Good finds in Gustavus

stealthy spiders, ambitious amphibians, strange ferns, and more

A summertime walk through woods and meadows is almost always good—birds are singing, flowers are blooming, and there’s always nice fresh air. But sometimes all the little pleasures form a base on which rest some observations of particular interest. Here are a few good ones from a recent trip to Gustavus.

–Dandelions had mostly gone to seed, so fields that had been golden with flowers were now white with plumes on mature seeds ready to disperse on the wind. But here and there we found a laggard flower, still yellow and conspicuous on the background of white. On one of these late bloomers there was a bumblebee, a strangely immobile bee. Looking more closely, we saw a yellow crab spider with the bee in its clutches. Crab spiders are venomous (to insects), immobilizing their prey and then sucking out the juices. Dinner was in progress and the bee would fly no more. Crab spiders are generally ambush-predators; some of them lurk on flowers in hopes that a tasty insect will alight. The color of the spider often matches the color of the flower on which it awaits a victim.

crab-spider-howard
photo by Kerry Howard

–The ponds at the gravel pits are a great place to see shorebirds, swallows, and kingfishers. There were sticklebacks swimming around and, in June, there were gravid females full of eggs. One pond held many thousands of toad tadpoles, swarming in the shallows where the water temperature was salubrious. They came in a variety of sizes—some at least six times bigger than the smallest. A female toad can lay thousands of eggs; the hordes of tadpoles that we saw undoubtedly had many mothers, which probably laid their eggs at somewhat different times, accounting for the size variation. None of them had begun to transform into toadlets; no little legs were visible. A dense pack of tadpoles clustered around a silvery object, each one trying to grab a mouthful. Looking closely, we discovered that the silvery object was a dead stickleback. Toad tadpoles commonly feed on algae and detritus, but they are also known to scavenge carrion and even the dead bodies of their comrades. Toad (and frog) populations have declined dramatically almost everywhere, and it was heartening to see this large aggregation of juveniles.

–Gustavus is noted for (among other things) its wide sandy beaches. On our way out to one of them, we heard some odd sounds, rather like the hooting of a small owl. As we listened carefully, however, it became apparent that several snipes were performing their aerial territorial display. It’s called ‘winnowing’, and it’s made by the rapid passage of air over the spread-out tail feathers, usually as the bird dives toward the ground from high in the air. Usually the male does this but sometimes females do too. I hadn’t heard this display for a long time and it was a gladsome sound.

–Out on the sandy beaches we found windrows of long, flexible tubes that were the former housing of certain marine worms. The worms were long gone, possibly starved at the end of winter when food is scarce. Then the tides presumably stripped the empty tubes from their attachment points and piled them up on the beach. This observation stimulated a lot of conjecture but no concrete answers.

–On the vegetated sand dunes there were lots of the strange little ferns called moonworts (a.k.a. grape ferns). They don’t look at all like ferns to the layman’s eyes, because the fronds are generally not very lacy or branched. We found many that appeared to be the common moonwort, but there were also a few much more robust individuals that were certainly a different species. On one of the postglacial-uplift meadows we found another kind, one that is now classified in a different genus; the fronds on this one (so-called rattlesnake fern) are somewhat more ‘fern-y’. All three of these are widespread species in North America and even beyond, but they are so odd that it is always fun to find them.

–The pilings of the public dock usually offer something even to a casual observer. Enormous white anemones, far larger than any we usually see in the rocky intertidal zone, wave their tentacles if the tide is in. Sea stars cling to the vertical surfaces too, but the largest ones have trouble hanging on when the tide goes out and leaves them above the waterline. Colorful sponges and tunicates add to the array. Sometimes there’s a giant whelk laying a coil of egg cases. Small fish sometimes gather under the docks and are visible between the pilings. And while one inspects the fauna on the dock, barn swallows are swooping overhead, gathering flies and mosquitoes for their chicks.

–We searched for lady’s slipper orchids (of which more, later). One clump of flowering stems still included a stalk with last year’s seed capsule, well dried. Someone opened the capsule to see if any seeds were left and found, instead, a tiny spider guarding her minute ball of orange eggs. We were sorry to have destroyed her safe-house!

–Sweetgrass grows in many Gustavian meadows and some of us stopped to braid some stems. Braided sweetgrass is used, especially by Native Americans, to construct baskets and decorative items, and we had to try just a simple braid. As we concentrated on our task, we heard thundering hoofbeats, getting rapidly closer. Turning around, we saw a fast-trotting female moose, followed by a young calf. They were so intent on getting away from whatever startled them that they ignored us and passed by, barely thirty feet away, and off they went, full tilt.

