How Heavy is a Cloud? and Other Weighty Subjects

Cloud on a scale (image from USGS)

11 October 2023

How heavy is a puffy white cloud? It depends on how big it is.

According to USGS, an average 1 kilometer by 1 kilometer cumulus cloud weighs about 1.1 billion pounds.

Notice that this calculation uses the metric system for the cloud’s dimensions because it’s so much easier to calculate the weight of a cloud using those units.

When the metric system began in France in the 1790s, the units had Earth measurements as their basis. A kilogram was the mass of water in a 10cm x 10cm x 10cm container (a litre). The cloud answer, above, was calculated in metric and expressed in kilograms, then translated to U.S. customary pounds.

Did you know that we use two measuring systems in the U.S.? Everyday things are described in U.S. customary measures (inches, feet, pounds) but, as described in Wikipedia, science, medicine, electronics, the military, automobile production and repair, and international affairs all use the metric system. Also, most packaged consumer goods in the U.S. have to be labeled in both customary and metric units.

All birds are measured in grams and centimeters. I can tell this common yellowthroat is being banded in the U.S. because there are inches on that ruler. But his tail is about 4.5cm.

Bird banding, common yellowthroat in hand (photo from Wikimedia Commons)

The U.S. is one of three major countries that do not universally use the metric system.

Map of metric and Imperial measuring systems from Wikimedia Commons

Why haven’t we completely adopted the metric system?

It comes down to three things: Time, Money and Congress. The change will cost time and money for U.S. industry, and designating an official measurement system requires an act of Congress. Whenever the subject comes up, lobbyists convince Congress to say “No.”

So for now we use two measuring systems.

p.s. Grams and pounds do not measure the same thing at all. Grams are a measure of mass (a fundamental property of matter). Pounds are a measure of force (the force of gravity on a mass).

If your mass is 68 kilograms, you are …
68 kg in Europe
150 pounds in the U.S.,
25 pounds on the Moon and still 68 kg,
0 pounds in outer space and still 68 kg
Your mass is 68 kg everywhere you go.

Read more here in Science News Explores: Explainer: How do mass and weight differ?

(credits are in the captions; click on the captions to see the originals)

Confusing Fall Chipping Sparrows

Tricky chipping sparrow, Frick Park, 7 Oct 2023 (photo by Charity Kheshgi)

10 October 2023

Migrating chipping sparrows (Spizella passerina) have just begun to arrive in Pittsburgh and they look different than they did last spring. The adults are fading and the juveniles, which never did match the adults, now resemble other species. We have a category for Confusing Fall Warblers. There ought to be one for Confusing Fall Sparrows.

From mid-March to mid-April chipping sparrows molt rapidly into breeding plumage with a rusty cap, a sharp white swatch above the black eyeline and rusty-orange tones on the wings.

Chipping sparrow in breeding plumage, April 2020 (photo by Lauri Shaffer)

In mid-August the adults being two and a half months of molting into duller non-breeding plumage, looking ragged in September and ending up with the brownish cap and muted facial markings of non-breeding plumage.

Adult chipping sparrow in October 2012 (photo by Steve Gosser)

Meanwhile the juveniles lose the spotted breast they fledged with and gain sharper facial markings. Sometimes they look like clay-colored sparrows which are indeed rare in Pittsburgh.

Let’s compare the young chipping sparrow at Frick Park to an October clay-colored sparrow: chipping on the left, clay-colored on the right below. These small photos are just like the long distance view in the field.

Chipping sparrow (by Charity Kheshgi) vs. clay-colored sparrow (photo from Wikimedia)

They look almost the same. What’s the difference?

  • The chipping sparrow has a strong black eyeline that extends all the way to its beak and its face patch has muted edges.
  • The clay-colored sparrow has no black between its eye and beak but it does have a dark “moustache” outlining the front edge of its face patch.
  • If you can see the top of the head, the young chipping sparrow may have thin white stripes but the clay-colored has a distinctly wide white crown-stripe.

And just to shake things up, there was a leucistic adult chipping sparrow at Frick last Saturday who looked as if he had been dunked face-first in white paint. His forehead, cheeks and throat were so white that it the camera had a hard time picking up the details.

