Friday, May 18, 2018

Nature: Better Than Fiction

Bliss. It was warm enough to wear shorts, but the mosquitoes hadn’t hatched yet, and the spring ephemerals were blooming. Days like that are rare in the Northwoods. So I kidnapped Mollie, the Cable Natural History Museum’s new curator, to show her Juniper Rock overlook on the North Country Trail.

In the parking area, two shining clusters of bloodroot flowers spread their white petals to the sun. We took that as a good sign. After hiking past numerous small patches of bloodroot we came to a patch of rich woods. Wild leeks created an emerald carpet on one side of the trail, and a rock outcrop glittered with blossoms on the other. I scurried from one patch of flowers to the next with my camera, like following a trail of breadcrumbs. Hepatica! Spring beauty! Bloodroot! Oh my!

Patches of bloodroot dotted the forest.

While I found both the purple and the white color morphs of hepatica, all the spring beauties had bright pink pinstripes. I’d just read a post about pure white spring beauty flowers on the “In Defense of Plants” blog, and was hoping to see one. Pigments are chemicals, and most pigments do more than just add color. The white pigments in spring beauty flowers protect them from herbivory and pathogens. On the other hand, if spring beauties with the pink stripes can manage to avoid being eaten, they will attract more insects, which is necessary for cross-pollination and producing viable seeds.

In areas where there are lots of white flowers of other species, the white spring beauties have even more trouble attracting pollinators and become even rarer than usual. With all the gleaming white bloodroot plants nearby, plus white hepaticas, the pink spring beauties had a monopoly on this patch.

Hepatica blossoms can be white or lavender.

I bent down to photograph one pin-striped blossom, and noticed a pale green spider clinging to the underside of the flower cup. “A crab spider,” I exclaimed to Mollie, “it’s lying in wait for an early spring bee!” Then as I leaned in closer for a second photo, I laughed out loud. The spider already had a little bee clasped in its jaws. I love when Nature does what you predict. And equally, I love when it surprises you. This was a little of both.

The bee sported a halo of short, white hairs around its thorax, along each skinny leg, and ringing each segment of its black abdomen. It must have been a female with all of those hairs ready to collect pollen to provision her larvae. The fuzz can also hold in heat produced by its wing muscles and help these early season insects fly even on chilly days.

Crab spiders wait on flowers to ambush pollinators.

This little lady looked similar to the hairy-banded mining bee we’ve highlighted in our new museum exhibit, but our Bee Buddy doesn’t emerge from its ground nest until late July when the asters bloom. Most of its cousins are early spring emergers, though. I used the WI Wild Bee Guide (https://energy.wisc.edu/bee-guide/) to try and key out the bee from my photo. I narrowed it down to a group of black and black-striped bees that includes mining, sweat, and cellophane bees, which the website noted “is a large group of bees from 4 different genera that are often difficult to distinguish from each other.” 

The crab spider was equally wonderful. As with bees, female crab spiders are bigger than the males. She can change colors to match her flower, too—from white to yellow to green—although the change takes several days. Crab spiders don’t build webs; they ambush unsuspecting pollinators with their crab-like front legs. Once prey is caught and subdued with venom, the spider holds its lunch with just her jaw while she slurps up the insect smoothie her enzymes have blended up.

I left the woods in an even deeper state of bliss than I’d entered it. Not only was it a beautiful day, but I’d observed some exciting natural drama.

The rest of my evening was spent getting ready for my summer sabbatical. As I packed natural history books about Alaska into a tub, I chuckled at how much my reading habits have changed since I was a kid. You couldn’t have bribed me to read nonfiction science books back then. I thought they were boring. I wanted stories with adventure, resourcefulness, mysteries, and magic. Laura Ingalls Wilder, The Boxcar Children, Anne of Green Gables, American Girls, The Bobbsey Twins, and Trixie Belden were my staples. I wrote fiction, too, either set in the pioneer days or magical kingdoms. I loved nature, and my heroines did too. They used medicinal herbs to cure people or conjured up the powers of nature to defeat evil. But today I write only nonfiction and mostly read it, too.

So what changed?

Somewhere along the way I realized that the stories in nature are as good as or better than anything we can invent. Spring beauty uses magic potions to defend itself and to attract suitors. Harried mothers are caught in the traps of a color-shifting villain (who turns out not to be evil). Don’t even get me started on the stories of parasites and symbiotic partners.

But none of those stories are apparent without careful observation, which is often carried out by dedicated naturalists, or by scientists conducting experiments. Adventure. . .resourcefulness. . .mysteries. . .magic. . .I still want to read and write about those themes; I’ve just discovered that I don’t need to invent anything. Nature has already done it for me. Scientists are busy translating, and I’m off to write those stories!

