Bison are pretty tough. At our Niobrara Valley Preserve, and at many other sites in the upper Great Plains, bison make it through the winter without any supplementary feed. They just eat cured grasses, grow a thick coat, and plow through snow and ice as needed. Bison don’t need humans to help with calving, and they protect their babies very effectively from predators. It shouldn’t be surprising, then, that animals like that would be completely unfazed by a little rain.
Yesterday, some of our Nebraska staff took a trip up to The Nature Conservancy’s Broken Kettle Grasslands in the northern Loess Hills of Iowa. Land steward James Baker led us on a very scenic hike before a band of cold rainy weather moved in. We then piled into some trucks with James and Director of Stewardship Scott Moats and went to visit the resident bison herd. The bison were peacefully grazing as we drove up, despite the pouring rain. When we stopped, a small group came over to check us out. Here are a few photos of those rugged bison, who didn’t need to huddle in dry and heated pickups to stay comfortable.
P.S. In case you had any doubt about my nerd qualifications, here’s one more piece of evidence. As I was working up these photos (in the backseat of a truck heading back to Nebraska) yesterday, I was looking closely at the streaks of rain captured by my camera. Based on the size of a bison calf’s eye and the length of the rain streaks closest to those eyes, I estimated that my camera captured about an inch of raindrop fall during the 1/250 of a second the camera’s shutter was open. Now, I’d want to do some actual measuring of bison calves’ eyes to check this, but based on that rough estimation, those raindrops were falling about 250 inches per second. Now, if I convert that number to miles per hour, I get 14.2 mph. A quick online search found that raindrops are estimated to fall at about 20 mph. I was pretty close!! I mean, given that I don’t really know how big a bison eye is or how close those raindrop streaks were to that eye… (NERD)
In case you hadn’t noticed, the climate is changing. Things are getting weird, and they’re going to get weirder. Here in central North America, we’re expecting more and more intense storm events and drought periods in the coming decades. Scientists are scrambling to figure out how to predict and facilitate the inevitable changes those crazy weather events will bring to natural systems, including prairies.
Fortunately, prairies have been training for this for a very long time. A few months ago, I wrote a post about the resilience of prairies, and how that resilience is built largely upon the diversity within their ecological communities and the size and connectivity of prairie habitats. Prairies that are relatively big and still have the majority of their potential plant and animal species are going into this encounter with rapid climate change with what you might call solid bench strength.
In sports, teams want to have lots of available players that represent a broad diversity of skills. Each opponent they face will have its own individual mix of power, endurance, speed, and other attributes. A successful team can build a roster for each game that counters their opponent’s strengths, no matter what they are. The number and quality of their players is a team’s bench strength.
Healthy prairies have great bench strength too. No matter what gets thrown at them, they can adapt by changing their roster of species. The speed at which they can drastically change the makeup of their “team” is impressive. Anyone who has spent many years watching the same prairie has seen this in action, but none of us have seen prairies go through what Professor John Weaver saw back in the 1930’s and 40’s.
Weaver, one of the best known prairie ecologists of all time, had been studying 30 “large typical prairies” across parts of Nebraska, Iowa, Kansas, and Colorado prior to the start of the Dust Bowl era. His baseline data gave him an invaluable opportunity to document the dramatic changes to the plant communities of those prairies during and after the droughts of the 1930’s. What he recorded, along with his former student F.W. Albertson, was an incredible testimony to the dynamism and resilience of those prairies. Their 88 page 1944 publication, entitled “Nature and Degree of Recovery of Grassland from the Great Drought of 1933 to 1940” encapsulates the bulk of their findings in one place, and is worth a read if you have the time.
One of the biggest plant community shifts Weaver and Albertson documented was the widespread and dramatic death of grasses such as big bluestem (Andropogon gerardii), little bluestem (Schizachyrium scoparium), and Kentucky bluegrass (Poa pratensis), and the subsequent rise of other grasses such as prairie dropseed (Sporobolous heterolepis), sand dropseed (Sporobolous cryptandrous), porcupine grass (Stipa spartea), and most of all, western wheatgrass (Pascopyrum smithii). Western wheatgrass populations exploded throughout the mid to late 1930’s, to the point where many prairies were completely dominated by it, to the near exclusion of other plant species. In fact, in a 1942 publication, Weaver said the following, “The large area of drought-damaged true prairie and native pasture now dominated by western wheat grass and the harmful effects of the successful competition for water of western wheat grass with species of greater forage value present a problem of much scientific interest and great economic importance.”