Leucistic adult chipping sparrow, Frick Park, 7 Oct 2023 (photo by Charity Kheshgi)
Leucistic adult chipping sparrow, Frick Park, 7 Oct 2023 (photo by Charity Kheshgi)
Leucistic adult chipping sparrow, Frick Park, 7 Oct 2023 (photo by Charity Kheshgi)

Theorectically leucism (lack of pigment) is in his genes so his face will always looks like this no matter what plumage he’s in. He’s the only chipping sparrow I can identify as an individual.

p.s. More confusion: When American tree sparrows arrive later this fall they’ll resemble chipping sparrows in breeding plumage, except that the chipping sparrows will be in non-breeding plumage. Click here and scroll down to see American tree sparrows compared to chipping sparrows at All About Birds.

(photos from Charity Kheshgi, Lauri Shaffer, Steve Gosser and Wikimedia Commons)

Birds Take a Taxi to Correct For Climate Change

Male European pied flycatcher (photo from Wikimedia Commons)

9 October 2023

Birds like the European pied flycatcher (Ficedula hypoleuca) that winter in the tropics and southern hemisphere do not use weather clues to tell them when to fly north in the spring. Instead they cue on changing day length and return at the same time every year. But as Earth’s climate changes, spring comes weeks earlier than it used to and their migration timing is out of sync. Scientists in the Netherlands decided to give a few lucky birds a lift (a Lyft?) to Sweden and it made all the difference.

Pied flycatchers prefer to nest in or near oak trees where their nesting season is timed to correspond with the peak of caterpillar season. Unfortunately, spring is two weeks earlier now in the Netherlands, pied flycatchers arrive too late and have locally experienced a 90% decline.

Female European pied flycatcher carrying caterpillars (photo from Wikimedia Commons)

The old timing of Netherlands’ spring is now found in southern Sweden so scientists at University of Groningen in the Netherlands and Sweden’s Lund University decided to see what would happen to migration and nesting success if a few pied flycatchers were transported (by car!) from the Netherlands to suitable habitat in Sweden.

Anthropocene Magazine reports, “For three springs, starting in 2017, scientists from the University of Groningen in the Netherlands and Sweden’s Lund University caught newly-arrived Dutch female pied flycatchers and drove them by car to a nesting spot 570 kilometers (354 miles) away in southern Sweden that was already home to other pied flycatchers.”

Range of European pied flycatcher (map from Wikimedia Commons)

The experiment was wonderfully successful. The Netherlands’ females were in sync with the food supply and were twice as prolific as their Swedish counterparts who were locally out of sync. After spending the winter in Africa the former-Netherlands females returned to Sweden and so did their offspring!

Later the research team proved that migration timing is genetically inherited in European pied flycatchers by taxiing a few eggs laid in the Netherlands to Swedish nests. Those offspring returned to Sweden the following spring on the Netherlands timing.

Taxi service cannot be the answer to out of sync migration but birds are adapting on their own. During the study, banding still continued at Netherlands nests and some of those youngsters were found nesting in Germany, halfway to Sweden. They flew there on their own.

Read more about the taxi ride experiment in Anthropocene Magazine: For some birds, a “taxi” helps recalibrate out-of-sync migrations.

(photos and map from Wikimedia Commons; click on the captions to see the originals)

Chances Are You’ll Hit a Deer in PA

Deer crossing a road at dusk (photo by “i threw a guitar at him” via Flickr Creative Commons license)

8 October 2023

Fall is deer crash season in Pennsylvania. November, October and December, in that order, are the highest months for deer collisions because the animals are on the move in the breeding season.

During the rut, bucks travel an average of 3-6 miles per day searching for and chasing does in heat. Females split from their fawns when they find a mate and the youngsters wander. All age groups are crossing roads more frequently and all of them are distracted.

In Pennsylvania it’s especially important to stay alert because our high deer population increases the odds of a collision. Last month State Farm Insurance reported:

 State Farm estimates over 1.8 million auto insurance claims were filed across the industry from July 1, 2022 to June 30, 2023 involving animal collisions. Pennsylvania had the highest number of claims out of all the states, with an estimated 153,397 claims for the same time period.

