Category Archives: Water and Shore

Reprise of Grassland Birds

Dickcissel in Clarion County, June 2012 (photo by Robert Greene, Jr)

24 June 2021

In early summer Pittsburgh birders tire of searching among dense leaves so we travel to Clarion County’s recovered strip mines for grassland birds. Yesterday five of us drove 90 minutes to look for open country birds we’ve found there in the past.

Dickcissels (Spiza americana) are back again this year and easy to find singing on the wires at Concord Church Road. These rare nomads were a Life Bird for me in 2012. Read this vintage article, Dickcissels, for the reason why they to come to western Pennsylvania.

At Piney Tract (actually a grassland) we saw Henslow’s sparrows (Centronyx henslowii) …

Henslow’s sparrow, Clarion County, Summer 2011 (photo by Steve Gosser)

and heard them …

And we saw a grasshopper sparrow (Ammodramus savannarum) singing …

Grasshopper sparrow, June 2017 (photo by Steve Gosser)

… but I could not hear him because I’ve lost the upper frequencies. Can you hear the really loud trill of this grasshopper sparrow?

We also looked for upland sandpipers (Bartramia longicauda) but, alas, they were not there. Seven years ago I saw four of these Magical birds at Mt. Airy.

Interested in exploring the Clarion County’s grasslands? Check out two locations plus photos in this vintage article: In The Scrubby Fields.

(photos by Robert Greene, Jr and Steve Gosser)

Can’t Fly Right Now

Canada geese during flightless period in July (photo from Wikimedia Commons)

23 June 2021

Feathers wear out so birds molt to replace them. Most species molt their flight feathers one pair at a time, losing a matching feather on each side, so they can continue to fly. Not so with swans, geese and whistling ducks. They replace all their feathers shortly after the breeding season in a single annual synchronous molt. During the molt they cannot fly.

Though it seems crazy to lose the ability to fly these large heavy birds are safe on water and unsafe in flight if missing a few feathers. It works for them to lose these flight feathers all at once.

Canada goose flight feathers highlighted on the wing (photo from Wikimedia Commons)

Geese rarely display their stubby wings but you can tell when they’re molting by looking at their tails. Most of the year their flight feathers cover their rumps (left). When molting (right) you can see a white rump patch.

Not-molting vs. molting appearance in Canada geese (photos from Wikimedia Commons)

Right now in Pittsburgh Canada geese are in their flightless period that lasts six weeks from mid-June to August. You’ll see them flock in or near large bodies of water, feeding on land and walking to the water to swim to safety. You might even notice they are not at grassy feeding places, such as Flagstaff Hill, which don’t have bodies of water nearby. Such sites are unsafe when they cannot fly.

Have you seen any Canada geese flying lately? No. Because they can’t.

p.s. Goose mitigation plans do not harass geese during their flightless period. The best mitigation is done before they nest. For example, see the Allegheny Commons goose mitigation plan here.

(photos from Wikimedia Commons; click on the captions to see the originals)

Solitary Sandpipers Nest In Trees

Solitary sandpiper, Cap Tourmente NWA, Quebec (photo from Wikimedia Commons)

11 May 2021

Whenever we see this sandpiper species he’s up to his ankles(*) in water and is poking with his long bill to eat insects, crustaceans, mollusks and amphibians.

Solitary sandpipers (Tringa solitaria) are distinguished from other shorebirds by a white eye ring, white spots on dark back, and the fact that they’re usually alone. We see them on migration as they travel between their wintering grounds in Central and South America and breeding grounds in the muskeg bogs and boreal forests of Canada and Alaska.

Everywhere they go they land on the ground and walk in water. I have never seen one in a tree and yet …

Solitary sandpiper range map from Wikimedia Commons

When solitary sandpipers reach their breeding grounds they nest in trees.

Solitary Sandpipers use old nests of songbirds in trees, especially those of American Robins, Rusty Blackbirds, Canada Jays, and Cedar Waxwings, which are usually near the trunks of small trees a few yards above the ground, but may be higher. [that’s 9 ft or higher]

Males identify old songbird nests that have potential, and females apparently make the final selection. Females modify the nest by removing old lining and often relining with fresh materials.

All About Birds, Solitary SANDPIPER ACCOUNT

The nest looks like this specimen at the Burke Museum. Notice that the eggs are pointed like common murre eggs.

Solitary sandpiper nest with eggs (photo from the Burke Museum via Flickr Creative Commons license)

It’s hard to imagine a shorebird standing in a tree so click here for a drawing of a solitary sandpiper at its nest from Birds of the World.

Incredible as it seems, this shorebird nests in a tree.

p.s. I know of only two other tree-nesting sandpipers: green sandpiper (a Eurasian relative of the solitary sandpiper) and Nordmann’s greenshank in Siberia.

(*) The backward-facing knees on birds are actually their ankles.

