Category Archives: Musings & News

Right Now You Can Kayak in Death Valley

Kayaking on Lake Manly in Death Valley (photo from Wikimedia Commons)

26 February 2024

In case you missed it …

During the Ice Age, the Pleistocene 2.58 million to 11,700 years ago, there was a lake 600 feet deep in Death Valley where Badwater Basin stands today. Named Lake Manly(*) by geologists, it disappeared 10,000 years ago.

Badwater Basin is 282 feet below sea level so any water that reaches it can only evaporate yet the evaporation rate is so high that the basin is a salt pan. Occasionally — decades apart — there’s enough rain to make a shallow lake.

Badwater Basin in normal times, Dec 2018 (photo from Wikimedia Commons)

In the past six months California has had two unusual rain events. On 20 August 2023 Hurricane Hilary dumped 2.2 inches and caused Lake Manly to re-form in place. (The deluge also closed the Death Valley National Park for two months.) Amazingly the lake persisted through the winter.

Lake Manly, Death Valley, December 2023 (photo from Wikimedia Commons)

And then the Atmospheric River event of 4-7 February dumped 1.5 more inches of rain. Lake Manly grew to a depth of 1 to 2 feet so in mid-February the National Park Service opened it to kayaking.

video embedded from Associated Press on YouTube

The last time the lake formed, in 2005, it lasted only about a week. This time NPS estimates it’ll be gone — or at least too shallow for kayaks — by April.

So if you want to kayak in Death Valley, get out there now before Badwater Basin returns to normal.

Lake Manly typically looks like this in Badwater Basin, (photo from 2010 at Wikimedia Commons)

Read more here at ABC News: An ancient lake has reemerged at Death Valley National Park.

p.s. From Wikipedia: “The lake was named in honor of William Lewis Manly, who rescued immigrants from Death Valley in 1849.”

Dr. Livingstone, I Presume

Dr. David Livingstone monument at Victoria Falls National Park, Zimbabwe, 22 Jan 2024 (photo by Kate St. John)

Reflections on Road Scholar’s Southern Africa Birding Safari, 19 Jan – 2 Feb 2024

18 February 2024

This statue of Scottish explorer Dr. David Livingstone stands in Zimbabwe at the western end of Victoria Falls. After African independence, European monuments were removed and European towns renamed but Livingstone’s statue still stands, the falls still bear the name he gave them(2), and the nearest town across the river is Livingstone, Zambia.

Twenty years ago, two attempts were made to remove Livingstone’s statue but “resistance to the removals from the local community has ensured that Livingstone’s statue remains where it was first erected, gazing sternly out towards Devil’s Cataract.(1)

Our Zimbabwean guide pointed to a word carved on the monument that is key to Livingstone’s legacy in Africa.

Liberator.

Dr. David Livingstone, 1864 (photo from Wikimedia Commons)

In America we think of Livingstone as a great explorer but in Africa it is his never-ending fight to end the slave trade that holds him in African hearts. Livingstone went to Africa as a Christian missionary doctor and fell in love with exploring, ultimately mapping three long journeys in southern and eastern Africa covering 40,000 miles(2).

Journeys of Dr. David Livingstone, final journey in red (map from Wikimedia Commons)

During his second expedition to the Zambezi River (1858-1864) he witnessed the horrors of the East African Arab-Swahili slave trade and vowed to end it. Men, women and children were captured in the interior and marched to trading posts on the Indian Ocean coast, one of which was Zanzibar a British colony ruled by Arabs.

East African slave trade (image from Wikimedia Commons)

Livingstone reasoned that if he became famous for finding the source of the Nile he could influence the British government to end the slave trade so he returned to Africa in 1866 to accomplish both goals.

Five years later, in the absence of news, Livingstone was presumed dead or lost. Instead he was still exploring, very weak and sick with malaria and without quinine to treat it because someone stole his medical kit. Meanwhile he wrote letters to Britain describing the slave trade but the slavers were the only ones available to carry his letters to the coast. Knowing that Livingstone was against slavery, they delivered only one of his 44 letters.

Livingstone’s disappearance was such a great mystery that the New York Herald sent journalist Henry Morton Stanley to Africa where he caught up with Livingstone at Ujiji in October 1871 and said, “Dr. Livingstone, I presume.”

