a beautiful riverside wildflower garden

What a surprise to find a lush wildflower garden growing in the damp soil at the edge of the St. Croix river at the Arcola Bluffs trail.  A trail along the river’s edge led me through dense clumps of Cardinal flower, Blue Lobelia, Obedient plant, and Prairie Ironweed.

cardinal flower-Lobelia cardinalis-

There were hundreds of individual Cardinal flower stems growing here in the semi shade and moist forest soil along the St. Croix river.

cardinal flower-Lobelia cardinalis-

With this many attractive red flowers, you would expect to see hummingbirds, and sure enough they showed up right as I began noticing the dense flower patch.

ruby-throated-hummingbird-on-cardinal-flower-1

Shot earlier in my backyard wildflower garden, but Ruby-throated Hummingbirds do love this plant.

white cardinal flower-Lobelia cardinalis

Among the hundreds of individual plants, there was one genetic mutant, a white form of the Cardinal flower.

White mutants of brightly colored animals or plants are usually genetic recessives, and are rare in the population. I imagine hummingbirds might skip over the nectar resources in this plant (wrong color to attract them), so it might not set much seed, which further contributes to its rarity.

Blue Lobelia - Lobelia siphilitica-

Another Lobelia species, the Blue Lobelia, was also growing in the riverside wildflower garden, although in much lower density.

Obedient plant - Physostegia virginiana-

I spotted just a few individuals of Obedient plant in this “garden”, although this plant is usually an aggresive colonist of open spaces in my backyard wildflower garden.

Prairie Ironweed - Veronia fasiculata-

Prairie Ironweed seems to like the wet river bottomland as well as it does the open prarie habitat. It’s large flowerheads were particularly attractive to honeybees.

Prairie Ironweed - Veronia fasiculata-

Has this lovely wildflower garden always been here? Did I just happen to hit it during its peak flowering? Other wildflower enthusiasts have reported lush blooms of cardinal flower along the backwaters of the Mississippi and St. Croix recently (late July-early August), so maybe I have just never discovered these little patches of colorful diversity along the rivers.

the wisent isn’t extinct…completely

The Wisent, or European bison, is a look-alike of the American bison, but its genetics tell a different story.

Wisent, European forest bison

Wisent, European forest bison, is really a grassland animal that takes refuge in the forest.

As the story goes, once upon a time between ice ages, steppe bison wandered the grasslands of Europe, Asia, and North America, traversing the Bering land bridge during glaciated times.  Cut off from Asia when sea levels rose, the steppe bison in North America underwent moderate changes to become the buffalo we recognize today, but then suffered huge declines in numbers when railroads through the central plains brought hunters that killed off huge numbers of them.

American bison

American bison in Wyoming

The steppe bison was also hunted extensively, and may have gone extinct from overhunting about 11,000 years ago.  But aurochs (European progenitor of cattle) and Steppe bison matings in Europe produced hybrids (now known as Wisent) that survived the hunting pressure, perhaps by retreating deep into the primeval forest.
European bison, Wisent

Wisent numbers also declined precipitously with settlement and expansion of agriculture in Europe, but a few remained in the small forest fragments, like the one near Bielowieza.

European bison, Wisent

Hybrids usually are less fit than their ancestors, largely because they are less fertile (e.g., mules), but in the case of the European bison hybrid, they appear to have survived both hunting pressure and the extreme cold of the interglacial periods better than their steppe bison ancestors, and retreated to the forest for protection.

How do we know this?  A fascinating study compared animals in cave art paintings with DNA fragments from bison remains of 15-50,000 years ago and found transitions in the DNA that coincided with animals represented in the cave art.  The animals represented during the coldest periods were the short horned, less humped at the shoulder, Wisent.**

Bison reserve, Bielowieza, Poland

The Bison reserve near Bielowieza has expansive enclosures for its animals, and lots of natural prairie grass for forage.

Captive breeding of Wisent at the Bison reserve just outside Bielowieza attempts to track genetic ancestry and propagate animals that could be released to the wild, but wild Wisent exist in small herds through the forest-grassland spaces in eastern Poland.  They are mighty hard to spot — judging from our early morning explorations of the area.