(photos and map from Wikimedia Commons, Burke Museum Flickr, click on the captions to see the originals)

Why Do They Wag Their Tails?

Two tail bobbers: Spotted sandpiper, Louisiana waterthrush (photos from Wikimedia Commons)

14 April 2021

One of the joys of early spring is finding the first Louisiana waterthrush (Parkesia motacilla) of the year as it forages along a stream and sings its loud distinctive song. The bird is so loud that we hear him first then look for movement along the water’s edge. He stands out because he constantly bobs his tail. In fact he bobs the entire back end of his body!

Just half a minute of this video illustrates what I mean.

A few weeks later the spotted sandpiper (Actitis macularius) arrives to walk the water’s edge bobbing the entire back end of his body, too.

Same habitat, same movement. Is there some advantage in drawing attention to one’s back end? Why do these birds wag their tails? I found a partial answer at All About Birds:

… waterthrushes don’t actually wag the tail, they dip (or teeter) the entire rear of the body by moving their ankle joints. This motion is very much like the bobbing of Solitary and Spotted Sandpipers, which share their wetland habitats. It’s been suggested that this habit might either help them avoid scaring off their prey or possibly startle their prey into motion.

All About Birds, overview of Louisiana Waterthrush

There’s plenty of time to watch them teeter in the weeks ahead. My first Louisiana waterthrush of 2021 was at Cedar Creek Park in Westmoreland County on 30 March. I expect the first spotted sandpiper next week.

Bonus! Here’s a closeup of a Louisiana waterthrush singing:

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

p.s. Others birds pump their tails including eastern phoebes, palm warblers, hermit thrushes, wagtails and pipits. It is not quite the same motion.

Easter Island has Christmas Birds

Moai on Easter Island (photo from Wikimedia Commons)

4 April 2021, Easter Day

When Europeans explored the Pacific they sometimes named islands for the day they found them. Thus Easter Island (Rapa Nui) was named by Dutch explorer Jacob Roggeveen who encountered it on Easter Day 5 April 1722 and Christmas Island (Kiritimati) was given its English name by Captain James Cook on Christmas Eve 1777.

Easter Island is best known for its nearly 1,000 stone statues, moai, created by the Rapa Nui people. Kiritimati (pronounced “Ki-rismas” in the local language) is so remote that it was used for nuclear bomb tests 60+ years ago. Today the entire coral atoll is a wildlife sanctuary.

Range map from Birds of the World via Wikimedia Commons

Christmas shearwaters (Puffinus nativitatis) are pelagic birds that nest on remote Pacific islands (map) and were named for their largest breeding colony at Kiritimati, Christmas Island.

Christmas shearwaters roosting on Tern Island, French Frigate Shoals, Hawaii (photo from Wikimedia Commons)
Christmas shearwater on nest with its single egg, Midway Atoll (photo from Wikimedia Commons)

They also nest on Easter Island … so Easter Island has Christmas birds.

p.s. Happy Easter 2021.

(photos and map from Wikimedia Commons, sound from Xeno Canto. Click on the captions to see the originasl)

These Tadpoles Migrate Every Day

Screenshot of western toad tadpoles from Tadpoles: The Big Little Migration

2 April 2021

Three weeks ago frogs were singing and laying eggs in the vernal ponds of southwestern Pennsylvania. Many of the eggs have hatched by now. What do the tadpoles do next? This video from a remote lake on Vancouver Island, BC, Canada provides a hint.

Maxwel Hohn spent four years filming a tiny migration we never see. Every morning western toad tadpoles (Anaxyrus boreas) swim from their nighttime shelters to feeding areas in the lake, then back again to hide at night. The result is his award-winning 8+ minute video: Tadpoles: The Big Little Migration.

Our eastern American toads (Anaxyrus americanus) are closely related to western toads so I wonder if they do this, too.

Meanwhile, if the video wasn’t amazing enough for you, here are two more amazing things about tadpoles and toads:

  • Don’t worry that our tadpoles won’t survive the freezing temperatures this morning in eastern North America. Even if the ponds freeze, tadpoles are able to overwinter under ice. See photos at What’s Under the Ice? Wow! Winter Tadpoles from Oakland Twp, Michigan.
  • Do you know where North America’s toads came from? South America. And they didn’t walk! “Based on DNA sequence comparisons, Anaxyrus americanus and other North American species of Anaxyrus are thought to be descended from an invasion of toads from South America prior to the formation of the Isthmus of Panama land bridge, presumably by means of rafting. — from the Wikipedia description of the American toad.

Male Ducks Use Their Heads

Male common goldeneye (photo by Steve Gosser)

28 March 2021

In early spring male ducks use their heads to put on a show for the ladies. What most impresses their females? For many it’s a toss of the head.

During courtship common goldeneyes (Bucephala clangula) seem to have rubber necks. Click here to see their vigorous head tossing.

