morning at the marsh

It’s amazing how much you can see early in the morning before the cyclists and hikers have hit the trails around the local marsh.  And it always amazes me to find such a diversity of wildlife inhabiting a small wild oasis in the urban landscape! I’m sure if I had spent more time on this hot, humid morning, I would have seen even more.

floating island-

Dense mats of cattails float around the marsh propelled by the prevailing water flow.  They attract a wide variety of wildlife that may hunt from their edges, nest in their stalks, and hide within small crevices from the peeping eyes of photographers.

great blue heron-

Great Blue Herons are often found along the shoreline, usually obscured by the vegetation.

great blue heron-

Another heron was making its way down toward the shoreline — perhaps the mate of the other one?

great egret-

I can always count on seeing a Great Egret or two foraging near the edge of the marsh.

green heron-

What else is hiding here in this vegetation near the shore? A Green Heron pops up to see if I’m a dangerous predator.

green heron-

A less nervous juvenile Green Heron hunted in the shallows.

common loon-

Out in the water, a Common Loon swam by.

double crested cormorant-

Nearby, a double-crested Cormorant surfaced from its dive, and took a look around.

I spotted something white way out in the middle of the marsh, swimming quickly away from me, and grabbed a quick shot of a Trumpeter Swan family with their two, seemingly newly hatched, cygnets.

trumpeter swan family-

It’s a bit late to find these newly hatched chicks; perhaps the first nesting failed and these are result of a second nesting attempt. The chicks have a lot of growing to do before they reach the body size of the adults which can weigh more than 20 lb.

trumpeter swan family-

the distraction lure

Some bird mothers go to great lengths to distract predators away from their nest and/or fledgling chicks.  They feign injury, flapping like they are wounded but can’t fly, chirping loudly to attract attention to themselves and away from their chicks.  I’ve seen Kildeer do this many times, as they lead me on a merry chase away from their nest.  For example…

But I’ve never heard of small songbirds using this strategy, until I saw it in action today when a female Indigo Bunting led me all over the backyard as I tried to find her nest and her chirping chicks.

indigo bunting-female feigning injury

Here I am, look at me, I’m helpless with my broken wings.”

Wings fluttering, hopping sort of helplessly through the grass, chirping continuously, and flying weakly from spot to spot, this female Indigo Bunting put on quite a show.

Moving around in the underbrush of the wildflower garden, I discovered two of her chicks, also chirping loudly, but hidden from view until one of them tried to cross a patch of grass.

indigo bunting-fledgling

Bunting chicks may fledge (leave the nest) after only 8 days, and can hardly fly more than 10 feet, so they tend to stay hidden in low, dense vegetation.

indigo bunting fledgling-

Not a very adept flyer yet…

indigo bunting-fledgling

The chick is not even fully feathered yet, has short stubby wing feathers, and no tail. It would be easy prey for a wandering cat…

Meanwhile, its mother is still chirping away at me, from all over the garden.

indigo bunting-female

first here…

indigo bunting-female

then here… (see that faint tinge of blue on her shoulder?)

indigo bunting-female

and finally right out in front of me.  Older females may be much bluer than this, with streaky blue patches on their shoulders, back, and tail.  But their overall drab plumage helps camouflage them while they care for the chicks.

indigo-bunting-male

A brightly colored male Indigo Bunting would attract way too much attention if he were feeding chicks in the nest.

Fun facts:

  • although Indigo Buntings are about the size of a Goldfinch and the female sort of resembles a female Goldfinch (but lacks those distinctive wingbars), they are actually members of the Cardinal family.
  • the blue color (especially evident in males) does not come from a blue pigment, but is due to special reflective particles in the feathers that scatter light and reflect blue wavelengths.  Read more about blue coloration in animals by clicking here.

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.

Above the treeline

The harsh climate takes its toll on life on mountain slopes at 68 degrees north latitude.  Above the treeline, there is a lot of exposed rock, covered in places with lichen.  A miniature forest about I inch high clings to rock crevices where moisture is greater, and what flowers are present, are tiny miniature copies of lusher vegetation down below.

Mt. Njulla, Abisko national park, Sweden

Exposed rock and patchy vegetative cover on Mt. Njulla, Abisko national park, Sweden

Mt. Njulla, Abisko national park, Sweden

The views of the mountains are spectacular as we climb Mt. Njulla, Abisko national park.

Mt. Njulla, Abisko national park, Sweden

Below our feet, a carpet of tiny plants and lichen have colonized the rocky crevices.

Mt. Njulla, Abisko national park, Sweden

The vista is 270 degrees of spectacular, snowy mountains and u-shaped glacial valleys. In today’s perfect sunny weather, we could stay and look out at the horizon forever.

Willow catkins, Mt. Njulla, Abisko national park, Sweden

Tiny willow plants send their catkins upward, the tallest plants I found.

Mt. Njulla, Abisko national park, Sweden

Some plants, like the trailing azalea, spread by sending out horizontal branches that cling to the rock surface on Mt. Njulla.

Mt. Njulla, Abisko national park, Sweden

The flowers buds are minuscule, the open flowers barely measure a couple of mm across. The leaves look almost like succulents, which might be a water conservation strategy in this arid environment. There are no pollinators around yet.

