Aug 20 2017

It’s Probably Mugwort

Published by under Plants

Mugwort leaves are white underneath (photo by Kate St. John)

Mugwort leaves are white underneath, June 2017 (photo by Kate St. John)

There’s a tall plant in the Composite family (Asteraceae) that used to confuse me, especially in early summer. Here’s a trick for identifying mugwort.  It’s everywhere right now.

Mugwort or common wormwood (Artemisia vulgaris) is an aromatic perennial native to Europe, Asia, northern Africa and Alaska(!).  It may have been brought here for medicinal purposes, but it spreads easily along roadsides and waste places.  I’m surprised it’s not on Pennsylvania’s Invasives list.

In early summer when mugwort is knee high, it looks like chrysanthemums because its leaves are similar — sharply lobed.  The trick for telling them apart is this:  Look under the leaf. The underside of a mugwort leaf is white (above).

Mugwort leaves (photo by Kate St.John)

Mugwort’s lower leaves in August (photo by Kate St.John)

 

By late August mugwort is three to eight feet tall with insignificant green flowers clustered at the leaf joints and at the tips of the stems.  The leaves near the flowers look different. They’re linear, not lobed.

Mugwort's insignificant flowerscluster on the stem (photo by Kate St. John)

Mugwort’s insignificant flowerscluster on the stem (photo by Kate St. John)

But it isn’t beautiful.

In August a mugwort patch looks tall and messy.

Mugwort looks messy where there's a lot of it in August (photo by Kate St. John)

Mugwort looks messy in August (photo by Kate St. John)

 

Wondering what it is?  Flip a leaf.  It’s probably mugwort.

 

(photos by Kate St.John)

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Aug 19 2017

More Monarchs Than Last Year

Published by under Insects, Fish, Frogs

Monarch butterfly on a zinnia (photo by Kate St.John)

Monarch butterfly on a zinnia (photo by Kate St.John)

It feels like a miracle.  After years of almost no monarch butterflies I’ve seen more in Pittsburgh this summer than I have for a long time.

Their relative abundance reminds me of the “old days” in 2011 when they were so plentiful.

Have you noticed more monarchs this year than last?

 

(photo by Kate St.John)

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Aug 18 2017

As The Crow Flies

On Wednesday we learned how flapping birds save energy.  Today we’ll watch them fly in slow motion.

In this video from India, see the house crows (Corvus splendens) use their slotted wings to stay aloft in the strong wind.  Someone off camera is tossing bread in the air.  The crows hover and flap to catch it.

Slotted wings save energy as the crow flies.

It looks like fun.

 

p.s. Test your skills at identifying birds in flight.  Find a pigeon (or three) that parachutes in to join the flock.  How can you tell it’s a pigeon? Pigeons have pointed wings.

(video by Sudhir, Suke on YouTube)

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Aug 17 2017

Listening To The Temperature

Published by under Insects, Fish, Frogs

Male fall field cricket (photo from Wikimedia Commons)

Male fall field cricket (photo from Wikimedia Commons)

On Throw Back Thursday:

There’s a Rule of Thumb that says you can tell the temperature –in Fahrenheit! — by listening to a cricket’s chirp.

Here’s how:

Thermometer

 

(photo of a fall field cricket (Gryllus pennsylvanicus) from Wikimedia Commons; click on the image to see the original)

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Aug 16 2017

Flapping Saves Energy

Multiple wingtips vortices roll off the tips of a flying jackdaw's wings (photo credit: Aron Hejdström via Science Daily)

Multiple wingtips vortices roll off the tips of a flying jackdaw’s wings (photo linked from viaScience Daily, credit: Aron Hejdström)

It doesn’t make sense but if your wings are the right shape flapping saves energy.

Birds and airplanes must constantly overcome drag to stay aloft. One source of induced drag occurs during lift when swirls of air, called vortices, roll off the wingtips.  This small plane generates a huge wingtip vortex, forcing it to burn more fuel as it flies.

Wingtip vortex from an airplane (photo from NASA in the public domain on Wikimedia Commons)

Wingtip vortex from an airplane (photo from NASA in the public domain on Wikimedia Commons)

 

Large soaring birds, such as turkey vultures, reduce drag in two ways. Their wingtip feathers form slots that break the single vortex into smaller ones (small is good!), and they turn their wingtips up as they soar.

