It’s a good ol’ fashioned blizzard here today. As I’m sitting snugly in my warm house, I’m feeling a little badly for some of wildlife out there in the snow and wind. The boys went outside to play in the snow for a little while, and both of them spent most of their time building shelters from the weather. Many wildlife species, of course, migrate to warmer places or find/build themselves underground burrows to overwinter in, but there are some animals out there in the prairie right now, and this has to be a bad day for them.
Sitting here on my comfortable couch, I’ve been thinking about the prairies I manage or help with, trying to remember what kind of cover is out there. Overall, I feel pretty good about the situation. Our shifting habitat mosaic approach involves providing a wide range of vegetation structure types in each of our prairies, including everything from short sparse vegetation to the kind of thick dense cover wildlife are probably seeking out today. Nelson (our Platte River Prairies land manager) and I have periodic conversations in which we try to envision ourselves as creatures that prefer various habitat types. How far would we have to travel to find cover? If we burn one patch of dense cover, where is the next closest patch of similar cover, and what would animals have to travel through to get to it? We have a lot of factors to consider and balance as we discuss management plans each year, so it’s always helpful to see the world through the eyes of the various species that will have to live with (literally) the decisions we make.
To be completely honest, I probably don’t think enough about winter cover as I’m trying to consider the perspective of various creatures. I’m more often thinking about nesting habitat for birds, breeding cover for small mammals, or sunning areas for invertebrates and reptiles that need to thermoregulate during the growing season. Days like today are a great reminder that while all those considerations are important, at least some species will probably live or die based on what kind of shelter they can find during winter storms like the one roaring outside right now.
I’m thinking today about meadowlarks, for example. As I’ve walked our prairies during the last month or two, I’ve seen a lot of meadowlarks flying around in small groups. My understanding is that meadowlarks that breed around here head south to Kansas or Oklahoma, and the ones we see during the winter come from up in the Dakotas. In other words, meadowlarks don’t migrate en masse to one general destination. Instead, each bird just goes a little southward from where they spent the summer. I wonder if they each wait until they start seeing birds from the north show up and then head south to get away from the crowd…
Regardless, birds like western meadowlarks need some kind of shelter out in the prairie on days like this. We know a lot less about the winter habitats used by grassland birds than we do about summer habitat use, and as far as I know, no intrepid biologist has yet gone out to see where meadowlarks or other birds are hanging out during blizzards. (If you’re an intrepid biologist who HAS done this, please let me know!) I think it’s fair to assume that most birds (and any other wildlife who aren’t underground) try to get out of the wind during this kind of storm. It’d be interesting to know whether they stay in open grassland and look for tall dense vegetation or venture into brushy or wooded areas where they might not normally go.
Not knowing much about individual wildlife species and how they each choose to shelter from winter storms, I guess the best strategy is to provide as many habitat types as possible so they can all find what they need. That way, meadowlarks can forage in short or “weedy” areas during pleasant sunny days, but move to a nearby patch of dense grass (or whatever other cover they like) when they need to nestle in thatchy vegetation and get out of the wind.
Here in our comfy house, we’ve been talking about trying to fix the drafty corner of our kitchen, where one of our walls needs a little better insulation. Our poor little feet get cold when we’re making toast on windy winter mornings! It’d be really nice to get that fixed. On the other hand, it’s just the kind of hardship that helps me understand what meadowlarks are going through on days like this. I bet their feet were cold at breakfast time too…
This post was written (and illustrated) by Evan Barrientos, one of our Hubbard Fellows back in 2015-2016. Evan now works for The Nature Conservancy in Oregon as a monitoring and outreach assistant.
When I worked for The Nature Conservancy near Wood River, NE, I lived close to a restored wetland. In late winter I would gaze longingly out my window at the clouds of migrating waterfowl whirling above the calm water. I wanted to photograph this spectacle but approaching the skittish birds through the open prairie seemed an impossible task. Then I met Michael Forsberg, famed Nebraskan wildlife photographer. I learned how he builds blinds out of garden fence and grass and sleeps in them, sometimes for days, in order to capture the most intimate moments of nature and share them with the rest of us. I wanted to learn this art too, so I decided to try building my own blind on the restored wetland. The result was a successful comic adventure that for some reason I never shared on the Prairie Ecologist, until now.