In other words, as they made massive substitutions within their lineups, prairies were changing so much they became almost unrecognizable, even to those who knew them best. Weaver and Albertson watched waves of forb species they’d always considered to be of little value become stars on the field, and they and others didn’t quite know how to react. Daisy fleabane (Erigeron strigosus), Missouri goldenrod (Solidago missouriensis), and heath aster (Aster ericoides) were all examples of wildflowers that suddenly rose to prominence in new and major ways. The two dismayed scientists described how heath aster, a “nearly worthless native forb,” formed near monocultures across wide swaths of prairie, to the extent that it “ruined many of the prairies…for the production of hay, because of its brush-like growth.” Others were out of their depths on this too, and Weaver and Albertson reported that “considerable native sod was broken because of the seriousness of this pest.” In the following sentence, however, they begrudgingly added a short sentence, “Of course, it did protect the soil.”
Exactly. While the strategy was foreign and frightening to those who hadn’t seen prairies dealing with these kinds of conditions before, those prairies were just doing what they’ve done many times before – making whatever roster adjustments were necessary to keep functioning at a high level. In addition to forb species they denigrated as weeds, Weaver and Albertson noted that many wildflowers with “large storage organs”, including bulbs and corms, also greatly expanded their population size during the dust bowl years. This included species like Violet wood-sorrel (Oxalis violaceae), bracted spiderwort (Tradescantia bracteata), windflower (Anemone caroliniana), and wild garlic (Allium canadense). Those species and others increased the size of the patches they’d occurred in previously, but also were found “in many new locations.” Other native forbs that became superabundant in some prairies, especially early in the dust bowl years, included prairie ragwort (Senecio plattensis), white sage (Artemisia ludoviciana), and yarrow (Achillea millefolium).
As rains started to return in the early 1940’s, Weaver and Albertson watched with amazement and renewed optimism as plant communities started “recovering”, which of course meant they were returning to a composition more familiar to the people observing them. Grasses were often the first to rebound in prairies, including big bluestem, which initially formed large and lush monocultures in many places. Wildflowers that hadn’t been seen for seven years or more, suddenly appeared everywhere, including blue-eyed grass (Sisyrinchium campestre), which grew “more thickly than if the stands of 7 normal years had been combined.” Downy gentian (Gentiana puberula), which had been considered rare prior to the big droughts, became much more common in the early 1940’s than Weaver and Albertson had ever seen before, with abundances of “15 or more plants in a space of a few rods”.
Stiff sunflower (Helianthus pauciflorus) returned fairly quickly to “normal abundance” by 1943, as did many others, including silverleaf scurfpea (Pediomelum argophyllum), cream wild indigo (Baptisia bracteata), and buffalo pea (Astragalus crassicarpus). Prairie violets (Viola pedatifida), pussy toes (Antennaria neglecta), and others came back more slowly, but returned nevertheless. Importantly, those returning species didn’t appear to be traveling from long distances. Instead, they simply re-emerged, either from seeds or underground buds, from where they’d been sitting on the metaphorical bench, awaiting the call to step up to the plate again.
The prairies we know today have been through a lot. In Nebraska and surrounding states, we have specific documentation of the kinds of extreme roster changes prairies can and have made to adjust to the world around them, thanks to the work of John Weaver and F.W. Albertson. If you have a favorite local prairie, and I hope you do, it’s important to remember that the way it has looked for as long as you’ve known it is only a small sample of what it’s capable of. Smart teams don’t reveal their secrets before they need to.
