Harbor birds and snowy tracks

loons, shrews, and a peripatetic dipper

Sometimes, perhaps especially during the holiday season, it’s hard to fit a long, exploratory walk in among all the other activities. Then a quick trip to the harbors may produce some interesting observations.

On a recent harbor visit, we enjoyed watching Pacific Loons. They dove frequently, but we never say a loon with a fish in its bill, so we guessed that they were foraging on very small fish or even invertebrates—small enough to be swallowed immediately. The loons sported a variety of plumages: one was in good adult plumage, one seemed to be an unusually young juvenile without the typical juvenile plumage, and most were in well-marked juvenile plumage (check a good bird book!).

Pacific-Loons,-adult-with-three-juveniles,-bob-armstrong
3 juveniles, and 1 adult, Pacific loon. Photo by Bob Armstrong

Pacific Loons winter all along the northern Pacific coast but nest on deep lakes in the Interior and across the Arctic tundra. Like other loons, they are typically monogamous and both parents incubate and rear the chicks. Loon legs are placed far back on the body, which is good for swimming and diving (when the legs are almost like propellers) but very bad for walking. So loons place their nests right next to the water’s edge. This makes them vulnerable to motorboat wakes that swamp the nest and to droughts that lower the water levels and make the nest too far from water.

The harbor visit also produced a couple of seals, several Marbled Murrelets in winter plumage, some Long-tailed Ducks, Red-necked Grebes, Barrow’s Goldeneyes, Buffleheads, one or two Great Blue Herons, and a Song Sparrow. We wondered if Song Sparrows (in springtime) might sometimes nest under the decking of the floats or if they merely forage there and nest, as usual, in shoreline shrubbery.

There were some large ‘jellyfish’ slowly pulsating in the cold water. Perhaps a foot or so in diameter, one was translucent white and the other was a murky orange with thick wads of tentacles. In our land-based ignorance, we didn’t have names for them.

On another day, after a recent snowfall, a tracking expedition was profitable. Snowshoe hares had seemingly conducted small riots under the spruces; their feet had created a maze of interlocking pathways and localized spots of concentrated activity. We saw no scats, perhaps suggesting that the hares had re-ingested them. Hares and rabbits (as well as many rodents) produce two kinds of feces: the ordinary kind, which is not re-ingested, and a softer kinds, produced by a digestive organ called a caecum, which is consumed—recycled, so to speak, to extract more nutrients from their food.

No small mammal trails were evident. Shrews, voles, and mice were presumably active but stayed under the soft snow. A porcupine lefts its customary trough where it had waded, up to its ears, in fluffy snow.

We followed the trail of an otter that seemed to know just where it was going. Several long leaps were followed by a smooth slide, then more leaps and another slide mark. Nobody else makes a trail like that! The otter had crossed a sizable pond, cut over a hill to another pond where it checked out a beaver lodge (from the outside), and gone down a small frozen stream to a deep channel where fish could be found.

The best find was along a shallow slough in which there were still small stretches of open water. A narrow furrow led out of one little pool straight over to the next one. ?A water shrew? But no, there seemed to be alternating footprints lightly covered with new-fallen snow. So, some critter that walked on two feet, from one bit of open water to the next, and then the next one, and so on for fifty yards or so. Finally we found some clearer footprints and a spot where something had landed and started to walk. Definitely a bird! But not a shorebird, because the hind toe was well-developed. So—a songbird, not very big, but not tiny, either. Well, who would be foraging in shallow water, going from pool to pool? Most likely an American Dipper, looking for aquatic insect larvae or maybe sticklebacks. Dippers often wander far from their nesting streams in winter. The real mystery is why it walked through the snow instead of flying.

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!