Special Note: Emily’s book, Natural Connections: Exploring Northwoods Nature through Science and Your Senses is here! Order your copy at http://cablemuseum.org/natural-connections-book/.

For 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! Our new exhibit: “Bee Amazed!” opened on May 1, 2018.

Friday, May 11, 2018

To Measure the Earth


Warm days in early spring are just delicious. In the Northwoods, it is a rare delight to walk slowly through the warm woods. Fall and winter require a certain amount of movement to keep fingers and toes warm and summer hikes are often chased by mosquitoes. There is one brief period, though—after the sun has strengthened, the wind has mellowed, and chilly nighttime temps are keeping the bugs at bay—when you can saunter comfortably.  

I was doing just that—and enjoying very much the warm rays on my bare arms—when a little orange and brown flutter caught my eye. Butterfly! I tracked its erratic flight path in the hopes that it would land and let me see it more clearly. Last year in mid-April I spotted a red admiral butterfly with those same shades of ripe tomato and fresh dirt, and I hoped this might be that old friend.



When the blur landed in the middle of the soggy gravel road, though, I could tell it was different. For one, its wingspan was just over an inch. Red admiral wings fan twice that wide. For another, the bright splotches of orange were not displayed boldly across its shoulders like an admiral’s stripes; they were coyly hidden on the hindwings. Then there was the halo of fuzz around its head, and the delicate fringe on all of its trailing edges. Could this bright little day-flier be a moth, I wondered?

Creeping forward as it sat resting on the gravel, I kept my shadow out of its space and readied my hands for the catch, while also preparing myself to be disappointed if it got away. I’m not sure which one of us was more surprised by my successful pounce, but I did end up in the possession a delicate sprite.

Luckily I’d been on my way home, and had less than a quarter mile of sauntering to go. It was relatively easy to scoot my new friend into the bug bottle sitting on my front windowsill (I’d been meaning to put the jar away for months, but as it turns out, it was in the perfect location), and get a better look. Each forewing was mottled brown with two white bars. The hindwings were mostly orange with black bars and a dark fringe along the edge. After readying my camera, I set the moth loose to climb up the window. The sun shone through its paper-thin wings. It was luminous. Each tiny scale on its wings sparkled in the warm spring light. After a series of glamour shots I released the moth back outside and worked on discovering its name.




Archiearis infans: that is its scientific name; but one entomologist called it “First-born Geometer,” and it’s also known as The Infant. Both names refer to its phenology as one of the first non-hibernating day-flying moths to emerge in the spring. It overwintered as a pupa, and must have finished metamorphosing in the recent warmth. Its adult life will last just a matter of weeks and be very focused on mating and laying eggs. It life cycle starts so early in spring that sometimes the caterpillars emerge before their food plants—birch, alder, poplar and willow—have leafed out. In that case they feed on the flower catkins of those trees instead.

While the adult of this moth is a shimmering beauty, its slender, green caterpillars have their own charm. They are inchworms!

Caterpillars—being insects—have six true legs. Most caterpillars also have additional pairs of prolegs down their length. Prolegs are fleshy stubs with gripping hooks that function as additional feet. Inchworms, though, only have two or three pairs of prolegs at their far end. To move, the caterpillar clasps with its front legs and draws up the hind end, then clasps with the hind end (prolegs) and reaches out for a new front attachment. This gives the impression that the little wiggler is using its characteristic looping gait to quantify every step of its journey. Its family name, Geometridae, means “earth measurer.”

They measure quite a lot of the earth, too. This family of moths contains more than 23,000 different species worldwide. The First-born Geometer ranges from Newfoundland south to New York, and all the way to Alaska.

All the way to Alaska. May 15 is my departure day, when I’ll begin my own journey to measure the earth in words and photos. The logistics of my four-month sabbatical become more daunting each week, so I’ve been drawing inspiration and courage from reading the words of other adventurous women: Chery Strayed’s Brave, Mary Oliver poetry, and An Unspoken Hunger, by Terry Tempest Williams have been on my nightstand.

In one chapter, Williams offers words of wisdom given to her for her college graduation: “Don’t worry about what you will do next. If you take one step with all the knowledge you have, there is usually just enough light shining to show you the next step.” That advice came from Mardy Murie—herself an amazing adventurer of the Alaskan frontier.

So, as I pack my bags, I’m thinking of both Mardy and the caterpillar. My first step will be home to visit my parents. From there, I’ll gather what light I can find, clasp tight with my hind legs, and reach out. . .

