Glacial Erratics

I'm inspired to share my experience with glacial erratics from reading Dan McShane's blogpost A Really Big Erratic White Rock in Jefferson County (1/20/2011) and Dave Tucker's blogpost Appeal to Citizen Scientists: Do you know of any Jackass conglomerate erratics? I could probably safely say that I've known some erratic jackasses during my lifetime but have yet to find any Jackass conglomerate erratics.

For the layman, a glacial erratic is a large rock transported some distance by a glacier from the rock's point of origin to the point where the glacier leaves it.  The erratic is usually composed of  a different type of rock than the rock or geologic conditions at its resting place.  It often looks out of character with it's surroundings.  Identifying the erratic's rock type provides clues to its point of origin and the sense of the glacier's movement (i.e. direction, distance).


My first sighting of glacial erratics was during numerous hikes through the Sierra Nevada in my formative years when I lived in southern California.  The Sierra provide many opportunities to view alpine glacial landforms.  The photo below shows a glacial erratic near Carson Pass.

In spite of the dense tree cover and dense development, glacial landforms are much in evidence in the Puget Sound region, and this includes large glacial erratics.  I live within spitting distance of the Puget Sound shoreline along Browns Bay north of Edmonds.  My favorite erratic is found along the shoreline here.  Call it the "home erratic" if you will.  At the highest tide it is almost covered providing a safe perch for herons and gulls.  At the lowest of the spring tides the entire rock is exposed.  I'm told by a diving friend that similar large rocks exist just offshore here.  I'm inspired now this coming spring to chip off a piece to see what type of rock it is.

Bering Glacier

After many years in my career as an environmental consultant I finally made it to Alaska. Opportunities came but then went with project cancellations or over-commitment to some other project. With good fortune I found myself on an early morning flight to Anchorage skirting the western Canadian coast and southeastern Alaska (the “panhandle"). It was mid-September and the weather would turn out fantastic for the week I was there in Anchorage. This post focuses on one small aspect of the trip and maybe on future posts I will talk about other trip details.

I have to admit that I have a big picture idea of Alaska’s geography but the details and native Alaskan names for places leave me dazed and confused in a similar fashion like place names in Hawaii. Whereas native Alaskan words seem heavy in consonants, Hawaiian names seem heavy in vowels. The words all sound the same in the respective languages.

The plane was very light and so we were allowed to change seats once we were at cruising altitude. The good stuff was all to the right side of the plane as we flew up the coast. One feature that really caught my eye was a huge glacier flowing from an icefield, terminating in an iceberg-filled lake separated from the Gulf of Alaska by a thin spit. The lake itself was drained by short river that paralleled the spit and eventually found an exit to the Gulf. The spit and the river that aligned with it indicated the direction of the longshore current; in this case from east to west (or, in the photo, from right to left).

DudeDiligence

USGS

It turns out that the glacier was the Bering Glacier, the largest glacier in North America. The iceberg-filled lake at its terminus is Vitus Lake. And the short river is the Seal River. The Bering Glacier is fed by the Bagley Icefield, the largest nonpolar icefield in North America.

Bering Glacier and Vitus Lake were named after Vitus Jonassen Bering, a Danish navigator who served in the Russian Navy. Bering was credited with being the first European to discover Alaska and its Aleutian Islands as well as the Bering Glacier that bears his name. These discoveries were made during what is known as the Great Northern Expedition. In 1741, the expedition anchored off Kayak Island, just a little to the west and out of the picture to the left. It was here that the ship’s naturalist, Georg Wilhelm Steller, would explore and take notes on the plants and animals he observed. Here Stellar was the first to record the raucous blue bird that bears his name, the Stellar’s Jay, one of my favorite birds who kept me company in the upper elevations of southern California’s mountains and now feasts at our bird feeder in the Puget Sound lowlands.

A fascinating read on Stellar is “Stellar’s Island” by Dean Littlepage.

STELLER'S ISLAND: Adventures of a Pioneer Naturalist in Alaska

NASA

Talking Points

Just got back from dinner at the Martin Hotel here in Winnemucca, probably the most famous Basque restaurant for a hundred miles. Of course, a hundred miles from here puts you in the middle of nowhere with yet another hundred miles to get to someplace else.

At a Basque restaurant, it’s country style seating so you get to sit with people you’ve never met.  Naturally, I was at a table sitting between two retired couples and the conversation touched on politics. There is quite a heated Senate race here between Harry Reid and the batshit crazy Sharron Angle. It’s more intense than even the Murray – Rossi race (my Starbucks pseudonymn is “Dino” for now; “Dino, your grande nonfat latte is up”).  The old folks don’t like Reid and one of the men said the incumbents aren’t following the Constitution. So “what part of the Constitution” I ask. Oh, gun rights. So “can you name any recent gun control legislation?” I ask. “Oh, they’re trying, they’re trying.” Look old man, try giving me some facts instead of barfing up Tea Party talking points. I didn't really say that.

Fortunately, we got on to other conversation and they were really genuinely nice people.  Both couples were touring around the west.  One of the couples just got back from hunting deer in Idaho.  Wolves are eating all the deer and elk because that's what wolves did before white people killed all the wolves.  I didn't jump on that topic.  At least there's more vegetation now that wolves are eating the herbivores.  We ended up talking about dogs and stuff, much more pleasant. 