Nationwide the odds of U.S. drivers hitting an animal are 1 in 127 this year. Drivers in West Virginia held on to the number one spot with the least favorable odds at 1 in 38. Montana (1 in 53), Pennsylvania (1 in 59), Michigan (1 in 60), Wisconsin (1 in 60) round out the top five most likely states to hit an animal while on the road.

State Farm: Likelihood of Hitting an Animal While Driving, 12 Sept 2023

PennDOT’s heat map of deer-vehicle collisions on state roads shows particularly high deer collisions in several areas including Allegheny County.

PennDOT heat map of deer-vehicle collisions on PennDOT roads in 2022 (generated at crashinfo.penndot.gov)

In fact PennDOT statistics show that for 2018-2022 Allegheny County leads all Pennsylvania counties in deer-vehicle collisions. Your chance of hitting a deer in Pittsburgh is particularly high.

Deer spooked near the road in WV (photo by Mike Tewkesbury, Creative Commons license via Flickr)

Statewide the odds of hitting a deer — or a deer hitting you! — are 1 in 59 and probably higher in Pittsburgh. This means that each one of us knows someone who will hit a deer in the year ahead. It might be us.

Stay alert behind the wheel, especially at dawn and dusk. Watch out!

Read more about deer-vehicle collisions at WESA: Deer Danger: Pennsylvania is No. 1 in the U.S. for car crashes with animals.

(credits are in the captions; click on the links to see the originals)

p.s. An interesting statistic from Cornell University’s Community Deer Advisor website:

Hunter harvest is the primary cause of white-tailed deer mortality in rural landscapes, while deer in suburban landscapes are more likely to die in deer-vehicle collisions. [p.10]

Managing a deer herd via vehicle collisions is both inhumane and costly for community residents. [p.30]

Cornell University: Integrated Approach for Managing White-tailed Deer in Suburban Environments

Seen in Late September

Honeybee on asters, Schenley Park, 28 Sept 2023 (photo by Kate St. John)

7 October 2023

The best photos from this week have been published already (Yesterday at Hays Woods Bird Banding) so I’m reaching back to late September for a few of things I’ve seen.

Bees of all kinds are attracted to deep purple asters beside the Westinghouse Memorial pond in Schenley Park. The honeybee, above, is hard to see near the flower’s orange center.

At Duck Hollow, yellow jewelweed still has flowers as well as fat seed pods. Try to pull one of the pods from the stem and see what happens.

Yellow jewelweed flower and seeds, Duck Hollow, 26 Sept 2023 (photo by Kate St. John)

On 28 September I explored the slag heap flats near Swisshelm Park where (I think) solar arrays will be installed. Because the slag is porous the flats are a dry grass/scrub land where this shrub would have done well except that it’s been over-browsed by too many deer. It looks like bonsai.

Deer damage at the future site of solar flats, NMR Valley, 28 Sept 2023 (photo by Kate St. John)

Deer overpopulation is also evident by the browse line at the edge of the flats.

Browse line at the edge of the future solar flats,NMR Valley, 28 Sept 2023 (photo by Kate St. John)

On 26 September at Duck Hollow I encountered an optical illusion where Nine Mile Run empties into the Monongahela River. It looks as if this downed, waterlogged tree is damming the creek and that the water is lower on the downriver side of it. This illusion seems to be caused by the smooth water surface on one side of the log.

Optical illusion: the log is damming Nine Mile Run, 26 Sept 2023 (photo by Kate St. John)

We found a tiny red centipede crossing the trail at Frick Park on 30 September …

Tiny red centipede, Frick Park, 30 Sept 2023 (photo by Kate St. John)

… and a puffball mushroom outside the Dog Park.

Puffball mushroom, Frick Park, 30 Sept 2023 (photo by Kate St. John)

On 27 September hundreds, if not thousands, of crows gathered at dusk near Neville Street in Shadyside before flying to the roost. I thought this would happen again the next day but they changed their plan and have not come this close again.

Hundreds of crows take off from a roof on Neville Street, 27 Sept 2023 (photo by Kate St. John)

Sometimes sunrise is the most beautiful part of the day.

Sunrise at Neville Street, 28 Sept 2023 (photo by Kate St. John)

These photos don’t give the impression that it’s been abnormally dry, but precipitation in Pittsburgh is down 6″ for the year. Almost 2″ of that deficit occurred in September. The Fall Color Prediction says our leaf color-change is later than usual.

