MTPR

Field Notes

Mon., Wed. Friday at 4:54 p.m.

For keen observers, a walk to the grocery store or a hike up a mountain can inspire questions. Where do magpies nest?  Why doesn’t a spider stick to its own web? How do water striders keep from sinking?  Every week since 1992, Field Notes has inquired about Montana's  natural history. Produced by the Montana Natural History Center, Field Notes are written by naturalists, students and listeners about the puzzle-tree bark, eagle talons, woolly aphids and giant puffballs of western, central and southwestern Montana.

Interested in writing a Field Note? Contact Allison De Jong, Field Notes editor, at adejong [at] montananaturalist.org or (406) 327-0405.

The Bitterroot Mountain range, part of the Idaho Batholith
Beth Anne Austein

The difference in temperature between the crust, mantle and core creates an effect where hot molten rock, called magma, slowly moves toward the surface in plumes, much like the wax of a lava lamp. This phenomenon, called convection, slowly moves the plates of the earth’s crust, grinding them against each other, causing volcanoes, earthquakes -- and mountains.

How Swallowtail Butterflies Survive The Winter

Oct 13, 2019
Butterfly pupa
Brad Smith (CC-BY-NC-2.0)

Fall is a hectic time of year in Montana. There are a thousand things to do before the first snow, and not nearly enough time. The days shorten, tourists leave, seasonal shops close, kids romp at the playground one last time, flower beds are mulched, snow tires put on the car, storm windows polished and mounted. You can feel the change in season just walking down the street: people hurry from building to building, head down and quiet, bundled up and hunched against the cold, looking for warmth, a fire, hot cocoa.

Spotfist (CC-PDM-01)

When I first moved out West, I was impressed by the large black-and-white bird I noticed strutting around my yard and campsites, its long black tail dragging on the ground behind it. The bird’s loud “mag-mag-mag” calls slowly became a familiar sound. Now the black-billed magpie has become an important symbol of the West to me, and whenever I see or hear it, I’m reminded how lucky I am to call the Rocky Mountains home.

Steve L. Martin (CC-BY-2.0)

Lichens don’t even need liquid water sources like rain or melting snow.  They can absorb moisture directly from the air.  You might think of them as natural weather instruments, because their ever-changing water content reflects the humidity of the air.  Oddly enough, some lichens are completely unable to absorb liquid water; if you submerged them, they would remain dry.

Why Don't Woodpeckers Get Concussions?

Sep 22, 2019
Male hairy woodpecker
Dan Streiffert (CC BY-NC 2.0)

... for Hairy Woodpeckers, “woodpecker” isn’t just a description, it’s a lifestyle. They get about 45 percent of their food from drilling into trees.  A male Hairy Woodpecker can peck up to 190 strikes per minute when excavating a nest. That’s about 1/7 the speed of a jackhammer, which operates at about 1,300 strikes per minute.

iStock

There is an ant and she is next to my foot, dragging a fly up the same hill that I have just stopped trying to drag myself up.  All worker ants are females and this particular female has a black fly in her mandibles, but she’s having a hard time keeping it there because she is negotiating her way backwards through lichen, and the uncooperative (i.e., dead) fly keeps getting hung up.

A Fisher's Guide To Preying On Porcupines

Sep 8, 2019
Fisher (Pekania pennanti), the carnivorous mustelid that co-evolved with porcupines
(U.S. Fish and Wildlife Service, Region 5)

As my dog starts to circle, the porcupine turns its rear end to my dog and begins to back into him, thrashing its tail back and forth. Lunging at the porcupine, my dog comes up with a face full of quills. As he winces back to my side, I begin to wonder what type of animal has the ability to prey upon a porcupine without receiving a penalty for its meal.

Freshwater diatom seen under a scanning electron microscope.
Courtesy UM Electron Microscopy Facility

The bottom of this shallow stream is covered with a complex community of algae, comprising many different species. Probably most abundant of all are the diatoms, many of which secrete a slippery mucus as they travel, leaving the rocks very slick.

Do Noxious Weeds Owe Their Success To Soil Microbes?

Aug 25, 2019
Ivar Leidus

"What exactly is a weed? This can be a tricky question to answer. A plant that is nurtured and cultivated by one gardener may be yanked out unapologetically by the next, in favor of something preferable. It seems that a weed to one person can be a prized plant to another.

Zion National Park (CC-BY-2.0)

Yellowstone National Park has lost much of its aspen forest cover — not just to the detriment of the aspen, but to all the other species that depend on them, including many birds, black bears, snowshoe hares, porcupines and beavers. I, too, miss the aspen, its knobby white trunk standing in stark relief against the dark-barked backdrop of spruce, fir and pine that forms most of my visual diet.

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