Category Archives: Water and Shore

This Week Saw a Sora

Sora at Schenley Park, 30 April 2023 (photo by Charity Kheshgi)

6 May 2023

This was the week the north wind blew and it rained until Friday. This week an American bittern and sora spent more than 7 days at pond-sized Panther Hollow Lake in Schenley Park. They were still there yesterday in sunshine.

After I saw the bittern in pouring rain last Friday the sora eluded me. On Sunday evening I drove to Schenley Park just before dusk and aaarrg! I left my binoculars at home! Too late to go get them I went down to the pond and hoped for a ‘naked eye’ sighting.

Soras (Porzana carolina) are in the rail family but aren’t nearly as “thin as a rail.” Instead they look plump but surprisingly small. They weigh as much as an American robin but have very short tails. Knowing what size to look for is key to finding one.

Standing silently at The Spot To See The Sora (birders’ pindrop) I watched the bird come out to feed at dusk among the reeds. Without binoculars he looked like this.

Lousy cellphone photo of a ‘naked eye’ a sora in Schenley Park, 30 April 2023 (photo by Kate St. John)

Charity Kheshgi had better looks than I did.

Before I left I heard the sora vocalizing after he’d walked back into the reeds. The Merlin app refused to identify him. (“That bird can’t be here so I’m not telling you it is.”) My Merlin recording is too muddy to post but this is what the sora sounded like:

(photos by Charity Kheshgi)

Look for One Thing, Find Another

American bittern at Panther Hollow Lake, Schenley Park, 28 April 2023 (photo by Charity Kheshgi)

Sunday 30 April 2023

Early Friday morning in pouring rain, Adrian Fenton was at Schenley Park looking for two soras reported the day before on eBird. Soras (Porzana carolina) are unusual in the City of Pittsburgh so it was worth the trip to look for them, but try as he might Adrian could not find any soras. Instead he found something much better.

At 7:29am I was writing Friday’s blog when I got Adrian’s Rare Bird Alert that there was an American bittern (Botaurus lentiginosus) among the reeds at Panther Hollow Lake. This bird is rare indeed! I dropped everything, put on my rain gear, and drove 5 minutes to Schenley Park.

Upon arrival I caught up with Adrian and he showed me where the bittern was. Except that I could not see it at first. Its camouflage is so good that it took me a while to latch onto the bird. Thank you, Adrian, for your patience!

More birders arrived, some looking from above on Panther Hollow Bridge. Charity Kheshgi viewed from eye level, as I had, and captured some great images of this cryptic bird.

American bittern at Panther Hollow Lake, Schenley Park, 28 April 2023 (photo by Charity Kheshgi)
American bittern at Panther Hollow Lake, Schenley Park, 28 April 2023 (photo by Charity Kheshgi)

Charity noticed that the bittern made a vertical wiggle with its neck and took a video. You can hear the sound of red-winged blackbirds and the ka-thunk of cars overhead on the Panther Hollow Bridge in the background. The wiggle is typical American bittern behavior though I’m unable to find an explanation for it.

By the end of Friday, 29 people had reported the bittern in eBird(*) but many more than that stopped by for a look. Some of them missed it on Friday, including Steve Northrop who found a sora that hadn’t been seen all day! See his checklist with sora photo.

So Friday came full circle with a search for a sora that found a bittern and a search for a bittern that found a sora.

On Saturday the bittern and sora were still present with an ever changing crowd of birders, binoculars, cameras and scopes. The crowd did not disturb the birds as the best viewing was from (up the hill) gravel paths 40 feet from the nearest water. The bittern was visible for most of the day Saturday, but the sora remained elusive. Around 6:30pm both birds put in an appearance and Steve Northop was there to witness it. Ta Dah!

Look for one thing, find another.

UPDATE on Friday 5 May 2023: Both the bittern and sora were still present on Friday 5 May in bright sunshine. By that time they’d stayed in Schenley Park more than 7 days and had become celebrities. My estimate is that 200 people came to see them, many of us multiple times.

