Category Archives: Travel

Quiz: Where Is The Largest Desert on Earth?

Quiz, Travel, Weather & Sky
Rippled sand of Sharjah Desert, UAE (photo from Wikimedia Commons)

Quiz! Where is the largest desert on Earth? What continent is it on?

By “largest” I mean square miles. By “desert” I mean …

A desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to the processes of denudation. About one-third of the land surface of the world is arid or semi-arid.

— Wikipedia entry for Desert

Did you know that the majority of deserts are not composed of sand dunes?

To get you in the mood, here are photos of deserts around the world.

The road to Mar Musa, Syria (photo from Wikimedia Commons)
Gobi Desert, Mongolia, in autumn (photo from Wikimedia Commons)
Valle de la Muerte, Atacama Desert, Chile (photo from Wikimedia Commons)
Arizona National Scenic Trail (photo from Wikimedia Commons)

Leave a comment with your answer. I’ll post the answer later today (see below).

Click here for a map (By the way, this map includes the answer but it doesn’t look that way!)

ANSWER: Antarctica! In fact both poles are deserts. The Antarctica Polar Desert is 5.5. million square miles, the Arctic Polar Desert is 5.4 million sq mi and the Sahara is 3.5 million sq mi. Read more about the largest deserts at geology.com.

Snow surface at Dome C Station, Antarctica (photo from Wikimedia Commons)

Why is it a desert? Because the air is so dry. As the Dan Satterfield explains in Scientific Facts That Are Not True:

It cannot be too cold to snow some. It can be too cold to snow a lot. As air gets colder, it can hold less moisture. This is why the Antarctic is the greatest desert on Earth. It’s drier in many places than the Sahara! Climate change is expected to cause more snow in polar regions, not less. Now you know why. (warmer air means it can snow more)

— Wild Wild Science Blog: Scientific Facts That Are Not True

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

Up to 55 mph Non-Stop For 11 Days

Alaska, Migration, Water and Shore
Bar-tailed godwit (photo from Wikimedia Commons)

14 October 2020

Yesterday the news broke that a bar-tailed godwit fitted with a satellite tracking tag had flown non-stop over the Pacific Ocean from Alaska to New Zealand in 11 days. During his 7,500 mile trip he reached speeds of up to 55 miles an hour. He’s an amazing bird from an amazing subspecies.

Bar-tailed godwits (Limosa lapponica) breed in Scandinavia, Siberia and Alaska and spend the winter at shores from Europe to Africa, from southern Asia to New Zealand. Most travel over or near land (see map) but the Alaskan subspecies, Limosa lapponica baueri, flies down the center of the Pacific Ocean to New Zealand. According to Wikipedia, this subspecies makes “the longest known non-stop flight of any bird and the longest journey of any animal without feeding.”

Late last year the Pukorokoro Miranda Shorebird Centre in New Zealand satellite-tagged 20 bar-tailed godwits to find out where and when they go. Tracked by the Global Flyway Network, godwit 4BBRW left Alaska on 16 September and landed in New Zealand on 27 September.

Find out more and see his route at The Guardian link below.

Route of bar-tailed godwit 4BBRW, Sep 2020 (map from Global Flyway Network, embedded from The Guardian)

(photos from Wikimedia Commons; 4BBRW map embedded from The Guardian article, complete route from Wikimedia Commons; click on the captions to see the originals)

p.s. Next spring he’ll fatten up to return to Alaska on one of these red routes.

Limosa lapponica baueri migration routes (image from Wikimedia Commons)

And he’ll look a lot fancier in breeding plumage.

Bar-tailed godwit in New Zealand in June, breeding plumage (photo from Wikimedia Commons)

Emergency Rest Stop For Birds

Migration, Travel
Mount Desert Rock, 2006 (photo by Justin Russell via Flickr, Creative Commons license)

If this were a normal year(*), my husband and I would be at Acadia National Park right now and I’d go on a whale watch tour in the Gulf of Maine to see shearwaters, storm-petrels and (rarely) a south polar skua. Overhead, far from shore, I’d also see migrating songbirds crossing the water from Nova Scotia to Acadia, still traveling during the day in order to make landfall.

Their journey across the Gulf of Maine — about 100 miles — mimics their 600-mile journey over the Gulf of Mexico from Louisiana to the Yucatan which takes 15-25 hours of non-stop flying. Even during the shorter Gulf of Maine journey some have to make an emergency rest stop on Mount Desert Rock, an inhospitable way station for songbirds, shown above.

Gulf of Maine (left) and Gulf of Mexico (right) — not to scale — non-stop journeys for migrating songbirds (maps from Wikimedia Commons)

This week millions of songbirds are crossing both the Gulf of Maine and the Gulf of Mexico.

