Category Archives: Water and Shore

Cuttlefish Communicate With Gestures. Is it Sign Language?

Young cuttlefish with arms up (photo from Wikimedia Commons)

13 May 2025

Cuttlefish are solitary creatures so researchers were surprised to discover that the animals routinely use complex arm gestures when they see another cuttlefish.

Sometimes they’d raise a pair of arms, almost as if waving, which the team dubbed the “up” sign. At other times, the animals swept all their arms to one side (“side”), folded them beneath their heads (“roll”), and touched just the tips of them together (“crown”).

Science Magazine: Watch cuttlefish communicate—with enthusiastic gestures

To confirm that common cuttlefish (Sepia officinalis) keyed on each other’s gestures, researchers played videos of a gesturing animal to one in the tank. The tank cuttlefish responded with more gestures, not merely mimicking (mirroring) the video.

The gestures generate sound/pressure waves that cuttlefish respond to even when they can’t see the animal who is gesturing:

The scientists observed the cuttlefish “signing” this way when they couldn’t see each other, so they used a hydrophone to capture the pressure waves produced from each sign. When the researchers then played back this sound for the animals without any visual cues, the cuttlefish often responded by signing—particularly right by the hydrophone, the researchers noted to Live Science.

Science Magazine: Watch cuttlefish communicate—with enthusiastic gestures

See gesturing cuttlefish respond to these cues in the video below. (If the narration is difficult to understand, turn down the sound and read the text.)

video embedded from ScienceAlert External Sources on YouTube

The next step will be to figure out if this is cuttlefish sign language.

Read more at Science Magazine: Watch cuttlefish communicate—with enthusiastic gestures.


For a deeper dive into the intelligence of cuttlefish see this 10-minute video about delayed gratification. It includes cute kids doing a similar delayed gratification experiment + speculation on why cuttlefish can wait for prey to become available.

video embedded from NOVA PBS on YouTube

The Kittiwake Hotel

Black-legged kittiwake at Svalbard, Norway (photo from Wikimedia Commons)

9 May 2025

Black-legged kittiwakes (Rissa tridactyla) are small members of the gull family that nest communally on sea cliffs.

Black-legged kittiwake sea cliff colony in Seward, AK (photo from Wikimedia Commons)

They are also happy to nest near humans as they do Lowestoft Telephone Exchange building in the UK.

At Kiberg, Norway a building’s exterior was refurbished to house kittiwake nests. As of 25 March this year, the Kittiwake Hotel was fully booked.

Kiberg has a human population of about 200 people.

View of Kiberg, Norway (photo from Wikimedia Commons)

It seems there are more kittiwakes in Kiberg than there are humans. 🙂

*A NOTE ON NAMES: In Europe these birds are simply called “kittiwakes” but North America there are two species: black-legged and red-legged kittiwakes.

Lady Mallards Are on Eggs

Female mallard (photo from Wikimedia Commons)

6 May 2025

When I stopped by Duck Hollow early this week I was amazed to see so few mallards and all of them male when only a month ago I saw many more ducks and both sexes. The difference now is that female mallards are on eggs. The males have nothing to do. They never incubate and they don’t help raise the kids.

Last month each female mallard chose a nest site under overhanging vegetation, typically on the ground and typically near water, where she laid a clutch of 1-13 eggs. She incubates the eggs for about 28 days and when she reappears she’ll have ducklings in tow. At night she will brood them until they’re two weeks old.

LINKED female mallard nests in urban planter (photo from Wikimedia Commons)

Urban mallards behave differently than wild mallards. Here are some interesting facts, paraphrased from Birds of the World:

  • Experimental evidence has shown that mallards may be able to assess mammalian predator risk by detecting the animals’ urine at potential nest sites.
  • Urban mallards sometimes nest on woodpiles, on buildings, and on artificial structures such as docks and boats. Not the female in a planter shown above.
  • Unlike wild mallards, urban mallards will re-nest if the first clutch is destroyed or if all chicks are lost to predation. They even raise second broods if they are in unnaturally crowded populations. (*So this is a puzzle: They are overcrowded yet they raise a second brood anyway. Why?)
  • It is rare for a female to abandon her nest during incubation but is common under crowding and in urban populations. (Crowding makes them crazy?)

In the coming weeks mallard eggs will hatch and families will appear on the water. Watch for scenes like this at the end of May.

Female mallard with ducklings (photo from Wikimedia Commons)

Green Heron Has a Bad Hair Day

Green heron with head feathers standing up (photo from Wikimedia Commons)

1 May 2025

Green herons returned to southwestern Pennsylvania last month to hunt our waterways for fish and crustaceans. When life is calm for a green heron — which is most of the time — he keeps his head feathers sleeked.

Green heron at Prospect Park, Brooklyn, NY (photo from Wikimedia Commons)

But when he feels threatened or he wants to threaten someone else, he raises his head feathers, squawks or clucks, and often tail-flips before he rushes his opponent. The further out he stretches his neck, the more upset he is.

video embedded from Wild Florida on YouTube

In this video you can see him tail-flipping.

video embedded from Wild Florida on YouTube

Watch out when green herons have a bad hair day!