(photos by Kate St. John)

Leave The Leaves

Fallen leaves in Schenley Park, Nov 2016 (photo by Kate St. John)

6 October 2023

In October we see woolly bear caterpillars (Pyrrharctia isabella) out in the open crossing the trails. Woolly bears overwinter as caterpillars so this month they’re busy looking for the perfect place to spend the winter in leaf litter, under bark, or beneath a fallen log.

Woolly bear, Isabella Tiger Moth caterpillar, 3 Oct 2018 (photo by Kate St. John)

Leaf litter is key winter habitat for a lot of insects including springtails, millipedes, earthworms, butterflies and moths.

Millipede(*) Hays Woods, Sept 2023 (photo by Kate St. John)

It also shelters salamanders and newts

Red eft among the leaf litter in West Virginia (photo from Wikimedia Commons)

… and provides an insect hunting ground for birds including eastern towhees, dark-eyed juncos, robins and mockingbirds.

Eastern towhee, male (photo from Wikimedia Commons)

If you’ve been thinking about “wilding” your yard — even just a little bit — now is a great time to start. Leave the leaves. You don’t have to leave it messy. Here’s advice on what to do.

Leaving the leaves and other plant debris doesn’t have to mean sacrificing your yard to the wilderness. The leaves don’t need to be left exactly where they fall. You can rake them into garden beds, around tree bases, or into other designated areas. Too many leaves can kill grass, but in soil they can suppress weeds, retain moisture, and boost nutrition. 

Avoid shredding leaves with a mower. Raking or blowing are alternatives that will keep leaves whole for the best cover and protect the insects and eggs already living there.

If you decide you need to clean up the leaves and debris in spring, make sure you wait until late in the season so as not to destroy all the life you’ve worked to protect. 

Xerxes Society: Leave the Leaves: Winter Habitat Protection

Take a break this weekend. Don’t bag those leaves! Just push them aside for wildlife. 🙂

(photos by Kate St. John and from Wikimedia Commons)

(*) p.s. The millipede was easy to photograph because it was dead, probably the victim of a parasitic fungus that prompts the millipede to climb high on a twig before it dies. I wrote down the name of the fungus when I took the picture but cannot read my writing. Perhaps it’s Anthrophaga myriapodia.

Do Blackpolls Sleep in Flight Over the Atlantic?

Blackpoll warbler in PA, Oct 2020 (photo from Wikimedia Commons)

5 October 2023

Some birds are champion fliers, staying airborne for days or months at a time. Scientists wondered if birds sleep in flight and proved that they do in a 2016 study of great frigatebirds, finding that the birds either “sleep with one half of their brains active, or with both hemispheres shut down at the same time.” Read more in this vintage article, Asleep in Flight.

Blackpoll warblers (Setophaga striata) are also champion fliers making a non-stop fall migration over the Atlantic Ocean of 1,900 miles in 72 to 88 hours. Traveling at 27 mph, they launch from the east coast between Nova Scotia and South Carolina and fly to their only stopover in Puerto Rico or Hispaniola (Haiti & Dominican Republic), then on to northern South America.

The blackpoll’s transoceanic path was proven in a 2015 study by Bill DeLuca and the Vermont Center for Ecostudies. VCE writes:

Bill DeLuca (Northeast Climate Science Center) and VCE solved this great modern-day avian mystery. Using light-level geolocators attached to Blackpoll Warblers in Vermont and Nova Scotia, DeLuca and colleagues documented the longest distance non-stop overwater flights ever recorded for a migratory songbird. During October, Blackpoll Warblers initiate a ~3-day non-stop transoceanic flight of ~2500 km from the north Atlantic Coast to Hispaniola and Puerto Rico. Radar data show migrating songbirds fly at 2,600 to 20,000 feet while making this journey. After a few weeks, they fly onto Columbia or Venezuela where they overwinter. Their spring migration route takes them over Cuba to Florida, where they journey up the eastern US seaboard to reach their breeding grounds in late May.

