April

winter or spring?

The ice is just starting to melt on my home pond, so there is a little open water at both the inlet and the outlet. As soon as there were a few square yards of open water, a pair of mallards moved in. They rested on the edge of the ice, dabbled in the shallows, and gobbled up sunflower seeds spilled from the feeders that hang over the pond.

Then one day I noticed quite a kerfuffle out there. The female was hard to see, posed rather flat on the water. The male was very excited, vigorously bobbing his green head up and down, and splashily diving near the female several times. Quite a showy preamble! Then he was on her back, nipping the back of her neck, and they were doing the mating thing.

She will probably lay seven to ten eggs and incubate them for about four weeks. So, if she and her eggs are lucky enough to avoid predation, I may see ducklings on my pond in due course.

A stroll to Nugget Falls yielded the first purple mountain saxifrage of the season, blooming considerably in advance of others in the area. The flowers of this species are usually female, with receptive surfaces for pollen, before they become functionally male, with ripe pollen. So this plant had perhaps lost its chances for seed production, because the flowers clearly presented mature pollen. If a bee now happens to find it and remove pollen, it would be difficult to find another plant ready to receive that pollen—unless some other plants open their flowers very soon. Maybe a bee can fly to the west side of the lake, where this plant blooms on the rock peninsula. Maybe it doesn’t pay to be TOO eager! Research has shown that seed production in the species is commonly limited by insufficient pollen deposition.

purple-mountain-saxifrage-on-April-10-2013-at-Nugget-Falls

In the same area, where mountain goats have been foraging and resting for months, I finally saw a nanny with a kid, moving up the ridge into the brush. The kid was pressed close to mama’s side, so what I really saw was a white blur with eight legs (well, seven legs, actually, but you get the idea…).

Another stroll, on the wetlands, treated me to my first ruby-crowned kinglet song, one of my favorites. They’ve been here for a little while, but I hadn’t heard them for myself. Six swans on the river took off when they saw me move, even though I was still pretty far away and partly concealed. Canada geese were also quite nervous and left the meadows for the far side of the river. Even the ducks were uneasy and sailed slowly away downriver (mallards, goldeneyes, ringnecks, buffleheads, green-winged teal). Sadly, I missed the mountain bluebirds that had stopped there on their way north.

A more strenuous outing took us, on snowshoes, up one of the forested slopes at Eaglecrest. We gained a fair amount of elevation and looked down on the upper cross-country ski loop and Cropley Lake. We watched a ptarmigan snatch buds from blueberry twigs, marching calmly from one bush to another. The first clue to its presence was a line of very fresh tracks in the fluffy snow that lay atop the hard crust.

The greatest fun concerned a raven. First, we heard a lovely little melody coming from high in the hemlocks. It was repeated several times. The song was unlike that of any other songbird that I know. So we couldn’t identify it—until one little trill was followed by a brief squawk. Then a raven flew in, carrying a stick, disappeared briefly, and then flew back the way it came. Back and forth it went, with a rush of air in the wing feathers, each time bringing a stick. All the sticks were about the same size, maybe a foot long or so. After the bird had made several trips, I finally spotted where the sticks were going: high in a hemlock, in a snug spot next to the trunk, was a dark lump. The next two times the busy raven arrived, we could watch it work the sticks into the existing structure. This raven was still building the nest exterior, a bit behind the others that I’ve watched, which have been gathering and carrying dry grasses for nest lining.

Ravens are technically songbirds, along with sparrows and warblers and thrushes, although that comes as a surprise to many folks. On this day, ‘our’ raven earned its technical classification, with it short, sweet, melodic song.

Then, on a fine, blue-sky day, Parks and Rec sashayed, in shirt-sleeves, up to Spaulding Meadows. We didn’t even need snowshoes until we reached the upper meadow, because the trail was well packed. This trail is far easier to negotiate in winter than in summer, because the myriad mudholes are frozen and snow-covered. The upper meadows looked like the skiing would be wonderful, and the two skiers that started out with the rest of us plodders soon disappeared and were not seen again that day. Just before the top, we found some tracks that I think were made by a pine marten. We perched on a snowbank for lunch, shielded from a little breeze by a stand of trees, and thoroughly enjoyed a view of the sunlit peaks around the glacier.

Birds in a snowy land

nest-building ravens, cocoon-tearing chickadees, and cockle-dropping crows

In the middle of March, I made a quick visit to Gustavus. It was snowing heavily, so the ferry ride was a ride in white-out most of the way. Good for taking naps (not to mention second breakfast and more than one cup of tea), making up for having to get up early and getting my gear on the luggage cart. A peaceful sort of trip.