Henry Morton Stanley greets Dr. David Livingstone at Ujiji (image from Wikimedia Commons)

Livingstone did not want to leave Africa so Stanley took Livingstone’s dispatches to Britain where they exposed the appalling massacres and cruelty of the slave trade.

British reaction was swift but Livingstone did not live to see it. “One month after his death, Great Britain signed a treaty with Sultan Barghash of Zanzibar, halting the slave trade in that realm. The infamous slave market of Zanzibar was closed forever.(2)

More than any of his contemporaries, Livingstone succeeded in seeing Africa through African eyes.

Princeton University Library: David Livingstone, 1813-1873

p.s. In the U.S. most of us don’t realize that the West African slave trade that our country participated in was not the only source of slaves. Britain outlawed the trans-Atlantic slave trade in 1807 but it continued elsewhere. For instance, Mauritania in West Africa did not impose penalties on its local slave trade until 2007. Today slavery persists in some parts of Africa. Read about Slavery in Contemporary Africa here.

(credits are in the captions) Footnotes on sources.

  1. Information on Dr. David Livingstone’s Statue, Siyabona Africa website.
  2. Summary of Livingstone’s life, Princeton University Library.
    • “Victoria Falls was the only site in Africa that Livingstone named with English words.”

Watch Birds Where It’s Warm

Black-crested jay at Canopy Lodge, 10 Jan 2024 @PanamaFeederCam on Twitter

12 January 2024

The weather is going to turn nasty tomorrow and very cold next week so it’s time to stay indoors and watch birds where it’s warm.

Tropical birds and feeder-hungry mammals visit the Panama Fruit Feeder Cam at Canopy Lodge. The black-crested jay, above, takes a look at a potential meal while a mother agouti, below, brings her cubs to the banquet. Agoutis show up in dark too.

Agouti family: mother and cubs, 12 Jan 2024 @PanamaFeederCam on Twitter

Watch birds where it’s warm on Panama Fruit Feeder Cam.

Live Panama Fruit Feeder Cam on YouTube

Follow @PanamaFeederCam on Twitter for quick updates.

How Did Dinosaurs Eat Tall Trees?

Animals on their hindlimbs: elephant, gazelle and four Sauropods (illustration from Wikimedia Commons)

10 January 2024

Today I found an illustration that’s full of surprises showing six animals in the rearing up position. With two humans for scale the animals are: an African elephant, a gerenuk, and four Sauropoda dinosaurs: Diplodocus, Giraffatitan, Barosaurus, and Opisthocoelicaudia. The black and white dot on the elephant and dinosaurs indicates the center of mass (COM) for balance; the tiny black square is the location of the hip socket.

The elephant and gerenuk (giraffe gazelle) both rear up to reach food but for many decades the idea that Sauropods lifted themselves from the ground was considered scientifically inaccurate.

This 1907 illustration of Diplodocus by Charles Robert Knight is so noted on Wikimedia Commons.

Diplodocus illustration by Charles Robert Knight (from Wikimedia Commons)
Wikimedia accuracy note about the Diplodocus illustration

The note says the picture is not factual because “Sauropods were terrestrial.”

Did Sauropods always keep all four feet on the ground? They ate tall plants, two examples of which still live today in California: coastal redwoods and giant sequoias. It makes sense they would have to rear up to reach them.

Coast redwoods and giant sequoia in California (photos from Wikimedia Commons)

And most Sauropods had very long tails to use as props the way woodpeckers do.

The five longest dinosaurs (image from Wikimedia Commons)

Put it all together with a lot more scientific information and the rearing up makes sense. Here’s the description on the illustration, formatted for clarity, that explains why Sauropods were better adapted for rearing than many modern mammals, such as elephants:

  • Sauropod necks and torsos are lightened because of an extensive air sac system which, combined with long, muscular, and dense tails, helps shift the centre of mass (COM) backwards, closer to the hip socket in some sauropod species.
  • Some sauropods have retroverted pelves which might have allowed the legs to maintain greater functionality when rearing.
  • [Bones in] the anterior part of the tail suggest flexibility, the tail being able to serve as a prop when in a tripodal posture.
  • The hip socket allowed for a large range of motion, more than needed for normal quadrupedal walking.
  • The wide strongly flared pelvis was thought to further aid stability in a tripodal posture.
Wikimedia Commons: Description of Sauopods Rearing illustration

Specifically for Dippy, “The Center of Mass (COM) of Diplodocus is estimated to be very close to the hip socket. This makes prolonged rearing possible and does not require much effort to do it. Combined with its long, massive tail acting as a prop, it was also very stable. Mallison found Diplodocus to be better adapted for rearing then an elephant.”