Seen This Week: Flooded Mon River, Redbuds and Rain

Redbud blooming on Clyde Street, 8 April 2025 (photo by Kate St. John)

12 April 2025

A week ago it rained and rained. All that water had to go somewhere and by Monday I could tell it had made it to the Monongahela River at Duck Hollow.

The mud bar at the mouth of Nine Mile Run was covered with fast moving water. A mallard barely had to paddle as he zoomed by.

Monongahela River running high, 7 April 2025 (video by Kate St. John)

Leafout continued with these box elder leaves at Herr’s Island on 9 April. Notice that they have the same 3-leaf arrangement as poison ivy but their shape indicates they are box elder.

Box elder leafing out at Herr’s Island, 9 April 2025 (photo by Kate St. John)

If it wasn’t raining it drizzled for most of the week. On Wednesday 9 April, rain and drizzle kept these tulips closed …

Tulips closed against the rain, 10 April 2025 (photo by Kate St. John)

… and the dusk-like conditions prompted seven deer to graze in full view behind Frick Fine Arts. These two didn’t care that I was looking at them. The other five crossed the driveway and melted down the hillside edge.

2 of 7 deer behind Frick Fine Arts, 10 April 2025 (photo by Kate St. John)

p.s. If all seven are pregnant does we can expect the herd to number 14-21 deer by the end of May.

Miniature Canada Goose? Or Something Else?

8 April 2025

I try very hard not to be gullible but sometimes I get taken in. Yesterday was a lesson in Do Not Believe Everything You See On The Internet even if you trust the source. I’m bringing this up today so you, too, can learn the truth.

Yesterday I saw an incredible photo of a very tiny goose from Wild Bird Fund, a trusted wildlife rehab agency in New York City and I believed it. Wrong! It was posted on April Fool’s Day. Duh!

The good news is that in looking up dwarf geese I learned that poor nutrition in the gosling phase can stunk the growth of a young Canada goose who then never reaches full size. Here’s the corrected news.

Now, what about that half-sized goose in the photo at top? Is it a dwarf? No. It’s a different species!

The Cackling Goose was long considered a group of smaller subspecies of the Canada Goose. In 2004, the smallest 4 of the 11 recognized Canada Goose subspecies were split out as the Cackling Goose. Canada and Cackling Geese hybridize in several locations, which can further complicate identification in the field.

All About Birds: Description of Cackling goose

Cackling geese (Branta hutchinsii) are about the size of mallards, have stubby bills, steeper foreheads and shorter necks. They are a Rare Bird in Pittsburgh though quite common in winter in New Jersey, the Great Plains and California’s Central Valley.

Two cackling geese with a Canada goose (photo from Wikimedia Commons)

A Canada Goose the Size of a Pigeon?

“The Canada Goose at Kennedy Lake is quite tame.” (photo by Brent Myers via Flickr Creative Commons license)

7 April 2025

UPDATE: Thank you Amber VanStrien for pointing out that Wild Bird Fund posted this “news” on APRIL FOOL’S DAY … And I fell for it. However, there really are dwarf geese that are less than half the size (44%) of a normal Canada Goose. See revised text below.

Typical Canada geese, like the one shown above, are large birds as tall as our knees when relaxed and foraging and bigger when angry. You can’t hold one in the palm of your hand so I was amazed to see this photo of a Canada goose in New York City that is only the size of a pigeon! (Hah! It’s an April Fool’s joke.)

“Lilligoosian” was supposedly in rehab at the Wild Bird Fund on Columbus Ave, Upper West Side, NYC –> 1/10th the size of a normal Canada goose, half the size of a mallard, and just a few grams heavier than a male pigeon.

Do very small birds like this exist?

David Sibley explains in his article Do “dwarf” birds exist? that “continued poor nutrition [during the gosling stage] results in birds that never reach full size and remain smaller than normal, as several studies on Snow and Canada Geese have shown.” For instance, from a study in 2015:

Canada goose goslings fed low-protein (10%) diets were on average 44% lighter in body mass, had slower growth rates and were delayed >20 days in reaching 90% of asymptotic size compared with Canada goose goslings fed 18% protein.

— from Ecological implications of reduced forage quality on growth and survival of sympatric geese

So “Lilligoosian,” the pigeon-sized Canada goose, was probably Photoshop’d but there are such things as dwarf geese. Goslings can be stunted by unhealthy food and reach only half the size of a normal Canada goose in adulthood.

Rare Goose Visits Pittsburgh

30 March 2024

UPDATE 14 April 2025: As of yesterday the barnacle goose was on the move. He was seen at Highland Park in the morning but not found in the evening.

Yesterday morning Amy Henrici found a barnacle goose (Branta leucopsis) with a flock of Canada geese on the Allegheny River in East Deer Twp. This is an incredibly rare bird for Pittsburgh considering that its winter range is in Northern Europe.

