Humpback Whales Love Anchovies

Mammals, Migration, Water and Shore
Humpback whales lunge-feeding on anchovies in Monterey Bay (photo by Robin Agarwal via Flickr Creative Commons license)

25 January 2023

Every autumn humpback whales (Megaptera novaeangliae) migrate past California on their way to spend the winter off the coast of Mexico. They will linger, however, if they find lots of anchovies. Humpback whales love anchovies.

The California anchovy population typically rises and falls in 10 to 30 year cycles based on ocean conditions and fishing pressure. It surged in 2013 when the New York Times made this video (click on the image below) …

Screenshot from New York Times article... Click here or on the image to see the video

… and surged again this summer. In June 2022 there were so many anchovies that people reported small fish raining down from the sky in San Francisco, probably dropped by passing seabirds. In July anchovies were trapped in oxygen-poor water and died near shore, making a smelly mess.

There were still lots of anchovies when the whales showed up this fall. Robin Agarwal took a whale watch out of Monterey Bay in early October and captured these scenes of lunge-feeding humpback whales.

The anchovies crowded close as the predators approached. The whales forced them to the surface where the tiny fish leapt out of the water to escape.

Humpback Whales lunge-feeding on Northern Anchovies (photo by Robin Agarwal on Flickr)

The whales opened their mouths and anchovies fell in.

In a surge year for anchovies, people feast too.

Anchovies at Valley Bar + Bottle Shop, Sonoma, California (photo from Wikimedia Commons)

Read more about the 2013 anchovy surge in the New York Times: With Extra Anchovies and Whale Watching.

See more of Robin Gwen Agarwal’s photos here.

(humpback whale photos in Monterey Bay by Robin Gwen Agarwal on Flickr, Creative Commons license, food photo from Wikimedia Commons; click on the captions to see the originals)

Reimagined Maps as Art

Musings & News, Water and Shore
U.S. watershed map by Robert Szucs at Grasshopper Geography (image from grasshoppergeography.com press kit)

24 January 2023

About ten years into his career as a digital cartographer Robert Szucs decided to experiment with data visualization and learned how to create strikingly beautiful, digitally accurate maps. He calls them “Maps Reimagined” and explains,

While my maps are always scientifically accurate, I think of them first and foremost as works of art.

— Robert Szucs, Grasshopper Geography Press Kit

His watershed maps became an Internet sensation a few years ago through digital sales on Etsy and news outlets including the Washington Post and Smithsonian Magazine.

The U.S. watershed map above is so detailed that you can pinpoint Pittsburgh in the Mississippi watershed at the conjunction of the Allegheny, Monongahela and Ohio Rivers.

Grasshopper Geography U.S. watershed map, cropped to highlight Pittsburgh at the conjuction of three rivers

Szucs has also produced collections of elevation, forest and human population maps.

There came a point when I said I can’t look at another green-brown-white elevation map again. I needed some fun. I needed colours. And for not the first or last time, I needed to create the maps I wanted to see.

— Robert Szucs, Grasshopper Geography Press Kit

This one dramatically illustrates that even the plateaus in the U.S. West are much higher than anything in the East.

U.S. elevation map by Robert Szucs at Grasshopper Geography (image from grasshoppergeography.com press kit)

See more maps and learn more about them at GrasshopperGeography.com.

(All images from grasshoppergeography.com press kit)

See The Green Comet … If You Can

Weather & Sky
Comet C/2022 E3 (ZTF) imaged using 300mm F/4 lens, 21 Jan 2023 (photo by Auvo Korpi via Wikimedia Commons)

23 January 2023

A green comet that last passed the sun 50,000 years ago set off a flurry of stargazing on the night of the new moon, 21-22 January. Even though Comet C/2022 E3 (ZTF) will pass closest to earth on 2 February it is best to see it now before the moon waxes to full on 5 February.

video from @MrSuperMole on YouTube

Comet C/2022 E3 (ZTF) is so faint that it must be viewed in a dark sky and is best seen via binoculars, telescope, or camera with telephoto lens — for instance, birding equipment. The photo above was taken with a 300mm F/4 lens. Click here for information on where to look.

With magnification and a star map all you need is a dark sky, but finding one is increasingly difficult.

A study published last week in the journal Science examined 12 years of citizen science reports of the constellations seen with the naked eye. The number of constellations seen from 2011-2022 went down as sky glow increased from lights on earth. As Smithsonian Magazine explains, the brightness of light pollution increased at a rate of 9.6 % per year. “That’s equivalent to the brightness doubling every eight years.”

Previous studies used satellites to measure earth lights reaching outer space but they missed the effect of ground lights inside our atmosphere. So the problem is worse than we thought. For a video illustration, see the 2016 article below.

We Cannot See The Stars

Meanwhile in Pittsburgh, we definitely have light pollution but our impossible hurdle is cloud cover. We have lots of clouds in the forecast for the next 10 days.

Pittsburgh 10-day forecast from weather.com app on cellphone (screenshot from Kate St. John)

Read more about the light pollution study in Smithsonian Magazine: Light pollution is drowning the starry night sky faster than thought.