(photos and video by Charity Kheshgi)

If You Want To Save Birds, Count Differently

Black-tailed godwit (photo by Andreas Trepte, via Wikimedia Commons)

18 April 2023

Black-tailed godwits (Limosa limosa) are large shorebirds with a worldwide distribution but are listed as Near Threatened because their population declined 25% in only 15 years, 1990-2005. Two thirds of them breed in Europe. In fact almost half the worldwide population breeds in the Netherlands alone.

The European breeders spend the winter in the Mediterranean and Africa including at the Tagus Estuary at Lisbon, Portugal. During spring migration the Tagus hosts up to 40% of all the black-tailed godwits on Earth. Anything that permanently disturbs the Tagus could hurt the godwits.

Black-tailed godwits feeding near Lisbon, Portugal (photo from Wikimedia Commons)

Two decades ago Lisbon, Portugal decided they really need a new airport so they proposed siting it at a former air force base across the Tagus in Montijo.

Proposed airport location at Montijo marked with red X (screenshot from Google maps)

The Montijo Environmental Impact Assessment (EIA) counted black-tailed godwits at feeding and resting sites and calculated how many godwits would be disturbed by the noise of air traffic at 65dB (decibels) (orange outline below, 55dB is the yellow outline). The airport’s EIA said only 0.46–5.5% of the godwits would be disturbed.

Spatial extent of two levels of noise predicted to occur over the Tagus estuary … for 30 sites used by individually tracked godwits between 2000 and 2020. (from “Conservation beyond Boundaries: using animal movement networks in Protected Area assessment” by J. Nightingale et al at ZSL Publications)

Though the EIA used the counting techniques that we use in eBird — the number of birds at rest or in the air at specific points — it doesn’t tell the whole story.

Josh Nightingale, a PhD student with the University of East Anglia and Portugal’s University of Aveiro, decided to study the birds’ flight paths and calculate their larger usage footprint in the Tagus Estuary. The more connections they make, the bigger the footprint.

The size of an impact/protection footprint depends on both the connectivity of impacted sites and the configuration of the entire network. Environmental Impact Assessments typically assume (a) a static population, ignoring connectivity: in such cases the footprint only covers the site(s) directly impacted (red circles). … A network with dense connections, such as (c), will typically result in a greater footprint. …Similarly, an impact on a central site (d) results in a larger footprint. (diagram and caption from “Conservation beyond Boundaries: using animal movement networks in Protected Area assessment” by J. Nightingale et al at ZSL Publications)

Fortunately many black-tailed godwits are banded so Nightingale could use 20 years of location data on 693 banded godwits, many seen twice on the same day in the Tagus area. He then drew connections from site to site to create the godwits’ airspace network. Nightingale also used a 55dB noise plot because that level of noise disrupts 50% of the birds.

Connectivity among sites used across the Tagus estuary. Blue lines indicate connections between sites in the godwit network, representing movements by individual marked godwits within a winter season. (diagram from “Conservation beyond Boundaries: using animal movement networks in Protected Area assessment” by J. Nightingale et al at ZSL Publications)

Nightingale concludes:

Frequent disturbance by aircraft is known to have fitness costs for waders by increasing their energy expenditure, and may cause permanent avoidance of habitat if chronic with long-term consequences for site occupancy. The Tagus godwits’ frequent trans-boundary movements mean that 44.6% of the SPA’s godwit population would be exposed to noise disturbance from the proposed airport, and 68.3% of individuals overall. This compares with estimates of 0.46–5.5% in the airport’s EIA.

“Conservation beyond Boundaries: using animal movement networks in Protected Area assessment” by J. Nightingale et al at ZSL Publications

Nightingale’s paper was published this month in ZSL Publications. Fortunately the Montijo site was placed on the back burner last July. Fingers crossed that this paper tips the balance in the godwits’ favor.

Black-tailed godwit flock in Europe (photo by Keith Gallie via Creative Commons license on Flickr)

In cases like these, if you want to save birds you have to count differently.

p.s. Read more about this study in Anthropocene Magazine: How You Count Birds Affects Airport Design and Permitting. Or this summary in Science Direct.