You could say I messed up from the start. The store was out of garden fence so I bought chicken wire instead, thinking it couldn’t be to different. It could. I spent most of the next afternoon pounding stakes; cutting wire, camo cloth, and grass; and zip tying it all together in the rough shape of a burrito with a hole at one end and a window at the other. The blind was placed right on the water’s edge and would have a spectacular view of ducks waking up in the golden light of sunrise. Or so I thought.
After leaving the blind out for two weeks to let the birds acclimate to it, I set out one March night with my camera gear and sleeping bag, crawled into the blind, and fell asleep to the quite murmurs of roosting mallards. I was so eager for sunrise that I had no less than five dreams of waking up in the blind. In one dream I woke up underwater. In another I woke up to find the wetland dry. When I finally did wake up, I discovered a snafu that I hadn’t even dreamt of: the blind had collapsed on me. The chicken wire couldn’t support the added weight of the morning dew, and in order for me to see out the blind’s window I had to prop the damn thing up with my head. In addition to being extremely uncomfortable, I worried that the floppy and occasionally cursing blob would scare away the birds. Fortunately, it did not. Maybe the birds thought it was too pathetic to be man-made, or maybe it looked like a decomposing tree trunk, but they didn’t seem to notice me at all. I knew I was okay when a Red-winged Blackbird strolled across the top of my head.
Pathetic as it was, I’m grateful to the blind for giving me intimate glimpses into the lives of birds that I never would have had otherwise. It’s not often you get to see wild animals behave truly naturally, not at all concerned about a human watching them. Watching a goose bathe in the golden light of sunrise, hearing Blue-winged Teal drakes whisper soft calls to an attractive female, watching beads of water drip from a Gadwall’s impermeable feathers; these were new and beautiful experiences for me. Thanks to the blind, I saw familiar birds in an entirely new way.
Pathetic as it was, I’m grateful to that blind for giving me glimpses into the lives of birds that I never would have had otherwise. It taught me a new way to appreciate wildlife, one that requires you to become a part of the landscape. Hunters and photographers know the value of extreme patience, but in today’s fast-paced society, rarely does the average person sit in a spot for hours and watch nature’s secrets reveal themselves. A blind, I learned, teaches you that patience and provides a window to a new view of nature. I hope to build many more blinds in the future, but never, ever again out of chicken wire.
The Nebraska Sandhills region consists of about 12 million acres of sand dunes with a thin layer of vegetation draped across them. That vegetation has come and gone over the last several thousand years, as long-term climatic patterns have shifted from wet to dry and back. We are in a relatively wet period (geologically speaking) today, and grassland is clinging to the hills. For now.
Except where it can’t. Here and there, throughout the sandhills, particularly on steep hills, sand breaks through. Most of the time, blowouts are triggered by a combination of topography and some kind of physical disturbance. A two track road or cattle trail up a steep slope, for example, or a favorite hangout of livestock. Just as with frayed fabric, once a small hole in the vegetation starts, it tends to spread. Most Sandhills ranchers see blowouts as a great risk to their livelihood and work hard to prevent them, or to heal them once they start. Those ranchers are encouraged in that view by watchful neighbors and a long history of agencies and university extension staff warning of the dire impacts of wind-induced soil erosion.
The Sandhills is ranch country, and all but a tiny fraction is privately-owned and managed for livestock production. Most ranchers are conservative with livestock numbers and grazing strategies, trying to preserve that thin fabric of grass that feeds their livestock, and thus their families.
While there are certainly places that are prone to wind erosion and practices that can accelerate it, the risk of blowout creation and spread has also become a kind of mythology. In much of the Sandhills, blowouts are actually difficult to create (we’ve tried) and the percentage of a ranch that could potentially be covered by blowouts is very small.
While conservative grazing has helped maintain healthy prairies in the Sandhills, it has also led to a loss of open sand habitat for a group of plant and animal species that depend upon blowouts and similar areas. Those species are important, but asking a rancher to allow, let alone encourage a blowout, is much like asking a business man to go to work wearing Bermuda shorts with his sport coat. The peer pressure and social norms associated with blowouts can be more influential than any potential loss of livestock forage they might cause. Just as farmers judge their neighbors by the weeds in their fields, Sandhills ranchers judge their neighbors by the blowouts in their pastures.