As we work to keep prairies healthy through this period of rapid climate change, it’s both useful and reassuring to remember what they’ve been through before. Today’s prairies certainly have additional challenges to deal with today, compared to the dust bowl days (more invasive species, more landscape fragmentation, etc.), but many should still have sufficient bench strength to make the adjustments they’ll need to make in the coming years. Our responsibility is to provide management that helps prairies sustain their plant and animal diversity, as well as to protect prairies from additional conversion to cropland or other land uses. Where possible, restoring prairie habitat around and between prairie fragments can also help build resilience. In short, we have to allow prairies to do what they do best – adapt and adjust. Prairies are wily veterans and they’ve been in this game for a long time. It’s a good bet they’ve still got a few tricks up their sleeve.
While I was in Iowa last week, I took advantage of some free time just before sunset to return to one of the restored (reconstructed) prairies we’d visited earlier in the day at the Kellerton Wildlife Management Area. As I walked into the prairie, I could hear a few straggler (desperate?) prairie chickens booming on their lek and I flushed a pair of northern bobwhites from the fenceline. Bobolinks, dickcissels, eastern meadowlarks and grasshopper sparrows were noisily announcing themselves across the prairie, and upland sandpipers were whistling and chattering above. The insects were less noisy but were abundant, once I started looking closely for them.
As the sun lowered itself toward the horizon, I reflected upon the various ways the success of this particular prairie restoration effort could be measured. It was certainly aesthetically pleasing, plant diversity was high, wildlife and insects certainly seemed to be responding well to it, and by replacing cropland with prairie, the Iowa DNR had – at least incrementally – defragmented the grassland landscape. Seems like success to me! …I decided to focus on the aesthetics for a while, and took advantage of the golden evening light until the sun disappeared completely.
I got the chance to spend a couple days in Iowa last week, talking about conservation grazing with staff of the Iowa Department of Natural Resources. They invited me to join a two day workshop discussing various ways to use grazing for conservation objectives. My main role was to kick off the meeting by providing various examples of objectives that can be addressed through grazing. Beyond that, I was asked to participate in the remainder of the workshop and contribute thoughts and ideas as appropriate. I am grateful to have had the opportunity to participate, and came away with a better appreciation for the challenges faced by Iowa prairie managers.
I thought I’d share some of what I covered in my presentation. Essentially, I focused on two broad categories of prairie management objectives that can be addressed through cattle grazing. Those are:
Reducing grass dominance to increase plant diversity
Increasing heterogeneity of habitat
Reducing Grass Dominance
Dominant grass species can sometimes suppress prairie plant diversity by monopolizing soil and light resources. Two categories of prairies seem particularly vulnerable to this: 1) prairies that have been degraded by chronic overgrazing or broadcast herbicide use, and 2) restored (reconstructed) prairies. In Nebraska and Iowa, dominant grasses can include non-native invasive species such as smooth brome (Bromus inermis), Kentucky bluegrass (Poapratensis), tall fescue (Schedonorusarundinaceus), and reed canarygrass (Phalarisarundinacea), as well as native species such as big bluestem (Andropogon gerardii).
When attempting to reduce the dominance of these grasses, it’s important to be clear about what you’re trying to accomplish. If the ultimate goal is to increase plant diversity, it’s not enough to just suppress the vigor of grasses. In order to be successful, a variety of other plant species have to colonize territory abandoned by that weakened grass. A late-spring prescribed fire can temporarily suppress the growth and vigor of smooth brome or Kentucky bluegrass, but often results in robust growth of big bluestem later that season. Trading a dominant invasive grass for an aggressive native grass may not be success if wildflower diversity remains low.
Grazing can play an important role in increasing plant diversity by repeatedly defoliating major grass species that limit plant diversity. The timing, stocking rate, and frequency of grazing can all be adjusted based on the grass species and objectives at a particular site. As an example, we sometimes combine an early spring prescribed fire with intensive grazing (through about June 1) to suppress cool-season invasive grasses such as smooth brome and Kentucky bluegrass. If big bluestem is abundant in the same place, we’ll leave cattle in for much of the summer as well, but at a lower stocking rate. The strategy is to suppress both the invasive cool-season grasses and the native warm-season big bluestem while allowing other plants to thrive and expand their footprint.