Northern Wheatear, Mt. Njulla, Abisko national park, Sweden

We hiked the mountain hoping to see reindeer foraging on the high slopes. But the only evidence of their presence was some poop.  This Northern Wheatear was the only bird we saw or heard on our hike. They breed in rocky habitat in Northern Europe after migrating from wintering grounds in Africa.

Mt. Njulla, Abisko national park, Sweden

Then, its back to our cozy cabin for dinner after a long day of hiking.

German Geese and other sights

The North American contribution to Europe — Canada Geese, the dominant species in parks world wide, and here in Kiel, Germany.

Canada Geese in Kiel, Germany park

Canada Geese in Kiel, Germany park

other sights of our daytime wandering through the botanical garden, the Old Town, and beach area.

Moorhen in the old botanical garden

Moorhen in the old botanical garden

Bullfinch

Bullfinch in old botanical garden

Ropes course, city park, Kiel, Germany

Challenging ropes course, city park, Kiel, Germany

Beachfront at Kiel, Germany

Beachfront at Kiel, Germany. Summer sunshine beckons on a warm day.

Old Town, Kiel, Germany

Old Town, Kiel, Germany. The city was 80% destroyed in WW2, so the “old buildings” were rebuilt. The streets are largely deserted and shops and cafes closed on Sunday. Everyone is at the beach — except us tourists.

the Polish prairie

The Bielowieza forest is surrounded on the Polish side by farmland, much of which is hayed for dairy cattle.  Polish farmers seem to prefer haying their meadows of grasses and forbs, rather than planting monocultures of alfalfa.  As a result, forest visitors (the human variety) are treated to a colorful scene of perennial blooms, very similar to that we see in Minnesota prairies, only with a lot more color.

http://www.sciencemag.org/news/2017/06/ravens-remember-people-who-suckered-them-unfair-deal?utm_source=newsfromscience&utm_medium=facebook-text&utm_campaign=ravensremember-13457

We were amazed to find a number of the same species present in Polish prairies as we might find along roadsides in the U.S.  Of course we call these weeds, and perhaps they are in Poland, too. Or perhaps they really are part of the natural prairie mixture.

Oxeye daisy

Oxeye daisy looks the same in the Polish prairie

Prairie near Bialowieza forest

Wild carrot, hawkweed, brome, and timothy are similar constituents in Polish and U.S. Prairies

White stork, prairie near Bialowieza forest

Of course the birds are quite different. In a Minnesota prairie, if I spotted a long-legged bird in the prairie, it would probably be a Sandhill Crane. In Poland, the long legged birds are likely to be White Storks, the ones that bring all the Polish babies…

White Stork, Poland

Prairie wagon, near Bielowieza forest, Poland

And the mode of travel through prairies is different too. We don’t have any of these nifty wagons in the U.S., unfortunately.

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.

Birds that buzz…

Two words that are usually said together:  bird song, or better yet songbirds, those usually small birds in your garden that produce the wonderful, lilting, sometimes piercing, often warbling, unique collection of notes that identifies each species.

But not all songbirds sing, or sing exclusively — some of them have adopted a buzz as part or all of their song. In fact, their soft buzzes or wheezes are remarkably similar and difficult to pinpoint when looking for that buzzing bird that you’re not really sure isn’t some sort of insect.  Why would male birds want to buzz instead of sing?

Take the Blue-winged Warbler for example; wouldn’t you assume from its name that its song would be a melodious warble, rather than a two-note “bee-buzz“?

blue-winged warbler-

A beautiful Blue-winged Warbler sitting out on the edge of the forest overlooking a prairie grassland, buzzing away.

blue-winged warbler-

A better look at the blue wing of the Blue-winged Warbler. He was little and mighty far away.

Just 20 feet away, a Clay-colored Sparrow is buzzing away, with a very similar, low frequency, raspy buzz call.

clay-colored sparrow-

Pale-colored, but with distinctive stripes on its head and face, the Clay-colored Sparrow blends in well to its usual background of dry grass.

clay-colored sparrow-

Its pink bill resembles that of a Field Sparrow, but its buzzing “song” makes it easy to identify.

Buzzing seems to be a common characteristic of “song” in grassland birds, like Grasshopper Sparrows and Savannah Sparrows.  So, one wonders if these birds are trying to avoid detection in prairie habitat by mimicking insects when they “sing”, or whether female birds just find buzzing particularly enticing?

It turns out that buzzing sound made with the bird equivalent of a larynx (called a syrinx), is actually quite physically challenging, and therefore could be an indicator to females of the quality of a potential mate.  German researchers* found that larger, more robust male Nightingales incorporated more buzzes in their song, and enjoyed greater attention from females than their less robust or younger competitors.

Another possible explanation for buzzing birds found in grassland habitats is that low frequency buzzing notes apparently carry long distances, and can be heard throughout and beyond the male’s territory.  Banded Wrens incorporated more buzzing notes in their early morning song that was directed toward other males in the nearby vicinity, at times before females were present.**

*Citation: Weiss M, Kiefer S, Kipper S (2012) Buzzwords in Females’ Ears? The Use of Buzz Songs in the Communication of Nightingales (Luscinia megarhynchos). PLoS ONE 7(9): e45057. https://doi.org/10.1371/journal.pone.0045057

**Citation: P.L. Trillo and S.L. Vehrenkamp. Anim Behav. Song types and their structural features are associated with specific contexts in the Banded Wren. 2005 Oct; 70(4): 921–935. https://dx.doi.org/10.1016/j.anbehav.2005.02.004

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-