Vermont Center for Ecostudies: Blackpoll Warbler

Notice in this eBird abundance map for the week of 2 Nov that blackpolls are:

  • bunched up on the East Coast from Massachusetts to North Carolina
  • at a stopover on Puerto Rico and
  • early migrants have already arrived in South America.
Blackpoll warbler weekly abundance map, week of 2 Nov 2007-2021 (map from eBird Status and Trends)

Watch them throughout the year in this eBird abundance animation.

Blackpoll warbler weekly abundance map (animation from eBird Status and Trends)

Of course I wondered if blackpoll warblers sleep in flight during their 3 day transoceanic trip, but we won’t find out any time soon. Blackpolls are way too small to wear the sleep monitoring gear used on the great frigatebird.

(photo from Wikimedia Commons, maps from eBird Weekly Abundance; click on the captions to see the originals)

ebird species migration weekly abundance trends

Yesterday at Hays Woods Bird Banding

Hermit thrush banded at Bird Lab, Hays Woods, 3 Oct 2023 (photo by Jared Miller)

4 October 2023

Joe, Sam and Jared joined me yesterday morning on an adventure to see Bird Lab at Hays Woods. The weather was perfect as we walked more than half a mile to the banding station. There we found Nick Liadis and his assistants about to do the second net-check of the day.

The mist nets that capture songbirds are set up in “alleys” of vegetation where birds might fly across. If a bird doesn’t see the net and tries to fly through, it falls into the pocket of extra netting material where it waits to be retrieved. Banders check the nets every half hour.

Bird banding mist net at Hays Woods, 7 Sep 2022 (photo by Kate St. John)

Captured birds are brought back to the banding table in cloth bags to keep them calm. Our group watched as Nick prepared to band three birds from the recent net check.

Bird Lab at Hays Woods: 3 workers (orange vests) and three observers, 3 Oct 2023 (photo by Kate St. John)

Each bag contains a surprise. The first was a recaptured Cape May warbler (Setophaga tigrina), originally banded on 20 Sep when it weighed 10.9g. Yesterday it weighed 13.8g for a gain equivalent to the weight of a ruby-throated hummingbird. Such a small bird in Nick’s hand, below.

Nick Liadis holds a Cape May warbler recaptured at Hays Woods on 3 Oct, first banded on 20 Sept 2023 (photo by Kate St. John)

It was the second Cape May warbler recapture this fall. The first one increased its weight by 50% in two weeks. About the first one, Nick wrote:

A cool recapture from my Hays Woods banding station! This Cape May Warbler was banded on 9/13 and we captured her again two weeks later. She originally weighed 11.6g and today weighs 15.4g. Interesting to see how long some of these birds hang around. I’d imagine she’ll be on her way very soon.

— Nick Liadis message, 27 Sep 2023

Next on the agenda was a hatch year (meaning “hatched this year”) male black-throated blue warbler (Setophaga caerulescens). His color was blue, but not vibrantly so, and his throat had tiny white flecks on it. I had seen a dull bird like this in Frick Park last week and didn’t realize that meant he was young.

BirdLab at Hays Woods: Hatch Year male black-throated blue warbler in partial adult plumage, 3 Oct 2023 (photo by Jared Miller)

At each successive net check new species showed up.

The hatch year hermit thrush (Catharus guttatus) shown at top was a sign that the mix of migrant species is changing. The insect eaters are nearly gone while the fruit and nuts migrants have arrived (*see note).

The hatch year female house finch, below, was probably born at Hays Woods. Many house finches in the eastern U.S. are permanent residents. Perhaps she will be, too.

BirdLab at Hays Woods: Hatch Year female house finch, 3 Oct 2023 (photo by Kate St. John)

An ovenbird (Seiurus aurocapilla) is always nice to see up close and I had no trouble identifying it because it showed its striped crown. I saw one in the hand at Bird Lab last year.

BirdLab at Hays Woods: Ovenbird, 3 Oct 2023 (photo by Kate St. John)

By 10:00am we’d been there an hour, it was getting hot (the high yesterday was 85°F!) and the birds were less active. Three of us hiked to the overlook and returned for one more net-check. This time only one bird was captured, a hatch year house wren (Troglodytes aedon) that Nick had banded on 9 August. This bird has spent the last two months foraging at Hays Woods and soon it will migrate to Central or South America.