Regardless of the social or economic ramifications of blowouts for ranchers, bare sand patches really are important habitats for many prairie species. The discussions I’ve had with ranchers about the ecological values of blowouts have always been polite, but I can’t say they’ve been met with great enthusiasm. I understand that, but that doesn’t change the need to continue having those discussions.
It may be that changing climate will render moot our discussions about whether or not to allow or encourage blowouts in the Sandhills. Eventually, we will experience enough consecutive years of hot dry weather that even the most conservative grazing won’t prevent widespread blowing sand once again. We can’t predict whether those conditions will arrive in the next few years, or not for many decades. When they do arrive, both the ecological and human communities of the Sandhills will be glad to have species that are well adapted to open sand. Plants like blowout penstemon and blowout grass, for example, can help restabilize areas of bare sand, and they also provide food for both livestock and wildlife.
For now, the Sandhills provides a vibrant grassland that supports both humans and wildlife. That will likely change at some point in the future. Hopefully, blowout-dependent species will find enough habitat to maintain their populations until we really need them.
…and hopefully no one will feel like they have to wear Bermuda shorts in order to make that happen.
Last week’s blizzard dumped about a foot of snow here in town, and about 18 inches out at our Platte River Prairies. Combined with wind gusts of 40-50 miles per hour, it was quite a weather event. Our school was closed for three days while everyone dug themselves out and road crews cleared off streets and country roads.
Blizzards are a part of life out on the prairie. School closings and sore shoveling muscles are pretty minor inconveniences compared to what grassland creatures without central heat and insulated windows have to deal with. On the other hand, prairie species have been doing this for thousands of years, so they’ve got it pretty well figured out. Prairie plants are mostly dormant this time of year, so snow and wind don’t really affect them at all. Many prairie animals are pretty dormant as well – lots of them spend the winter either below ground (or water) or nestled into deep thatch. Quite a few mammals, amphibians, insects, and others can slow their metabolisms enough that they can survive the winter without having to search for food or shelter once they’re settled in.
Other animals, however, stay much more active during the winter months, and a blizzard can cause them more problems than it does their more dormant peers. It’s really hard to gauge how this blizzard might have affected those animals, but during a couple short outings, I’ve tried to see what I can. It’s not hard to find tracks of deer, coyotes, and various kinds of birds, but that doesn’t say much about what percentage of those animals did or didn’t make it through the storm. My guess is that most of them did just fine, and the warmer temperatures this week are melting the snow pretty quickly, reducing stress on animals that have a hard time moving through or finding food in deep snow.
I walked through some of our Platte River Prairies on Saturday morning, and can empathize with the deer and coyotes whose tracks I saw around me. I probably only walked a half mile, but even that distance was exhausting. Warm temperatures on Friday had begun to melt the snow and then that soft top froze overnight. Every step I took on Saturday morning sounded like, “Crinch, Foomp!” as my boot would very briefly rest on the frozen crust and then pop through as I put more weight on it. Repeating that process in knee-deep snow for a half a mile was more than enough for me. It looked like most of the deer I saw were having the same issues.
Based on their track patterns, I bet it would have been funny to watch the coyotes walk through the snow. I would see a few sets of tracks up on top of the snow, followed by deeper tracks where they’d fallen through the thin crust. I imagined a poor coyote walking as gingerly as possible on the crust, only to fall to its chest on the next step and have to flounder back up again. And for what? There weren’t many tracks of prey species, apart from birds, which probably just laughed at the coyotes as they flew away from them.
Speaking of birds, I saw some songbird-sized tracks where tree sparrows (I assume) and others were feeding on seeds from prairie plants. I also saw numerous tracks of pheasants and northern bobwhites (quail). The quail seemed to have no trouble staying up on the snow’s crust, but the pheasants’ feet were punching through more often, so they probably had much less fun running around. Regardless, both species must have found abundant shelter on our properties – probably hunkering down within or behind thick clumps of vegetation to escape the driving snow and wind. Canada geese were noisily flying over the river Saturday morning, so they apparently weathered the storm. There were a few sandhill cranes in the river valley (early migrants) before the blizzard, but I don’t know if they stuck around or headed back south to escape the weather.