Naturalists love to look for animal tracks in the snow and conjure up stories to go with them, but there was so much fresh snow falling that tracks were covered quickly. So animal-tracking was not very exciting, but bird-watching offered compensations.

A thick blanket of powdery snow lay on the ground, and snow continued to fall. But that didn’t deter a pair of ravens. They flew back and forth between a tree behind the house, where they had nested last year, and a flat area just across a small river. Coming back from over the river, they often carried big wads of moss; on other trips, bundles of long strips of plant fiber dangled from their bills.

My friends said that the long fibers came from dead cottonwood trees, so we went over to look. Beavers had felled cottonwoods and willows here, and moose had left the marks of their lower incisors on the fallen willows. On a cottonwood log, the loose outer bark had been pulled away and dropped in small pieces on the snow, and the fibrous inner bark had been peeled off, exposing the bare wood. This was where the ravens had been at work.

The ravens were clearly lining a twiggy nest basket with moss and bark, and lots of it—a cushy bed for the eggs still to come. An eagle cruised up the river and received a rough welcome from the ravens, which escorted it off into the distance. Maybe the ravens were just making sure that this eagle knew there was a no-fly zone here, ahead of the time when the nest would have occupants.

One day we saw a raven flopping about in the deep, fluffy snow—taking a snow-bath. It pushed its head forward into the snow, rubbing on both sides, then vigorously threw snow over its body with flapping wings. Moving to a new, still undisturbed, spot, it repeated the process. I wonder if snow works as well as water, for a bath.

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Rolling in the snow. Photo by Bob Armstrong

The ravens aren’t the only ones who know that spring is coming. Oregon juncos are singing and the sapsuckers are back from winter quarters. Although magpies are still around and so are slate-colored juncos, these will soon head for the Interior, where they nest.

Other birds were out foraging in the snowy landscape. A little group of pine grosbeaks flitted through the shrubbery, chatting quietly with each other and nibbling willow buds. One of them dropped down to the snow and ate the seeds from a fuzzy seed-head that poked up from the snow at bird’s-eye level. Of course, we had to determine what kind of seeds they were, which led to some discussion and then back to the books. Ah, they were the seeds of big-leaf avens, a fairly common plant of open areas.

Just over our heads, a chestnut-backed chickadee perched on an alder, pecking and pulling furiously at something for several minutes. Finally, it began to extract and eat some bright green bits. After it flew off, our further inspection revealed that the chickadee had found a cocoon stuck to the alder twig. The cocoon was very tough—not easy for us to tear open even with forceps (we had to use scissors), but the persevering chickadee had won the prize inside and eaten all the juicy bits except for the very end of the pupa, leaving a fragment of pupal skin. That was one happy chickadee! We wondered how they learn to recognize insect cocoons as potential food sources.

When the tide went out, we strolled along a snow-free beach; what a relief from floundering in the knee-deep white stuff, too soft for those little snowshoes, typical of our area and never meant for powder snow, to do much good. Here the crows were plucking cockles from the silty sand, flying up a few feet, and dropping them. This is a common behavior by which crows crack open a shell to get at the edibles inside, but it depends on the shell landing on something hard enough to crack it. On this beach, there weren’t many rocks, and the chance of dropping a cockle and having it hit a rock was small. One crow tried two different locations and dropped its cockle sixteen times (!!) before it could eat its prey.

There was a stiff on-shore breeze that buffeted the foraging crows. So, instead of their usual walking gait, they often faced into the wind and side-stepped—just as I used to do when wading a fast-moving stream.

Snow!

a heron in the forest, a frozen feast, and raven excavations

The first halfway decent snowfall in mid November drew me out to look for animal tracks and anything else of interest. I went with a friend to the forested banks of the lower reaches of Eagle and Herbert rivers. Deer, both big and small, had wandered extensively throughout the area. Mink had a regular route along the top of one river bank. Porcupines had been out before the snow stopped falling, but squirrels left very fresh prints. Just as we were commenting on the lack of bird tracks, we happened upon some clear prints left by a heron strolling through the forest.

Then we heard a ruckus made by some squabbling ravens, over on a sandbar across the river. We approached quietly, with several trees (and the river) between us and the gang of ravens, but they spotted us immediately and took off. A number of magpies then moved in. The big attraction was the bony torso (spine and rib cage) of a deer, already well picked-over but still clearly worth serious attention. We settled down among the trees to watch.

We counted at least nine magpies; the precise number was not readily determined, because they were constantly flying to and fro: pecking and tugging briefly, then departing for a few minutes, and returning to grab another morsel. Were they caching these little bits of meat or just going off to eat each bit in peace? All those magpies seemed to be able to forage together without altercations (unlike the ravens); there apparently was room around and even inside the rib cage for them all.

