Berner’s Bay

day 2 of 2

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The day dawned gray and cool, with a sharp breeze coming down from the north and big swells rolling in from the south. The combination of swells with the chop from the opposite directions would make for interesting paddling.

On the previous day, we’d notice clouds of white birds over on the Berners River, so we knew that the eulachon must be headed upstream. The herring shoal that entertained us last night had moved on, and we intended to check out the action at the eulachon run. The plan was to paddle across to the west side of the bay and hike up along the Berners River.

The tide was starting to go out, which meant that finding a good place to park our kayaks near the mouth of the Berners River would be difficult. Vast amounts of silt come down the rivers into the bay, creating a broad apron of shallows all across the north end of the bay. If we left our boats anywhere along the shore at low tide, they could be stranded far from water deep enough to float even a kayak (unless we waited for hours, until the tide rose again). Parking on the inviting sandy beach would mean that we’d have to carry our boats hundreds of yards over the tideflats to reach navigable water. So we hauled them up on some miserable, slippery, slimy rocks on a steeper shore, where the distance to water would be less.

Snowbanks still lined the fringe of trees above the high tide line, but spring was indicated by a few nearby wildflowers in bud and bloom. The cold north wind spattered our glasses and binoculars with rain as we trudged up the edge of the tideflats, but the white clouds of gulls drew us on, up the river.

The sandy flats, exposed by the outgoing tide, held a record of other recent visitors. A pair of moose had just passed by, leaving one set of very large footprints and another set of somewhat smaller ones (?perhaps from last year’s calf?). In the fringing willows we also noted many broken branches where wintering moose had pulled down twigs to eat. A beautiful trail of an otter was so clearly defined that we knew this animal had been there that morning. There were slightly fuzzier prints of mink and a possible wolf, from an earlier time.

Most interesting, maybe, were the large prints (about seven inches wide) of Brother Bruin, ambling up and down the gravelly shore. The shape of the foot pads suggested ‘brown bear’. A large and very fresh pile of fist-sized droppings hinted at the possibility that we might be under observation ourselves.

With all the interesting things along the way, our progress was slow. Eventually, however, we got far enough upstream to watch the gulls snatching fish and trying to steal fish from each other. Dozens of eagles stood around on the sand bars or perched in the trees, just watching; since ‘taking turns’ is not likely to be part of eagle etiquette, perhaps they were sated. In some of the slightly deeper channels, we could make out long columns of dark forms slowly swimming upstream, running the gauntlet of predators.

On the way back to our boats, we noticed wads of what looked like tiny eggs, washed up on the sands. Our best guess was that these were eulachon eggs that had stuck to each other rather than to sand grains. Eulachon eggs have a double membrane around them. The outer one breaks open and folds back to make a little pedestal that normally attaches to a grain of sand. The egg then incubates in cold, fresh water until it hatches and the tiny larva washes out to sea. But these clumps of eggs (if that’s what they were) were doomed, all stuck together and getting washed into salt water way too soon.

After lugging our boats about a hundred yards back to floatable water, we headed back to the cabin. The water was smoother now, and the going was easy. A squadron of about forty sea lions reared up, giving us the eye and a continuous roar as we went by—a trifle unsettling, even when you know it’s all talk.

So the weekend was a huge success. We’d won the lottery and got to the bay when things were happening, with a bonus of many other attractions, including good company. Our cups were running over, leaving lots of good memories.

Gambling on Berners Bay

playing the annual wildlife lottery

Going to Berners Bay in spring is always a bit of a lottery—you never know what you might see there. Maybe nothing much, except some scenery. But if you hit it just right, things can get pretty interesting.

When the eulachon (a.k.a. hooligan) are in the bay, staging for their spawning migration up the rivers, there might be dozens upon dozens of sea lions, foraging cooperatively and rafting up to rest from their exertions. Harbor seals would be there too, in quantity, and humpback whales would be likely to cruise through. Orcas may arrive, in search of unwary sea lions or seals.

Once the hooligan are in the rivers, the action in the bay dies down. Tens of thousands of gulls and ten hundred eagles gather to gorge on these oil-rich, slow-swimming fish, which run a fearsome gauntlet of predators in the lower reaches of the rivers.

Springtime also brings shoals of herring, which often spawn in the bay. That draws lots of eagles, which line the shore and swoop down to snag a distracted spawner. Gulls feast on the eggs that coat the rockweed in the intertidal zone, and humpback whales come to fill their maws with fish.

One year, our annual kayak junket to Berners Bay happened when both hooligan and herring were bringing in hordes of predators, and the bay was a crazy place. We hardly knew where to cast our watchful gaze!

