The Daily Bucket is a regular feature of the Backyard Science group. It is a place to note of any observations you have made of the world around you. Rain, sun, wind...insects, birds, flowers...meteorites, rocks...seasonal changes...all are worthy additions to the bucket. Please let us know what is going on around you in a comment. Include, as close as is comfortable for you, where you are located. Each note is a record that we can refer to in the future as we try to understand the patterns that are quietly unwinding around us.
January 20, 2014
Salish Sea, Pacific NW
(All photos by me. In Lightbox...click to enlarge)
Harlequin ducks (Histrionicus histrionicus) winter along the coast in the Northwest, and then leave in spring for mountain streams to nest. Even in winter I don't see these small diving ducks often because they prefer rough turbulent water, feeding around offshore rocks. However the other day, in the last light of this January afternoon, I was lucky enough to see a flock in Outer Bay, from the road. Here are six of them, and a view of this bay, which faces the Strait of Juan de Fuca and swells from the open ocean.
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The breeding males are colorful and distinctively patterned with white markings. Variations on these white markings can be used to distinguish other members of the population, as described in Birdweb:
The distinctive Harlequin Duck is a small sea duck with a small bill, short neck, and long tail. Males in breeding plumage are unmistakable with their dark blue color, rufous sides and crown, and striking white patterning on the face, neck, sides, and back. In non-breeding plumage the males are brown with white on the face and a round white spot at each ear. A subtle white shoulder stripe and white on the wings distinguishes the male in non-breeding plumage from the juvenile and the female, which look similar.
In this group, besides the males in breeding plumage, there's a non-breeding male (to the right) and a juvenile (to the left). I don't know why some males are in breeding colors at this time of year and others aren't; it's implied in some resources these are immature or bachelor males, but I'd welcome an explanation from someone who knows ducks better - in the comments?
For whatever the reason, the less colorful Harlequins were a bit rambunctious, challenging and barreling into each other with lots of splashing and squeaking.
(more "histrionics" below...)
These two tussled for a minute, and then both turned on the colorful males, in a fountain of sea spray and noise.
Mostly, these ducks were cruising the shallows searching for fish or crabs, or diving for them. They have excellent underwater vision.
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Harlequins pair up in winter. In Montana,
John Ashley, a harlequin expert who teaches courses on the duck at the Glacier Institute (says) "bachelor harlequins arrive in Montana in mid- to late April. Paired ducks show up about two weeks later. The female brings her mate home to her natal stream.” (Montana Outdoors)
The duck on the right did not take part in the shenanigans. May be an adult female? ;-)
The Eastern populations - described as "Endangered" in Canada and "Threatened" in the U.S. - are decimated due to hunting since the late 1800s but with protection in the last few decades their numbers are increasing there.
In Washington state, the breeding range overlaps closely with National Parks and National Forest land...that relative remoteness is helpful in maintaining Harlequin populations in the west here, but they are still considered a "Species of Concern."
The western Canadian Harlequin populations are healthier than in eastern Canada, but the Harlequin Duck Population Monitoring program in British Columbia reports declining populations there since the early 1990s, likely due to development pressures and recreational activity along the coastline. Peter Clarkson, of the HDPM program, remarked in an email communication (in which I had submitted photographs of two banded local oystercatchers) that 3 Harlequins had recently been resighted in the Georgia Strait (between Vancouver Island and mainland BC), confirmed to be at least 18 years old! A bit of good news, however,
The combination of human stresses on breeding, moulting and wintering habitat may be taking their toll on the western Harlequin Duck population. The species' narrow ecological niche, low reproductive capability, delayed sexual maturity, and specialized habitat requirements limit its ability to adapt to a changing environment. - HDPM
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In the same bay, several Red-Breasted Mergansers (Mergus serrator) swam into the Harlequin flock. They are considerably bigger ducks, and the merganser male went after our Harlequins. These mergansers also winter in these bays, and feed on the same marine prey.
This contretemps was over quickly and all the ducks went back to cruising along the surface in the the fading sunlight, until a walker on the beach approached. The Harlequins formed a row and swam away from shore.
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What's up this winter day in your neighborhood? Please share your nature observations in the comments :)
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