A juvenile eagle arrived, briefly scattering the magpies, but they soon moved in again—on the side of the carcass away from the eagle. This was not very profitable feeding for the big bird, however, and it soon departed. Meanwhile, one or two ravens cruised by, or perched up in the spruces, occasionally hopping over the sand toward the bones but nervously taking off without feeding there again. Maybe nine magpies were too much for them, but I think they knew we were still there and did not like being watched.

A few days later, we had wonderful snow and lots of it. Spruces bore thick white blankets on drooping branches and alders bent almost to the ground under the heavy load. Rather than do the various tasks I was ‘supposed’ to do, I took off out the road to do a little exploring on snowshoes. ‘Twas the first time on ‘shoes this season, and it showed (sadly). Tracking was good, however: fresh deer trails, old otter slides leading from one patch of open water to another, not-so-old porcupine trails, deeper than the otters’ marks, a few squirrels, and a mink.

Two ravens were assiduously digging in the snow, in selected spots, tossing snow aside with their bills. Sometimes they dug down several inches, apparently getting very small, unidentifiable items. What could they be finding, and how did they know where to dig? I shared a few crumbs with them.

That lovely snow didn’t last, here near sea level. But I sure liked how it brightened up our short days!

Bits and pieces

observations of mallard chicks, mosses, and the raven-eagle interface

Sometimes my local peregrinations don’t yield a suggestion for an essay on just one thing. Instead, I get a little scrapbook of unrelated vignettes on various topics. Here is one such scrapbook:

A friend and I were watching a brood of young mallard ducklings on one of the Dredge Lakes. No attendant female was evident for quite some time. Then in flew a female, calling as she descended. Every duckling immediately perked up and, in a bunch, they all rushed over to her, peeping all the way, as if to say, Mama, where were you? We missed you!

This same mallard family was peacefully foraging along the shore a few days later. We heard a sudden ruckus, as the female was loudly protesting something. We peered through the brush and saw a bald eagle swooping down over the ducklings. At each pass, the fuzzy youngsters dove frantically beneath the surface of the pond. The buoyant ducklings popped back up to the surface as soon as the eagle went by. One, two, three passes, and the empty-fisted eagle retired to a tall spruce to rest and reconnoiter. After a few minutes, the eagle tried again, three or four passes, with no luck. Then it gave up. These mallard ducklings were more fortunate than merganser families that can often be seen in Mendenhall Lake. Sometimes eagles wipe out entire broods of unlucky mergansers.

I always enjoy watching ravens in the grocery store parking lots. Perched up on the lamp-posts or along the edge of the roof, they flirt and gossip and groom and wait for a likely-looking pickup truck that might have something interesting and edible in the back. This strategy must pay off fairly often, because the birds keep on watching and investigating. One raven was seen near a local thrift store, where food was not likely to be discovered. But this hopeful (or desperate?) bird was hopping into the open trunk of a car that was merely delivering donations to the store. No rewards there!

Recently I watched a raven, yelling and fussing, chasing an eagle for several minutes. I did not see the outcome of that encounter, but a friend saw a similar interaction, with a visually pleasing (to the observer) outcome. In this case, when the chase was over and the eagle departed, the raven indulged in several barrel rolls and half-twists, in which it was soon joined by another raven, probably its mate. I have to think that the aerobatics were a kind of celebration. Ravens are known to raid eagle nests for the eggs, and now I wonder if eagles reciprocate, trying to snatch raven chicks, causing parental ravens to defend their broods. After all, they were recorded, a few years ago, grabbing heron chicks from the nest.

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An uneasy truce? Photo by Jos Bakker

I was reminded, just the other day, of some very interesting and pretty mosses. Most mosses produce dry spores in small capsules that open to let the breezes waft away the spores, to land more or less at random. But some mosses disperse their spores differently, in a way that greatly improves the chances of a spore landing on a patchily distributed substrate that is suitable for germination and growth. These specialized mosses produce sticky spores that do not fly on the wind. Instead, these mosses produce scents from the expanded base of the spore capsule, and the aroma of carrion and decay attracts certain flies that commonly feed on dung or, in some cases, rotting flesh and bones, usually of mammals but sometimes of birds. The flies land, the spores stick to them, and the flies carry the spores to another dung pile, which provides the necessary conditions for the germination of the spores. I’m told that some of these mosses carry specialization one more step: some depend on herbivore dung while others focus on carnivore scat. Making sure that the spores arrive in a good spot is a nifty way to increase the success of your offspring!