Did I say the food was delicious at the Martin Hotel?  Chicken noodle soup, salad that comes with beans (the Basque way is to top your salad with beans), tender beef tongue slices in gravy, mashed potatoes, and corn.  I had pork chops, three of them, breaded and boneless.  I chased it all down with two Ruby Mountain ales, although the meal included some red wine in carafes.  Dessert was bread pudding with whipped cream.  It was Monday and the place was packed.  Lots of cowboy hats, laughter, and conversation.

Wood Recycling

I learn a lot about the natural world just hanging out on the patio grilling burgers and drinking beer. This time of the year, the great Pacific dampwood termites swarm, the fertile winged ones rising into the skies to start new homes in the fallen trees and branches rotting in the deep forest beyond our back fence. Their flight seems strained and clumsy on oversized wings.

I watch a dragonfly dart through the air along a straight path then suddenly switch direction looping back and doing it again along the same path. In one instant it deviates slightly from its chosen path, grabbing a hapless flying termite in midair, and then continuing along the same flight path. A few seconds later, the dragonfly drops the termite, which flutters downward slowly at the pace of a downy feather onto the patio, the gossamer wings no longer beating a struggling flight. I examine the fallen termite and observe that it seems generally intact but is missing its abdomen. This leads me to believe that the dragonfly simply eats the tender abdomen and casts away the remaining hard parts that include the head, thorax, legs, and wings.

Trees fall in the forest; they rot in place, broken down by fungi and termites. Termites swarm and take flight, most ending up trapped in spider webs or snagged in midair by the colorful and graceful dragonflies. This is how wood gets recycled in the natural world. Sure, I’ll have another beer. Barley and hops get recycled, too.

Seal Pup

The edge of Puget Sound is a mere 700 feet from my front door as the Northwestern crow flies.  On quiet mornings or evenings I can smell the salt air.  I usually take a walk the beach with my dog Ranger about every weekend, unless the tide leaves little beach exposed.

Sometimes I will see a seal slowly raise its head just above the water maybe 50 or so yards out.  They watch me as I walk the beach then slowly dunk down again.

At this time of the year, the mother Harbor seals have given birth.  They will leave their newborn pups on the beach while they go off and forage.  It is very important to understand that the pup is not abandoned and is best left alone.  Ranger spotted this one before I did but I was able to call Ranger back before the pup panicked and broke for the water.

Another sign of fall are the Heerman's gulls having made their annual migration northward from the beaches of Baja California.  They'll head south again before winter's wet and chill hit.  These gulls are all gray with a beautiful red beak. 

Pigeons, Windows, and Ectoparasites

Warning: This post is not for the squeamish. It contains graphic photos of a dead pigeon.

Pigeons or technically Rock Pigeons (Columba livia) are ubiquitous in the urban environment of temperate latitudes. Its natural habitat is open and semi-open environments with cliffs, usually on coasts, in western and southern Europe, North Africa, and into South Asia. The urban environment provides similar cliff-like structural elements on buildings as well as abundant food sources (don’t feed the pigeons). I’m not a big fan of pigeons but I can appreciate their adaptability.

Window strikes kill between 100 million and 1 billion birds in North America each year (David Malakoff, Audubon magazine, March 2004). Because glass is transparent and reflective, the birds see a reflection of the outdoors and try to fly through what looks like unobstructed open space. Like a science fiction force field, they are immediately repelled. We have birds occasionally strike the windows of our home, most recently a Red-breasted Nuthatch (Sitta Canadensis), who did recover but remained dazed on the ground for more than a few minutes. Some birds do not recover and it’s always a sad moment when this happens.

I had some field work last week at a vacant car dealership, the kind of place with large showroom windows and the perfect environment for pigeons. Below the large windows, I noticed a dead pigeon on the ground with a trail of dried blood trickling from its beak.

It was an obvious window strike. If you look close at the next photo, you can see the faint impression of two bird strikes on the window. The impression shows the body and outstretched wings in flight.

I took a close-up photo of the pigeon’s head. I could see a few specks but without my geezer glasses they were just specks. When I downloaded the photo, I noticed that some of the specks were actually insects, bird lice.

The next photo is an extreme enlargement showing one of the lice.

Pigeons, and probably most wild birds, harbor an attractive mix of ectoparasites. The one in the enlarged photo is likely a slender pigeon louse (Columbicola columbae). The slender pigeon louse belongs to a group of lice known as chewing lice, specifically to the Superfamily Ischnocera, who feed on the downy part of feathers and softer fur. The slender pigeon louse eats the fluffy parts of the pigeon’s feathers. Think about this the next time you’re inclined to feed pigeons.

Relationships

At this time of the year, as summer wanes, the rim of Puget Sound is ringed in bright yellow flowers of Puget Sound gumweed (Grindelia integrafolia). The gumweed seems to thrive in the breezy salt air and sandy soil that fringes the Sound. It is a harbinger of fall and of the dull gray days to come.

The lives of gumweed and a drab grayish brown moth known as the Hooded Mountain Owlet (Cucullia montanae) are intertwined. It was the colorful caterpillar curled inside a flower that caught my eye as I walked the sandy flats at Meadowdale Beach.

The Hooded Mountain Owlet moth flies in July and August. The caterpillars feed on gumweed then pupate underground. There is only one generation per year.

Puget Sound gumweed ranges from British Columbia to northern California, seldom straying too far from salt water. It is a member of the sunflower family (Asteraceae), whose members include such familiar plants as dandelions and many others.