The description also points out that Giraffatitan, the second dino from the left, would have a hard time rearing. His COM was too far from his hip socket and his tail was short.

So it’s likely that Dippy reared up on his hind legs and could do so for hours while he browsed the trees like a deer.

Outdoor statue of Diplodocus carnegii, named Dippy, wearing a winter scarf at The Carnegie Museum of Natural History (photo from Wikimedia Commons)

Way cool, Dippy!

Dippy celebrates the Winter Solstice, 2022 (photo by Kate St. John)

(credits are in the captions with links)

Using Salt to Get Water

Salt shaker (photo from Wikimedia Commons)

19 December 2023

You’ve probably noticed that in humid weather table salt clumps in the salt shaker and sticks to the top. That’s because at the molecular level salt’s ions have a net positive charge that attracts atmospheric water which has a net negative charge. Salt literally pulls water out of the air and builds crystals. This process can make the top of the salt shaker moist or dampen a salted road on a humid day.

Can salt’s natural means of pulling water from the air be used to gather water in a larger way? Researchers led by Marieh B. Al- Handawi investigated Athel tamarisk (Tamarix aphylla), a desert plant native to Africa and Asia that takes up saline water with its roots and secretes excess salt through its leaves.

Tamarisk salt cedar, Tamarix aphylla (photo from Wikimedia Commons)

The tiny leaves are arranged alternately, almost wrapping the branches. The salt crystalizes on the leaves. Look closely and you can see tiny crystals.

Closeup of Athel tamarisk branch (photo from PNAS: Harvesting of aerial humidity with natural hygroscopic salt excretions)

The smaller crystals stay on the plant and attract more water, especially overnight as shown on this branch in the early morning (8 a.m.) with condensed water droplets.

Athel tamarisk: A branch recorded in the early morning (8 a.m.) showed condensed water droplets. (PNAS: Harvesting of aerial humidity with natural hygroscopic salt excretions)

As the sun gets higher it evaporates the water, leaving behind larger salt crystals which fall to the ground.

A branch recorded in the late morning (11 a.m.) was encrusted with salt crystals. (PNAS: Harvesting of aerial humidity with natural hygroscopic salt excretions)

Every day the water cycle repeats: (A) branches attract water overnight, (B) water evaporates during the hot day while salt crystals grow, (C) water is gone and crystals are large, (D) during overnight high humidity the crystals attract water from the air and the plant absorbs the water. — paraphrased from PNAS: Harvesting of aerial humidity with natural hygroscopic salt excretions.

The tree is “drinking” from its leaves.

Researchers observed that at least one type of salt, lithium sulfate, forms small crystals that remain on the leaves and absorb water from the air. When the team added colored water to salty leaves, they watched the liquid stick to the crystal crust, then absorb into the plant’s leaves—evidence that the salty coating acts as a bona fide water collection mechanism.

Science Magazine: Desert trees may pull water from thin, dry air using salt-encrusted leaves

The tree is very salt tolerant so this water collection process won’t translate directly for humans. But perhaps we’ll find a way.

For more information see Science Magazine: Desert trees may pull water from thin, dry air using salt-encrusted leaves or the PNAS publication Harvesting of aerial humidity with natural hygroscopic salt excretions.

(photos are from the Open Access PNAS article: Harvesting of aerial humidity with natural hygroscopic salt excretions)

They Want to Cull Barred Owls Again

Barred owl, 5 May 2005 (photo by anonymous)

30 November 2023

Sometimes history repeats itself.