This year, 2011, was different again. The eulachon were up the rivers, attracting clouds of gulls, and only a few sea lions and seals remained in the bay. The herring had spawned recently, and their eggs glistened on the rockweed when the tide went out. The gulls were all busy with the hooligan in the rivers and ignored the herring eggs, and the mobs of eagles were notably absent.

Instead, we saw acres and acres of surf scoters—there must have been ten or twenty thousand of them. What a racket! They spent a lot of time apparently loafing and talking. Every so often, a group of them would head to the shore and nibble on herring eggs, sometimes pulling off chunks of seaweed too. I suspect they were also diving for mussels. Or they would suddenly all dash across the water with great splashing, for no apparent reason. When thousands of ducks do this all at once, it creates quite a ruckus.

Bonaparte’s gulls were diving after pink salmon fry that thronged the shallows and maybe also juvenile herring in the deeper water. Barrow’s goldeneyes in small squadrons swam along the rocky shore, gobbling up herring eggs. A kingfisher dove repeatedly and seemed to catch a salmon fry on almost every try. Three solitary black bears foraged on separate beaches.

A little walk in the woods produced three very dead and dried herring, perhaps dropped by some inept or unlucky eagle or gull. Another possibility, however, is that ravens had grabbed a fish as it tried to spawn in shallow water, or had stolen it from another bird, and stashed it in the trees. Years ago, when I was studying predators at the eulachon run, we noticed ‘rains’ of dead eulachon falling from the trees when the wind blew; they’d been stored up there by a gang of scavenging ravens.

Another stroll in the woods found us in a soggy little opening where lots of skunk cabbage grew. But instead of a cheery array of bright yellow, there were only stubs barely showing above the muck. Something had messily chawed them all off, right down to the mud line. The culprit left evidence of its passing: huge cloven hoof prints and occasional clusters of digested pellets about the size of the end of my thumb. Moose were introduced to the Berners Bay area some decades ago and they have found a nice smorgasbord there—we also noted well-browsed alder shrubs along the upper beach.

So, although we missed the show at the hooligan staging in the bay and the show at the spawning herring, we found plenty to see!

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.

Cruisin’ to Berners Bay

in search of an annual wildlife congregation

Every year, Juneau Audubon offers several spring cruises to Berners Bay, not far north of town. There is always a hope that the cruise might happen to arrive in the bay during the time when the hooligan (=eulachon=candlefish=salvation fish) are running. this is hard to do, because the hooligan spawning run is short, only a week or two, and the timing varies from year to year—and it may be getting earlier than it was a few years ago.

When the hooligan come in, they mill about in the bay for a while, and that’s when the marine mammals enjoy a feast. Whales pass through, and seals hang out on a reef near Slate Cove. Steller’s sea lions stock up on the fatty little fish before heading out to their outer-coast rookeries for pupping and mating. On the rookeries, males don’t feed for several weeks, being busy defending harems and mating; females give birth and nurse the newborns, which costs them a lot of energy—so putting on some fat ahead of all that activity is essential. Years ago, when we studied the predators at hooligan runs, we counted over two hundred sea lions in the bay on some days, making a racket and leaving hooligan-grease slicks on the water.

Hooligan spawn in the lower reaches of the glacial rivers that enter the bay, and sometimes the seals and sea lions follow their prey up-river. It was quite a sight to watch a big bull sea lion humping hastily over the sand bars to reach deeper river waters and the up-running spawners.

thayers-gull-with-eulachon-by-bob-armstrong
A Thayer’s Gull with eulachon. Photo by Bob Armstrong

Birds come to the spawning run in droves. White clouds of over forty thousand gulls would be calling, chasing, pirating fish from each other, loafing on the sands. Eagles lined the river banks—we estimated that there could be a thousand or so. Local ravens and crows scavenged hooligan that were stranded by out-going tides and stashed their prey in the grass or fed them to chicks in the nest. Even dabbling ducks, such as mallards, chowed down moribund hooligan.

In some years, herring also spawn in the bay about the same time as the hooligan run. Herring spawn on the seaweeds along the rocky shores and attract hordes of egg-eating scoters and gulls, along with eagles interested in the fish themselves.

It was all very exciting! But, as a naturalist aboard the cruises this year, I had to tell folks to imagine all that predatory excitement. It seemed as if the hooligan run was over, although gulls still hung out along the edges of the river mouths. We heard rumors that the herring were in, and getting ready to spawn, but it didn’t seem to be happening just yet.

