Exploring and Speculating in the Snow

Snow is a great boon to anyone trying to figure out what’s happening in the prairie during the winter. I’m just a casual observer, not a researcher of winter activity, but it’s definitely a topic of interest. A fresh snow fall provides a chance to look at tracks and try to interpret what’s happening.

Last week, I saw a couple interesting things in nearby snow-covered prairies. The first is something I’ve seen often before, which is evidence of the importance of western ragweed as a winter food. Ragweed plants sticking up above the snow are very commonly surrounded by bird tracks, and I saw lots of that at our family prairie last week.

Western ragweed (Ambrosia psilostachya) sticking out above the snow last week, showing the large nutritious seeds just sitting there ready to eat!
Bird tracks around western ragweed plants.

I know people tend to scoff at, or actively dislike ragweed, but it’s hard to dispute its value to wildlife. I understand those of you with severe allergies to ragweed pollen not being fans. Beyond that, though, it tends to get an undeserved bad rap from farmers/ranchers who mistakenly think it is aggressive and outcompetes grasses. The reverse is true – its populations expand when the grasses are weakened and shrink when grasses are strong.

Others dismiss it because it is a ‘weed’ and/or doesn’t have showy flowers to attract pollinators. Sure, it’s very common, and perpetual high abundance can be a sign of poor prairie management, but it’s also a native plant that plays an important role in grasslands. In addition to its ability to fill and temporarily hold space when the surrounding plant community is stressed, it’s impossible to dismiss the attractiveness of its seeds to wildlife. If you have any doubt, look for ragweed plants the next time you’re in a snowy prairie. Most likely, you’ll be able to follow tracks right to them!

Here, you can see both bird tracks and a few dropped seeds below the plants, where birds were pulling other seeds off to eat.

The second interesting thing I saw last week connects to another observation earlier this year. Back in April, I was walking through a recently burned area at Prairie Plains Resource Institute’s Gjerloff Prairie and found a pile of seeds I’m pretty sure were from marbleseed, aka false gromwell (Onosmodium molle). They might also have been from fringed puccoon (Lithospermum incisum) – the seeds of those two species are awfully similar.

Seeds at Gjerloff Prairie after a spring prescribed fire. I think these are from marbleseed, based on their size, though they might have been puccoon seeds too.

The way the seeds were gathered together made me think it was a seed cache, created by some kind of mouse the previous year. The fact that it was still there after the winter made me wonder if the mouse didn’t survive (or just didn’t find its cache). Either way, it was neat to see and fun to speculate about.

Last week, at our family’s prairie, after perusing the bird tracks around ragweed plants, I came across a mouse trail that led to a small area where it looked like the mouse had dug down to the ground. The tracks led pretty directly to the excavation site, making me think the mouse probably knew where it was going (as opposed to just wandering/foraging randomly).

Mouse tracks and an excavation.

Looking closely in the hole, I saw some seeds that looked just like the ones I discovered at Gjerloff Prairie back in April. Aha! More evidence. I know mice create seed caches, but I don’t know much about what kinds of seeds they might store, where they store them, or how good they are at finding them later. If anyone can enlighten me on this subject, I’d love to hear from you.

Here’s another photo from a little closer to the hole. I used Photoshop to open up the shadows and show the details inside the hole, and you can just barely see a few remaining seeds at the bottom. (Click on the image to see a closer view).

Just based on observation and speculation, it looks to me like some small mammal harvested and piled some marbleseed/puccoon seeds up – presumably in the early to mid summer when those seeds were ripe. (Based on a lot of years of seed harvesting, those seeds disappear from plants pretty quickly after they’re ripe – probably because of mice!) Then, on a sunny day after a snow, that same mammal (?) appears to have trekked across the snow and dug up the cache. Did it know exactly where it was? Based on the tracks, it sure looked that way to me – either that or it somehow smelled the seeds beneath the snow. One way or the other, I’m impressed.

As I said at the beginning of this post, I’m no expert on winter survival, especially by birds and small mammals. I do, though, enjoy trying to figure out what I can learn through observation, and snow is really helpful in that venture. Last week’s snow is melting fast now, but I’m hoping for a few more chances to explore later this winter. If anyone can help me interpret what I saw in these photos, I’d sure appreciate it!

Pondering Winter Wildlife Cover From My Comfy Couch

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.

Calvin was able to dig out a little shelter in a drift. He was still pretty glad to come in and get some hot chocolate a few minutes later…

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.

Many parts of our family prairie have pretty short vegetation structure during the winter, but we always try to leave some patches of taller grass as well.  This is kind of in-between.  It’s not really dense enough to provide great cover from the wind, but has places for small animals to hide while they’re out feeding.

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.

Somebody is apparently sheltering in place under the snow here.  Probably not a meadowlark…

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…


Meadowlarks could learn from opossums, who either take over abandoned burrows from other mammals or find a nice wood pile to shelter in during cold weather and blizzards.