Over the Thanksgiving weekend 6 greater white-fronted geese (Anser albifrons) showed up in western Pennsylvania — four in Lawrence County and four in Armstrong County.
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.
Greater white-fronted goose (detail from the Crossley ID Guide Eastern Birds, arrow added to indicate white front)
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:
Ring-billed gull and common merganser, Duck Hollow, 23 Nov 2022 (photo by Charity Kheshgi)
26 November 2022
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.
Pied-billed grebe in silhouette, Duck Hollow, 23 Nov 2022 (photo by Charity Kheshgi)
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.
Common mergansers at Duck Hollow, 16 Nov 2022 (photo by Charity Kheshgi) Common merganser, not showing its crest, Duck Hollow, 16 Nov 2022 (photo by Charity Kheshgi) Common mergansers — unique field marks in blue (photo by Charity Kheshgi)
Female red-breasted mergansers (Mergus serrator) lack those sharp lines. The colors blend from one to the other.
In 1994 dozens of bald eagles were found convulsing, dead or paralyzed near Arkansas’ DeGray Lake. Autopsies revealed the eagles died of a new disease called avian vacuolar myelinopathy (VM) that manifests as brain lesions. The dying spread to Florida, Georgia, the Carolinas and Texas (hashed areas on the map below) and continues to this day. In 2021 scientists discovered what causes VM. It’s a chain of events that begins when we use an aquatic weed killer to control an invasive weed.
VM occurs in watersheds where A. hydrillicola colonizes H. verticillata. Watersheds where VM has been diagnosed (indicated by black crosshatching). Watersheds where H. verticillata has been confirmed to be colonized with A. hydrillicola are shown in red, and watersheds where A. hydrillicola has not yet been observed on H. verticillata are shown in yellow. Watersheds not yet screened for A. hydrillicola, but where H. verticillata occurs, are shown in green. This map, embedded from NIH, is current to fall 2019.
The invasive weed is hydrilla (Hydrilla verticillata) that spreads easily and clogs waterways. It’s a huge problem in many southeastern states, especially in Florida.
Integrated chemical plant management plans to control H. verticillata should avoid the use of bromide-containing chemicals (e.g., diquat dibromide). [The neurotoxin] AETX is lipophilic with the potential for bioaccumulation during transfer through food webs, so mammals may also be at risk.
(photos and diagram from Wikimedia Commons, map embedded from NIH; click on the captions to see the originals)
(*) The mystery was solved when scientists discovered that the toxin came from bromides that did not occur naturally. From NIH, Hunting the eagle killer: A cyanobacterial neurotoxin causes vacuolar myelinopathy: “Laboratory cultures of the cyanobacterium, however, did not elicit VM. A. hydrillicola growing on H. verticillata collected at VM-positive reservoirs was then analyzed by mass spectrometry imaging, which revealed that cyanobacterial colonies were colocalized with a brominated metabolite. Supplementation of an A. hydrillicola laboratory culture with potassium bromide resulted in pronounced biosynthesis of this metabolite. H. verticillata hyperaccumulates bromide from the environment, potentially supplying the cyanobacterium with this biosynthesis precursor.”
Greater yellowlegs, Duck Hollow, 30 Oct 2022 (photo by Lisa Kaufman)
31 October 2022
Birds are considered rare when they show up at a time or place that’s unusual for them. The rarest are the birds out of place, two of which we saw yesterday at Duck Hollow.
The surf scoter (Melanitta perspicillata) first seen at Duck Hollow by John Flannigan on 26 October was still present on the 30th. Autumn is the right time of year to find a surf scoter migrating through Pennsylvania but Pittsburgh is a rare place to find one. Surf scoters nest in Alaska and northern Canada and spend the winter at the coasts.
We saw the scoter yesterday drifting downstream beyond the Homestead Grays Bridge in a view similar to Michelle Kienholz’s photo below. This dark and distant duck with a ‘Roman nose’ and some white on its head/face was a Life Bird for many in the group. (Click here for a better photo by Justin Kolakowski.)