(photos from Wikimedia Commons and by Keith Gallie via Creative Commons license on Flickr; Lisbon-Montijo map screenshot from Google maps, additional map and diagrams from“Conservation beyond Boundaries: using animal movement networks in Protected Area assessment” by J. Nightingale et al at ZSL Publications. Click on the captions to see the originals)

Lady Mallards Prepare To Nest

Female mallard (photo from Wikimedia Commons)

10 April 2023

While songbird migration picks up in April, lady mallards are preparing to nest.

Everything about the nest is done by the female. She picks the site, she makes the nest, she lays the eggs, she incubates.

Female mallard nests in urban planter in Göteborg, Sweden (photo from Wikimedia Commons)

Here are some cool facts about mallard nesting (Anas platyrhynchos), gleaned from Birds of the World.

  • Mallards pair up in autumn so they get down to the business of nest site selection as soon as they’ve chosen their breeding home range. The search begins “generally 5-10 days after first Persistent Quacking by hen.” Have you ever noticed first Persistent Quacking? I have not.
  • The pair searches together by “making low circling flights over the area, usually in the evening.” They land together at likely spots, she walks into cover, he waits outside. Watch for this in the evening at Duck Hollow, Wingfield Pines, North Park, etc.
  • “Experimental evidence suggests that mallards and several other dabbling ducks may be able to assess predation risk by detecting predators’ urine.” They can smell the snakes and raccoons!
  • Mallards usually nest on the ground “in upland area near water under overhanging cover or in dense vegetation for maximum concealment.”
  • Urban mallards get creative. They nest in planters, woodpiles, docks, boats, artificial structures and sometimes on buildings.
  • Mallard hens do not carry nesting material to the site. Instead they make a bowl and pull at nearby vegetation to line the bowl with plant litter, leaves, etc. They pull tall vegetation to drape over the nest and increase cover.
  • The first egg is laid 1-4 days after nest site selection. She lays one egg a day usually in the morning. Clutches consist of 1-13 eggs. The larger clutch sizes probably include eggs dumped by other female mallards!
  • She waits to begin incubation until the clutch is complete.
  • During incubation she plucks down from her breast to line the nest and cover the eggs.
  • Recess! “The female usually leaves the nest once in early morning, returning before 9:00 and once in late afternoon, leaving after 16:00. Recess lasts 15–60 minutes.”
  • If something eats her eggs, a wild mallard won’t renest but an urban mallard will. Some urban mallards raise second broods in unnaturally crowded populations.
  • Her chicks hatch in about 28 days.
Female mallard nests by a building. Notice the down she pulled from her breast to line the nest (photo from Wikimedia Commons)

In about 28 days I’ll tell you what happens next.

(photos from Wikimedia Commons; click on the caption to see the original)

He Doesn’t Just Stand Around

Reddish egret, Marco Island, FL (photo from Wikimedia Commons)

10 March 2023

Egrets and herons are known for standing completely still and waiting for a fish or frog to swim toward them until they stab and grab it from the water.

Reddish egrets (Egretta rufescens) seem manic by comparison, “dancing” so much that they look crazy. Their hunting techniques include:

  • Foot wiggle
  • Umbrella wings
  • Stab the water
  • Prance and dance
  • Hover-fly with dragging legs

Watch for these antics below.

This immature bird’s umbrella wings look like a victory pose:

There is one notable moment when a reddish egret will stand around. According to Birds of the World, during Pair Formation in the breeding season (April) the “Male takes up position atop mangrove canopy or on low-growing vegetation and “stands around” in Upright Display position.” He’s waiting to win a mate.

If you want to see a reddish egret visit a coast highlighted on the map below. This bird only fishes in shallow saltwater.

Range map of reddish egret from Wikimedia Commons

Despite its large range the reddish egret occupies a restricted habitat and is patchily distributed. It is listed as Near Threatened.

