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.

a different look

This is the time of year we begin to see birds migrating back to their southerly winter homes, but many of them look very different than they did when they arrived here in the spring ready to breed.  Most birds have two outfits in their wardrobe:  a non-breeding basic plumage that may be drab but serviceable for all-around activities, like migration and over-wintering; and a brightly colored (in the case of males) alternate plumage that is meant just to show off their stuff in the breeding season.  In some cases, bills, skin around the eyes, feet, etc. may also be brightly colored, only during the breeding season.

Here’s a look at how this works in a small diving “duck” (not really a duck) called the Pied-billed Grebe, whose basic, non-breeding plumage gives no trace of the pied bill.

pied-billed grebe-basic, non-breeding plumage

Pied-billed Grebes were diving among the lily pads looking for small fish or crayfish lurking there.

pied-billed grebe-basic, non-breeding plumage

No trace of that characteristic marker of the broad black stripe on the bill though.  The one at the bottom of the image still has the faint head stripes of juvenile plumage.

pied-billed grebe juvenile

Typical juvenile plumage in the Pied-billed Grebe

pied-billed-grebe-breeding adult

A few months earlier adults looked like this, with a more definite black stripe through the pale, silver bill.

Pied-billed_Grebe_and young-Audubon

Earlier in the breeding season, both adults and youngsters looked quite a bit different than they will during the non-breeding season. Photo from Audubon field guide.

Of course seasonal changes in the grebes are far more subtle than those in some of the warbler species that take on completely different colors and color combinations between basic and alternate (breeding) plumages.  For example, gorgeous red Scarlet Tanagers molt to a green-gold plumage in the non-breeding season, making them look like a completely different species.

scarlet tanager plumage molts

the not-so-secretive Sora

Soras are a type of marsh bird that I rarely see because they are usually tucked away deep in the vegetation, obscured by tall stems and leafy plumes.  But this morning, a couple of Soras ventured out into the open water on the edges of the Mississippi marshes to forage, seemingly oblivious of the much larger ducks and geese around them.

Sora

Soras are a type of rail related to coots, moorhens, and gallinules.  They have a distinctive triangular shape, yellow bill, black mask, red eyes, yellow green legs with long toes, and usually carry their short tail feathers straight up in the air.

Sora

Mottled, rich brown feathers on their back help them blend into the edge of the marsh where they forage and nest.

Soras typically grab insects or seeds from the top of the water, occasionally probe into soft mud, walking quickly through the water and vegetation.  The adventurous Soras I watched this morning walked right up to and around resting ducks, paying no attention to their greater bulk, as they searched for hidden food items.

Sora and molting Wood Duck

The molting male Wood Duck seemed wary of the Sora though.

Sora and molting Wood Duck

Sora

Sora, just passing through…ducks don’t care

Sora

Long toes, with webbing between them, help Soras cruise through muddy muck of the marsh.

During the breeding season, we often hear the high-pitched descending notes of the Sora’s whinny call, but rarely seen them.  They are busy producing a lot of little Soras in a nest that might hold as many as 18 eggs, stacked in rows on top of each other.  Since the Soras start incubating before all the eggs have been laid, they hatch asynchronously, and the first youngsters to hatch jump out of the nest join one of the parents while the other parent continues to incubate.

Rumble.com produced an excellent video of Sora and Virginia Rails in their native habitat:

here’s looking at you

A blackish oblong shape moved slowly across the road toward my front lawn the other day.  I had no idea what it was until it got much closer.

snapping turtle-

A rather large snapping turtle was moving from the lake across the street from my front yard to the ponds beyond my backyard.

snapping turtle-

Large, widely spaced eyes help them see a wide range of view, but not when their head is pulled back into their shell.  

snapping turtle-

snapping turtle mimicking a cobra?

snapping turtle-

Is this how it sees what’s ahead?

snapping turtle-

finally on the move again….

Snapping Turtles are fearsome predators, with powerful jaw muscles that can close the mouth with such force and velocity they can bite a small pineapple in half, or amputate human fingers.  Needless to say, I left this one alone.  They are at or near the top of the aquatic food chain as adults, but take 15-20 years to mature to reproductive age.  Few snapping turtle hatchlings survive to adulthood, but adults are very long-lived.

following Mom

A common sight in lakes and ponds this time of year is a brood of little ducklings paddling very close to their mother.

mallard hen and ducklings

A mallard hen escorts her newly hatched brood across the pond to better foraging habitat.

wood duck hen and brood

Wood duck hatchlings have to paddle fast to keep up with their mom.

Mother Duck’s large body moving around the nest was the first thing the newly hatched ducklings saw, and within a day’s time, they imprinted on her, meaning their brains became wired to follow that object faithfully until they mature to full independence.

wood duck hen and brood

Whatever mom does, the ducklings do. When it’s time to rest after hunting for bugs, the ducklings take a break with their mom.

There is a critical period for this type of “filial imprinting” to occur — usually within 24-48 hours of hatching.  Whatever large, mobile object the hatchling sees, it follows — even if it is a human.  This type of imprinting is of obvious survival value to precocial birds, those that are mobile immediately after hatching, as they learn survival skills and are protected by at least one parent.

Konrad Lorenz and imprinted geese

Konrad Lorenz, an early 20th century behavioral biologist, studied imprinting in Greylag Geese by attending to them immediately after hatching.  From then on, they followed him faithfully wherever he went.