While it was a bit disappointing, perhaps, to miss the big show, I suspect that the folks on board were not unhappy at all. We saw a fine display of “pec-slapping” by humpback whales: whacking the water with powerful slaps of their long pectoral fins. The pectoral fins of humpbacks are longer, relative to body size, than those of other whales. Those mighty pecs are reportedly used to herd small fish, in fighting off attacks by orcas, and in making a swimming whale very maneuverable. They may also be used as some kind of display (still to be studied), and male humpbacks sometimes use them as props for their headstand posture while they sing during the mating season in winter.

Near Tee Harbor we chanced upon several orcas (=killer whales), splashing about and moving along the shores. There were several orcas, including one quite small one, mostly foraging independently, not in a close bunch. I guessed that these were likely to be the fish-eating ‘resident’ sort of orcas, probably after spring king salmon. Orcas had recently been seen near downtown in Gastineau Channel too, and we wondered what had lured them there.

We were treated to the delightful presence of several Dall’s porpoises, rushing hither and thither, sometimes riding our bow waves. A picturesque little flight of swans headed north, against a backdrop of the Chilkats. And I have not even mentioned the pigeon guillemots, marbled murrelets, loons, Arctic terns, scoters of two species, and clusters of Bonaparte’s gulls dipping down to the water surface to snatch some tiny prey.

Altogether, very satisfactory wildlife viewing, and fine days on the water!

Glaucous-winged gulls

musings on an often-overlooked species

These are one of our most common gulls around here, and they are easy to watch, so I thought perhaps it was time that I write something about them. These gulls are bigger than the medium-sized Mew Gulls and the small Bonaparte’s Gull, but about the same size as Herring Gulls, which are also quite common, and Thayer’s Gulls, which come through on spring migration. At least as adults, however, they are easy to distinguish from Herring Gulls and Thayer’s Gulls, because they lack the black wing-tips of those two species. The adjective ‘glaucous’ means ‘gray’.

Young Herring and Glaucous-winged Gulls are much harder to tell apart, but it can be done. These big gulls take three years to reach adult plumage and sexual maturity. So they spend two years in immature plumages, which feature various shades of brownish gray but no black (check a good field guide!).

Thousands of Glaucous-winged Gulls attend the eulachon spawning run in Berners Bay in spring. They swoop and dip down to nab the weak-swimming fish, but they sometimes miss, leaving a fish with puncture wounds. They also scavenge eulachon stranded by an out-going tide or dropped by other predators. In our study, adults were more successful at catching fish than immature gulls. Young birds gathered in small gangs on sand bars and chased more successful foragers in attempts to steal a fish. However, their attempts at pirating fish from other birds were not very successful, even when the victim was a smaller kind of gull. Indeed, the immatures were notably poor at pirating fish from other birds, and would have garnered more fish if they had caught fish from the river for themselves.

Other species of gull are there too, all gobbling up the fat-rich eulachon. Adults of all species were about fifty to sixty percent successful at diving for their prey. The big gulls could swallow the fish quickly, reducing the risk of another bird stealing the prey. But the little Bonaparte’s Gulls often had trouble swallowing a fish, especially the larger male fish. The longer handling time meant that these gulls were more likely than the bigger gulls to lose their fish to a pirate.

All kinds of gulls gather at salmon runs in summer and fall, but they tend to forage in different ways. For example, at pink salmon runs in Juneau, adult glaucous-wings foraged more often on carcasses than did immatures, and immatures were more often seen feeding on loose and drifting eggs. These eggs were doomed in any case, because they were not buried in the gravels to incubate. Adult glaucous-wings occasionally pulled live salmon from the stream, poking initially at the eyes or at the vent area to force extrusion of eggs. Neither age class foraged much on intertidal invertebrates.

In contrast to the adult glaucous-wings, the medium-sized Mew Gulls fed mostly on invertebrates in the intertidal rockweed and to a lesser extent on salmon eggs. The small Bonaparte’s Gulls foraged mostly on eggs, and less frequently on intertidal invertebrates.

In winter, there are often quite a few Glaucous-winged Gulls in Auke Bay and the downtown harbors. There they forage on whatever they can catch, including larval fish (?capelin), shellfish, and sea stars. A sea star seems to be mostly bony plates and very little soft tissue, so I wonder just how much nutrition a gull can extract from eating one. I also wonder if some of the sea stars that are missing one or two arms might have been assaulted by a big gull. Sometimes, however, these gulls are reported to swallow whole sea stars; this process apparently takes a considerable time.

glaucous-winged-gull-with-starfish-2
Photo by Bob Armstrong

Opportunistic foragers, the big gulls can also be found picking bits of meat off discarded deer carcasses on the beach and scavenging whatever looks edible at the dump. Sometimes they pirate mussels from scoters, and swallow them shell and all. They hang around our grocery store parking lots with the ravens, hoping for a handout or some goodies in the back of a pickup truck.