Prairie Blizzard Survival

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.

Knee-deep snow and even deeper drifts buried these sunflowers and many other tall prairie plants. The Nature Conservancy's Platte River Prairies, Nebraska.

Knee-deep snow and even deeper drifts buried these sunflowers and many other tall prairie plants. The Nature Conservancy’s Platte River Prairies, Nebraska.

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.

Songbird tracks around an indiangrass seed head at Lincoln Creek Prairie in Aurora, Nebraska.

Songbird tracks around an indiangrass seed head at Lincoln Creek Prairie in Aurora, Nebraska.

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.

Ring-necked pheasant tracks.

Ring-necked pheasant tracks in our Platte River Prairies.

Tracks from a covey of quail (Northern bobwhite) running around on the snow in our Platte River Prairies.

Tracks from a covey of quail (Northern bobwhite) running around on the snow in our Platte River Prairies.

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.

This Eurasian collared-dove

This Eurasian collared-dove died shortly after the blizzard.  Based on the tracks leading to its final resting place, it wasn’t a peaceful passing.

Collard-doves, of course, are not native prairie species, but it's hard to say whether that had anything to do with this one's death. I've seen quite a few others knocking around town over the last few days, so it looks like most of them survived.

Collared-doves, of course, are not native prairie species, but it’s hard to say whether that had anything to do with this one’s death. I’ve seen quite a few others knocking around town over the last few days, so it looks like most of them survived.

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…

Patches of Fire and Habitat

It’s been a difficult year for conducting prescribed fires so far – the wind seems to be blowing even harder and more consistently than in recent memory.  And that’s saying something, living in the Great Plains.

A couple of weeks ago, we were able to pull off one prairie management burn here in the Platte River Prairies.  The fire went well, and this week I took a quick walk through the burned area to see how the regrowth of vegetation was coming along.  It’s been a cold and dry spring, following a dry fall and winter, so plant growth has been slow, but things are finally starting to kick in.  Within the burned area, many plant species are a little behind their compatriots growing outside the burned area, but others are ahead.  Those that are behind are the species that were already starting to grow when the fire came through – those species had to start again, so are behind schedule.  The species that are further ahead in the burned area are those that are taking advantage of the warmer soil and have either germinated or emerged faster than those in the cooler soil of unburned areas.

Regrowth in sand prairie burned a couple weeks ago.  The wildflower in the foreground is shell-leaf penstemon (Penstemon grandflorus).

Regrowth in sand prairie burned a couple weeks ago. The wildflower in the foreground is shell-leaf penstemon (Penstemon grandflorus).

Regardless, plants are growing well in the burned area.  That’s good, because cattle will arrive within the next week or so, and we want the burned area to be particularly attractive to those grazers.  One of the major objectives of our fire was to concentrate grazing in one portion (the burned patch) of the prairie this season, leaving the remainder of the pasture with much less intensive grazing.  Hopefully, the result will support our efforts to create a variety of habitat patches across our prairies, and to shift the location of those patches from place to place each year.

The patch we burned this spring has had no fire and very little grazing over the last couple of years.  Last year, it had tall vegetation and abundant thatch – conditions that favor a certain set of plants and animals, but not others.  This year, it will have very little thatch and the vegetation will be short in stature because of season-long intensive grazing.  Next year, it will begin a multiple season recovery period from that fire and grazing until it is burned again sometime down the road.  (You can read more about patch-burn grazing here.)

Burning a different patch of prairie each year helps ensure that a mixture of habitat types is always available and most or all wildlife and invertebrate species can find the habitat they need.  Our prairies usually have a patch of very short habitat, several patches in some stage of recovery from intensive grazing, and some areas that are tall and very lightly grazed – or ungrazed.  Some animals will follow those habitat patches across the landscape.  Others will go through boom and bust periods within one portion of a prairie, depending upon what conditions they thrive best under.

Because we’re always changing the location of habitat patches, plant species also experience changing conditions from year to year.  This means that some species flourish one year, but may have to wait a few years before those favored conditions return.  In the meantime, other plant species will find success.  Constantly changing conditions help ensure that no group of species becomes too dominant, but that all species can survive and maintain a place in the plant community.  Our long-term data has shown the our plant communities have stable to increasing plant diversity under this kind of management, and we’re not seeing any plant species disappear.

This burned patch makes up between a third and a fourth of a 110 acre management unit in our Platte River Prairies.  Burning only a portion of each unit each year helps ensure good wildlife habitat and changing growth conditions for plants, but also helps avoid catastrophic impacts on species vulnerable to fire.

This burned patch makes up between a third and a fourth of a 110 acre management unit in our Platte River Prairies. Burning only a portion of each unit each year helps ensure good wildlife habitat and changing growth conditions for plants, but also helps avoid catastrophic impacts on species vulnerable to fire.

Another benefit of burning only a portion of our prairies each year is that it helps us avoid catastrophic impacts on plant and animal species that are negatively impacted by fire.  Invertebrates that overwinter above ground, for example, can be destroyed by an early season fire.  Growing season fires can kill animals (invertebrates and vertebrates) that are unable to escape by leaving the area or retreating underground.  These kinds of impacts are somewhat unavoidable, regardless of the season of fire, but by burning only a portion of our prairies, we can try to restrict impacts to a relatively small proportion of the population of each species, allowing the majority of individuals to survive and recolonize the burned patch over time.  Burning an entire prairie, especially in highly fragmented landscapes in which recolonization is unlikely, can result in completely and permanently obliterating vulnerable species from a site.

Hopefully, the wind will pause a few times during the remainder of the spring, and we’ll create a few more burned patches in our prairies.  If not, we’ll try to create patches of short habitat by haying or by temporarily fencing cattle into an area to knock vegetation height down.  We’ve found that all three methods (burning, haying, temporary enclosures) can create a patch that attracts livestock grazing afterward – and therefore pulls that grazing off of other portions of prairie.  There are lots of ways to create patchy habitats, and none are necessarily best.  As long as there is always a mixture of habitat types across our sites, we feel pretty good about our management.

Hopefully, the species living in our prairies feel pretty good about that management too.