In 2013 US Fish & Wildlife proposed an experiment: Kill 3,600 barred owls (Strix varia) in the Pacific Northwest to keep them away from their close relative, the northern spotted owl (Strix occidentalis). Barred owls had spent 100 years expanding westward to the Pacific coast where they became more successful than their habitat-constrained spotted cousins and even interbred with them. Though barred owls are native to North America and moved west on their own, USFW dubbed them “invasive” and proposed killing them wherever found near spotted owls.

Nationwide comments on the culling proposal were overwhelmingly negative but local comments were in favor. The experiment went forward and barred owls were killed according to plan. The final paper describes barred owl “removal”.

Barred owls detected in treatment areas were removed using 12-gauge shotguns and well-established field protocols (20, 22, 23). A total of 2,485 barred owls were removed from treatment segments of five different study areas during the experiment (Table 1). The mean number of barred owls removed per year was highly variable among study areas, ranging from a low of 15.8 barred owls per year in Green Diamond (GDR), to a high of 251.5 barred owls per year in the Oregon Coast Range (COA).

— FWS.GOV Study Results: Invader removal triggers competitive release in a
threatened avian predator

The five locations where removal occurred, called “treatment” areas, and the number of barred owls killed are shown in the screenshot of Table 1.

Table 1 from FWS Barred Owl Removal study

Interestingly at two of the five study sites — Hoopa-Willow Creek and Green Diamond, California — the killing of 494 barred owls made little to no difference for the spotted owls. Click here for the graph that shows this.

However, USFW declared the experiment a success and recently drafted a new “Barred Owl Management” proposal to continue killing barred owls and expand the project further in California. The draft is currently in its 60-day public comment period: November 17, 2023 – January 16, 2024 during which we are free to express our opinion.

Read about the proposal and download relevant documents at Fish and Wildlife Service seeks public comment on draft strategy to manage invasive barred owls. Click here to submit a comment online or paper-mail your comments to the address below. The comment period ends on 16 Jan 2024.

Public Comments Processing; Attn: Docket No. FWS-R1-ES-2022-0074
U.S. Fish and Wildlife Service Headquarters, MS: PRB/3W
5275 Leesburg Pike
Falls Church, VA 22041–380

p.s. Here’s what I thought of this idea 10 years ago. I haven’t changed my mind.

Watch Out for the Thagomizer!

Stegosaurus stenops, life reconstruction (image from Wikimedia Commons)

20 November 2023

For those who love dinosaurs, Stegosaurs are a recognizable favorite. These plant-eating armored animals wore rows of raised plates on their backs and spiky tails to protect them from the carnivores, especially the Allosaurus, a theropod ancestor of modern day birds.

When threatened, the Stegosaur swung its tail to batter its attacker with the spikes.

Stegosaurus tail detail, in the Royal Belgian Institute of Natural Sciences (photo from Wikimedia Commons)

This display at the Denver Museum of Nature and Science shows an Allosaur ready to bite a Stegosaur while two Stegosaur young run beneath her. Look closely in the background and you can see that the end of her tail — the spikes — are out of sight as they swing at the Alloasaur’s back.

Allosaur attacking Stegosaur, Denver Museum (photo from Wikimedia Commons)

When paleontologists were puzzled by a hole in this Allosaur vertebrae (at left) they figured out that a Stegosaur spike fits the hole (at right). Bone piercing bone in real time. Ouch!

Stegosaur tail spike pierced an Allosaur backbone (image from Wikimedia Commons)

The arrangement of the tail spikes had no name until “Kenneth Carpenter, then a paleontologist at the Denver Museum of Nature and Science, used the term when describing a fossil at the Society of Vertebrate Paleontology Annual Meeting in 1993.” — quote from Wikipedia.

The name came from a Far Side cartoon in 1982 when Gary Larson invented it as a joke. “Now, this end is called the thagomizer … after the late Thag Simmons.”

The name caught on and is now official.

thagomizer is the distinctive arrangement of four spikes on the tails of stegosaurian dinosaurs. These spikes are believed to have been a defensive measure against predators.

Wikipedia: Thagomizer account

The rest is history.

Watch out for that thagomizer!

(credits are in the captions. Tip of the hat to Jonathan Nadle who told me about the thagomizer.)

