OKPILAK CAMP – The Seasons are Changing

Our camp is blessed, although at times it seems otherwise, by five or more major channels and many minor branches of the combined Okpilak and Hula Hula rivers. These braided river systems fan out into 7 km+ of sand, mud and shallow waters as their distributaries carry nutrients to the coast.

During my two week stay here, the brilliant colors of the tundra flowers (yellow Arctic Poppy, red and purple lousewort and creamy-white Dryas) have faded to brown and silver seed heads. The Arctic Sulfur butterflies and the bumblebees are making the most of the waning season of abundance.

Our local breeding birds are now fledging their young, or are close to it. On the freshwater tundra lagoons, clamorous Pacific and Red-throated Loons, Cackling Geese, Tundra Swans and Long-tailed Ducks all have downy chicks. Except for a tardy family of Semipalmated Plovers, most of the locally hatched Pectoral Sandpipers, Semipalmated Sandpipers and Red-necked Phalaropes are at the coast; or already in the first stages of the long migration south.

Here is where Stephen Brown of Manomet, Roy Churchwell of the University of Alaska and Steve Kendall of the Arctic National Wildlife Refuge have combined to lead a hardy crew of field biologists in a study of the significant of the coast for migrant shorebirds, and the seasonal differences in timing and breeding success from year to year.

We count the species, numbers and distribution of shorebirds on the mudflats and we sample invertebrate food. We also mist net Semipalmated Sandpipers which are banded, weighed, measured (and some blood-sampled) to assess length of stay and accumulated triglyceride fat levels.

Then there are the predators; also regularly surveyed. At Okpilak we have ravens, Glaucous Gulls, Parasitic Jaegers, Peregrine Falcons and Snowy Owls from the air. Also Red Foxes, Polar Bears (4) and the fresh tracks of Arctic Wolf and Grizzly Bear in the mud as the big predators follow the abundant Caribou. The carnivorous mammals have also taken their share of nesting shorebird adults, eggs and chicks this summer.

As the seasons are changing, more migrant shorebirds pass through the Okpilak/Hula Hula delta. Whimbrel call their seven-note whistles; Black-bellied and American Golden-Plover, Western, Stilt and Baird’s Sandpipers are frequently seen. None stay long now – even the Semipalmated Sandpipers show rapid population turnover; we seldom resight our banded individuals after two days. As always, the unforgiving arctic winter looms on the horizon and the migrants are all headed south.

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