When the moon covers the sun, we have a solar eclipse. What do you call it when birds do that?–Kim Young-ha
Ducks are a bit weird. If you’ve ever scrutinized your reference books or field guides you may have noticed that sometimes the bright plumage of the drake is labeled “winter” and not “breeding.” This is because many species of drakes with brilliantly-colored plumage during most of the year molt into a relatively drab, female-like plumage called eclipse plumage during a short post-breeding period in summer. Their nearly year-round brilliance is briefly in eclipse.
After our return from a recent Alaska trip, several birder friends from Texas asked what we had seen. Chris replied “Mallard drakes in eclipse plumage, for one.” The reaction was similar to the one he gets when someone asks why there are not astronomical eclipses all the time (“The plane of the moon’s orbit is inclined by 5 degrees to the plane of the ecliptic.”): bewildered stares.
This reaction is likely because only a handful of duck species breed in Texas, and more than half of these (Mottled Ducks and Fulvous and Black-bellied Whistling-Ducks) lack strong sexual dimorphism and a brilliantly colored drake. Only in Blue-winged Teal and Wood Ducks does the the possibility exist of seeing a drake noticeably in eclipse along the Upper Gulf Coast of Texas. In the case of the former, the casual birder would likely think he/she was looking at a hen. In the case of the latter, likely a juvenile or hen. Also, since none of these Texas duck species are typically a cause for excitement among birders, these drakes probably wouldn’t get a second look. In northern regions, where many duck species breed, an oft-asked question among those not clued-in to eclipse plumage is: “Where do all the beautiful drakes go in the summer.”
What is the purpose of eclipse plumage? An adaptationist explanation is that after breeding the drakes no longer need the brilliant colors, so when they enter the molt for their primary (flight) feathers, they lose their showy colors, too. This makes sense ecologically in that when molting primaries they are unable to fly, so being more camouflaged like the females would be adaptive. The hens typically molt their primaries later in the summer, when the ducklings are quite independent.
Travel birding is a worthy endeavor because the insights you gain can be applied frequently at home. The next time I see drakes in the summer here in Texas, I’m sure to look a little harder at them. Maybe you will, too.
Sonny: Is there any special country you wanna go to?
Sonny: Sal, Wyoming’s not a country.
–Dog Day Afternoon (1975)
What with Elisa up in Wyoming to observe the astronomical, and Chris back in thrall attending to the physical, we’re tapped out. Not to worry–we’ll be back on the ball soon with more images and prose celebrating our feathery friends. As we enter these sweaty dog days, we’re dreaming of the first blue norther (and northern and high places)! If you’re on the Texas Gulf Coast, we bet you are too!
One of the great surprises for us on St. Paul Island was the low diversity and abundance of larids. We saw nothing like the large mixed flocks of seagulls and terns we are accustomed to around here. To be sure, there were lots of Black-legged Kittiwakes (and a few Red-legged Kittiwakes), but we only observed two species of gulls, Glaucous and Glaucous-winged, and no terns whatsoever. One of the local guides also said there were Herring Gulls around, but we couldn’t swear to seeing one. Further, the only confident identifications of Glaucous Gulls we made were a couple of completely white juveniles that we saw from a distance. Thayer’s Gulls and Black-backed Gulls do occur in the Pribilof Islands in summer, but none were apparent to us.
We know a lot of birders can take or leave gulls (Elisa for one!), a likely reason being difficulties in identification–especially the dramatic changes in appearance many species make from year to year early in life. Chris generally makes an effort to identify any gulls that he sees when visiting coasts. And terns are among his favorite birds, which is why he found the absence of terns on the island a bit of a disappointment. Based on reading, we had reason to expect Arctic Terns on St. Paul. Luckily, we saw Arctic Terns around Anchorage so we didn’t miss them entirely during this trip. Aleutian Terns can theoretically make an appearance on the island during spring and fall, but not summer. Oh, well.
Another big surprise was the small number of Northern Fulmars. According to the literature, the Northern Fulmar is one of the most common tubenoses in the world and one of the most abundant breeders on St. Paul Island. But we saw only a few breeding pairs. More fulmars are killed by commercial fishermen than any other seabird, but fulmar populations are large. In the North Atlantic, fulmars have even increased in numbers in recent years. Perhaps had we visited a bit later we would have seen more.
One of the things about travel birding is that it forces you to confront your assumptions. At first we thought the low diversity and abundance of gulls on St. Paul might have had something to do with island biogeography (or the toll humans have been taking on nature). Now it seems clear it has more to do with larid biogeography. Most gulls really do stick close to continental shores and do not range far out to sea. Exceptions include Herring Gulls, Glaucous, and Glaucous-winged Gulls (and the kittiwakes, the most sea-loving of all the gulls, of course)–exactly the ones that occur on St. Paul. Despite the fact that we see seagulls by the sea they are not really seabirds, at least not the way alcids and tubenoses are.