Among hooded mergansers (Lophodytes cucullatus) the head tossing is enhanced by their white hoods? Click here to see.

Male hooded mergansers, 2013 (photo by Steve Gosser)

(photos by Steve Gosser)

Osprey Back Yet?

Young osprey (photo by Dana Nesiti)

26 March 2021

There’s a Rule Of Thumb that says: Pittsburgh area osprey return from winter migration around St. Patrick’s Day.

This year the earliest eBird reports for southwestern Pennsylvania show osprey in Beaver and Butler Counties on 20 March 2021 and arriving this week along the Ohio River and at many lakes.

I haven’t seen an one yet so my goal this weekend will be to find an osprey, maybe at the Duquesne nest site.

My goal after that is to see an osprey do this …

(photo by Dana Nesiti)

Evolve Quickly!

Snail kite with island apple snail, Harns Marsh FL, 2017 (photo from Wikimedia Commons)

Native from Florida to Argentina, the snail kite (Rostrhamus sociabilis) is a gregarious bird of prey that eats only one thing: freshwater snails in the genus Pomacea. Its beak is specially shaped to do so.

Snail kite, Florida 2019 (photo from Wikimedia Commons)

The Snail Kite’s slender, deeply hooked, sharp-tipped upper mandible permits it to cut the columellar muscle of Pomacea snails and remove soft tissues from the shells. The arc of the upper mandible approximates the inner spiral of the snail’s shell.

— paraphrased from Birds of the World, Snail kite account

In the old days before humans took over Florida’s landscape, snail kites ranged over half the state, but we drained and diverted more than 50% of Florida’s wetlands, the snail kite population crashed and was listed as Endangered in 1967. Twenty years ago, from 2000-2007, their population dipped so low that scientists feared they would go extinct in the U.S. Then a curious thing happened. Their food supply changed and the kites changed so they could eat it.

Before this century the snail kite’s main food was the native Florida apple snail (Pomacea paludosa) but an invasive species, the island apple snail (Pomacea maculata), arrived in 2000 and began to spread in Florida’s lakes and water management areas.

Island apple snails eating rushes (photo from Wikimedia Commons)

The island apple snail is two to five times larger than the Florida apple snail as seen below. (The white-and-gray bars are each 5 cm.)

Size comparison of Florida apple snail (P. paludosa) to Island apple snail (P. maculata). Each scale bar is 5 cm (images from Wikimedia Commons)

When the island apple snail first arrived in Florida the snail kite population dropped but less than a decade later the population began increasing. Did the birds initially have a tool problem? Were their beaks too short to get at the snail inside the larger shell? A recent study from the University of Florida indicates this was probably the case. Since 2007…

Researchers found that the birds with bigger bills were surviving, and their offspring were inheriting the bigger bills. …

“We found that beak size had a large amount of genetic variance and that more variance happened post-invasion of the island apple snail. This indicates that genetic variations may spur rapid evolution under environmental change,” Fletcher said.

— paraphrased from UF study: Bird evolves virtually overnight to keep up with invasive prey

We think of evolution as a very slow process but for the snail kite it happened quite fast. Those with longer bills survived. Nowadays they easily eat island apple snails.

Male snail kite with island apple snail, Florida, 2016 (photo from Wikimedia Commons)

When it’s a matter of life and death, evolve quickly!

Read more at the University of Florida study: Bird evolves virtually overnight to keep up with invasive prey.

(photos from Wikimedia Commons; click on the captions to see the originals)

Goose Barnacles, Barnacle Geese

Goose barnacles, Lepas anatifera (photo from Wikimedia Commons)

20 February 2021

Goose barnacles often attach themselves to old wood and float from tropical seas to northern shores including the shores of Britain. The barnacles pictured here and in the video below are Lepas anatifera. Their bodies are supported by a long, flexible stalk (a peduncle) that resembles a goose neck. 

Goose barnacles and barnacle geese have similar names because people linked them to explain where the geese came from.

Every fall barnacle geese (Branta leucopsis) migrate to Britain and the east coast of the North Sea where they spend the winter. Those in Britain arrive from their breeding grounds in Greenland.

Barnacle geese (photo from Wikimedia Commons)

In the Middle Ages people didn’t know that birds migrate so they worked to explain the sudden appearance of full grown geese that they never saw nesting. Their explanation was that goose barnacles floated to shore, took root, and produced a tree that produced barnacle geese. This notion persisted for hundreds of years, from at least the 12th to 16th centuries.

Barnacle Geese. Facsimile of an Engraving on Wood, from the “Cosmographie Universelle” of Munster, folio, Basle, 1552

Nowadays that story sounds silly but we shouldn’t be too smug. We still create stories to explain things we don’t understand and spread them quickly on the Internet. In the future our fantastical stories will sound silly, too. I can think of a few about the coronavirus.

(photos from Wikimedia Commons; click on the captions to see the originals)