You might wonder if imprinting only occurs in birds.  The answer is NO, but there are different types of imprinting, even in birds.  Social and sexual imprinting are key to making sure an individual associates with members of its own species.  Keith Kendrick* cross-fostered sheep and goats immediately after birth (i.e., goats mothered the lambs and sheep mothered the kids), and found that male offspring (but not females) were subsequently irreversibly attracted both socially and sexually to their foster mom’s species more than their own.

animal-imprinting-in sheep and goat (Kendrick, 1995)

Sheep and goat buddies.  From How Stuff Works.

Sort of makes you wonder about Tarzan being raised by apes…

*Kendrick et al. 1995. Mothers determine sexual preferences.  Nature 395: 229-230.

Midsommer in Sweden’s archipelago

More than 44,000 islands make up the archipelago off Sweden’s east coast, and they are a popular destination, especially during Midsommer festivities. A ferry trip to one of the most distant islands, Üto — site of one of Sweden’s oldest iron mines — was a great way to end our European tour.  Some of the sights included:

Sweden archipelago islands

View from the ferry to Üto island, pronounced nothing like it is spelled.

Sweden archipelago islands

The best way to get around the island from the ferry landing, on bikes.

Uto island, Sweden archipelago islands

Sailing and swimming are top priorities on a warmish weekend in midsummer.

Sweden archipelago islands

Sweden archipelago islands

We pass cute farm houses…

Poppies, Sweden archipelago islands

And flowers (red poppies)

Bell flower, Sweden archipelago islands

And bell flowers…

Lupine, Sweden archipelago islands

And lupines…

Sweden archipelago islands

And something I don’t recognize…

Uto island, Sweden archipelago islands

And finally come to the beach at the far end of the island.

Uto island, Sweden archipelago islands

Crashing waves and cold water, perfect for swimming, but not for me.

Lupine, Sweden archipelago islands

Good bye Sweden, I hope to return some day.

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.

an unexpected visitor

Back when we had sunny days a couple of weeks ago, I found a lone Pelican resting at the edge of the Grass Lake marsh.  What was it doing here, all by itself?  Why was it so sedentary, just sitting for hours on the dead cattails?  I guess I’ll never know, but the bird has since disappeared.  Other visitors speculated that it was sitting on a nest — nope, I verified that when it stood up.  Some thought it might be injured and couldn’t fly away. That’s possible, since it was so sedentary, and it did look like one wing was sort of droopy.

White Pelican-

Just sitting, enjoying the early morning sun

White Pelican-

Yawning, stretching, and finding a new sitting position. No nest under its body, and I wouldn’t think the Pelican would try to nest out in the open like this all by itself.

White Pelicans, once rare here, now choose the shallow prairie pothole lakes in western and southwestern Minnesota to breed.  They have rebounded dramatically from a complete absence of nesting birds over the period from 1878 to 1968 to over 20,000 nesting pairs in Minnesota currently, largely due to the conservation and management efforts of the non-game wildlife staff in the MN Department of Natural Resources.

White Pelicans typically migrate from their winter headquarters in the gulf to Minnesota lakes in early spring (March).  It’s a welcome sight to see them in formation overhead, white bodies and wings outlined with black wing tips soaring overhead.

white-pelicans flying-

white-pelican-flying

white-pelicans-flying-

White Pelicans at Pelican Lake, Minnesota photographed in April 2014.

Pelicans are highly social and nest in large aggregations.  They live and hunt communally, using teamwork to scare up and harvest fish from the surface of the water. A single Pelican foraging for itself, like the one I found at Grass Lake, might be far less effective in gathering food.  I hope it recovered and flew off to join its friends somewhere on a distant lake.

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.

the underwater hunter

Quite by accident, while I was out in the Grass Lake marshes looking for the ospreys that should have been near their platform nest (the one usurped by a Canada Goose), a lone Common Loon popped up right in front of me.

Common Loon-

The morning had the perfect kind of filtered sunlight to bring out all the “color” in this black and white bird. For example, I’ve never noticed before how just the right angle of light turns the usually dark feathers below its white necklace into a turquoise band.  The loon’s head feathers are actually faintly iridescent.

During the breeding season, both male and female loons have brilliant red eyes, which might well be an indicator of their readiness to mate.  But loons are fiercely territorial and protective of their chicks, driving off other loons or intruders (like Canada Geese) far larger than they are, and it has been suggested that their red eyes are a threat advertisement of their presence.

Common Loon-viewing fish underwater

The loon frequently dipped its head below the water while paddling around.  It looks like a snorkeler checking out underwater life.

Common Loon-

Several times, following a bit of snorkeling, the loon would quickly dive below the surface, never making a sound or a splash.  I never saw it bring up a fish to swallow, but loons often swallow their smaller prey while underwater.

The Common Loon, or Great Northern Diver, as it is known throughout its range in Eurasia, has some unusual anatomical adaptations for its underwater life:

  • solid, instead of the hollow bones that characterize most birds, decrease the bird’s buoyancy in water and allow it to sink quickly during a dive
  • legs are placed so far to the rear of its body, loons can’t stand up on land, but must push themselves forward on their belly
  • rather short wings decrease drag as the bird propels itself through the water, but the trade-off is that reduced lift provided by the wings requires a long space for taking off into the air

But how does a bird that depends on its eyes for hunting underwater see both in air and in water?  Some have suggested that the birds’ third eyelid (nictatating membrane) which usually has a protective function, is more transparent in loons and other diving birds, and acts like a pair of goggles to preserve an air space between the pupil and the water.  Check out the video below for a good illustration of the underwater swimming activity of these unusual birds.

Common Loon-