Another favorite dolphin game is to ride the pressure wave at the front of a fast moving boat. Called “bow riding,” the bow wave pushes dolphins fast forward without any flapping on their part.
Dolphins like this game so much that they rushed toward the whale watch boat. Robin Agarwal says of this photo, “Pacific White-sided Dolphins and Northern Right Whale Dolphins stampeding towards the boat to bow ride – my favorite sight in the world.”
Here they are bow riding with an “unusual swirl color morph” among them.
During the Christmas Bird Count, volunteers count birds in more than 2,500 count circles in North America. Each circle is 15-miles in diameter and has its own compiler who coordinates the count for a single scheduled day.
You can go birding outdoors or count birds at your feeder (if your home is in a count circle). No experience is necessary. The only prerequisite is that you must contact the circle compiler in advance to reserve your place.
In mid November hundreds, perhaps thousands, of American robins (Turdus migratorius) were in the east end of Pittsburgh but left abruptly when the weather dropped below freezing on November 18th. By the 21st it was 17 degrees F and the robins were long gone.
Robins can cope with cold weather but not with frozen ground so they stay just south of the freeze line as winter approaches.
eBird distribution maps for June-July and December-February show that robins vacate the north to populate temperate zones in winter. June-July is dark purple with robins everywhere. In Dec-Feb they concentrate in the Pacific Northwest and northern California and in the U.S. southeast all the way to Florida.
Robins were on the move here in November. Now they’re south of us, wrapping up.
(photos by Robin Agarwal and Douglas on Flickr via Creative Commons license; click on the captions to see the originals)
Seven years ago this week Dorothy, the peregrine matriarch at the Cathedral of Learning, permanently disappeared and was replaced by “Hope” a bird that had formerly nested at the Tarentum Bridge. (Click here to read about the changeover.)
Dorothy was the bird that got me hooked on peregrines. By December 2015 I had watched her for 14 years and was not surprised she disappeared because she was elderly and in ill health. It was hard to watch Dorothy’s decline. She had been so vibrant in her prime.
Much has changed in seven years. Dorothy’s successor was a grave disappointment but Hope’s successor, Morela, is as queenly as Dorothy herself. We are lucky to have her.
Today in a trip down memory lane here’s a video tribute to Dorothy.
Panther Hollow Lake in Schenley Park has had problems for decades but there was hope they would be solved by an ambitious 2016 plan to rehab the lake and daylight Four Mile Run downstream. Unfortunately the plans were so ambitious that they had to be put on hold this month.
The lake’s problems are legion. It is really only the size of a pond and is filled with sediment. The shallow water cannot replenish fast enough so algae blooms in summer; sometimes fish die. Its unnatural concrete edges prohibit lakeside vegetation that could absorb water and it does not flow into any creek or river. Instead Panther Hollow Lake dumps 68 million gallons per year of clean water into a sewer pipe.
The sewer pipe is what used to be Four Mile Run plus lots of sewage. When there’s not much rain the pipe carries its contents to the water treatment plant at Alcosan.
But in a downpour the pipe is overloaded and floods the downstream neighborhood called The Run.
In 2016 Pittsburgh Water and Sewer Authority’s Draft Green Infrastructure Plan (PWSA at pgh2o.com) proposed dredging the lake, removing the concrete surround, and building a new dam so the lake would be a good depth.
It also proposed daylighting Four Mile Run in Junction Hollow — in other words, making it flow on the surface in daylight instead of in a pipe underground. Here’s an example of a daylighted stream in Yonkers.
DEP would not approve the dam as designed. It had to be much larger to meet current dam codes.
Daylighting Four Mile Run in Junction Hollow would be a long permitting nightmare because it must be put back into a (new) pipe to get under the railroad and Second Ave on its way to the Monongahela River.
The dam would have to be placed on railroad property and the railroad had already said no.
So PWSA updated the project to solve the biggest problem — flooding in The Run. Described in a public meeting on 14 Nov 2022, the revised project map shows no work in Schenley Park. All work will occur in The Run.
Improvements to Panther Hollow Lake are on hold again. Fortunately the flooding will be solved in The Run.
In 1976 Jerry Kemperman and Burton Barnes discovered that 106 acres of quaking aspens (Populus tremuloides) in the Fishlake National Forest of Utah were actually all the same male plant, one root with thousands of suckers that grew into trees. It came to be known as Pando — “I spread.”
