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)
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:
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.
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.
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.
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.
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.
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.
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.
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:
Mike lives in Saskatoon, Canada where beavers (Castor canadensis) are more common than they are in Pittsburgh. Mike photographed seven at once last spring.
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.
Persistence pays off! ?? Whoever wrapped this tree forgot to fasten the edges together. Spud found the seam and worked her way in, and eventually left with the yummy tree inside. #beavers#funnyanimalspic.twitter.com/tR6XHjgeXW
— Mike’s Photos and Videos of Beavers (@MDigout99) March 2, 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.
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.”
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 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.
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:
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.
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 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)
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.
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.
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.