Turkey vulture (photo by Chuck Tague)

Turkey vulture (photo by Chuck Tague)

Southwest Airlines turns up its wingtips, too, to save fuel.

Wingtip on a jet, tip turned up to reduce wingtip vortex (photo from Wikimedia Commons)

Wingtip turned up to reduce wingtip vortex (photo from Wikimedia Commons)

 

But what about smaller birds that flap all the time?  Are they doomed to inefficient, labor-intensive flight?  A new study from Sweden says no.

Biologists at Lund University studied jackdaws (Corvus monedula), a corvid smaller than the American crow. Using mist and multiple cameras they found that the birds’ slotted feathers, specifically designed for flapping flight, also break up the vortex into multiple swirls.  See them rolling off the wings in the study photo at top.

Now that we know slots are efficient for both flapping and soaring, what prompted their development? The study’s authors “propose the hypothesis that slotted wings evolved initially to improve performance in powered (i.e. flapping) flight.”

In fact, flapping saves so much energy that author Anders Hedenström suggests, “We could potentially build more efficient drones to fly with active wingbeats. Within a ten-year period, we could see drones which have the morphology of a jackdaw.”

Read more about the study at Science Daily or the original paper here at The Royal Society.

 

(photo by Aron Hejdström linked from Science Daily)

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Aug 15 2017

How Will Birds React To The Eclipse?

Asleep: mallard and European coot (photo from Wikimedia Commons)

Two birds roosting, mallard and European coot (photo from Wikimedia Commons)

How will birds and animals react to the solar eclipse on Monday, August 21?  Will they act differently during the total eclipse (from Oregon to South Carolina) compared to the partial eclipse here in Pittsburgh? You can help Science answer these questions.

We have anecdotes about animal behavior during solar eclipses but not a lot of scientific data.

People have noticed that birds stop singing, farm animals return to the barn, and night critters wake up.  Are they reacting to totality as if it’s a miniature night?  Or is it something else?

Science doesn’t have answers because the data has been hard to collect.  To reach a conclusion, the scientific method gathers data over and over again under the same conditions.  It’s hard to do for total eclipses because in any one location they occur as much as 400 years apart.

Scientific method diagram (image from Wikimedia Commons)

Scientific method diagram; Knowledge is Gained (image from Wikimedia Commons)

 

But this time will be different. On Monday August 21, thousands — or even millions of us — will collect data on animal behavior before, during, and after the eclipse thanks to the Life Responds: Solar Eclipse 2017 project and the iNaturalist app. The project will analyze our data and repeat the experiment during the next eclipse.

Here’s how you can help.  (Instructions are from the Life Responds: Solar Eclipse 2017 project.  Click the link for more information.)

Before the eclipse. Day(s) ahead of time.

  1. Download the free iNaturalist app to your Android (Google Play) or iPhone (App Store)
  2. Open the app and create an account at iNaturalist.org
  3. Practice using the app. Here are some instructions.
  4. Inside the app, join the Life Responds project
  5. Decide where you’ll be observing the eclipse and know when it’ll be at maximum darkness.

On the Day of the Eclipse:

  1. When you get to your observation site, choose the birds and animals you’ll observe.
  2. Post at least 3 observations of the birds/animals in iNaturalist at the times below. Add anything interesting you notice in the Notes.
    1. 30 minutes before maximum darkness.
    2. During maximum darkness or totality
    3. 30 minutes after maximum darkness.
  3. Make additional observations if you wish.

The cool thing about this project is that you don’t have to be in the path of totality to provide useful data.

Do the birds stop singing at dark and restart when it’s light? (This is a trick question! Few of them sing in August.) Do the chimney swifts dive into chimneys to roost?  Do the squirrels go to bed?  Do the deer come out?  What about your pet?  And if you’re a beekeeper, how are your honeybees?

I’ve downloaded the app and I’m ready.  I sure hope it isn’t cloudy on Monday, August 21!

 

(photo from Wikimedia Commons; click on the image to see the original)

p.s. Observing Machines:  If you’re in a city in the path of totality, the street lights will come on.  Will they come on in Pittsburgh?