At low stocking rates, cattle tend to keep big bluestem closely cropped, but don’t target most wildflower species. We usually see an abundance of new plants growing in and amongst the weakened brome, bluegrass, and bluestem during the year of grazing and the following year. Those new plants include both short-lived “opportunistic” plants and longer-lived perennial plants. The result is a bump in plant diversity. If we repeat the same kind of treatment every few years, we can often maintain a richer plant community than we can with other management options such as fire or mowing alone.
There are countless ways to employ cattle grazing to weaken dominant plants and stimulate higher plant diversity. I’ve written about other examples previously. You can find a couple of those here and here.
Increasing Habitat Heterogeneity
Cattle grazing can create habitat structure that other management options such as fire and mowing can’t. As they work to meet their nutritional needs, cattle graze some plant species (mostly their favorite grasses) preferentially. Stocking rate, or the intensity of grazing, correlates with grazing selectivity. At low stocking rates, cattle are free to eat only what they really want, resulting in closely cropped patches of grass interspersed with taller clumps of less palatable grasses and wildflowers. When stocking rates are higher, cattle are forced to eat a wider range of plant species, creating a more uniformly short vegetation structure. Both the “lower-stocking-rate-patchy-habitat” and “higher-stocking-rate-uniformly-short-habitat” can be valuable to wildlife and invertebrate species.
The ideal situation is to provide the widest possible range of habitat types within a prairie, or within a series of adjacent or connected prairies. That way, regardless of their habitat needs, most wildlife and invertebrate species will be able to find a place to live. Changing the location of each of those various habitat types from year to year helps keep any species (plant or animal) from becoming so abundant that it impacts other species to the point of reducing diversity.
Because of the unique vegetation structure created by grazing, a wider range of habitat types can be created with grazing than with either fire or mowing. However, it’s also very important to ensure that grazing doesn’t have a detrimental impact on plant diversity in the name of creating wildlife habitat. Significant periods of rest from grazing and careful monitoring of grazing impacts and populations of sensitive plant species are important. If conservation is the primary goal, grazing should be used only when there are specific objectives to meet, not as a default strategy.
I’ve written much more on the topic of creating heterogeneous habitat with grazing in previous posts as well, and you can find a couple examples here and here.
Setting Useful Objectives – And Then Using Them
Regardless of the management tool(s) being employed, the biggest challenge for a prairie manager is to set clear objectives and then follow up on them. Start by defining the outcome you want (different habitat structure, more plant diversity, etc.) and then describe precisely what success looks like. Monitoring doesn’t have to mean spending hours on your knees with a plot frame, it just means measuring the outcome you desired.
For example, if you want more habitat diversity, you could start by listing the types of habitat structure you want (tall/dense, short sparse, patchy forbs with short grass, etc.) and how much of the prairie you’d like to be in each category. Then, you could make a rough map of how the site looks before the treatment and estimate percentages of each habitat type. After your grazing, fire, or mowing treatment, make another map and see if you reached your objective.
If plant diversity is important, decide how you will measure that. This is where a plot frame and repeated sampling across a prairie can be helpful, but there are simpler ways as well. You could pick out 3-5 small areas (less than 10 square meters) that you can find each year and then annually list the plant species you find in each area to see if that number changes over time. You don’t have to identify all the species, just list how many there are. If you are using grazing, it’s also important to figure out which plant species are favorites of the cattle and use that information to ensure that your management allows those plants enough rest from grazing that they can bloom and make seed every few years.
Most importantly, your objectives should drive the adjustments you make to management from day to day and season to season. If you can define what you want, you can see if your management is moving you in the right direction. It’s fine to change objectives as you learn, or as conditions change. In fact, in our Platte River Prairies, while we have some broad objectives (plant and habitat diversity), we set new specific objectives and management strategies each year to respond to what we’re seeing on the ground.
Cattle grazing is just another tool that can be used for the conservation of prairies. It’s not appropriate for all prairies or situations, but can help meet some objectives in ways that other tools (fire, mowing, herbicides) can’t. Conservation grazing differs from ranching in that income doesn’t have to be a major part of the decision-making process each year. On land where conservation is the primary objective, managers can decide when and how to employ grazing (or not) based purely on the conservation challenges they face.
Thanks again to the Iowa Department of Natural Resources for inviting me to their conservation grazing discussion last week. I was impressed by the thoughtfulness and creativity of the staff I met, and I look forward to hearing more about their prairie management and restoration work down the road.