It’s rare to find evidence of the animals that didn’t make it through storms like this. Animals that die in a blizzard either get buried by snow or eaten by others – or both. I did find one collared-dove here in town that died soon after the storm, but that was the only obvious death. Because life on the prairie has always been difficult, prairie species have developed strategies to survive just about any event, including droughts, floods, fires, and blizzards (including blizzards much worse than ours last week). We humans living in prairie country might think we’re pretty tough, but we have it pretty cushy compared to those creatures who actually live in the prairie itself.
Speaking of which, it looks kind of cold and windy out today. I think maybe I’ll just stay indoors and cook myself a warm meal for lunch…
Karen Hamburger, a longtime volunteer with us, recently passed along another batch of trail camera video clips from our Derr Wetland Restoration. You might remember seeing some of her video in an earlier post.
This time, much of her footage was centered around beaver dams. There were quite a few video clips of beavers repairing dams or swimming past, along with otters, muskrats, ducks, and other wetland creatures. However, Karen also captured some more terrestrial species using the beaver dams.
I often use beaver dams as a convenient bridge to cross a stream, and I know I’m not alone in that. It makes sense that those same dams are important crossing locations for many wildlife species as well. Karen’s trail cameras documented some of those crossings, including species such as bobcat, raccoon, coyote, and white-tailed deer. See below.
In addition to wildlife, Karen’s camera also caught another creature crossing a beaver dam at our wetland. Not once, but twice, she documented photographer Michael Forsberg working his way across the stream with camera in hand.
Mike has been photographing the wetland for many years, and has his own set of camera traps (trail cameras) at the site. He has also been helping us capture timelapse imagery from the site through both the Platte Basin Timelapse Project and Moonshell Media. This time, Mike got caught on the other end of the camera.
Beavers play important engineering roles in landscapes. Their dam construction activities change water flow patterns, flood low-lying areas, and create important habitat for many plant and animal species. Karen’s videos are a good reminder that beaver activity not only affects wetland species, it also affects movement patterns of terrestrial species by providing stream crossings. As beaver dam locations change, wildlife have to adjust their travel accordingly, and it’s fun to think about how those movement changes could ripple through ecosystems. The location of a stream crossing for both predators and herbivores affects where those animals choose to forage, for example. The fate of a plant or small mammal could well be decided by where a deer or coyote can cross a stream – which may be determined by where a beaver family decides to place a dam. Fascinating!
This post is written by Dillon Blankenship, one of our two Hubbard Fellows.
Back in December we kept pretty busy with fence work. The barbed wire fences at a few sites needed to be repaired, and some had to be taken down and rebuilt from the beginning. Single wire electric fences were taken out altogether and will be replaced this spring to accommodate new grazing configurations.
The barbed wire fences we removed were old and in bad shape. Their wire was loose and rusty; t-posts were bent over or leaning.
I am struck by how dramatically the landscape is changed by the mere removal of a fence. Despite the remaining row of interspersing trees or scraggly smooth brome, fencelessness returns a semblance of the infinite horizon. Of course, I want to see the trees and brome erased too, but these things take time and getting the old fence out of the way begins the process.
Even when the next piece of land is a dusty field of corn stalks – much less imposing post-harvest- the lack of fence is liberating. I am free to view the landscape as it once was and I imagine that wildlife can more freely roam about the planet.
Though it is easy to romanticize the open range, fences obviously have some utility.
Barbed wire fencing is a relatively inexpensive way of delineating property boundaries. It confines one’s own livestock and/or protects crops and pasture from being damaged (by stray vehicles, your neighbor’s cattle, etc.). In our restoration work on the Platte we use fences not just to keep cattle in, but also (using single strand electric) to manipulate where and when they graze to suit our particular management objectives – such as controlling certain plant species or promoting others while maintaining a diversity of habitat types.
Though these are compelling reasons to keep fences around, I remain frustrated by the inconveniences they create. I have already mentioned the aesthetic inconvenience. To my eye – even with agriculture playing a prominent role in the landscape mosaic – the Plains look more expansive and beautiful without fence lines. The image of an unfenced pasture is striking for its rarity.
Fences can also be problematic for certain wildlife. While deer are pretty good at jumping over most fences, animals further west like bighorn sheep and pronghorn need special accommodations for safe passage. Free-roaming bison, of course, have little hope in our highly fenced world – we must confine them to their own big area saying “this is yours, but go no further.” Even birds are affected, sometimes colliding with and becoming entangled in barbed wire. Field fences, though not insurmountable, present their own challenges for ground dwelling creatures.