Tiny Blue Lights In The Woods

14 November 2023

On my way to somewhere else I found … tiny blue lights in the woods. I have never seen them in person but these photos from Anna Ruby Falls Recreation Area in the Chattahoochee National Forest are intriguing. Bioluminescent mushrooms glow green, fireflies glow yellow-green, but these are blue.

Each light is one of two ends of a fungal gnat larvae (Orfelia fultoni). This photo by Alan Cressler, embedded from Flickr, shows what the larva looks like during the day.

Orfelia fultoni, Anna Ruby Falls Recreation Area, Chattahoochee National Forest, White County, Georgia 5
Orfelia fultoni, Anna Ruby Falls Recreation Area, Chattahoochee National Forest, White County, Georgia 5 (photo embedded from Alan Cressler on Flickr)

Alan Cressler describes them:

Orfelia fultoni, Anna Ruby Falls Recreation Area, Chattahoochee National Forest, White County, Georgia:

This is the only bioluminescent fungus gnat larvae in North America. Both whitish ends of the larvae emit a blue light used to lure prey. Although they may be common in proper habits, apparently there are very few places in the southeast where they form extensive colonies. One place is Dismal Canyon in Alabama where they are locally called “dismalites”. I was invited by my friends who work for the Chattahoochee National Forest to view and photograph the extensive colony at Anna Ruby Falls Recreation Area. Locally the event is called “fox fire” and there are scheduled night hikes to witness the amazing colony. Other than the guided night hikes, after hours entry into the area is prohibited.

Fungus gnat larvae live within a slime tube and develop a network of sticky filaments that capture prey that are attracted by the blue glow. The sticky filaments can be seen in the photos.

Orfelia fultoni, Anna Ruby Falls Recreation Area description, Alan Cresler on Flickr

In the photographs above, the lights don’t look connected but you can see how they move in this video in New Zealand. The bluish glow worms in New Zealand are not the same species but they have a similar appearance and behavior.

video embedded from PBS Deep Look

Back in Georgia the foxfire glows mid-May through June when the gnat’s larval form is alive. Night hikes are offered during those months but pre-registration is required and the hikes fill up fast. Don’t wait until May 2024 to check this website for Foxfire Night Hikes at Anna Ruby Falls: https://gofindoutdoors.org/events/foxfire-night-hikes-coming-soon/

(Originals and credits of the slideshow photos can be seen by clicking on each photo)

A Wasp, An Oak, and Indelible Ink

Screenshot from Making Manuscripts: Oak Gall Ink (source video below from the British Library on YouTube)

12 November 2023

Nowadays it’s rare to write anything by hand unless it’s the size of a Post-It note. When we really want to say something we use keyboards and touch screens to generate digital text read on screens or, less often, on paper. Our writing equipment becomes obsolete so rapidly that our computers and cellphones are replaced within a decade. (Who among us is still using the same cellphone since 2013? Do we even remember what model it was?)

So consider this: Humans used the same writing tool, the same indelible ink, from the 5th to the 19th century. When applied to parchment, it is readable 1,700 years later. The ink is easy to make by hand from natural ingredients and is still used in calligraphy today. To make iron gall ink, the process starts with a wasp and an oak.

When a cynipid wasp lays an egg in a developing oak leaf bud, the hatched larva secretes a substance that makes the oak surround it with a gall. The wasp (Andricus kollari) and the oak marble gall below are from Europe but similar wasps and oak galls occur in North America(*).

The outer shell of the gall is rich in tannins whose presence protects the wasp from predation.

Oak marble gall on white oak forced by Andricus kollari (photo from Wikimedia Commons)

When crushed and soaked in water the galls’ tannins give color to the ink.

Oak marble galls on the twig, forced by Andricus kollari (photo from Wikimedia Commons)

Two more ingredients transform the ink for final use: Iron sulfate dissolved in water makes the ink black.

Iron sulfate crystals (photo from Wikimedia Commons)

Gum arabic dissolved in water makes the ink sticky enough to hold onto parchment or paper.

Gum arabic in lumps and powder (photo from Wikimedia Commons)

This video from the British Library shows how iron gall ink is made.

(video embedded from the British Library on YouTube)

Eventually we used paper instead of parchment, even for important documents, and iron gall ink fell out of favor because the acid in iron sulfate makes the paper disintegrate. To solve that problem we invented paper-friendly inks and then computers.