I traveled to Iowa this week (more on that next week) and just happened to arrive during the emergence of one of the world’s most intriguing insects – the periodical cicada (Magicicada sp). Made up of seven different species, periodical cicadas are found only in eastern North America and are named for their long life cycles of either 13 or 17 years.
All cicadas (that I know of) spend most of their lives underground as larvae before emerging for a brief, noisy life aboveground. What makes periodical cicadas unique is not so much the length of time spent as larvae – though it’s longer than other cicada species – but rather the synchronization of their emergence. The common dog-day cicada, for example spends multiple years underground as a larva, but we see adults every year because their emergence is staggered across years. In contrast, periodical cicadas synchronize their emergence so the entire population in a particular area is on the same schedule. That timing of emergence, however, does vary by region across North America, so while seventeen-year cicadas are out in Iowa, Illinois, and Missouri this year, they emerged last year in an area covering states including Maryland, New York, and Virginia. People living in eastern Nebraska will get a chance to see them in 2015.
Emerging as adults in hordes probably helps ensure the survival of individual periodical cicadas (and their species) because predators can’t eat nearly enough to put a dent in the population. If periodical cicadas showed up in huge numbers every year or two, there would surely be predators with life cycles timed to take advantage of the abundant food source. However, the extreme length and synchronization of the cicada life cycle has apparently kept any predator species from being able to take advantage (evolutionarily) of the phenomenon. Fortunately for us, cicadas are harmless to people, and even the damage they do to trees by feeding and laying eggs in stems is almost always temporary.
There is much more fascinating information about periodical cicadas, but others have already covered it far more completely than I can. If you’re interested, I strongly encourage you to visit the magicicada.org to learn more.
Guest Post by Eliza Perry, one of our Hubbard Fellows. All photos are by Eliza.
Anne and I have been spending a lot of time with bison over the last four weeks, something neither of us ever thought we’d do. First, we went four hours northwest to TNC’s Niobrara Valley Preserve, our largest property in the state and home to two herds of bison. We were there to help with the roundup of the east bison herd. I didn’t grow up around livestock, so this event was really thrilling for me. Because they are herd animals, bison can get very aggressive just by being separated from the pack, leading to a lot of banging and even some blood. Corrals are designed to safely and efficiently move livestock to minimize their stress. The hope is that the less time they spend inside the corral, the less stressed and agitated they will become and the fewer injuries they will sustain. We didn’t know how to help at first, but soon got the hang of closing the heavy iron gates at just the right moment to allow a manageable number of animals to clamor through the corral system at one time. We must have done okay because we were invited back to a second round up.
Next we drove four hours northeast to visit TNC’s Broken Kettle Grasslands Preserve, Iowa’s largest contiguous prairie, to see how another preserve operates and lend a hand for a few days. Emily Hohman, the preserve’s land steward, showed us around and taught us to winterize fire equipment, which will be important at home after we finish our fall burns. Emily is in charge of stewardship for all of western Iowa, including the management of Broken Kettle’s bison herd. We discussed the challenges of managing large preserves with limited staff in a primarily production-oriented setting, circumstances that we at Platte River Prairies are very familiar with. We also got to whip around in the loess hills on six-wheelers while herding cattle.
On our way back from Iowa we stopped by the Niobrara Valley Preserve again for a board meeting, this time without seeing any bison. But the next week we were back to round up the west herd for a few more days. We got to use the newer corral system, which has several hydraulically controlled gates for an even safer and more efficient sorting process. Because we had already learned the ropes (no pun intended) at the last roundup, Anne and I were able to jump right in.
The evening before the board meeting at the Niobrara Valley Preserve, the staff and trustees met up in the nearby town of Ainsworth for some dinner and socializing, which meant I got to drive through the Nebraska sandhills at sunset. My camera can’t capture how epic this landscape looked at this time of day. It’s nothing like any other place I’ve ever seen.