Finally, here’s a little mystery. I have observed that robins rototill moss beds, in search of small invertebrates. Ravens and crows sometimes pluck hundreds of tufts of grass and moss from broad reaches of lawns. Mallards grub up square yards of moss and debris, in search of spilled seeds from a bird feeder in early spring. And bears rototill more deeply, in their quest for the roots and stem bases of northern ground cone. But deep in the forest this spring, a friend and I found many places where some creature had scuffled up big patches of leaf litter. Most of these places seemed to be where snow had stayed a bit late and few green shoots were present. This is not good habitat for robins or mallards, and the scuffled places seemed too shallow for bears. The question is Who did it and what were they searching for?

First snows

some tracking discoveries and other observations

One of my favorite activities in winter is to go out looking for animal tracks in the snow. In early-mid November this year, the snow was perfect: not a lot of it, but soft enough to register animal passage and firm enough to hold the tracks’ shapes.

So, off to Eaglecrest I went, with two good friends who like these little explorations too. We found lots to look at. Porcupines had plodded in and out among the trees, in some cases making small highways of repeated use. A few red squirrels had ventured out of their burrows. A weasel had covered a lot of ground, bounding with shorter leaps when it went uphill. It investigated many a fallen log and stump in hopes of nice lunch. Weasels have to eat a lot, just to keep warm and feed their active metabolism.

Voles (or maybe mice – it’s often hard to tell which) had run over the snow from one grass tussock to another or from log to bush and back again. These were the most common tracks, often right out in the open meadows, where they might be easy marks for predators. But we saw no signs of lethal events.

Near the road, we found a spot where an indisputable mouse had hopped across. On either side of its trackway were marks of a tail flick. It couldn’t have been a vole, whose tails are very short, so it had to be a mouse. Why it had flipped its tail from side to side was not clear, however; we speculated that perhaps it was slightly off balance on the coarse cobbles at the edge of the road and used its tail to restore an even keel.

mouse-tracks-kmh
Photo by Katherine Hocker

We found a few lines of tiny tracks that were made by shrews. Emerging from one dime-sized hole, crossing over the snow to an equally minuscule hole, occasionally they tunneled just barely below the snow surface.

 

Every so often, we looked up instead of down and noted that quite a few trees had long-dead tops. No mystery there, given the howling gales that sometimes whip through this area. But none of the lower, lateral branches had grown upward to replace the missing tops. We’ve all seen conifers whose original ‘leader’ at the top of the tree has been killed but a lateral branch just below it has taken over as leader, creating a kink in the trunk. We puzzled over why this hadn’t happened on the trees in which the entire top was dead.

 

An answer might lie in the way that hormones control growth. Normally, the leader at the top of a conifer suppresses the growth of lower branches; this is known as apical dominance. But the effects of apical dominance diminish as the distance from the leader increases. So, perhaps, when the entire top of a tree is killed, the distance from the leader was so great that there was no dominance exerted on the remaining branches. Thus, the lower branches had not been suppressed and they did not respond to the loss of the tree top.

 

A few days later I walked out into the Mendenhall Glacier Recreation Area near Crystal Lake. Tracking was still good and there had been lots of activity. A porcupine had trundled across the ice on the lake, and a weasel (I think) had walked (not bounded) along the footpath. Squirrels and snowshoe hares had crossed the path.

 

The most interesting marks were made by a bird, whose wingspan exceeded five feet—surely an eagle. Its wing tips brushed the snow in several places around a patch where the snow had been disturbed. Here I could see some heavy-duty bird tracks, confirming the presences of an eagle. All around this area were raven tracks too. But there was no clue about what the eagle was after—unless it might have been a raven (eagles do capture ravens sometimes). It seemed unusual for an eagle to be hunting in a wooded area where the only open ground, where an eagle could spread its wings, was the path itself.

 

Lots of stories in the snow, so winter was off to a good start for me!

Of wolves and ravens

the complex relationship between two animal nations

A major source of mortality for wolves, in areas without much human interference, is starvation. Because food-deprivation is a real risk, much of what wolves do is driven by the search for food. An adult wolf can gobble down prodigious amounts of meat in one day. For example, on Isle Royale in Lake Superior, where wolves have been studied for decades, adults averaged about six kilograms (over thirteen pounds) of meat (usually moose) per day.

The traditional explanation for why wolves often hunt in packs is that there is a greater chance of a successful hunt if more wolves participate. That supposition often may be true, for wolves hunting moose or deer or other ungulates. Even so, on Isle Royale, only about six percent of moose chases were successful, even for packs of ten to sixteen wolves.