Iron gall ink has oxidized the cellulose, causing the paper to disintegrate (from Wikimedia Commons)

Medieval manuscript creation used natural products from animals, plants and minerals. See the process from parchment to ink to binding in this 6-minute video from the Getty Museum.

video embedded from the Getty Museum on YouTube

Read more at Making Ink From Oak Galls: Some History & Science.

(*) p.s. The amount of tannin varies by type of gall and the tree species the gall came from. Galls with the most tannin work best.

(credits are in the captions)

Changing Bird Names Yet Again

Wilson’s warbler (photo from Wikimedia Commons)

6 November 2023

By now you’ve probably heard that a lot of bird names are going to change in the U.S. and Canada.

The American Ornithological Society [AOS] has vowed to change the English names of all bird species currently named after people, along with any other bird names deemed offensive or exclusionary.

NPR: These American birds and dozens more will be renamed, to remove human monikers, 1 November 2023

The AOS can do this because they have jurisdiction over all the bird names in the Americas. Every year they make 5-10 name changes, usually among scientific names due to new DNA research, and we birders cope. This project is larger and will take several years as they change the common English names of 70-80 birds.

Stop Change

My first reaction was typical. I don’t like change unless I instigate it so I thought: “This sounds like an overreaction to the name problem. All the field guides will be out of date(*ummm, they already are). It’ll be an ordeal to change the data when 4-letter bird banding codes, based on the English names, change as well. I don’t want to do this. Stop Change.”

But then I changed my mind because … I made a list of names that will change and began to invent new ones and the new names were better than the old ones. I could see the point. Here are two examples.

The Wilson’s warbler (Cardellina pusilla), pictured at top, has held the same English name for 185 years, though its scientific name has changed five times since it was first described in 1811 by Alexander Wilson. Its current 4-letter banding code is WIWA.

Suppose it’s new name becomes “black-capped warbler” as suggested by my friend Shawn Collins. It’s so much more descriptive! When someone asks, “What is that warbler with the black cap?” the answer is obvious. The new banding code would be BCWA.

The Cooper’s hawk (Accipiter cooperii), doubly named for ornithologist William Cooper, is most often noticed near backyard bird feeders because it eats birds for a living.

Cooper’s hawk looking for prey (photo from Wikimedia Commons)

[The Cooper’s hawk] it is an inconspicuous species. However, since the 1970s, Cooper’s Hawks have commonly nested in suburban and urban landscapes, such that it is likely the most common backyard breeding raptor across North America.

Birds of the World: Cooper’s hawk account

Suppose its new name becomes “backyard hawk.” When someone says, “There’s a hawk in my backyard…” the answer is almost obvious (there are several possibilities). The new banding code would be BAHA.

AOS might not use these suggestions but I’m happy to have found names that are unique and available as well as the proposed banding codes.

So now I’m a bit excited by the prospect of fixing up the people-names.

Meanwhile, learn more about the project at AOS’s English Bird Names Project FAQ and the people behind some of the names at Learn About the People Certain Birds Are Named After.


p.s. Who was Alexander Wilson? According to Wikipedia he was:

  • Born in Scotland in July 1766
  • Held all kinds of jobs: herder, journeyman, peddler, weaver and then…
  • Became a poet, sometimes satirical & incendiary enough to get arrested. One popular poem started a libel suit against him which he countered by blackmailing the libeler.
  • He was living in poverty so he decided to emigrate to America in 1794 at age 27.
  • In the U.S. he taught school for 5 years until he got into a scandal with a married woman.
  • And then he met naturalist  William Bartram who encouraged his interest in birds and painting. Wilson traveled, sketched, painted and described birds. His illustrations and descriptions of 268 birds included 26 which had not been described before. The way he posed the birds inspired other bird illustrators including Audubon.
  • He died in poverty in 1813 at age 47.

When Alexander Wilson got hooked on birds he became a very good observer, illustrator and ornithologist in the final decade of his life (1802-ish to 1813). Wilson’s warbler was named for him 25 years after his death.

Humans are complicated.

(credits are in the captions except for the Stop Change sign formerly used by Pittsburgh Regional Transit to denote a BUS stop change. I used to have that sign hanging in my office.)