(photo from Wikimedia Commons, video from @MrSuperMole on YouTube, screenshot from weather.com on cellphone)

On Finding Pellets

Bird Anatomy, Bird Behavior, Birds of Prey, Peregrines
Red-tailed hawk casting a pellet, 2018 (photo by Chad+Chris Saladin)

22 January 2023

This red-tailed hawk is not consuming the lump near his mouth. He’s casting a pellet of indigestible bones, fur and feathers that came up from his gizzard. Pellets are a normal by-product of digestion in birds of prey. If you find one, it can tell you what the bird was eating.

We always find pellets during annual maintenance at the Pitt peregrine nestbox including these three found during our 9 January visit (paperclip for scale). The pellets can be many months old.

Peregrine pellets from Cathedral of Learning nestbox, 9 Jan 2023 (photo by Kate St. John)

A closeup shows feathers and bones (no fur*) but is not very enlightening due to the pellet’s age. Fortunately I stored the pellets in a ziploc bag. After they thawed a small fly appeared inside the bag, hatched from eggs laid on the pellet in much warmer weather. Ewww!

Closeup of peregrine pellet (photo by Kate St. John)

I imagine the pellets came from Morela since the green perch is one of her favorite places to rest and digest.

Morela casting a pellet, 17 Dec 2021 (photo from the National Aviary snapshot camera at Univ of Pittsburgh)

Peregrine pellets are slightly longer than a paperclip. Some birds make much larger pellets.

On a hike at Audubon Greenway Conservation Area last Wednesday we found a surprisingly large pellet containing fur, bones and a big tooth. It was so large that we wondered if a bird could produce it. I didn’t pick it up but it looked as though it could span my palm.

Pellet found at Audubon Greenway, 18 Jan 2023 (photo by Kate St. John)
Alternate view of pellet found at Audubon Greenway, 18 Jan 2023 (photo by Kate St. John)

A Google search revealed that great horned owl pellets are 3 to 4 inches long, usually cylindrical and tightly compacted. This one may have opened up because it was soaked by heavy rain.

Great-horned owl clutching a feather (photo from Wikimedia Commons)

So what did the owl eat? Whose big tooth was that?

Learn more about owl pellets at The Owl Pages: Digestion in Owls.

* p.s. There is no fur in peregrine pellets because they don’t eat mammals, only birds.

(photos from Chad+Chris Saladin, Kate St. John, the National Aviary snapshot camera at Univ of Pittsburgh and Wikimedia Commons)

Up To The Rooftop

Bird Behavior, Peregrines
Ecco about to leap up to the roof at the Pitt peregrine nest, 20 Jan 2023

21 January 2023

Peregrine news at the Cathedral of Learning is pretty quiet lately.

Morela did not stop by the nest yesterday but Ecco visited a couple of times including a surprise approach to the snapshot camera.

His favorite way to leave was by jumping to the roof.

(photos from the National Aviary snapshot camera at Univ of Pittsburgh)

If You Think Gray Squirrels Are Cute …

Mammals
Gray squirrel (photo from Wikimedia Commons)

20 January 2023

Squirrels can be annoying at bird feeders but their expressions can be endearing.

If you think our eastern gray squirrels (Sciurus carolinensis) are cute you ought to see the native red squirrel of Europe (Sciurus vulgaris).

These native squirrels have been declining in the UK, Ireland, and Italy due to competition from eastern gray squirrels, imported from North America in the 1890s and spread by humans to new locations(*).

However, the native red squirrels are stabilizing in Scotland, in part because European pine martens (Martes martes) are increasing and they selectively prey on gray squirrels.

The European pine marten is pretty cute, too.

European pine marten (photo from Wikimedia Commons)

p.s. Gray (grey) squirrels are invasive in the UK but a 2016 study found that their populations are genetically distinct from their neighbors and they didn’t invade new places on their own. Humans spread them!

One of the worst offenders at spreading grey squirrels was the 11th Duke of Bedford, Herbrand Russell. Russell was involved in many successful animal conservation projects, but released and gifted many grey squirrels around the UK from his home at Woburn Park.

Russell also released populations [of grey squirrels] in Regent’s Park, likely creating the London epidemic of greys. 

— Imperial College London: Don’t blame grey squirrels: their British invasion had much more to do with us

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

Fermented Fruit Tastes Too Good

Mammals
Groundhog hanging onto a tree (photo from Wikimedia Commons)

19 January 2023

Fermented fruit tastes so good that wild animals large and small overindulge until they can barely walk.

Some, like this red squirrel, are puzzled by the odd feeling that overcomes them.

video from @TheSun on YouTube

Groundhogs just keep going despite that wobbly feeling, not realizing that it’s hazardous to stand up. This particular groundhog got grouchy. He’s not a happy drunk.

video from @DJSKROBOT on YouTube

And then there’s the story of a drunken moose who got stuck in a tree.

Why The Apple Tree Came Down

(photo from Wikimedia Commons, videos from @TheSun and @DJSKROBOT on YouTube)

The Forest Lives in Mortal Fear of Its Deer

Deer
Buck browsing a tree in Schenley Park, August 2022 (photo by Kate St. John)

18 January 2023

I now suspect that just as a deer herd lives in mortal fear of its wolves, so does a mountain live in mortal fear of its deer.