Bison reserve, Bielowieza, Poland

Bison reserve, Bielowieza, Poland

**http://www.nature.com/news/mysterious-origin-of-european-bison-revealed-using-dna-and-cave-art-1.20822

the primeval forest

Imagine getting a glimpse of what a mature forest looked like during the Middle Ages, say around 1400 A.D. New oak, linden, and yew trees were just starting to grow in the few sunlit gaps in the forest then where some unfortunate older trees had fallen.

Light gaps in mature forest

Light gaps created by fallen trees in Bialowieza forest in the eastern edge of central Poland provided space for new seedlings to start their journey upward toward the light.

500 year old English oak, Bialowieza forest, Poland

500 year old English oak, Bialowieza forest

Amazingly, some of those very individuals are still standing today in the Bialowieza forest, one of the last true remnants of Europe’s northern temperate hardwoods.  They escaped the axes of Prussian loggers, the devastation of World War I, and the bombs of German invaders during World War II. They tower over the rest of the forest canopy, some of them climbing straight up 200 feet or more.

The forest primeval is a special place with great diversity of species, as well as ages of individuals, an almost closed canopy that lets in little light to the shaded forest floor, and an open, spacious understory with short ground cover, most inviting to the casual hiker.

Bialowieza forest, Poland

But we stay on the marked paths here, because this is a well protected area, nationally and internationally. Root systems of large trees need protection from the soil compaction caused by hundreds of visitors walking nearby to marvel at the height and girth of these trees.

Huge Scots Pine, Bialowieza forest, Poland

Huge Scots Pine, About 300 years old

Around every corner of the path, there are slight changes in the forest structure and composition. We find a new set of species in wetter areas than drier ones, and stagnant pools harbor another small ecosystem of life.

Forest pool, Bialowieza forest, Poland

Forest pool in the Bialowieza forest

Water pools in some areas of the forest, creating smaller ecosystems within the forest ecosystem. Salamanders, frogs, dragonflies, iris, ferns, a variety of aquatic plants, and plenty of mosquitos could be found here.

One could spend dozens of years studying this place and not know all of its secrets, but today we got a brief glimpse of something unique in the world.

on the edge

Tromping around Weaver Dunes, south of Wabasha MN, for 8 hours trying to identify every bird we could find was exhausting but rewarding, and what an absolutely beautiful day to participate in The Nature Conservancy’s bird blitz on May 12.

Cape May Warbler-

First bird of the day — Cape May Warbler, high in a leafy tree (bane of photographers — the tree, not the bird)

The spring migration was running a little behind schedule, but we managed to find (and identify) 58 species (which admittedly doesn’t sound like a lot for 8 hours of work).  We explored a variety of habitats, but the best places to look were edges between shrub and forest, or prairie and forest.

Yellowrump Warbler-

Yellow-rumped Warblers outnumbered other warbler species, and thankfully posed at much lower elevations in the trees.

Rose-breasted Grosbeak-

We only saw one Rose-breasted Grosbeak, and he was quite shy about coming out in the open to show off his raspberry bib.

Lark Sparrow

Lark Sparrows were more common than the warblers, flashing their white outer tail feathers as they flew. True to their name, their song is much more of a warble than a buzz — i.e., lark-like.

Lark Sparrow

Lark Sparrows typically nest in shrubs and forage in grassy areas removed from the nest. They have the unusual habit of walking, instead of hopping.

Northern Waterthrush-

Down at the edge of a small pond, a Northern Waterthrush hunted for insects.

Northern Waterthrush-

A distinctive eyestripe and wagging tail made this large warbler easy to identify.

Brown Thrasher-

A Brown Thasher was very uncooperative about posing, and remained hidden in the dense foliage of trees in the grassy savannah.

Baltimore Oriole-

Orioles foraged high in leafy treetops, but were easy to find by listening for their characteristic song.

Gray-cheeked Thrush-

Another edge-lover found skulking among the low vegetation in the woods surrounding a pond was the Gray-cheeked Thrush, with its characteristic white eyering.

Our efforts were added to those of the birders walking other TNC properties throughout the tri-state region of MN, North Dakota, and South Dakota.  Together all observers on May 12 found over 200 different bird species, or approximately 50% of those known to reside or pass through MN on migration in May.  Not bad…it’s a nationwide competition, so we’ll see how MN bird numbers stack up with those elsewhere in the U.S.

