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.

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

Follow @PanamaFeederCam on Twitter for quick updates.

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.

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.

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

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.

Way cool, Dippy!

(credits are in the captions with links)

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.

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.

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!

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.

A 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.)

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.

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.

[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.)

27 October 2023

In school we learned geography on flat maps using the Mercator projection. Google Maps uses a version called Web Mercator.

The Mercator projection that transforms our 3-dimensional Earth into 2-dimensions was invented in 1569 for use in navigation, which is why Google uses it. Unfortunately it totally distorts the size of land closer to the poles. It makes Greenland look big, maybe bigger than Africa. New Zealand is often cropped off this map.

The animation at top alternates between the Mercator projection and each country’s actual relative size. Hello, Northern Hemisphere, you aren’t as big as you think you are!

If we correct for size, as in the Gall-Peters projection, we mess up shapes and navigation.

Every flat map has distortions. This 6-minute video explains why. There is no right answer.

Making a flat map of the Earth is like trying to cut an orange peel to make it lay flat on the table. Good luck!

p.s. Here’s a screenshot from the thetruesize.com mapping tool that Johnny Harris mentions at the end of the video. Its initial screen demonstrates that the contiguous U.S. + China + India can easily fit into Africa with room to spare. Try it at thetruesize.com

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