Pando weighs 6,600 tons making it the heaviest known organism on Earth and it is very old, though no one is sure whether it’s 10,000 or 80,000 or even a million years old.
However, almost as soon as Pando was discovered researchers found that sections of it were not rejuvenating because new sprouts were being overbrowsed by deer. In that part of the U.S. the species is mule deer (Odocoileus hemionus).
So they fenced it — twice — one fence in 2013, another in 2014.
Then in 2018 Paul Rogers and Darren McAvoy of Utah State University conducted a followup study sampling Pando’s health inside and outside the deer exclosure fences and concluded that the fencing was not working.
According to September 2022 Sci.News “The unfenced areas are experiencing the most rapid aspen decline, while the fenced areas are taking their own unique courses — in effect, breaking up this unique, historically uniform, forest. … Fencing alone is encouraging single-aged regeneration in a forest that has sustained itself over the centuries by varying growth.”
“One clear lesson emerges here: we cannot independently manage wildlife and forests.”
Aldo Lepold’s experience in his early career when he worked to eradicate wolves from the American West changed his perspective on trees and deer. At one point he shot an old female wolf and was there to see the green fire go out of her eyes as she died. He wrote …
I thought that because fewer wolves meant more deer, that no wolves would mean hunters’ paradise. But after seeing the green fire die, I sensed that neither the wolf nor the mountain agreed with such a view.…
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. And perhaps with better cause, for while a buck pulled down by wolves can be replaced in two or three years, a range pulled down by too many deer may fail of replacement in as many decades.
Though they breed in the arctic around the world, the North American population stays west of the Mississippi. These geese are rare in Pennsylvania.
Their “greater” and “white-fronted” adjectives don’t make much sense unless you know the species they resemble in Europe.
They are “greater” because they are larger than the lesser white-fronted goose (Anser erythropus) that occurs only in Eurasia and is now Vulnerable to extinction.
They are “white-fronted” because they have white feathers on their faces surrounding their beaks, a field mark that distinguishes them from the similar greylag goose (Anser anser), another Eurasian species.
Only a handful of greater white-fronted geese are seen in western Pennsylvania in any given year, and then only in late October through early March.
If you see a goose that resembles this one check its field marks carefully. It may be an odd domestic goose, described here:
(images from Wikimedia Commons, map embedded from allaboutbirds.org)
The graphic above is based on Stacker’s article, States With the Worst Droughts, that ranks states by average percentage of land in drought from 2000 to March 2021. Listing the states in order, I grouped them in 10s with darkest Orange indicating the top ten drought states and darkest Green for the 10 wettest. (White = the middle 10)
The top state for drought is Arizona. No surprise; it’s a desert.
The state with the least drought is Ohio!
Georgia and South Carolina stand alone with a lot more drought than their neighbors. Their drought ranking is like Kansas.
Hawaii (dark orange) and Alaska (dark green) are at opposite extremes.
As climate change continues to unfold human populations will migrate from less habitable to more habitable locations. In the U.S. we can expect people to move west to northeast in the coming century — from more drought to less.
This week Charity Kheshgi and I saw ring-billed gulls (Larus delawarensis), a common merganser (Mergus merganser) and a few pied-billed grebes (Podilymbus podiceps) at Duck Hollow. All three species visit the Monongahela River in November when freshwater freezes up north.
The common merganser gave us an opportunity to mentally compare her field marks to a similar bird. Here are some tips.
Female common and red-breasted mergansers are so similar that it takes some practice to tell them apart. Charity’s photos show the common merganser’s two unique field marks:
A sharp demarcation between dark head versus white breast / gray back.
A sharply defined white under-chin.
Notice the common merganser field marks in three photos.
Female red-breasted mergansers (Mergus serrator) lack those sharp lines. The colors blend from one to the other.
Note that the presence of a head crest is not a reliable difference between the two; both can display it.
So here’s a quiz: Which species is in the photo below? Are these common or red-breasted mergansers?
Kites sometimes fly with the birds. A distant raptor soars at center-bottom of the photo above. Kite + Bird.
In 1914 this kite was becoming a plane. Kite = Plane.
Some kites are birds. More than two dozen species of raptors are named “kite” including the Mississippi kite (Ictinia mississippiensis) of North America and the red kite (Milvus milvus) in Europe. Kite = Bird.
Putting them all together, Chris Darbey (@chrisddarbey) photographed a red kite with a jet contrail. Kite=Bird + Plane.