Special Note: Emily’s book, Natural Connections: Exploring Northwoods Nature through Science and Your Senses is here! Order your copy at http://cablemuseum.org/natural-connections-book/.

For 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI. Our new exhibit: “Bee Amazed!” is open!

Friday, May 4, 2018

Even Mighty Silver Maples Need Bees

A warm spring morning and a bluebird sky lured me outside. Camera in hand, I wandered the neighborhoods of Duluth, admiring the frilly clusters of blossoms on the silver maple trees. I stopped under one tree that seemed to have all male flowers. Tiny bouquets of eager stamens erupted out of the red base of each blossom. The delicate stalks of the filaments lived up to their botanical term—looking as fine and translucent as monofilament fishing line. Anthers tipped the filaments with lures of mauve-colored pollen.



Trees that bloom in early spring before the leaves unfurl, and before it’s warm enough for most pollinating insects to be active, are generally wind pollinated. The bee I spotted buzzing from twig to twig didn’t agree, though. Zooming in on my photos later, I confirmed that it was a European honey bee. I hadn’t noticed a hive in anyone’s backyard, but since this neighborhood contains quite an assortment of chicken coops, someone’s probably raising bees as well.



All flowering plants have pollen. They have to: pollen is the source of the male gamete of a plant that fertilizes the ovule. This means that even wind-pollinated plants can provide food for bees in early spring. But pollen only comes from male flowers, or from flowers that have both male and female parts. The female flowers of silver maple are on separate branches or even separate trees from the pollen-male flowers. If they want a bee to bring them pollen, they must offer nectar as a reward.

I’d recently read that silver maple flowers don’t provide nectar. But online beekeepers’ forums tout silver maple as a source for abundant pollen as well as some nectar, while lamenting the years when it’s too cold for their bees to take advantage of these resources.

Silver maple seems to have a great system. In cold weather, when pollinators aren’t active, wind may do a decent job of transferring its pollen. When things warm up, though, silver maple can take advantage of the services of bees.

Silver maple isn’t the only plant that encourages bees while also having a back-up plan. In addition to their charming, well-known blossoms, violets—another early spring bloomer—produce small closed flowers underground. The drab, white flowers never even try to attract a pollinator. They just self-pollinate and produce fruits that release their seeds directly into the soil. It’s an efficient system, with no resources wasted trying to attract finicky insects. But self-pollination doesn’t allow for genetic exchange, which would strengthen diversity in the gene pool.

Some plants put such a high value on genetic exchange that they always require cross–pollination (pollen from another plant of the same species) in order to successfully set seed. Apples, blueberries, melons, cucumbers, and squash are just a few examples. Worldwide, bees pollinate about one-third of all food crops, and an even higher percentage of native plants.

Even when a species of plant has a back-up plan (like maples and violets), research has shown that plants pollinated by bees are healthier, more diverse, and produce more seeds. Plus, as flowers have evolved to appeal to different types of bees and pollinators, their colors, shapes, scents, and diversity have become attractive to humans, too.

Pollinators support plant communities, which ensure a healthy and adequate supply of food and shelter in our ecosystems. Plants pollinated by bees provide fruits, seeds, and vegetation at the base of the food web, and their energy is carried up the food chain as carnivores eat herbivores. Those plants also provide shelter and habitat for pretty much everything. Bears eat many bee-pollinated fruits, but probably would prefer to eat protein-rich bee larvae instead of honey. Many birds eat fruit, but they also eat and insects (including the bees themselves) that feed on the bee-pollinated plants. And birds build their nests in trees and shrubs using materials from plants. Deer munch on your flower garden, and wolves munch on deer. Even a mighty silver maple tree benefits from the work of tiny bees.

So it worries me that more than half of native bee species are declining, and nearly one in four species are at increasing risk of extinction. Our industrial agricultural practices are partly to blame, but habitat destruction and pesticide use are problems on many scales.

The solutions are also applicable on many scales, including that of your own backyard. You can provide habitat by planting native flowers that will bloom throughout the spring, summer, and fall. But be wary of cultivars, because they often lack the specific cues or abundant nectar to attract bees. As you tend your yard, avoid using pesticides whenever possible. Leaving parts of your yard “messy” will provide bees with bare soil, rotting logs, fallen leaves, dried plant stems, and other important components of their habitat for nesting and overwintering.



Special Note: Emily’s book, Natural Connections: Exploring Northwoods Nature through Science and Your Senses is here! Order your copy at http://cablemuseum.org/natural-connections-book/.

For 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! Our new exhibit: “Bee Amazed!” opened on May 1, 2018.