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Aug 14 2017

Boogie-Woogie Aphids

Published by under Insects, Fish, Frogs

Beech blight aphids, 9 Aug 2017 (photo by Kate St. John)

Beech blight aphids, Butler County, PA, 9 Aug 2017 (photo by Kate St. John)

Last week Andy Zadnik and volunteer Tom Koehler from the Western PA Conservancy showed us amazing aphids on a beech tree at Wolf Creek Narrows.

Beech blight aphids (Grylloprociphilus imbricator) are nicknamed “boogie-woogie aphids” because they waggle their bodies when disturbed.  A puff of wind or a jolt to the branch will start them waving to ward off predators.  My photo is out of focus because the aphids would not stand still when I got close!

Like all aphids these suck the juice of their host, the beech tree, but their scary name (blight) is misleading.  Beech blight aphids rarely hurt the tree and are easily knocked off by a stream from a garden hose. Once on the ground the nymphs can’t fly up because they have no wings, though their mothers do.

Beech blight aphid colonies are sought by ants, wasps and a fungus for their sweet honey dew.  They’re also sought by predators that they mesmerize with their dance or sting with their tiny mouth parts too small to hurt mammals.

This video by the Capital Naturalist shows how they dance.

What’s the boogie-woogie all about?

Click on these links to see what really scares these aphids:  Harvester caterpillar eating aphids, Harvester butterfly ventral view (wings closed) and dorsal view (wings open).

 

(photo by Kate St. John)

 

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Aug 13 2017

Primrose Moths

Primrose moths on a primrose, Allegheny County,PA, 6 Aug 2017 (photo by Kate St.John)

Primrose moths on a primrose, Allegheny County,PA, 6 Aug 2017 (photo by Kate St.John)

Last Sunday I found a crowd of pink and yellow moths head down in a common evening primrose.  Bob Machesney identified them as primrose moths (Schinia florida).

I should have guessed their name.

Moths are often named for their host plant and so are these. Primrose moth caterpillars eat evening primrose, biennial gaura and other members of the Evening-primrose family (Onagraceae).  In July and August the adult moths fly at night and spend the day resting on their host plants.  That’s why there were so many on one flower.

Keep an eye out this month for beautiful pink moths on primrose and biennial gaura.  Here’s a common evening primrose (Oenothera biennis) without a moth in it.

Common evening primrose (photo by Kate St. John)

Common evening primrose (photo by Kate St. John)

Click here to see biennial gaura whose flowers are actually quite small.

And here’s what the primrose moth looks like in a museum, mounted to show all its features.  Amazingly its antennae are pink.

Primrose moth specimen, mounted (photo from Wikimedia Commons)

Primrose moth specimen, mounted (photo from Wikimedia Commons)

 

(primrose photos by Kate St. John. photo of mounted primrose moth from Wikimedia Commons; click on the image to see the original)

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Aug 12 2017

Gone To Seed

Published by under Plants

Wild Bergamot gone to seed, late July 2017 (photo by Kate St.John)

Wild Bergamot gone to seed, late July 2017 (photo by Kate St.John)

Is this a daisy-like green flower with six petals?

No.

The green “petals” are sepals. The two lavender and white tubes on the left provide a clue. The central disc used to hold the flowers.

This is wild bergamot (Monarda fistulosa).  When in bloom it looks like this.

Wild bergamot in bloom in 2016 (photo by Kate St.John)

Wild bergamot in bloom, early July 2016 (photo by Kate St.John)

Still don’t recognize it?  Click here to see a flower bed full of Monarda fistulosa.

It’s a challenge to identify flowers when they’ve gone to seed.

 

(photos by Kate St. John)

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Aug 11 2017

Tiny Bathing Beauties

 

In August the hummingbird population is at its peak as adults and this year’s juveniles prepare to migrate.  Searching for nectar, they visit flowers and backyard feeders.  They’re also attracted to shallow, running water.

Here are two soothing videos of hummingbirds bathing.

Neither one describes where it’s located and that presents a challenge …

Can you identify these tiny bathing beauties?

 

(videos from YouTube. Click on the YouTube logo on each video to see the original.)

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