Barnacle geese breed in the Arctic — Greenland, Svalbard and Siberia — plus a few places in Northern Europe, and spend the winter in Ireland, the UK, and the coast of the North Sea.

Range map of barnacle goose, distinct populations (map from Wikimedia Commons)

My original guess was that this one accidentally turned southwest (instead of southeast) when it left Greenland and eventually arrived in Pittsburgh 3,000 miles away.

But I’m probably wrong! Mike Fialkovich pointed out that there’s a Greenland population that regularly migrates along the East Coast:

Barnacle Geese are annual in southeastern PA, appearing in fall and late winter/early spring. They typically are present a few days and then move on, presumably migrating back to the breeding grounds.

— Mike Fialkovich comment on this article, see comments section

So this goose may well be a southeastern PA visitor that made his way west of the Appalachians. But he’s the first to make it here!

Many birders have visited the hotspot to catch a glimpse of the bird. Corvus captured awesome photos.

My day was so busy on Saturday that I did not go see the goose but I’ve seen them in Finland so I didn’t feel too bad. I stopped by Sunday morning, 30 March, and saw him for myself.

Barnacle goose at Creighton, PA 30 March 2025 (photo by Kate St. John)

I can’t believe I wrote about barnacle geese just three weeks ago, knowing we would never see one in Pittsburgh because they never come here. And now one has.

p.s. Here’s how they got their “barnacle” name.

Population Hit by Bird Flu Recovered in Just 2 Years

Barnacle goose closeup (photo from Wikimedia Commons)

9 March 2025

Every autumn barnacle geese (Branta leucopsis) leave their arctic breeding grounds and migrate to Europe. In 2021-2022, those wintering at Solway Firth, UK(*) became infected with highly pathogenic avian influenza (HPAI) H5N1 and 31% of them died. Even though their population had been devastated, they recovered to full strength in just two years. This can give us hope for North American birds hit hard by bird flu.

Wild barnacle geese breed in Greenland, Svalbard and Siberia yet each population has its favorite wintering site as shown on the map. Counts on the wintering grounds are directly tied to one breeding location.

Distribution of barnacle geese highlighting the studied population in 2021-22 (map from Wikimedia Commons)

The winter population at Solway Firth breeds at Svalbard.

Wintering flock of barnacle geese in the fog at Solway Firth (photo from Wikimedia Commons)

When bird flu hit Solway Firth in the winter of 2021-2022 researchers began a two+ year study to measure the demographic impact of the major HPAI outbreak on barnacle geese. During the outbreak they carefully counted dead goose carcasses and, thanks to fencing, were able to extrapolate for predation.

By February 2022 the barnacle goose population had dipped precipitously, but in the two years that followed the number of juveniles increased even faster. High birth rates on the breeding grounds quickly made up for the loss of adults.

Year to year maximum late-winter count of barnacle geese at Solway Firth. From Impacts of highly pathogenic avian influenza (HPAI) on a Barnacle Goose Branta leucopsis population wintering on the Solway Firth, UK

Researchers speculated that …

The large impact of HPAI-related mortality on the Solway Barnacle Goose population was rapidly recovered, probably through a combination of the widespread development of natural immunity and high levels of breeding success in the years following the outbreak.

Impacts of highly pathogenic avian influenza (HPAI) on a Barnacle Goose Branta leucopsis population wintering on the Solway Firth, UK

In Pennsylvania, snow geese have been hard hit with wild bird flu. It will be interesting to watch how their winter population fluctuates in the eastern U.S. in the years ahead.

p.s. We don’t have barnacle geese in the U.S. Here’s look like.

Barnacle geese (center of photo) look unique but are similar in size to their nearest relative the cackling goose.

One barnacle goose with many cackling geese (photo from Wikimedia Commons)

Size comparison! Though cackling geese look like Canada geese they are much smaller. Thus barnacle geese are smaller than Canada geese we see in Pittsburgh.

Two cackling geese with a Canada goose (photo from Wikimedia Commons)

(*) Solway Firth forms the western border of Scotland and England.

Remembering When I Climbed Lake Superior

The mountain of ice on Lake Superior was glacial blue in the distance, 16 Feb 2014. People provide some scale (photo by Kate St. John)

27 February 2025

This morning I am in Duluth, Minnesota where today’s temperature will range from 30°F to 39°F, far warmer than my last visit in February 2014 when it was 16°F to 0°F.

That was the winter of the Polar Vortex when it was so cold for so long that Lake Superior froze solid — a rare occurrence because it is so deep. When our birding group reached the shore we saw big hills of ice and very few birds. So we got out of the van and climbed the lake.

Standing on Lake Superior’s ice while I take this photo of the mountain of ice in the distance, 16 Feb 2014 (photo by Kate St. John)

This week I won’t be climbing the lake because nearly all of it is open water (shades of blue on the map). In fact, as of last Saturday, total ice cover for all five lakes is only 38.5% (gray and black on the map).

Great Lakes ice cover 22 Feb 2025 from Great Lakes Environment Research Laboratory

Note that Lake Erie was more than 90% frozen because it’s so shallow.