My biggest complaint is that fence lines are often poorly managed. They can be difficult to work around when treating invasive species, which makes them prime habitat for encroaching trees and exotic plants. Substantial tree lines are common along fences in central Nebraska. In many cases, I suspect the fence came first. While a fence itself is usually not too problematic from a grassland habitat perspective, fences that grow up with trees begin to act as fragmenting agents – deterring grassland bird nesting and generally diminishing the openness favored by grassland species.
So where does that leave us?
There are already a lot of good ways to mitigate fence impacts for wildlife – increasing visibility for birds and using smooth wire with particular spacing for large mammals. Sometimes wooden fences are better alternatives, though more resource intensive (got any spare cedars?). While these address the wildlife objection, they don’t do much for the aesthetic or management elements.
Single-strand, smooth wire, electric fences are simple and temporary, offering reprieve from the oppressive four-strand barriers and better accessibility for management – you can drop the wire and drive right across. Moreover, when you move these fences every year like we do, fence-line management is less of a problem because the following year any given line-site will be back in the management regime of fire, grazing, and manual treatment. This system suits my preferences well, but its greatest assets are also its ultimate downfall.
Even when electrified, single wire fences are often not enough to keep cows in – and, I imagine, never keep in sheep or goats. Also, deer are pretty good at going right through, knocking the wire off the insulators – which is hard to monitor when you have a lot of wire out there. I was going to say that their temporary-ness was another drawback – a guarantee that you have to work fence every year. However, tree and exotic species management need to happen every year anyway, so maybe it wouldn’t be that much work and I feel like removing 20 years of trees from an unmaintained fence probably takes much more time than monitoring and moving temporary fences.
My dream of fencelessness is really thwarted at scale. At places like TNC’s Niobrara Valley Preserve with over 50,000 acres to manage, you really just need a sturdy fence that doesn’t have to be constantly checked… or so I thought. I recently learned about innovations in fencing that have been experimented with over the last decade. I had been thinking that something like the invisible fences people use for pets might be an interesting option to scale up, but there are better systems already in play.
Instead of building (or burying) an actual fence, there are folks putting GPS collars on cows and then using digital mapping software to “draw” fences on the landscape which deliver a slight shock (like an electrified fence) when cows cross the satellite-imposed boundary. These digital fences can be placed at property boundaries, around sensitive vegetation or aquatic features, and across a pasture to suit a particular grazing regime – all with the swipe of a computer cursor. It could be modified on the fly, which is even easier now that so many people are carrying smartphones (this technology is already being utilized for things like increasing center pivot irrigation efficiency via monitoring and adaptive management). Doesn’t that sound incredible? No fences breaking up the landscape (which is aesthetic, but also means less work for ranchers), safer corridors for wildlife, less potential for tree encroachment, and better accessibility for managing invasive weeds. Cool.
The system is bound to have its own problems – technical glitches will happen on occasion (with the software or and the collars), there will be new opportunities for trouble-makers to tamper with private property (“digital cattle rustlers”), star-up costs, you name it – but I really like the potential something like this has for prairies and the ranching community.
Nonetheless, most of us aren’t quite there yet, which brings me back to the old-fashioned fence. For now I guess I’ll have to get over it and get on to other things; just manage my own fence better and become hardened to the unavoidable taunting of unnatural tree lines and fence rows on the landscape.
It feels good to vent a little bit here. As it warms up I cease writing and return to work on the post and wire repairs. I return to the prairie and reflect on these musing, “Alas, this is a necessary, if unfortunate evil” and the new fence goes up. I find solace that its days could be numbered.
Last week, Jasmine (one of our two Hubbard Fellows) and I spent a morning at the Derr Wetland Restoration here in the Platte River Prairies. We wanted to get some photos and video of the site before the latest snow melted.
…Ok, to be honest, we were mostly hoping to test out the capabilities of our new drone (UAV). Two of our Nebraska board members, Jim and Nancy Armitage, donated the funds to purchase the drone as a way to help us better capture our sites and the work we’re doing here in the state. We’re just starting to figure out the potential for drone photography, but I sure like what I see so far!
