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-

She did it!

Yes, Mother Goose did it, at least I’m going to believe she did.  Mother Goose was gone from the osprey nest platform, but there were some brand new goslings in the pond at the base of the tower at Grass Lake.  Somehow four little fluffy ducklings, looking recently hatched, may the ones that survived the plunge down to the pond and are now happily swimming around with their parents.Canada Goose family-

Canada Goose family-

Canada Goose family-

Father Goose watches protectively as a rather hungry hen munches on grass and the goslings explore dirt and possibly eat some bugs.

Canada Goose family-

Canada Goose family-

See you later…

an unusual sighting

For the past several years, a pair of ospreys have raised 2-3 chicks each year at the local marsh that surrounds Grass Lake, using a high nest platform erected specifically to entice them to breed there..

osprey-pair

The pair of Ospreys on their nest platform in June, 2016.

But this year, they must have arrived a little later than usual, because an interloper arrived first to claim the 50 foot high platform for her own nest.

canada goose-on osprey nest

It looks like Mother Goose tidied up the stick nest, before adding her own downy breast feathers to the nest cup.  Although her nest is well protected from danger of flooding on the osprey platform, it is exposed to aerial predators like Bald Eagles that might fly over.  

What is peculiar about this is that Canada Geese usually nest on land surrounded by or near the water on an elevated mound — but not this elevated!

great blue heron-and-canada geese-

While the hen incubates her eggs on her mounded nest, the gander runs protective interference and wards off potential predators or nosy herons.

Mother Goose usually sits tight on the nest, incubating her clutch of 6-8 eggs for most of a month or so, but Father Goose will take over at times so that the hen can stretch her legs and get a bit of food for herself.  Knowing how much space Canada Geese need to land on water or land, I have to wonder how good they are at making a touch down in the limited space of this nest platform.

Once the ducklings hatch, they usually move immediately into the water with their parents.

canada-goose-and-ducklings-1

It’s safer to be in the water because ducklings are vulnerable to a wide variety of predators on land.

Being nothing more than downy balls of fluff, they certainly can’t fly yet, so what will happen to the ducklings raised on an osprey platform?

Transformations

Marked transformations of the landscape and its inhabitants occur daily now in the upper Midwestern U.S., as the weather is warming up.  I took an early morning walk around the settlement ponds beyond the backyard and found quite a few changes since the week before.

backyard pond

early morning reflection in one of the ponds

The trees have leafed out, the grass is greening up nicely, and wildlife has again taken up residence there.

canada geese-

A pair of geese claimed one end of the pond as theirs — encouraging another pair to move away.

great egret-

A Great Egret fished along the shore…this is the first one I’ve seen so far this year.

great egret-

They seem to love dining on miniscule fish fry they find on the edges of the pond. The bird caught three in quick succession.

male wood duck-

Only male Wood Ducks patrolled the pond’s edges; perhaps the females are all sitting on eggs somewhere.

And of course, a symphony of Chorus Frogs added their music to the landscape.

western chorus-frog-calling

Indvidual tiny Boreal Chorus Frogs emit incredibly loud calls, and together with the other 100s in the pond, their “symphony” is deafening.

Each day brings new surprises — stay tuned for next week’s report on the pond.