend and photographer, then began a photo sequence to document the molt and agreed to
share his photographs for this article.
I believe most birders would agree that it is
uncommon to have the chance to track the molt
sequence of a single bird in the wild. In this case,
two factors provided us with this opportunity.
Fig. 1. A hatch-year Harlequin Duck in Davis County, Utah,
was photographed on 28 September 2011. Note the
loosely textured, “soft” feathers. Photo by © Paul Higgins.
Fig. 2. Two “female-plumage” Harlequin Ducks were photographed on 12 October 2011. The first arrival—“Harley
One”—is the top left bird. Photo by © Paul Higgins.
Fig. 3. The initiation of molt became evident as the face
pattern began to change and the two white spots on the
wing (precisely, on the tertials) appeared on the individual
that arrived first. At this time the male began to appear
significantly different from the two other birds in the
group, which we could now identify as females. This
image is from 25 October 2011. Photo by © Paul Higgins.
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A Few Terms, and an Appeal for Clarity
Steve Howell, who has done a great deal to advance birders’ understanding of molt, readily acknowledges that the
topic of molt can be offputting. As Howell has noted, many birders find that “molt is messy.” True, a molting bird may
be literally messy, but a larger part of the problem is that birders often get hung up on terminology—which, unfortunately, has been rather inconsistently applied in the literature. Terminology differs between British and American
birders, between bird banders and museum workers, and even among field guides published by the same publisher!
Let’s try to keep the terminology simple, and to a minimum. The bird discussed in this article was unquestionably
in its first year of life, or first plumage cycle. It was hatched in the summer of 2011, and it was shot and killed before
the stroke of midnight on New Year’s Eve of 2012; thus, it was in what bird banders refer to as its hatch year. By October of 2011, as is clear from the photos, the bird was in the process of growing in new feathers; in other words, it
was in the process of molt. But what plumage was it molting from, and what plumage was it molting into? Given
the dates of observation, a reasonable first guess would be that the bird was molting from its juvenile plumage
into its first-winter plumage. In ducks, this first post-juvenile plumage is known as the formative plumage. (It was
formerly referred to as the first-basic plumage.) Thus, we would say that a bird in the process of acquiring its formative plumage is undergoing its preformative molt.
As noted in Howell’s Peterson Reference Guide to Molt in North American Birds (Houghton Mifflin, 2010), however, the
first-fall molt in ducks is, well, messy. Possibly, some ducks have an extra plumage—albeit a rather imprecisely defined one—between what we are referring to here as the juvenile and formative plumages. (However, this molt has
not been documented in sea ducks, such as the Harlequin Duck.) Here’s an idea: Let’s simply document what we saw
(by way of photos), and let’s succinctly describe what we saw (by way of words).
By far the best way to begin to understand molt is to study actual birds. In the past, we had to base such studies
on museum specimens, but there is a huge limitation to that approach: Birds only die once. With the proliferation of
good digital cameras, though, everything has changed: We can study the same bird repeatedly, throughout the
course of an entire molt, or even multiple molts.
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Fig. 4. By 30 October 2011, reddish feathers were appearing on
the flank of the hatch-year male. Photo by © Paul Higgins.
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Fig. 5. The next changes included (1) an expanding white stripe
above the eye along the crest of the head and (2) white feathers
showing up as a vertical bar on the breast. This image is from
3 November 2011. Photo by © Paul Higgins.
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First, because there were so few Harlequin
Ducks available for study, we learned which
was which; throughout the period of observation, we were certain of the identity of Harley
One. Second, the birds were obligingly tame,
allowing leisurely and prolonged study.
The Harlequins arrived in Utah near the end
of September 2011 and remained until they
were shot by a hunter near the end of November 2011. We were saddened by the loss of
these rare Utah birds that we now considered
friends. As hundreds of birders stopped along
the road to view and photograph the rare Utah
visitors, the ducks went about their feeding,
bathing, and preening without disruption even
when birders and photographers outnumbered
them. The hunting event ended our photographic sequence of the molt, and the opportunity to view winter and spring changes in the
other two birds. We would have liked to have
documented more fully the first-winter molt of
the Harlequin Duck.
Recommended Reading
and Future Study
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Birders interested in learning more about molts
and plumages would do well to study Steve
Howell’s Peterson Reference Guide to Molt in
North American Birds (Houghton Mifflin, 2010).
The introductory sections are excellent, and the
family accounts answer many questions—and
raise many new questions! For a quick introduction to molts and plumages, check out
Howell’s two-part primer in Birding (Part 1, October 2003 issue, pp. 490–496; Part 2, DecemFig. 6. By 8 November 2011, black feathers were
appearing on the breast of the first-cycle male,
and he was becoming increasingly different from
the female (right). Photo by © Paul Higgins.
Fig. 7. With every passing week, the appearance
of the male was more and more like illustrations
of first-winter plumage described in field guides.
This image is from 11 November 2011. Photo
by © Paul Higgins.
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Fig. 8. A white spot appeared on the rear flanks
(below the tail) by 11 November 2011 (see Fig. 7)
and shows well in this 15 November 2011
image. Photo by © Paul Higgins.
B I R D I N G • M AY 2 0 1 2
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Fig. 9. By 20 November 2011, the black feathers on
the breast were becoming dominant and the whiteto-amber stripe along the head crest was more
prevalent. Photo by © Paul Higgins.
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Fig. 10. The last photo in this sequence was taken on 25 November 2011, when
the appearance of the bird’s head and breast fairly closely resembled that of a
“textbook” adult male. But note the brown wings; adult males have gray wings
with additional white spots on the wing coverts. Photo by © Paul Higgins.
ber 2003 issue, pp. 640–650). Finally, every serious student of
molts and plumages will inevitably gravitate toward Peter Pyle’s
magisterial two-volume Identification Guide to North American
Birds (Slate Creek Press). The work contains extensive jargon and
terminology (how could it not?), but the terms are consistently
applied. If you stick it out with Pyle, you will become a more
knowledgeable birder.
The aforementioned reference works are indispensable, but
don’t lose sight of the most important thing of all. Go out in the
field, study real birds, and learn. A particularly powerful method
is to identify a particular resident individual, and then study
its molt over the course of several months.
Acknowledgments
First and foremost, I am grateful to Paul Higgins, who provided the 10 photographs that are the entire basis of this article. Also, I thank Steve Howell and Peter Pyle, who made
helpful comments on an earlier draft of this article.
The moral of this story? Carry your
camera, and stick with the bird. In the
years to come, birders will greatly
advance our understanding
of molts and plumages.
Glacier National Park,
Montana; April 2005.
Photo by © Tom Ulrich.
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