Here is a short 3 minute video of footage shot from the drone, followed by some still photos from the same morning. Both the aerial video and still photos provide powerful images, but the video certainly captures the context of the site in a way that’s not possible for me as I walk along the ground with my camera. I think the drone is going to be an awesome complement to the other ways we photograph and monitor our sites – it’s going to be exciting to keep exploring the possibilities. Stay tuned for future videos!
As we near the end of another year, I’ve put together a collection of my favorite images from 2014. I hope you enjoy them. Though I traveled to prairies in several other states this year, all of my favorite images ended up being from Nebraska. (No offense to the beautiful grasslands in those other states – it’s just the way it worked out this year.)
The slideshow will run on its own, but you can speed it up by clicking on the arrows to move through the images.
Thanks, as always, for your interest in prairies and this blog. Knowing there are others who enjoy the beauty and complexity of prairie landscapes is very satisfying. Have a great holiday season!
If you want to see similar collections of images from previous years, here are links to 2013 and 2012.
Some people say it’s dangerous to make assumptions. I disagree. In fact, assumptions are both necessary and empowering. Land managers make assumptions all the time. If we didn’t, we’d never get anything done.
Assumptions are only dangerous when they are either unrecognized or untested. For example, it’s reasonable for me to assume that my car’s engine has an adequate amount of oil in it, but it would be irresponsible not to check the level now and then to be sure. Without the assumption that I still had oil, I’d probably stop to check my oil every mile or so and I’d never get anywhere. In order to move forward, I have to make reasonable assumptions, including that my engine hasn’t lost all of its oil since the last time I checked it.
As land managers, we have to take a similar approach. Much of the time, we assume that species and ecological systems are reacting predictably and positively to our management, but we also do spot checks to reassure ourselves. Often those evaluations involve nothing more than a walk through a prairie to see how things are looking, but in some cases might conduct more intensive data collection.
Land managers also make broader assumptions about how restoration or management projects will contribute to conservation objectives. As we plan projects, we make educated guesses that help us design our work effectively. Then we implement the project and see what happens. If we didn’t make assumptions, we’d be paralyzed by indecision and never get anything done.
It is critically important, however to recognize what assumptions we’re making, and to test them when we have the chance. Here are several examples of assumptions we make in our Platte River Prairies management, and some of the ways we’re testing them.
Assumption #1. Prairie plants can survive periodic intensive grazing.
Grazing is an important part of our management. Most commonly, we employ variations of patch-burn grazing, in which a portion of a prairie is grazed pretty intensively for most of one growing season and then allowed to recover for a couple years before it’s intensively grazed again. We use grazing to manipulate plant competition, especially by suppressing the vigor of dominant grasses to produce more plant diversity. It also is our primary tool for creating heterogeneous habitat structure, including important habitat conditions (such as short grass/tall forbs) that are difficult or impossible to create without grazing.
Our data show that overall plant diversity is thriving under our management, and it’s easy to see the variety of habitat conditions we create each year. However, we’re making the assumption that we’re not losing any plant species due to periodic intensive grazing. It’s an informed assumption, based on experience and our understanding of history, including the kind of fire/grazing interactions that happened in these prairies over the last several thousand years. Regardless, it’s an assumption, and one we need to test.
We collect annual data from some prairies and less frequent data from others that allow us to track individual plant species over time. So far, we’ve not seen any indication of plant species that are disappearing under our management. Even if we weren’t rigorously collecting data, we could still test our assumption by simply tracking the population size of species most likely to be impacted by grazing. We could use techniques such as photopoints or walking transects, or we could just mark and watch individuals or patches of plants over time.
Assumption #2. Some exotic/invasive species are not harmful enough to warrant eradication efforts.
We have more than enough invasive species to deal with on our sites, so we have to be selective about which to spend most of our time on. We set priorities based on experience, and focus most on those species we think have the greatest potential to harm plant diversity or habitat quality. However, we recognize that our assumptions about impacts could be wrong, so we test them – both through general observation and data collection. I’ve written before about data we’ve collected on both Kentucky bluegrass and sweetclover impacts, for example.
Assumption #3. Restoring cropland adjacent to a small prairie will increase its conservation value.