(photo and map from Wikimedia Commons, videos embedded from American Bird Conservancy and @wideangl on YouTube, tweet embedded from Twitter)

Beavers on Video, Castor Up Close

Beaver swimming in Saskatoon, summer 2022 (photo from Mike’s Photos and Videos of Beavers)

5 March 2023

Since January I haven’t heard anything about the beaver in Frick Park but I’ve been watching beavers up close at Mike’s Photos and Videos of Beavers (@MDigout99).

Mike lives in Saskatoon, Canada where beavers (Castor canadensis) are more common than they are in Pittsburgh. Mike photographed seven at once last spring.

Seven beavers and one Canada goose in Saskatoon, spring 2022 (photo from Mike’s Photos and Videos of Beavers)

He’s able to get close for photos and videos because he’s patient, non-threatening, and willing to lie on his belly to get a good shot.

Twitter home of @MDigout99

His persistence pays off. Watch this beaver eat a tree (3 minutes).

He also documents their behavior. For instance, how long does it take a beaver to break into an unfastened tree fence? See below.

Check out his daily photos and videos at @MDigout99 on Twitter. Click here for his videos on YouTube.

(photos and videos from Mike’s Photos and Videos of Beavers, @MDigout99)

Waves Glow Blue At Night

Breaking blue wave at San Diego during red tide, 2011 (photo by Kevin Baird via Flicker Creative Commons license)

26 February 2023

If, like me, you live far from the ocean you may never have seen breaking waves glow blue at night. This bioluminescence is caused by single-celled organisms floating in ocean surface water whose defense mechanism creates blue light when they feel threatened.

Blue wave at Seal Beach, CA during red tide 2011 (photo from Wikimedia Commons)
Breaking blue wave at night during red tide in San Diego, 2011 (photo by Kevin Baird via Flicker Creative Commons license)

Bioluminescence is relatively rare on land (think fireflies and fungi) but is common in the ocean where 76% of the organisms can create their own light through a chemical reaction between oxygen and the enzyme luciferase. The color is predominantly blue, the wavelength that travels furthest in water, and is a useful adaptation in the deep where sunlight cannot penetrate below 200 feet.

The glowing blue waves pictured above are created by dense populations of marine plankton called dinoflagellates. During the day they color the water red — a “red tide.”

Red tide at La Jolla, CA in 2005 (photo from Wikimedia Commons)

Some are toxic but in San Diego in 2011 the organism was identified as harmless Lingulodinium polyedrum so it was safe to swim. ( Lingulodinium polyedrum might be top center below.)

Dinoflagellates as seen through an electron microscope (image from Wikimedia Commons)

Dinoflagellates automatically glow to warn off predators so when a wave begins to break and the jostling mimics a predator, the glowing begins. When the wave subsides the glowing stops. You can see the red tide of dinoflagellates in front of the blue wave below.

Breaking blue wave during red tide (photo from Wikimedia Commons)

Watch it in action in this video from 2011.

Red tides happen fairly frequently in San Diego, though not every year, and they tend to be benign. (They are generally NOT benign in Florida!) Learn more about the 2011 bioluminescence in this video:

(photos from Wikimedia Commons and by Kevin Baird via Flickr Creative Commons license)

Humpback Whales Love Anchovies

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

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

See more maps and learn more about them at

(All images from press kit)

Winter Birds at the Beach

Sanderlings in December (photo from Wikimedia Commons)

3 January 2023

When we think of the beach in winter it sounds pretty bleak but not if you’re a birder. Shorebirds, sea ducks, loons and gulls leave the icy north to winter on the Atlantic and Pacific coasts where they hang out on beaches or just offshore, especially near jetties.

If you can’t travel far from Pennsylvania, visit the New Jersey shore to see thousands of wintering birds. GetToKnowNature describes what you’ll see in her video “Welcome to the beach in winter.” Click here or on the screenshot below to see it on Instagram (you don’t need an account to see it) or here for YouTube.

Screenshot from GetToKnowNature winter beach video on Instagram

(photo from Wikimedia Commons, screenshot from GetToKnowNature video on Instagram)