BirdLab at Hays Woods: House wren, 3 Oct 2023 (photo by Jared Miller)

We left Bird Lab and headed back to the parking lot where the fleet of enormous dump trucks, seen at 8:30am, were still shuttling dirt to/from Duquesne Light’s dirt road. Duquesne Light is building an access path to the cliff edge where two transmission towers need to be replaced and moved away from the landslide zone.

Thanks to Jared Miller for sharing his photos, shown above.

Bonus Bird: After the banding, a rare bird at Duck Hollow:

At 10:30am I received an alert that a migrating American avocet (Recurvirostra americana) was hanging out at Duck Hollow. Avocets in Allegheny County are One Day Wonders. I had never seen one here because I waited a day to go see them. So I made the short trip from Hays Woods to Duck Hollow and digiscoped this lousy picture. The light was too bright to see its faint orange color but you get the idea.

American avocet at Duck Hollow, 3 Oct 2023 (photo by Kate St. John)

p.s. (*) Two of the phases of fall migration: ** Insect eaters such as warblers, flycatchers, swifts and swallows migrate through in September because the bug population is going to die when cold weather hits. ** Fruit and nut eaters, including thrushes and sparrows, pass through in October.

(photos by Jared Miller and Kate St. John)

Coffee Grounds Replace Plastic in 3D Printing

Making coffee: a pour-over (photo from Wikimedia Commons)

3 October 2023

… and there’s a Pittsburgh connection.

When you make coffee, what do you do with the spent grounds? Some people compost them at home or use them as fertilizer. You can even turn them into an insect repellent or natural cleaning scrub. But most of us just throw them away.

Use coffee grounds (photo by Kate St. John)

When Michael Rivera was in grad school at Carnegie Mellon he spent a lot of time at Arriviste Coffee Roasters in Shadyside. At the time, Arriviste paid a service to collect their coffee grounds but the service stopped during the pandemic and the spent grounds piled up.

Arriviste Coffee Roasters (banner from Facebook page)

Rivera was working on 3D printing technology and saw how to solve two problems at the same time: (1) Reuse coffee grounds instead of throwing them away and (2) Reduce plastic use in 3D printing.

The vast majority of 3D printing machines use thermoplastic to make new objects by melting it and reforming it with the print head.

Four 3D printers making medical face visors (photo from Wikimedia Commons)

It can take a lot of plastic to make an object, particularly a large one.

3D printer creating a statue at 3D Printer Shootout Testing – Day 3 (photo from Wikimedia Commons)

Rivera is now a postdoctoral researcher at University of Colorado Boulder where he further fleshed out his idea of using spent coffee grounds instead of plastic.

Rivera and colleagues mix dried spent coffee grounds with two common food additives — cellulose gum and xanthan gum — and then mix in water.

“You’re pretty much shooting for the consistency of peanut butter,” Rivera said.

You can’t load that ooze directly into a 3D printer. First, Rivera does a little jury-rigging, modifying a printer with plastic tubes and a syringe filled with coffee paste. When dried, the coffee grounds material is about as tough as unreinforced concrete.

Science Daily: 3D printing with coffee: Turning used grounds into caffeinated creations

Here’s a coffee-based 3D print, photo embedded from the Ars Technica article.

Coffee-based 3D print (photo by Michael Rivera embedded from ars technica article)

The resulting objects are completely recyclable.

“You can make a lot of things with coffee grounds,” River said. “And when you don’t want it anymore, you can throw it back into a coffee grinder and use the grounds to print again.”

Science Daily: 3D printing with coffee: Turning used grounds into caffeinated creations

Here’s how Rivera and his team make 3D objects with coffee grounds.

video embedded from Univ of Colorado Boulder on YouTube

Read more about the project in Ars Technica: Don’t throw out those used coffee grounds—use them for 3D printing instead and the published study in July 2023 in the Association for Computing Machinery.

p.s. Does the reuse of coffee grounds sound familiar? I blogged about it a few weeks ago but forgot to mention it until Jennie Barker made the comments below.