Considering that our American birds have to navigate and survive stormy weather and drastic climate changes, glass windows and glass-covered buildings, marked habitat alterations, and depleted food supplies from all the pesticide and herbicide applications, it’s a wonder that we see the diversity that we do.

Not just another Nuthatch

Calls of familiar bird species sound quite different in the Arizona woodlands than they do in the Minnesota backyard, and there’s a good reason for that — the birds themselves are different.  Take White-breasted Nuthatches (WBN) for example.

In the eastern U.S. and Canada, we hear a nuthatch advertise its presence with its familiar, nasal “yaankk, yaankk” call.  But in more western forests, the call is fainter, faster, more repetitive, and higher — more like “yirr, yirr, yirr”.  Now this may be entirely too nerdy for consideration here, but the birds even look different.  Can you spot the differences?

white-breasted-nuthatch-carolina

A white-breasted-nuthatch-eastern form

white-breasted-nuthatch-western form

A white-breasted-nuthatch-Rocky Mountain form

Look at the amount of black on the top of the head, and the color in the feathers that cover the wings (called wing coverts).  The eastern, Carolina form of the WBN has black edging on the feathers that cover the wings; the Rocky Mountain form has none of that. The eastern form has a much wider black stripe on the top of its head, and less white between the black stripe and its eye than the Rocky Mountain form.

So what?  Well, these are the kinds of differences, including the differences in the call, that allow birds to discriminate more carefully about who they will or won’t mate with during the breeding season.  And there aren’t just two forms of WBN, but likely as many as four, according to the latest poll by ornithologists in the know.

white-breasted-nuthatch-

Not just any nuthatch, but an Eastern, Carolina, White-breasted Nuthatch, thank you.

A key geological event that formed the basin and range regions of western North America is probably responsible for the differentiation of subspecies (forms) of many bird species, like the White-breasted Nuthatch.  Three distinct forest regions developed during glacial cycles in the U.S. and Canada in the past 14 million years, resulting in eastern (east of the Rockies), interior west (Rockies to the Sierras) and Pacific coastal (Sierra crest to the Pacific Coast) forests.  Geographic separation and then specializations by interbreeding populations in these regions have produced the distinct differences in the birds.

The differences might seem slight to some of us, but to the birds (and to the ornithologists that catalog them), they may be enough to separate them into three or four distinct species.

Colorful Northwoods in the borderlands

Even the dull gray skies couldn’t diminish the amazing color in the landscapes along the north shore of Lake Superior this week.  Although the maples had largely dropped their red and gold leaves throughout the inland forests, the golden glow of birch and aspen leaves more than made up for it.  You get a really good idea of just how dominant these trees really are in the total landscape when you see them highlighted against the evergreens.

colorful-northwoods-northeastern MN

Where the forest meets the shoreline of Lake Superior at the very tip of the arrowhead that makes up northeastern Minnesota. This scene is about 1 mile from the Canadian border.

colorful-northwoods-northeastern MN

The Pigeon River marks the boundary between the US and Canada in this part of Grand Portage State Park.  Across the river is Canada’s Pigeon River Provincial Park.

colorful-northwoods-northeastern MN

Hello Canada!  The Pigeon River may have moved its channel in this area, because a survey marker for the border was located not far from where my husband is sitting.

colorful-northwoods-northeastern MN

It’s quiet in the Northwoods as we hike along — nothing to distract us from noticing the colorful display around us as we hike.

colorful-northwoods-northeastern MN

Round birch leaves on the ground make it look like the hiking trails are paved with gold coins.

Robin-nanza

One of the many waves of migratory birds that has arrived in the Twin Cities area in the past couple of weeks was Robins — a bonanza of Robins — a “robinnanza”.  These are not your usual noisy, chattery backyard robins;  they are instead secretive, quiet, stealthy birds that fly silently through the forest and gang up together for bathing in small forest streams.

american-robin-

Big and beautiful, with their newly molted and bright-colored orange and gray plumage — about two dozen of them crowded in a small forest stream for a bathing party.

american-robin-

It’s a daily (or more often, perhaps) ritual for these birds, especially in this delightful babbling brook.  Cold water is no deterrent.

american-robin-

Now feeling so much cleaner…

american-robin-

Having gotten rid of all the dusty dirt under those brand new feathers, Mr. Beautiful hops up on a branch to dry.

