The best way to see the forest and prairie scenery in Bielowieza is to grab bikes and tour the countryside. Many roads to some of the small villages are less traveled by car and perfect for birding bikers. Here are a few of the things we saw.
The Wisent, or European bison, is a look-alike of the American bison, but its genetics tell a different story.
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.
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.
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.
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.**
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.
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.
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.
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“?
Just 20 feet away, a Clay-colored Sparrow is buzzing away, with a very similar, low frequency, raspy buzz call.
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
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.
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.
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.
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.)
We spent the weekend in central Minnesota taking photos of different stages of prairie restoration. Prairie grasses are above knee high already, and there are quite a few perennial forbs flowering — injecting some highlights of color into that huge expanse of green.
Many thousands of years of growth of perennial prairie grasses in this area resulted in a several feet thick layer of black, organic-rich soil — perfect for farming. But as a result, less than 2% of the original 19 million acres of native prairie remain.
Where there are large acreages of prairie or grassland landscape, we can usually find some of the native prairie animals and plants that live there. What a treat to drive down one gravel road that dead-ended in a soybean field and find a family of Sandhill Cranes walking through the meadow grasses.
Seen in central Minnesota just after sunset and following an intense thunderstorm.
It’s corn harvest time in parts of Minnesota. Most the fields have either been cut down to stubble, or had the stubble plowed under, but a few fields were still being harvested when we drove through central Minnesota the other day.
Rail cars full of corn dot the landscape, trucks hauling grain crowd the highways, and grain silos are bulging with feed left over from last winter’s storage plus the additional grain deposited this fall. Sometimes there just isn’t anywhere to put all that corn, except on the ground waiting for the next available transport.
As nighttime temperatures dip toward freezing, the trees are starting to show a little color. It’s just the beginning of the most colorful season of the year —
Fall weather and decreasing day length signal animals to begin making preparations for winter — either storing food (like the squirrels have been doing) or eating like crazy to get fat enough to migrate south. Waves of warblers and other small songbirds have been moving through the Twin Cities recently, and some wind up in the backyard, looking for insects on late-blooming plants.
Seed-eating migrants might find a banquet waiting for them too, as perennial plants put forth their seed crops.
With all the rain late this summer, I hope this will be one of the most colorful fall seasons in recent years. But that depends on the day-night temperature differences in the next few weeks. So, stay tuned for more posts on fall color later.