(photos from Wikimedia Commons, Kate St. John, Arriviste Coffee Roasters Facebook banner, and embedded photo from Ars Technica; click on the captions to see the originals)

Invasive Look-Alike of Devil’s Walking Stick

Tennessee warbler on Aralia sp., 6 Sept 2023 (photo by Dave Brooke)

2 October 2023

In September birders lurk near devil’s walking stick in Frick Park because the plants attract birds on migration. Crawling with tiny insects and full of fruit, devil’s walking stick is often swarmed with visiting warblers, cedar waxwings and robins. But is it really devil’s walking stick (Aralia spinosa)? Or is it the invasive look-alike Japanese angelica (Aralia elata)? Or even worse, is it a hybrid?

I didn’t know about this possibility until Dave Brooke posted photos of two warblers on devil’s walking stick. The first was a Tennessee warbler, at top, followed by a Cape May warbler, below, that landed on the same perch in the same pose just 25 seconds later.

Cape May warbler on Aralia sp., 6 Sept 2023 (photo by Dave Brooke)

Anne Swaim responded to Dave’s post saying “Probably Aralia elata, the Japanese Angelica. Great bird attractant (but really invasive.) Same genus as the native Devil’s walking stick.”

Native to eastern Russia, China, Korea and Japan, Japanese angelica (Aralia elata) was brought to the U.S. as an ornamental plant. It’s well known in eastern Pennsylvania and New York state because those areas are outside Aralia spinosa‘s native range. Pittsburgh is on the border though, so I always assumed I was looking at the native plant.

Aralia spinosa‘s native range (map from Wikimedia Commons)

It’s so hard to tell them apart that New York Botanical Garden posted this guide to invasive look-alikes. Here’s a screenshot from the Aralia sp pages:

screenshot from Mistaken Identity? Invasive Plants and Their Native Look-Alikes, A Guide for the Mid-Atlantic (posted by NY Botanical Garden)

Their Quick ID is helpful for non-botanists like me.

Quick ID of Aralia elata (invasive alien):

  1. Leaf veins: Main lateral veins running all the way to the tips of teeth at the leaf margin.
  2. Inflorescence: Inflorescence shorter, typically 30–60 cm long, and WITHOUT a distinct central axis (often wider than long, with base usually surrounded by and even overtopped by foliage).

Quick ID of Aralia spinosa (native):

  1. Leaf veins: Main lateral veins branching and diminishing in size before reaching the leaf margin (smaller branching veins may run to the tips of teeth)
  2. Inflorescence: Inflorescence longer, often 1–1.2 m long, WITH a distinct central axis (typically longer than wide, base usually elevated above foliage).
Mistaken Identity? Invasive Plants and Their Native Look-Alikes, A Guide for the Mid-Atlantic (posted by NY Botanical Garden)

I tried to identify the plants at Frick by looking at the leaves but it’s very hard to do. The easiest way is by looking at the inflorescence — the tower of flowers.

Japanese angelica’s (Aralia elata) inflorescence basically lies flat. It does not have a central stem and the leaves may cover some of the flowers. Here’s Japanese angelica at Frick.

Inflorescence below the leaves = Japanese elata in Frick Park (photo by Kate St. John)

Devil’s walking stick’s (Aralia spinosa) inflorescence stands tall above the leaves on a central stalk.

Inflorescence above the leaves on a central stalk = Devil’s walking stick (photo by Tom Potterfield via Flickr Creative Commons license)

Now I’ve started looking at all the Aralias and asking: Which one are you?

You might know of a stand of a devil’s walking stick you’d like to examine too. To figure out its identity download the Mistaken Identity guide at nybg.org ==> https://www.nybg.org/files/scientists/rnaczi/Mistaken_Identity_Final.pdf

Also see Tom Potterfield’s Flickr album with photos of both species.

Meanwhile, for the sake of the warblers I am deciding not to get excited that these plants are alien. The birds love them so much and I love the birds so …

p.s. Read more about Japanese angelica’s invasive qualities at the Brandywine Conservancy: Invasive Species Spotlight: Japanese Angelica Tree (Aralia elata). Here’s where it occurs in the U.S. Yes, in Allegheny County. Wonder who planted it.

Japanese angelica in the U.S. (map from Invasive Plant Atlas, EDD)

(photos by Dave Brooke, nybg.org, Kate St. John and Tom Potterfield. Click the links in the captions to see the originals)