— Aldo Leopold, A Sand County Almanac: “Thinking Like A Mountain”

Aldo Leopold (1887-1948), quoted above, was a writer, philosopher, forester and conservationist. In the early 1900s he participated in a project to eradicate wolves from the American West. Back then it was thought that the absence of wolves would be great for our range cattle but no one considered what would happen to the landscape without the apex predator. Thirty years later Leopold wrote about it in A Sand County Almanac. We see the same results in Pennsylvania and in Pittsburgh’s parks today.

  • In the absence of hunters (wolves) the deer proliferated.
  • Deer still ate what they always ate, but the higher population consumed so much more.
  • The deer’s favorite food plants disappeared first; all new growth was consumed. The deer covered more ground and ate less favored plants.
  • After a couple of decades with constant browsing and so many plants missing, the landscape cannot regrow itself. The range failed within 20-30 years.

It’s not the mountain rocks that are afraid of deer. It’s the forest that fears for its life because deer are its predators.

Doe and fawn browsing on a tree (photo from Wikimedia Commons)

When the deer population is in balance with the habitat, the forest is fine. When the population is too high the forest shows signs of distress on its way toward failure including browse lines and small bonsai-like trees, as seen in Schenley Park below.

Deer damage: Browseline in Schenley Park, Sept 2022 (photo by Kate St. John)
Bonsai-like deer damaged sapling, Schenley Park, Oct 2022 (photo by Kate St. John)

In Riverview Park deer overpopulation has encouraged the proliferation of invasive Asian jumping worms (Amynthas agrestis) and led to a host of other problems including erosion, described by Mark Kramer in How One Park’s Ecosystem — and Maybe its Legacy — Is Eroding Away.

Amazingly, it all started with the decision to remove an apex predator. We humans are the reason why there are too many deer and, so far, we haven’t had the will to reduce their population to a sustainable level.

In the meantime the forest is afraid for its life.

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

How Fast Is The Wind Blowing?

Weather & Sky
Oak leaf on an updraft in winter (photo by Marcy Cunkelman)

17 January 2023

We can’t see the wind but we can guess its speed by watching what it does to leaves and flags …

Wales national flag blowing in the wind (photo from Wikimedia Commons)

… and then using the wind speed chart from the National Weather Service (NWS) to make a guess. My guess for the above photos is a Gentle Breeze 8-12 mph or a Moderate Breeze 13-18 mph but it’s hard to tell.

Estimating Wind Speed (chart from the National Weather Service)

NOAA weather satellites don’t see the wind either but they can see the clouds moving in three layers.

  • High level clouds (cirrus) at 23,000 to 46,000 feet
  • Mid level clouds at a level of 10,000 to 23,000 feet
  • Low level clouds are below 10,000 feet

In their animations of satellite images we can almost see the wind but not its speed.

For instance, in this GOES East animation from last Thursday 12 January 2023 we can see the Atmospheric River pumping into California and a low pressure system moving up the Ohio Valley.

GOES EAST satellite, GeoColor timelapse images, 12 Jan 2023 6:56Z-10:51Z (animation from NOAA)

NOAA’s computers use the animated maps to calculate wind speed and direction. The result, called Derived Motion Winds, plots the wind height, direction and speed on a map.

Legend for Derived Motion Winds: Wind Height and Speed (NWS)

Here’s the same timelapse with Derived Motion Winds. Notice that the layers often don’t move in the same direction or at the same speed. You’ve felt this in an airplane as a “bump” when the plane rises or descends between conflicting layers.

GOES EAST CONUS, Derived Motion Winds 12 Jan 2023 (animation from NOAA)

You can “see” the wind anywhere in the Americas by choosing a satellite to view (list on the left) at the NOAA GOES Imagery Satellite Maps. Click on Derived Motion Winds if available.

To view the current GOES East satellite, pictured above, visit these links:

(photos from Marcy Cunkelman and Wikimedia, maps and animations from NOAA and the National Weather Service)

Lake Effect Clouds and the Classic Gleam at Sunset

Weather & Sky
The Gleam At Sunset, 14 Jan 2023 (photo by Kate St. John)

16 January 2023

Pittsburgh’s skies were oppressively gray on Saturday with thick Lake Effect Clouds but the forecast promised the clouds would break in early afternoon so I planned a walk in Schenley Park for 2:30pm. Hah!

By 3pm the clouds were still thick and gray and the revised forecast predicted they would break up in the 4 o’clock hour. Of course! We were about to get 15-30 minutes of full sun immediately followed by sunset at 5:15pm, a classic Gleam At Sunset. I timed my walk to arrive at Schenley’s golf course by 4:45pm.

My photos show what happened: the classic gleam, an unexpected sun pillar, and a beautiful red sky at sunset.

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If you’ve never heard of Lake Effect Clouds and the Gleam At Sunset, find out more in last month’s article:

Why Do We Have a Gleam at Sunset?

(photos by Kate St. John)