Long ago, when the world was still quite new, there were no winds at all, neither the gentle breeze of summer nor the fierce winter gale. Everything was perfectly still. Nothing disturbed the marsh grass on the shore and when snow fell, it fell straight to earth instead of blowing and swirling into drifts as it does now . . . . Origin of the Winds, Aleut legend
The four Pribilof Islands lie in the Bering Sea about one-hundred fifty miles north of the Aleutians. Of St. George, St. Paul, Walrus, and Otter Islands, only St. Paul and St. George are inhabited. St. George and St. Paul are birding meccas, more so the latter because of better weather conditions for aviation in and out despite the former having a great deal more cliff habitat and many more birds.
Seventeen species of alcids have been observed on and around St. Paul Island. Many of these species are rare, threatened, or endangered. In summer, however, seven species are common, and these are the birds we spent a considerable time with in early July as part of a bird photography workshop conducted by Canadian photographer Chris Dodds. Least Auklets seemed to be the most abundant of the alcids on the cliffs, followed by Thick-billed Murres and Parakeet Auklets. Crested Auklets, and Horned and Tufted Puffins were less common. Common Murres were observed infrequently: We only observed them in flight around the sea cliffs.
The seven species of alcids are all cliff-nesting species and spend most of the year out to sea when they are not breeding or raising young. With the exception of Least Auklets which we also observed and photographed at Anton Larsen Wall, a man-made breakwater composed of boulders of volcanic rock, all species were photographed on cliffs overlooking the Bering Sea. Many of these sites seem quite precarious and dangerous (for birds and humans alike), and one section of cliff housing Crested Auklet nesting sites collapsed into the sea while we were visiting.
According to reports and historical records, the abundance of birds and other animals has decreased dramatically on St. Paul. According to Chris Dodds who has visited the island approximately thirty times in the last few decades, the abundance of birds has dropped by about 90% in that time. Aerial photos of the island on display in the King Eider Hotel, the only lodging available to visiting birders, also show a steep decline in northern fur seal abundance since the mid-twentieth century.
The decrease in seabird abundance on St. Paul likely reflects a general drop in bird abundance across the northern Pacific. On this trip, the local guides and Chris Dodds kept mentioning nesting failures and weird timings of birds coming and going across the island. Many causes have been suggested for the current avian crisis from human overfishing, to birds being killed in fishing nets, oil spills, other pollution, and “the blob,” a mass of unusually warm surface water that has disrupted the marine ecosystem causing mass starvation. Whatever the cause(s), if you want to see these incredible animals we suggest not waiting as the task will only become more difficult with time. Think of the northern Pacific as the American West–circa 1890.
You can’t wait for inspiration. You have to go after it with a club. –Jack London
Coming and going from a photography workshop on St. Paul Island, Pribilof Islands, Alaska we had the opportunity to spend about two days photographing wildlife in the Anchorage area. We spent most of that time at Potter Marsh, but managed to make a visit to Cheney Lake on a tip (thanks to DK and LG) that Red-necked Grebes were nest-sitting there.
The Potter Marsh boardwalk is a well-known birding hot spot just south of Anchorage. Here, elevated walkways wind through marsh and surrounding woodlands: We added a number of new species to our list including Alder Flycatcher, Common Redpoll, Mew Gull, and Arctic Tern. We also saw Mallard drakes in eclipse plumage (and birds molting into said) for the first time. The density of visitors (and boardwalk vibration caused by footfalls) reminded us of Brazos Bend State Park where the constant flow of foot traffic can preclude serious photographic work and observation. Nevertheless, Potter Marsh is well worth a visit, especially early in the morning.
Although most of the time on St. Paul the weather consisted of some combination of fog, rain, sea mist, and wind, our time in Anchorage was mostly pleasant with sunshine and patchy clouds or an occasional thin covering of clouds with temperatures between 50º and 70º F.
The highlight of Cheney Lake was a nest-sitting Red-necked Grebe with two chicks. The babies clambered around the adult. Occasionally the other parent would deliver a small fish to the young birds. We also observed the nest-sitting parent feed the chicks white downy feathers it plucked from its own breast. These ingested feathers are thought to aid in the formation of pellets. These pellets are composed of feather fragments and indigestible particles like fish bones and are ejected through the gullet.
All in all, this was an excellent trip, and we learned a great deal. Much of what we learned during the workshop will take time to digest (and to acquire and master some new software!). But on the journey up and back we learned we should slow down in arriving at a place–and not only because getting to St. Paul requires eleven hours in a plane over three legs. We could have easily spent several more days in Anchorage birding. And even with that we would not have even begun to scratch the surface of the rich nature this city and environs offers.