Visiting Yakutat

a festival of terns… and lots more to see

In early June, I had the privilege of participating in the Yakutat Tern Festival. This gave me the opportunity of visiting an area of Southeast that I’d never explored before (as well as meeting some new and interesting folks). There were only two familiar faces, one of which belonged to Linda Rosenthal; she was there as a visiting musical artist, and her violin wizardry kindly provided the introduction to my seminar!

From my little explorations, several natural history items stand out. Brown bears lived up to their reputation of being very common. In just over four days, I saw nine of them, at least one every day. Some were grazing in the meadows, including three young cubs whose mother was not in evidence but must have been somewhere nearby.

We saw several Caspian terns—huge (for a tern), with a big red bill and a raucous voice. Much more common are two smaller terns: the Arctic tern, which also nests in Juneau, and the Aleutian tern. Yakutat is reputed to be the southernmost nesting colony of the Aleutian species on mainland North America; this species also nests along the Aleutian chain and the coasts of western Alaska and eastern Russia.

Aleutian-Tern-and-Mount-Saint-Elias-2-by-Bob-Armstrong
Aleutian tern. Photo by Bob Armstrong

The small terns look quite similar to each other, but the Aleutian tern has a distinguishing white forehead mark on its black cap; it also has a slightly shorter tail and a darker back, as well as a call that differs from that of the Arctic tern. Both species feed on small fishes and sometimes shrimp-like invertebrates. Both species are long-distance migrants: our familiar Arctic terns go all the way to Antarctica after the summer nesting season here, so they enjoy perpetual summer (when it is winter here, it’s summer down there, of course). The Aleutian tern migrates from here down the coast of eastern Asia to the seas around Indonesia. I wonder what they eat down there: tropical seas are usually said to be less productive than high-latitude waters, which is why our humpback whales come up here from their winter quarters in Hawaii.

Because they usually nest on the ground on sparsely vegetated sandflats (Arctics reportedly in slightly more open areas than Aleutians), both species are too easily subject to disturbances that ruin their nesting attempts—humans and their dogs can have devastating effects on a whole colony of terns. Of course, wily predators such as ravens are eager eaters of eggs; coyotes (and foxes is some areas) like both eggs and adults if they can get them. Sometimes a whole colony deserts a traditional nesting area and goes elsewhere, and sometimes the whole group just gets wiped out. So little is currently known about Aleutian terns that the loss or reduction of known colonies raises concern about the population status of the species, so studies are now underway in Alaska to discover if the birds have established new colonies to replace the lost ones.

We saw several parasitic jaegers (in German, jaeger means ‘hunter’), harassing gulls that were actively fishing. Jaegers are kleptoparasites, stealing prey from other birds that catch prey for themselves. One jaeger dove repeatedly at a small gull that held a just-caught fish, following every evasive action of the gull, until the gull finally gave up and the jaeger got the fish. Parasitic jaegers nest on the tundra up north, where they are quite capable of catching their own prey; their kleptoparasitic habits are exercised chiefly on migration and in winter.

In among the several kinds of gulls were black-legged kittiwakes, which resemble gulls but technically are not gulls. I seldom see them in Juneau, although they nest in Glacier Bay. Kittiwakes are typically cliff- nesters, but the Yakutat forelands do not offer many cliffs, so these individuals may nest across the bay near the glacier or perhaps they are non-breeders.

Other sightings that provoked thought include the observation of large differences among beaches in the animal remains that were left by a receding tide. One large sandy beach yielded shells and claws of Dungeness crabs and the shells of razor clams. Another had some mussels and clam shells (more like many Juneau beaches). And one had nothing at all except one long-dead sea star—that seemed very odd.

On one large sandflat there were moonworts growing among other sparsely distributed plants. Moonworts are rather peculiar fern relatives about which relatively little is known. Recent research has found two new species of moonwort in Southeast (I was told that Yakutat is one place where they live), but for those of us who are not specialists, they look very much alike.

We found a small colony of cliff swallows, which stick their gourd-shaped mud nests to rocky cliffs or the sides of buildings and I-beams under bridges. From almost every nest opening peered the face of an adult bird, while other adults flew back and forth, sometimes delivering a tasty morsel to the nest occupant. We inferred that one adult was incubating eggs or brooding very small chicks while the other adult of the pair went hunting. Male and female cliff swallows equally share the parental tasks of incubation and feeding chicks.

Barn swallows were tending their nests too, and every morning brought a chorus of bird song from several species of sparrow and warbler, especially in the alder and willow thickets. Worth getting up for!