Read about what they find if they stop on Mount Desert Rock in this 2013 article No Food, No Water.

p.s. (*) Alas, it’s not a normal year. We wish we could go to Maine but COVID-19 precautions canceled any idea of flying and even if we drove to Maine we’d have to quarantine in the hotel for 14 days, using up our entire vacation and prohibiting any whale watch tour. Sigh.

A Face That’s Hard To Love

Travel, Water and Shore
Marabou stork closeup (photo from Wikimedia Commons)

The Marabou stork (Leptoptilos crumeniferus) can’t help it, he’s ugly. His face is hard to love.

When he’s amorous, or hot, or in a bad mood he inflates his fleshy throat sac which intimidates the other storks. It’s ugly, too.

Maribou stork with throat sac inflated (photo from Wikimedia Commons)

Find out more about him in this vintage article …

The Undertaker

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

Smaller is Normal

Alaska, Bird Anatomy, Climate Change
Song sparrow, western Pennsylvania (photo by Steve Gosser)

From their 29% population decline to the continued loss of federal protection the news about birds has not been good in recent months. When a December 2019 study from Chicago’s Field Museum found that North American birds have been shrinking since 1978 you may have wondered, “Is this bad news for birds?” Not exactly.

The study published in Ecology Letters measured 70,000 window-killed birds collected in Chicago since 1978. Analysis showed that the 52 species significantly declined in body size during the 40 year period (1978-2018). This mirrors a 2010 study conducted at Powdermill Nature Reserve in Pennsylvania which used 46 years of banding data (1961-2007) to analyze the body size of nearly 500,000 birds in 102 species. Powdermill also saw a decline in body size.

Both studies correlated the annual mean summer temperature of the species’ breeding range and reached the same conclusion: As the climate heats up, birds are getting smaller.

We should expect this.

There’s a biological rule of thumb called Bergmann’s Rule which states that, within a species, populations living in colder climates have larger body size than those in warmer climates. Bergmann’s explanation is that large animals have a lower surface-area-to-volume ratio so they lose heat more slowly in cold climates while small animals have a higher surface-to-volume ratio and can cool off faster when it’s hot.

Song sparrows (Melospiza melodia) provide a good example of Bergmann’s rule because they range across North America from Alaska to Newfoundland and south to Mexico. I saw their variability up close in the Carnegie Museum of Natural History’s Section of Birds in December 2016. My photo below shows sparrows collected in Alaska in the top row, sparrows from Pennsylvania on the bottom.

Song sparrows in Carnegie Museum of Natural History collection, Alaska on top row, Pennsylvania on bottom row (photo by Kate St. John, Dec 2016)

Here’s a closeup placed side by side (below):

  • On the left, two song sparrows collected in Pennsylvania: Pittsburgh (leftmost) and Geneva Marsh.
  • On the right, song sparrows collected in Alaska’s Aleutian Islands at Unalaska (leftmost) and Sanak.

Alaskan song sparrows are so large that they have to be placed sideways in the tray!

Smaller size is normal where it’s warmer.

It isn’t bad news for birds and it tells us two additional things:

  1. Birds’ bodies have been registering climate change long before we humans noticed or admitted it.
  2. Birds can evolve quickly when they have to.

Read about the Field Museum study at North American birds are shrinking. Read more about the Powdermill study at Birds are getting smaller.

p.s. This article was inspired by Andrew Nikiforuk’s As The Birds Vanish.

(top photo by Steve Gosser, remaining photos by Kate St. John)

Seaside Nestcams To Watch This Winter

Nesting & Courtship, Travel, Water and Shore

Here are two seaside bird cams to watch while we wait for Pittsburgh’s eagles and peregrines to lay eggs in the coming months.

Above, a northern royal albatross (Diomedea sanfordi) couple nests on camera at Taiaroa Head Nature Reserve in New Zealand. The pair have lots of combined experience — he’s 21 years old, she’s 25 — so they know their egg, laid in Nov 2019, is due to hatch at the end of this month (January 2020).

Since New Zealand is 18 hours ahead of Pittsburgh it’s best to watch from noon to midnight Eastern Time if you want to see the birds in daylight. This is a perfect schedule if want to kickback at the end of the day. See the northern royal albatrosses at their nest on Cornell Lab’s Royal Albatross bird cam.

Just one time zone ahead of Pittsburgh, the female Bermuda cahow (Pterodroma cahow) rejoined her mate at their nest on Nonesuch Island, Bermuda on 10 January 2020. Almost immediately she laid her single egg. Watch their reunion in this short video.

Bermuda cahows come to and fro at night so Cornell Lab’s Bermuda Petrels bird cam is best to watch at the end of the day .

In late February or early March the cahow’s egg is due to hatch. By then the Hays bald eagles will have eggs.