Surf scoter at Duck Hollow, 26 Oct 2022, 5:44pm (photo by Michelle Kienholz)
Our favorite rare bird of the day was the greater yellowlegs (Tringa melanoleuca) that we heard before we found him. Greater yellowlegs had never been recorded at Duck Hollow in autumn and rarely show up in Allegheny County even in spring. They nest in Canada and Alaska and spend the winter near the US southern coasts and in Central and South America.
When we heard his call (similar to audio below) we went down to the shore to find him.
Greater and lesser yellowlegs are similar but our bird’s vocalization, his slightly upturned beak and his behavior were diagnostic.
Generally walks with high-stepping gait; occasionally runs with neck extended. Movements rapid and jerky.
Dolphin skin constantly flakes and peels as new skin cells replace old cells. A bottlenose dolphin’s outermost skin layer may be replaced every 2 hours. This sloughing rate is 9 times faster than in humans. This turnover rate ensures a smooth body surface and probably helps increase swimming efficiency by reducing drag (resistance to movement).
We know these things about dolphins because some have a close association with humans. Veterinarians and trainers take an active interest in the welfare of animals in their care.
Dolphin veterinarians are especially concerned that as dolphins age, their heart health may suffer. This includes the dolphins in the U.S. Navy’s Marine Mammal Program in San Diego.
Last year the Navy asked for proposals to place heart monitors on their aging dolphins to unobtrusively monitor them as they move about in the ocean. There are many challenges to doing so including the dolphins’ skin. Because the skin turns over every two hours nothing can stick to it for long. I wouldn’t know about their skin if I hadn’t heard about the heart monitors.
The vast majority of us rarely if ever seen dolphins in the wild and know very little about their lives. We are mesmerized when we see them this close.
In September large, dark brown sea ducks swim in rafts off the coast of Maine. When they aren’t resting on the water they dive for mussels and crustaceans or walk up on the rocks to stand among the seaweed.
They vaguely resemble the lead field guide pictures for common eider (Somateria mollissima) but their current plumage is motley and variable. Right now common eiders are in eclipse.
Like many ducks and geese, eiders completely molt their tail and wing feathers after the breeding season, rendering them flightless for 3-4 weeks. Flight is restored in time for fall migration, but then they molt their body feathers. All told the process takes 4+ months.
To see eiders in all their glory watch them in breeding plumage from January to early June.
A 6 September 2022 press release announced explosive news for the state of Maine: Lobster should be off the menu to save right whales.
Today the Monterey Bay Aquarium Seafood Watch program added more than a dozen fisheries, including the U.S. American lobster fishery, to its “Red List” of seafood because they currently pose risks to the survival of critically endangered North Atlantic right whales. Seafood Watch provides recommendations for seafood buyers based on sustainability criteria. … [Currently] more than 25,000 restaurants, stores, and distributors — including Whole Foods, Blue Apron, HelloFresh, Cheesecake Factory, Compass Group, and ARAMARK — have committed to using Seafood Watch ratings to guide purchasing and menu choices and to avoid red-listed seafood.
Mainers reacted angrily. Sadly this clash could have been avoided but instead it unfolded like a slow motion train wreck for at least 20 years. Here’s how we got to this point.
Since at least 2001 NOAA Fisheries, which sets rules to protect fisheries and marine wildlife, has known that the second leading human cause of right whale deaths is from entanglement in vertical-hanging fishing gear including gillnets and the ropes of fish and lobster traps.
Whenever possible rescuers from the Coast Guard and Florida Fish and Wildlife sail out to cut the lines from entangled right whales (photos at top in 2014 and below in 2004) but a portion of rope usually remains with the whale because it’s embedded in a wound.
I hope the impasse ends soon, though it doesn’t affect me personally. My husband is a Fish Frowner — no “fishy” smells at home — so I’ve rarely eaten seafood for 40+ years and, given the choice, I prefer shrimp to lobster. So glad the shrimp red list got solved.
(photos from Wikimedia Commons and via Flickr Creative Commons licensing; click on the captions to see the originals)
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