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.

Photo of the Week – January 19, 2018

Let’s talk for a minute about the plains spadefoot and their awesome vertical-pupilled eyes.  You might think the spadefoot is a toad.  If so, you’re wrong  …kind of.  Also, you might think the word “pupilled” isn’t a real word, and anyway it should only have one ‘L’.  Wrong again – (I just looked it up).

The plains spadefoot (Spea bombifrons).  The coolest toad, or whatever it is, you’ll ever meet – if you’re ever lucky enough to meet one.

Toads, you see, have dry skin with little “warts” (no,they aren’t really warts, and don’t cause you to get warts).  Spadefoots have the kind of moist, slightly slimy skin that is more typical of frogs.  In addition, the plains spadefoot is missing the raised parotoid glands behind its eyes that are typical of true toads (see photo below).  So, clearly, the spadefoot is not a toad, it’s a frog.

True toads have dry warty skin and big parotoid glands behind their eyes, as seen in this boring, but useful, photo of a Great Plains toad (Anaxyrus cognatus).

Well, wait just a second, Herp-a-long Cassidy.  It’s not that simple.  As it happens, Anurans – the taxonomic group that includes frogs and toads – is a kind of spectrum, rather than two distinct types.  There are “true frogs” and “true toads”, but there are a lot of in-between species too, which don’t really fit either category.  Spadefoots don’t really identify as either frogs or toads.

The northern leopard frog (Rana pipiens) is one of the “true” frogs. If you watch them carefully, you might notice that they carry their noses just a little higher in the air than other so-called frogs.

Regardless of labels, the plains spadefoot is a fascinating creature, and one that is rarely seen, even in states like Nebraska where it is considered to be common.  In fact, despite the fact that it’s a grassland animal, and I’ve been exploring and studying grasslands for about 25 years, I’d never seen one in person until last summer.  (Thanks to Keith Geluso, by the way, for finding one at The Niobrara Valley Preserve and allowing me to photograph it!).

The reason they’re rarely seen is that plains spadefoots spend the vast majority of their lives underground, emerging only during and after heavy rains between April and July.  They are known as “explosive breeders” because they have to breed and get their offspring to maturity very quickly.  It’s a race between tadpoles and the temporary rain-filled ponds.  To help ensure survival, there are two types of spadefoot tadpoles; herbivores and carnivores/cannibals.  If the tadpole’s pond comes and goes so quickly that no algae or other vegetation has time to grow, at least some tadpoles can still find food – even if that food consists of siblings.  Spadefoots can go from egg to mature in around two weeks if they have to, which is pretty impressive.

Except for the brief periods when plains spadefoots make an appearance to breed and feed, they basically live their lives underground, in a kind of dormant state.  Their “‘spadefoot” moniker comes from a dark hard “spade” on their rear feet, which they use to quickly burrow down into loose soil.  While it might seem crazy that spadefoots live almost all of their lives in dormancy, there are a couple nice perks associated with the strategy.  First, it’s a pretty slick way to avoid predators.  Second, it allows spadefoots to colonize areas of grasslands far from permanent water – they don’t need access to streams, ponds, or lakes like their other Anuran cousins.  Instead, they just sit in quiet solitude until a good hard rain, and then party down.  All things considered, that might not be a terrible life.

Spadefoots are stinking cute.

Many thanks to Dan Fogell, both for his excellent book, “A Field Guide to Amphibians and Reptiles of Nebraska”, and for helping me better understand the frog-toad-etc spectrum this week.