Sojourn in Sitka

natural history and music harmonize beautifully

In late June I went to Sitka with some friends, in time to catch the final performance of the Sitka Music Festival. The music was wonderful, as always, and I had a small bonus: the panoramic windows of Sitka’s Centennial Hall gave me a view of a parade of ravens, flying by ones and twos, all in the same direction—a visual treat to add to the musical one.

Another objective of the Sitka visit was going out the St Lazaria Island, which I hadn’t seen in many years. Getting there is always chancy, because the island is fully exposed to the wide Pacific and the waters can be forbidding. On this morning, however, the weather gods were smiling, and we had a good ride. On the way out, we found a ‘smack’ of moon jellies—there must have been millions of them. They are said to be short-lived, and males and females are separate individuals. They feed chiefly on zooplankton and size reportedly depends in part on how well fed they are. I found no information on why they aggregate in huge groups such as the one we saw; is it for reproductive purposes or for feeding or by happenstance?? Several deer foraged on the beaches, and we passed a big flotilla of rhinoceros auklets. A gang of male sea otters, and a separate group of females with pups, were wary of our presence, and no wonder–they are hunted very heavily.

Then we got to St Lazaria. Some humpback whales lazed along the outside of the island. I was intrigued by the number of sooty shearwaters floating and diving. They come to our summer to forage but return to the New Zealand area to nest in the austral summer. Although Arctic terns, which have the reverse pattern –they nest here but spend the austral summer near Antarctica, are said to hold the long-distance record for annual migration, the shearwaters (sooty as well as short-tailed) must be close rivals.

St Lazaria is a remnant of an ancient volcano (older than Mt Edgecombe on neighboring Kruzof Island). Basalt cliffs rear up out of the sea, making two summits connected by a lower, grassy saddle that can sometimes get pounded by high seas. Broken basalt columns make great nest ledges for several thousand common and thick-billed murres, whose constant conversation and squabbling create quite a din. Nesting on these tiny ledges is a risky business for an egg, which might roll off when jostled by a parent. But murre eggs, only one per nest and laid on bare rock, don’t have the conventional egg shape; instead, they are rather pointed at one end, so they tend to roll in a circle instead of off the ledge as an ordinary egg would do.

Pelagic cormorants nest there too, using somewhat larger ledges, and each pair tends several eggs. Tufted puffins nest at the tops of cliffs, where accumulated soil allows them to dig their burrows. They were feeding chicks when we were there but were distinctly shy about returning to their burrows when our boat was nearby. There were lots of gulls nesting in the grassy area; I saw glaucous-winged gulls but, sorry to say, I did not bother to see if any other kinds of gulls were there. There was too much else to see! Added to the mixed community of nesters were some pigeon guillemots and black oystercatchers; up in the shrubbery on top of the summits I heard song sparrows and maybe a fox sparrow. Peregrine falcons nest there every year—with dinner all around them (!)—and had chicks out of the nest already.

What we did NOT see were the many tens of thousands—one estimate says a quarter of a million– of storm petrels that nest in burrows in the soil atop the summits. They are the focus of long-term research, monitoring the population and nesting success. They are seldom seen on the island in the daytime because they forage all day at sea and return to their nests only when it is dark. Parents feed their single chick on plankton and stomach oil (partly digested plankton, a concentrated pabulum!) for about two months. Mated pairs are reported to stay together for many years, with little straying (unlike many other supposedly monogamous birds).

This brief experience brought back strong memories of a similar site (Puñihuil) near the island of Chiloé in southern Chile, where I studied birds in the south temperate rainforest for many years. The sea stacks there were held the nesting burrows of two kinds of penguin, and ledges for various gulls and some very classy cormorants, and we could see steamer ducks and the local ‘sea otter’ (really a converted river otter). Another spectacular wildlife show!

 

Spring in Berner’s Bay

so much to discover and ponder!

Every year, exciting things happen in Berners Bay. Eulachon (a.k.a. hooligan) run into the rivers to spawn. Herring come in great shoals and often spawn on the rocky shoreline there. And, of course, hordes of their predators come to feast. Every year, also, a little group of kayaking friends tries to be there when all that show is going on. It’s a bit of a lottery: sometimes we find an almost empty bay; sometimes we hit it big-time. This year was a good one!

We got off the beach in Echo Cove by nine o’clock, in good paddling conditions. On the way up-bay, we saw several humpback whales, cruising around, frequently lunge-feeding. This was a good sign that there might be a show developing in the bay. A strange sight was a northern harrier being chased by a squad of gulls. Had it tried an on-the-water snatch, arousing their defensive reaction?

A snarling, writhing ball of dark fur resolved itself into two river otters as we passed. “Otter-wauling” seems to accompany the mating process in otters for some unexplained reason. Although otters mate in spring, the undeveloped embryo does not implant in the female’s uterus until fall, and the cubs are born the following spring. Delayed implantation is common among members of the weasel family.

