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.

a foxy morning

What a delight to see my favorite canids lounging in my Minnesota backyard this morning.

red fox-

In addition to brief, one minute naps, there was quite a lot of scratching and grooming going on.

red fox-

And when they stopped digging at their own fleas or whatever was itchy, they groomed each other.

red fox-

red fox-

must be some good stuff inside the other fox’s ear…

I watched these two foxes for several minutes, but can’t figure out if they are a male-female pair, or two youngsters, or what.  Male foxes are usually noticeably bigger then females, and these two seem to be identical in size. They do seem a bit small and skinny, so maybe they are younger, but this year’s kits would not be this big yet, having been born in late March, and just out of their den in early May.  It’s a mystery.

red fox-

Shot through the not very clean porch window at 500 mm —

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

Legacy of the Warsaw zoo

The Warsaw zoo occupies almost 100 acres of forested land across the Vistula river from the Old Town of Warsaw.  Although the city, including the zoo, was largely destroyed by the Germans during World War II, it has literally risen from the ashes, to become one of the most beautiful European capitols.

Warsaw looking toward the Old City

A Warsaw boulevard on a Sunday afternoon, looking toward the Old City. No litter, no cars, no homeless, just people out enjoying a summer day.

Warsaw zoo landscape across the Vistula river

Warsaw zoo landscape across the Vistula river

I was particularly interested to see the zoo after reading “the Zookeeper’s Wife” by Diane Ackerman.  Zoo director Jan Zabinski’s pioneering efforts to provide spacious housing with natural habitat for his zoo inhabitants have again been realized.  The enclosures for gorillas and chimps far surpasses those I’ve seen at other zoos.

Male silverback Gorilla at the Warsaw zoo

Male silverback Gorilla at the Warsaw zoo.

The "villa" occupied by the Zabinsky family at the Warsaw zoo

The “villa” occupied by the Zabinski family at the Warsaw zoo has been converted to a museum to showcase the role the family played in hiding hundreds of Jews fleeing the Warsaw ghetto.

Entry to the tunnels at the Warsaw zoo

Entrance to one of the many underground tunnels between the villa and the animal enclosures.

Jan brought “workmen” to the zoo from the ghetto to help rebuild enclosures, and they were subsequently hidden in small rooms under animal enclosures, until they could be moved from the zoo to outlying farms, and eventually to hopefully escape from the Germans.

The monkey house at the Warsaw zoo

The monkey house at the Warsaw zoo was one of the many places Jews were hidden, sometimes for weeks, in cramped, freezing cold quarters underground.

Today, you wouldn’t know all that transpired here 70 years ago, because it is as peaceful and scenic a place as any you could visit.

Lion, Warsaw zoo

One of the lions at the Warsaw zoo in a large, natural enclosure.

Indian rhinos, Warsaw zoo

I felt kind of sorry for the Indian rhinos that were trying to socialize despite being separated by an electrical barrier, presumably for good reason.

European bison, Warsaw zoo

The animals we were most interested to see were the European bison, which unlike its North American cousin is a forest animal. Unfortunately it was nap time, and they were uninterested in showing off.  It’s hard to judge from an animal lying down, but they seem a bit smaller than buffalo.

read more about Warsaw in my other blog, Traveling Two: http://sbchaplin.wordpress.com

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

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?