However, more successful hunts by large packs don’t mean more meat for each wolf, because the meat is divided among all the members of the pack. It turns out, from studies on Isle Royale and in the Yukon, that when wolves are hunting moose or deer, a pack of only two wolves obtains the highest yield of meat per wolf.

But many wolf packs are larger than two, and some are much larger. In some cases, a family with offspring will hunt together while the young are learning their techniques. Many packs, however, are composed of unrelated adults, sometime ten or twenty or even more.

So the question is Why are wolf packs often so large, given that large packs do not result in the best-fed wolves?

This is where the ravens come into the story. Ravens are well-known to attend wolf kills (of ungulates). They often follow a hunting pack of wolves and may even notify nearby wolves of an available winter-killed carcass. But ravens cannot get at the meat, except for the eyeballs and perhaps the tongue, until the carcass is opened by the slicing teeth of the wolves. When the wolves are there, they open the carcass and ravens can feed.

A single raven may ‘steal’ as much as two kilograms (about four and a half pounds) of meat from a large carcass, eating some on the spot and caching the rest. And sometimes there are many ravens attending a single carcass; five or ten ravens at a carcass is not uncommon, and occasionally, over a hundred ravens have come to one carcass.

Although wolves and ravens sometimes feed placidly side by side, in many instances the wolves defend their carcass from ravens. Wolves don’t conceal their kills the way the grizzlies or pumas often do. Instead, they commonly rest near the carcass in between bouts of feeding and try to chase the ravens away. They eat very fast, too, which helps to reduce the loss of meat to scavengers (and to other wolves in the pack). Nevertheless, big packs are better at excluding the ravens than small packs are. So, where ravens are likely to ‘steal’ a sizable proportion of the meat, a big wolf pack will end up with more meat per wolf, despite having to share with each other.

The flight of the hummingbird

(with Johannes Brahms)

A Juneau Jazz and Classics concert in the chapel at the Shrine provided some extra entertainment, in addition to wonderful music. To the consternation of audience and musicians, a hummingbird flew in through the mistakenly open door and zoomed straight up to the high windows in front.

There it fluttered futilely against the glass for long minutes. The musicians stopped playing a Brahms string quartet to ask if anything could be done about this distraction. Nothing practicable was available, so the music went on, many more minutes, to the end of the piece.

The stage manager then found a hummingbird feeder full of sugar water and offered it to the hummer on a high window ledge, but we couldn’t tell if the bird drank. And the bird refused to leave the window to follow the feeder out the door. So the stubborn hummer just continued to try to fly out the closed window.

After much cajoling and pleading, the crowd finally left the room. Then, as a few remaining folks watched, the exhausted bird slid down the long wall to the floor. An observer crept up to it, trapped it in a shirt, and gently hand-carried it out the door. There it was greeted by a number of lingering music-lovers. As recommended by hummingbird researchers, its captor placed the bird’s bill in an opening of the feeder, in hopes that it might drink a little, but again we could not be sure it did.

The bird was too weary to struggle, and seemed to have gone into torpor (an energy-saving, inactive mode). It was placed under a leaf in a flower basket near the feeder, now restored to its usual place. After a minute or so, its little black eye peered over the edge of the basket, so there was hope that it would soon visit the adjacent feeder. And the second concert went on as scheduled.

The story wasn’t quite over, though. A member of the audience, who had left before the bird was captured, told a family member on the East Coast about the plight of the bird in the chapel. So the bird’s fame spread from coast to coast. Furthermore, I’ve been told that this male rufous hummingbird is now on Facebook, along with a young admirer.

A few days later, a hike in Sheep Creek Valley found the Parks and Rec group strolling between dense stands of still-leafless salmonberry canes. Spring is coming late this year, and we didn’t hear the usual pleasant cacophony of bird song in the valley. Robins were there; we found a nest and some broken egg shells, indicating that some eggs had hatched. Fox sparrows sang in the willows but remained inconspicuous. A few Wilson’s warblers and Pacific wrens sang in the distance. At lunch on the streambank, a female rufous hummer buzzed the colorful packs and jackets.

A friend found an immobile and apparently torpid hummer perched at a feeder. After several minutes, a crow came along, hopped and flew toward the feeder, and butted the hummer with its bill. The hummer dropped off the feeder, the crow disappeared, and the fate of both is unknown. Do crows eat hummers? I’ve seen Steller’s jays try to catch them, and maybe crows would do so too.

An unrelated item: a recent beach walk yielded one interesting observation. A raven flew by with a large brownish object in its bill. When it landed on the logs at the top of the beach, I could see that its prey was a big Dungeness crab, probably almost eight inches wide. The raven held the crab properly—from the back, so the formidable claws were safely pointed away from the bird’s head. Clever bird!