(videos from Cornell Lab bird cams)

Near Threatened Eagles: A Life Story

Birds of Prey, Travel
African crowned eagle, Kenya (photo from Wikimedia Commons)

The amazing photo below of an eagle’s claw and a human hand left me wondering, Who is this bird and why are his claws so big? Today I’ll tell you a bit of his life story.

The talons of a African Crowned Eagle compared to a hand.
byu/edison_1 inpics
Juvenile crowned eagle in captivity (image from r/pics on Reddit)

Shaped like a giant goshawk with a feather crest, the crowned eagle (Stephanoaetus coronatus) lives in the riparian forests of sub-Saharan Africa where it eats monkeys, small forest antelopes (duikers), “mouse-deer” (chevrotains) and “rock rabbits” (rock hyrax). Click on the links to see photos of these unusual animals.

Crowned eagles weigh only 6-10 pounds, smaller than bald eagles, yet they routinely capture mammals twice as heavy as they are. Reports say they can fly with prey that outweighs them, but they normally rip it apart on the ground and cache pieces in the trees. For this lifestyle they need large talons.

Adult African crowned eagle,South Africa (photo from Wikimedia Commons)

Deforestation in Africa is destroying the crowned eagles’ high-canopy habitat and their population is declining. They are listed as Near Threatened by the IUCN.

African crowned eagle in flight (photo from Wikimedia Commons)

Fortunately they nest in safety at Zimbali Coastal Resort near Durban, South Africa. Watch them at the nest in Zimbali’s 8-minute video.

(photos from Wikimedia Commons, embedded Reddit post; click on the captions to see the originals)

Science By The Seat Of Our Pants

Musings & News, Travel
screenshot from CalTech video: The Science of Booming Sands – 2015

For thousands of years people have known that certain sand dunes make a low humming sound, the musical note of G, E or F. It occurs when the sand is moving but you can force the sound if you slide downhill. Why does it hum?

A decade ago scientists at CalTech studied two humming sand dunes in California to answer that question. They found that for the sand to sing, the grains have to be all the same size, the dune must have a slope greater than 30 degrees and be over 120 feet tall, and the sand must be dried under the desert’s summer sun. It was very hot work.

The humming sound occurs naturally when the sand moves but that doesn’t happen on a predictable schedule so the CalTech team forced the sound. Dr. Melany Hunt explained,

Usually we would trigger it by having a number of people slide down the dune in unison. We always called it ‘Science by the seat of our pants.’

Learn about their study in this short video from CalTech or hear the sound as it’s being made in this vintage article: Singing Sand.

(screenshot from CalTech video: The Science of Booming Sands – 2015)

Some Cape Cod Birds

Travel
Sanderling at Corporation Beach, MA, 19 Oct 2019 (photo by Bob Kroeger)

27 October 2019

This month’s trip to Cape Cod provided me with a brief change of scene and a brief change of birds. On October 18 and 19, local photographer Bob Kroeger showed me many of his favorite birding spots. Here are some of the birds we saw, with thanks to Bob for the photos.

Sanderlings (Calidris alba) never come to Pittsburgh but they spend the winter at Cape Cod. It was fun to see them poking the sand with their beaks and bathing at the water’s edge at Corporation Beach.

Sanderlings bathing at Corporation Beach, MA, 19 Oct 2019 (photo by Bob Kroeger)

Ruddy turnstones (Arenaria interpres) are an extremely rare bird in Pittsburgh that also winters at Cape Cod. They aren’t ruddy in the fall, but their legs are still orange.

Ruddy turnstone (photo by Bob Kroeger)

Great blue herons (Ardea herodias) were plentiful in the marshes. They’re huge in flight!

Great blue heron in flight (photo by Bob Kroeger)

We found one or two blackpoll warblers (Setophaga striata) at nearly every place we stopped. This one at Long Pasture still has hints of black on his face and the telltale yellow feet. They are on their way to Brazil.

Blackpoll warbler (photo by Bob Kroeger)

We found a flock of 25 palm warblers (Setophaga palmarum) at Cape Cod Organic Farm, all of them the duller western birds. In mild winters palm warblers stay on the Cape.

Palm warbler (photo by Bob Kroeger)

Most plentiful by far were the “myrtle” yellow-rumped warblers (Setophaga coronata) who’ve come to stay for the season. The winter birds look dull but in Bob’s closeup below you can see his feather details.

A close look at a yellow-rumped warbler (photo by Bob Kroeger)

Best only-at-the-sea birds: At Wellfleet Bay on the 21st I saw distant flocks of 200 brant (Branta bernicla) and 60 common eider (Somateria mollissima).

Most amazing sound: The wing whistle of a flock of scoters passing overhead. Sounds like this.

Best mammal : A coyote crossing the road near Monomoy.

Craziest bird: A wild turkey running non-stop around a parked car in Harwich, like this. I’m waiting for the day I see this in Pittsburgh. 😉

(photos by Bob Kroeger. See more photos on his Facebook page)