The prairie restoration work we do is not focused on re-creating historic landscapes, but on trying to decrease the impacts of habitat fragmentation. We assume that adding diverse prairie plantings around and between isolated prairie fragments will increase population size and connectivity for plants, insects, mammals, birds, reptiles, and more. Bigger and more interconnected populations should be more viable than smaller and isolated populations.
Our assumption seems reasonable, but it’s expensive to harvest and plant more than 200 plant species in a crop field, so we need to see if we’re actually achieving our objective. More importantly, we need to be able to show policy makers that this kind of strategy produces substantial ecological impacts. Unfortunately, this kind of assumption is logistically difficult to test.
We have a long way to go, but we’re starting to look at whether various species living in our unplowed prairies are also found in adjacent restored prairies. If those species aren’t using the new habitat, our strategy isn’t helping them. If they are, that’s good to know – though there are still more assumptions to test (e.g., do those new habitats facilitate successful breeding and/or migration and colonization?). So far, some preliminary investigations indicate that most ant and bee species appear to use restored habitats, and we’re now looking at small mammals and grasshoppers as well.
Assumption #4. We can maintain healthy populations of all prairie species through our “shifting mosaic” approach to wildlife habitat management.
This is a big one, and is very difficult to test. We assume that by creating a variety of habitat conditions each year – including tall/dense, short/sparse, and mixed-height vegetation – all of the species in our prairies (insects, mammals, birds, plants, etc.) can find what they need each year. On top of that, we’re assuming that as we shift the location of habitat conditions between years, species can either move to appropriate habitat or hunker down until better conditions cycle back through.
As with our assumption about plants and grazing, historical context applies. Prairie species evolved in grasslands that were subjected to fire, grazing, and drought, and preferred habitat conditions for any particular species would have shifted around the landscape from year to year. However, much is different today, including the size and fragmentation of grasslands, the presence of invasive species, and much more. Are today’s species able to survive significant variations in habitat conditions from year to year? Can a species that needs thatchy cover successfully find more of that habitat after a fire burns through its current location? If so, how far can it travel, and through what kinds of habitats?
We haven’t gotten as far in testing this assumption as we have with some others, but we think a lot about it. We’ve been gleaning information on animal movement from the scientific literature, and will meet with university scientists next month to discuss potential collaborative research on this topic. Most importantly, we recognize that we are making some big assumptions about our management strategies, and we keep those assumptions in mind as we make our annual plans. For example, we try to think about factors such as travel distance between similar habitat types (tall/dense or short/sparse habitats, for example) and we try to leave unburned refuges within large burn units. Hopefully, we’ll get more guidance soon, but in the meantime, we’re moving forward the best we can.
Just as I watch for signs that my car’s engine might be getting low on oil as I drive, I also watch for signs that our land management strategies are working as we want them to. (More on that in an upcoming post.) Recognizing the assumptions we’re making is a critical piece of successful management, but testing those assumptions is just as important. Assumption testing doesn’t have to involve intensive data collection; it can be as simple as making some annual notes about whether or not a particular patch of wildflowers is still there, or keeping track of how invasive species respond to various management treatments. If we know what we’re uncertain of, we’ll be more thoughtful about management decisions and more observant of their impacts.
What assumptions are you making? Are you working to test them?
…oh, and don’t forget to check your oil now and then.
As we continue to transition into winter, many wildlife species are watching food supplies dwindle around them. Flowers have been done blooming for a long time, and now even their seeds are starting to disappear. A few hardy insects are still around, but most have either died off or have found a comfortable place to spend the winter.
Sunflower seeds are a very attractive late fall/winter food source for many wildlife species, including many birds. During our fall seed harvest each year, we definitely notice the impact of bird foraging – especially if we wait a little too long to gather seeds. Large flocks of migrant birds can quickly deplete a stand of sunflowers of their seeds. That can be frustrating for tardy prairie ecologists, but has bigger implications for resident prairie animals that depend upon those seeds for winter survival.
Fortunately for resident wildlife, migrant birds don’t get all the sunflower seeds, so at least some are left for winter foragers. When snow covers the ground, sunflowers and other plants that still hold seeds become particularly important for wildlife. Some animals have already built up caches of stored seeds to eat when snow covers the ground, but other species – especially birds – have to make do with what’s sticking out above the snow. It’s easy to see which plants have the best food supply by looking at the tracks in the snow around them!