Last week, I attended the Nebraska Natural Legacy Project’s annual conference, which was terrific. At the end of the conference, I had the chance to go on a boat tour of the Missouri River south of Nebraska City. The tour was led by Gerald Mestl (Nebraska Game and Parks Commission) who did a great job of explaining both the history and current status of the river. We also got to see examples of side channel and bank restoration efforts and hear about ongoing research and monitoring efforts on fish and other Missouri River species.
I’d love to give you a full recap of the information Gerald gave us on the tour, but I honestly don’t remember much of it. Unfortunately for Gerald, but to the great entertainment of those of us on the tour, our attention much of the boat trip was diverted by numerous flying carp. Yes, you read that correctly.
Asian carp, particularly silver carp, have invaded the stretch of the Missouri we were touring. Silver carp are an invasive fish species that quickly become the dominant fish species in a lake or river (by biomass), though it’s not always clear what or how much negative impact they have on the ecosystem they invade. Because silver carp are plankton feeders, they probably compete most with other species utilizing that same food source, including many larval fishes, paddlefish, and freshwater mussels. Gerald said that so far they’ve not seen any obvious impacts from the Asian carp invasion of the Missouri, with the possible exception that paddlefish weights seem to be less than they used to be. Of course, that doesn’t mean other impacts won’t arise as time goes by and more research is conducted. Unfortunately, once Asian carp become established, there doesn’t seem to be a way to remove them from an ecosystem.
While there are concerns about what the impact of silver carp (and other Asian carp, including bighead and grass carp) will be on the Missouri River ecosystem, those of us on the boat tour last week were mostly concerned about ducking them as they came flying past or into our boats. It turns out that silver carp have a propensity to jump (up to 10 feet!) out of the water in response to the vibrations caused by boat motors. This wasn’t much of an issue in the main channel of the river, but as soon as we entered any side channel or backwater area where the water wasn’t strongly flowing, silver carp started flying out of the water like big slimy popcorn (or something). Thus, my recollection of the tour and the information poor Gerald was trying to impart to us goes something like this:
“Historically, the banks of the Missouri River often consisted of steep banks that were being actively eroded by the flowing channel. Some estimates are that those banks could shift an average of 180 feet a year! That’s really important to understand because LOOK OUT!!”
“Ok, anyway… Another important thing about the historic river is that it was full of snags (dead trees). Navigation was really tricky because of all the big cottonwood skeletons along the bank and shallow islands. Today, we don’t see much of that kind of habitat, which was probably really importWATCH YOUR HEAD!!”
“Yeah, so there are a number of fish species that aren’t doing well in the Missouri or lots of other similar rivers that have been severely altered. Benthic (bottom-feeding) fish, in particular, are having a hard time, including species such asWHOA!! DID YOU SEE THAT??”
“We’ve been doing quite a bit of research on some of these rare fish and learning a lot. For example, it appears possible that pallid sturgeon (a federally-listed species) might actually be periodically moving from the Missouri into the lower Platte River for certain reasons. If that turns out to be true we might have to re-evaluaWOW! LOOK AT THE SIZE OF THAT ONE!!”
“Here at Hamburg Bend, there was a big restoration project that included the creation of a side channel that now forms a shortcut through a big bend of the river channel. That side channel provides important habitat for a number of species, includOH MAN! DID THAT ONE HIT YOU IN THE HEAD??”
“Ok, where were we… oh yeah, so the current main channel of the Missouri River has been constrained to a 600 foot width. That’s much less wide than the historic channel, and of course because it no longer is allowed to move around the floodplain, we don’t see the kind of bank erosion and associated habitat that used to be so important for thiWOOHOO!! DID YOU SEE HOW HIGH THAT ONE JUMPED??”
“On another subject, there has been some interesting recent research on turtles and their use of the Missouri River. Among other things, they’re seeing some surprisingly long-range movement of turtles – including one that traveled 50 miles upstream! That’s really interesting, and makes you think abouHEY! HEADS UP!!”
“You know, one of the main challenges of the Missouri River is the balance between recreational, flood control, and navigational needs (among others). Trying to figure out how to restore and manage flows and habitats is complicated by LOOK – TWO MORE!!”
“Oh never mind… let’s just watch carp for a while. At least that way we canI THINK THAT ONE JUMPED OVER THE WHOLE BOAT!!”