Way back last fall, we rented the Forest Service cabin for the last weekend in April. Because there were six of us and the cabin is small, two of us chose to set up our tents near the cabin. Cosiness is nice, but there are limits…

Arriving at the cabin about noon, we had plenty of time for settling in and then doing a bit of exploring. Some of us hiked over to the waterfall to see if dippers live there (they do). Along the quasi-trail that squirms along just above the edge of the cliffy shoreline, we found the feathery remains of some predator’s lunch. A few yards farther one, there was another one. And then another. We puzzled over the identity of the feathered prey—black and white, yes, but there are many black and white birds. Then we found yet another scattering of feathers, with some bones and a bill. Aha! These were the remains of a Common Murre. As we scrambled along, eventually we found nine of ten leftovers from the lunch of the predator(s)—probably eagles. So we called this route Murre-der Row.

murre-der-2011-kh
Field sketch page documenting Murre-der evidence. Illustration by Katherine Hocker

That evening, things were popping right in front of the cabin. Bonaparte’s Gulls were diving for tiny fish near the shore—probably catching young pink salmon that had hatched recently. A shoal of herring arrived and predators soon followed. Sea lions, mostly juveniles, were having a grand time, often porpoising in pursuit of their dinner. Some invisible underwater predator, presumably a big fish such as a king salmon, was terrorizing the herring too. Panicked herring were leaping every-which-way out of the water. Some of them stranded themselves, or stunned themselves, on the shoreline rocks. The local raven took full advantage of these freebies, making regular trips, fully loaded with fat herring, from the rocks to a particular place (presumably a nest) south of the cabin.

This same raven, or its mate, had earlier scavenged things from the outflow of the tiny stream by the cabin, where previous cabin users had dumped their garbage. Body parts of Dungeness crab still lay near the tideline, along with bits of cauliflower (!), which were wisely rejected.

As twilight crept in, we heard the song of our first Hermit Thrush. A fine ending to a good day.

Fritz Cove

wildlife spotting and speculation along a quiet stretch of highway

It was murky sort of day, low overcast, occasional rain squalls, and sloppy snow underfoot. Our schedules didn’t offer many breaks either, so we opted for an easy walk along the North Douglas Highway.

The beach by the North Douglas boat ramp could well be called our very own ‘Skeleton Coast’ (with apologies to southwestern Africa), for the number of picked-over, disassembled deer carcasses reposing on the cobbles. Two eagles each claimed a deer head, while ravens, crows, and gulls squabbled over the few remaining scraps.

A couple of humpbacks cruised and dove, attended by a small gang of sea lions. Either the whales weren’t stirring up much tasty fare for the sea lions, or they had already provided very well for the ‘lions, which spent a good deal of time lolling about, floating belly-up or side-up, poking out a fin or two occasionally.

We counted nineteen kinds of birds (and there may have been more). All the usual suspects were there. We watched a red-throated loon with a long, wriggly fish, which was finally subdued and swallowed. There were a few Pacific loons and what we thought was an immature yellow-billed loon. A duo of common murres was a nice surprise. The only songbird was a song sparrow, which—around here—could well be called a beach sparrow.

A mixed flock of numerous scoters included mostly surf scoters, some white-winged scoters, and a probable black scoter. The scoters were diving, apparently for mussels. Most of the birds were diving independently of each other, with only a few of their famous chain-dives (in which a whole line of birds all comes up a spot where, one by one, they go down; a little later they all come up, one by one, at another spot a short distance away. I’ve never been able to find out why they do that.)

Several glaucous-winged gulls were hanging out with the scoters, mostly behaving very casually and innocently, floating around together. But every so often, a gull pounced on a scoter that was just coming up with food in its bill. At least some of those pounces made the scoter release its catch, to the benefit of the piratic gull. But many attempts at piracy seemed to fail. More puzzling was the observation that a gull would jump on the back of a floating scoter, forcing the scoter under the surface. Are the gulls trying to make the scoters dive for food or are they just having fun?

A few days later, it was still raining, and blowing, and I stopped at the North Douglas boat ramp. I was attracted by dozens of crows in the parking lot and on the cobbly beach. I pulled up near the far end of the lot, away from the crows, and just sat there to watch what was happening. It soon became clear: the crows were collecting small mussels from the beach, flying up and dropping them on the hard blacktop surface (and on the beach cobbles). By careful watching, I determined that sometimes a mussel shell cracked after one drop, but sometimes it took four drops of the same mussel before the crow could gain access to the soft interior.

crow-with-mussel-by-bob-armstrong
Photo by Bob Armstrong

The height of the drops varied greatly, from about five feet to maybe twenty feet or so, and longer drops seemed to be more effective. But a high-flying crow took longer to descend to its prey, which gave other crows time to sneak in and appropriate it. There were many attempts at stealing food from each other, so theft was a real risk. There was a trade-off between effective cracking and protecting the prey from competing crows.

I would love to know more about the energetics of this behavior. Flying up and then zooming down to protect the food takes energy. If a crow has to fly up three or four times, does the energy in one mussel fully repay that effort? Once a mussel shell cracked, the crows would poke and pry to extract the insides, often holding down the shell with a foot. Can crows wrench out the strong muscle that bivalves use to shut the shell—that muscle is very tightly attached to the shell, or can they only feed on the other organs?

This was also a bathing place for the crows. A pothole in the blacktop had collected rainwater. It was big enough for two crows to fit in at the same time, with much exuberant flapping and splashing. Occasionally several crows would line up politely to have a turn at their public bath. Bathing was not as competitive as feeding!