Previously, I wrote a post querying why readers thought Robins bathed so much, and one reader suggested it was because they dig around in the dirty leaves so much.  Indeed, there was an ample display of that behavior near the stream bank, where Robins were furiously poking into and throwing leaves up in the air as they explored what lay beneath.

american robin

Tossing leaves in the air from the muddy ground probably deposits quite a bit of dirt on the thrower.

I poked at a few leaves myself, and found some spiders and mealy bugs crawling around under them, so no wonder the Robins have congregated in this rich hunting ground near a lovely bathing spot.

forest-stream-

the forest stream last March in this same spot, just as the watercress was beginning to grow

Fall-ish

Warm days, cool nights, sometimes rainy and blustery — that’s fall.  You never know what it’s going to be like because the weather changes day to day, or even from morning until evening.  But the combination of short daylength (less than 12 hrs of daylight) and very cool nights starts the color change in the vegetation that we love to see.  (For an explanation of how that color change happens — click here.)

fall-prairie-wm-obrien-park-

Not all plants are as sensitive to the daylength and temperature cues — making the fall season a long and colorful display.

fall-color-

Maples and aspens are some of the first to show their fall colors, and oaks are one of the last, making the forest a kaleidoscope of green, yellow, red, and orange.

new-england-aster-

A few remaining flowers like this New England Aster can still be found in the prairie, but there are few insects around.

milkweed-pod-

Milkweed pods open to disperse their airborne seeds.

yellow-rumped-warbler

Yellow-rumped Warblers are one of the more abundant migrant species, found and heard in almost every habitat — even the prairie.

nashville-warbler-

Waves of warblers (like this Nashville Warbler) move through with the weather fronts in the fall. But these are wary little birds, and even harder to photograph in the fall when they are feeding ravenously to replenish their migratory fat supply than they were back in the spring when they came through on their way north.

a nifty smart phone feature

My Samsung phone has a magnifier, which is great for older folks who forget their reading glasses when they go out to a dimly lit restaurant.  But I discovered another use for the magnifier the other day when I was trying to photograph moss with a telephoto — a bad idea because of the lack of depth of field.

moss on rotted log

The telephoto shot had about 1/4 of the field of view in focus.  Even the phone camera couldn’t capture the sea of moss on the rotten log adequately.  This was about as close as I could get without blurring out part of the shot.

I turned on the magnifier function, held the phone next to the moss as steadily as possible, pressed “capture”, and then saved the image.  Wow — a super-sharp close-up with more magnification than the phone camera alone could produce.

moss sporophyte capsules

The beak-like things on long stalks above the moss “leaves” are the sporophyte capsules, which will release spores to further colonize the rotted log.  This is unedited — just as it came out of the phone camera.

Magical oak forest

There are more than 30 species of oaks from all over North America and parts of Europe at the Berkeley Botanical Garden on the University of California campus. Although many species are evergreen, most of the trees are bare of leaves right now, which lets us admire the bizarre twists and contorted shapes of their bare branches.  Click on any of the images to get a larger view of the magical forest.

oak forest-berkeley botanical garden-

It was a very gray, overcast day when I visited the Botanical Garden, and I decided to add a bit of Photoshop magic to the odd shapes I found among the oaks.  I thought this might made a great setting for a children’s story — now if only I could come up with one.

oak forest-berkeley botanical garden

Some of trees had cracks and knotholes in just the right places to imagine a tree face there. I wished there had been sunlight streaming through the forest instead of gray, dull light.  So I added some.

oak forest-berkeley botanic garden

I wonder what makes these branches twist and wind around this way…the branches seem to start off straight and then bend at will.  Gnarled, knotty trees like this were the inspiration for the forest in Walt Disney’s animation of Snow White.

Oaks are generally slow growing, laying down wood in dense, tight circles each year, making them ideal for building structures that can withstand a lot of stress.  In addition, its fine grain is sought after for its beauty and texture in furniture.  And, of course, oak has a star role in the festivals and rituals of many early cultures, including its use as a prediction for the coming planting season by the Druids.

The only plausible answer I could find as to why oak branches twist into such grotesque shapes is that it might distribute the weight of the heavy, dense wood more equitably, so that they are less likely to break off.  But I’m open to other suggestions if you have them.