“So, that’s our tour for the day. Thanks for coming out, and I hope you enjoyed it. Sorry about all the fish slime on your shirt. I hope that bruise on the side of your face heals ok…”
Back in June of this year, I went up to The Nature Conservancy’s Broken Kettle Grasslands in northwest Iowa for a meeting on prescribed fire. As we were starting a field tour, a group of us was walking from the parking lot to the hills when we spotted this tiny little turtle (about the size of a 50 cent piece). I hung back and followed it around with my camera for a few minutes before catching up with the group again.
Painted turtles are common but fascinating creatures with lots of interesting natural history trivia – especially related to temperature. First, the gender of turtles is determined by the temperature of the eggs in their underground nest. Males are produced in cooler temperatures, and females are produced in warmer temperatures. A second temperature-related fact is that painted turtles hatch out of their eggs in the fall, but remain underground through the winter and emerge in the spring, surviving temperatures down to at least 5 degrees F. They eat the shells they hatched out of and, apparently, get some nutrition from the surrounding soil minerals. Finally, the basking that painted turtles do in the sun not only helps them with thermoregulation but also activates enzyme production for digestion of their food.
I just returned from a trip to The Nature Conservancy’s Broken Kettle Grasslands in Iowa. Scott Moats, who has managed the preserve for 15 years, is one of my favorite people to work with. His ability to interact with people – especially his neighbors around the preserve – and his enthusiasm about his site and his work make him fun to be around. This week he’d organized a meeting of conservation professionals from around Iowa to talk about the ecology and implementation of prescribed fire. I enjoyed the chance to be a part of the group and learn from Iowans about fire – and prairies in general.
The Conservancy reintroduced bison to Broken Kettle in the fall of 2008, and I was able to be there as they came off the truck. Since then, I’ve tried to make it back up to visit them when I can. After our meeting on Thursday, we had some free time in the evening, so three other Conservancy employees and I struck out across the prairie on ATVs to find the bison.
Luck was with us. As we neared the gate to the bison pasture, the whole herd (or at least most of it) was standing right inside the gate. We watched and followed at a distance as they grazed and worked their way slowly up and down a couple of hills. I was hoping to get some photos, but the light was a little harsh – and then as the light started to get better (as the sun got lower) the bison moved so they were between me and the sun.
At one point, a small group of animals started grazing their way toward where our ATVs were parked. When they got close, they stopped grazing and wandered over to see us up close (I’m guessing). The four of us just sat quietly for the examination, and when they’d seen enough, they wandered off in the other direction.
I’d been photographing the bison with a long telephoto lens, but as they came closer, I switched to my wide-angle lens. The photo shown here was taken with that lens. It turned out to be the only keeper photo of the evening (tough light conditions to work with!). Right after the small group checked us out, the sun went behind a dark cloud and never reemerged.
What is it about bison that stirs up people’s imagination?
Whatever it is, it was in full force in October 2008 when the brand new bison herd rolled off the truck at The Nature Conservancy’s Broken Kettle Grasslands in northwestern Iowa. I was fortunate to be on hand for the event, and it was a treat to see the bison, but also to see the excitement of the people gathered around to welcome them. As the bison milled around the corral, getting used to their new home, everyone watching was doing the same thing – imagining what they would look like when they were eventually released into the hills just to the east. In addition, I’m absolutely sure that everyone there was thinking about what it must have been like hundreds of years earlier when seeing bison in the same hills would have been exciting, but not particularly surprising. We’re very fortunate that we can not only conjure up images from the past, but that we can also envision a future for the American bison – a species that could easily have gone the way of the passenger pigeon.
The above photo was taken in May of 2009 – the spring after the bison were brought to Broken Kettle, and not long after the first calves were born. I spent an evening and morning following the bison around their new home, making sure to keep my distance to avoid making them nervous. (No one wants a nervous bison.) I hope to make it back up to visit them soon.
The herd at the Broken Kettle Grasslands has now grown from 28 to 51. The long-term goal is to grow the herd to about 250 animals. If you’re interested, you can click here to read more about the bison at the Conservancy’s Broken Kettle Grasslands and the plans for their future.