Category Archives: Water and Shore

Tracker Eggs May Save Endangered Turtles

Green sea turtle (photo from Wikimedia Commons)

Green sea turtles (Chelonia mydas, above) are endangered and olive ridley sea turtles (Lepidochelys olivacea, below) are vulnerable even though both have a wide distribution in the tropical oceans. The threats they face are caused by humans including boat strikes, nets, poaching of the adults and collecting their eggs.

Olive ridley sea turtles nesting in Mexico (photo from Wikimedia Commons)

Back in 2015 conservation scientist Kim Williams-Guillén came up with a way to protect turtle eggs by using GPS-equipped decoys. Her award-winning idea was tried recently in Costa Rica with the results published this month in Current Biology.

Green sea turtle laying eggs (photo from Wikimedia Commons)

A team of scientists led by Helen Pheasey placed a decoy egg in each of 101 clutches of green sea and olive ridley turtles. 25 of the clutches were stolen by poachers. Five of the GPS eggs were taken for a ride. One traveled 85 miles. This diagram from Current Biology shows the decoys and the routes they traveled.

Decoy eggs, data, and estimated routes used by turtle egg traffickers (illustration from Current Biology PDF. Click this caption for the full description)

Revealing the trade routes is a step toward saving the turtles though not the silver bullet. Conservation laws and their enforcement can be ambiguous from country to country. As Science Magazine explains:

Ultimately, though, scientists and nonprofits are going to need to engage communities with local outreach and education programs to save sea turtles, Williams-Guillén says. “The real meat and potatoes of conservation isn’t going to come from deploying eggs.”

Science Magazine — Endangered baby sea turtles may have new savior: GPS eggs

Every little bit helps. Fake eggs will allow more baby turtles to hatch and walk to the sea.

Baby green sea turtle (photo from Wikimedia Commons)

Read more in Current Biology Magazine: Using GPS-enabled decoy turtle eggs to track illegal trade.

(photos from Wikimedia Commons, diagram from Current Biology Magazine: Using GPS-enabled decoy turtle eggs to track illegal trade; click on the captions to see the originals)

Avoiding Hurricane Laura

U.S. Doppler Weather Radar, 26 Aug 2020, 9:48pm EDT (from National Weather Service)

27 August 2020

Last night two hours after sunset bird migration was intense over the southeastern United States. The birds showed up as blue blobs on Doppler weather radar but there was a noticeable gap over Louisiana, southern Mississippi and southeastern Alabama. The birds were avoiding Hurricane Laura.

This National Weather Service radar map from 26 Aug 2020, 9:48pm EDT shows where the birds won’t go. (I’ve added a pink line to illustrate their self-imposed boundary.) I believe the small blue blob south of the pink line –at Jackson, Mississippi — is a sign of birds leaving for safer locations.

Humans were urged to leave too because of the coming storm surge, 20 feet high, as illustrated in the Weather Channel video below.

As of this writing (27 Aug 2020, 6am) about 150 people chose to stay home in the path of the storm.

Birds don’t have our brains but they know to avoid Hurricane Laura.

(maps from National Weather Service, click on the captions to see the originals; embedded tweet from The Weather Channel)

Why Are The Rivers Full When Rainfall Is Low?

Monongahela River running high even though there’s a drought, 8 Aug 2020 (photo by Kate St. John)

In this 8 August 2020 photo, the Monongahela River is full near the Homestead Grays Bridge, yet rainfall since June 1 is down 2-4 inches in the Monongahela watershed and the ground was bone dry at that time. This got me thinking … How could the river be full when we’re nearly in a drought? The abundance of water is deceiving.

Ever since Europeans arrived in western Pennsylvania they’ve worked to make our rivers more navigable. In the early 1800s these efforts barely made a dent, especially in late summer when the dry season turned the rivers into shallow pools and rivulets. The Lewis & Clark Expedition coped with this after they left Pittsburgh a month later than planned. Embarking on 31 August 1803 the Ohio was so low that the expedition had to push and drag their laden keelboat over many shoals. It took them a week to reach Wheeling. (read more here).

Keelboats and flatboat on Ohio River, early 1800s (image from Wikimedia Commons)

In 1824 Congress authorized the U.S. Army Corps of Engineers to get involved and the navigation improvements became permanent. By 1929 locks and dams had transformed all three rivers into chains of lakes. (read more at From Rivers to Lakes: Engineering Pittsburgh’s Three Rivers)

Braddock Lock and Dam on Monongahela River, 2017 (photo from Wikimedia Commons)

Because of the “lakes” we have lots of river traffic, making the Port of Pittsburgh the 15th largest port in the U.S. when measured in domestic trade. On the Mon River the trade seems to be mostly coal.

Coal barge and pleasure boat on the Monongahela River (photo from Wikimedia Commons)

The river is full when rainfall is low because the water is controlled for navigation.

Oh well.

p.s. Some people say the dams are for flood control but the locks and dams don’t perform that service. As Rob Protz points out, the flood control dams are very different. (See the Conemaugh River Dam.) Even with those dams in place we still get floods, though perhaps less frequently.

At the edge of the Mon River at Duck Hollow, 17 Feb 2018, 9:30am
The Mon River flooding the parking lot at Duck Hollow, 17 Feb 2018, 9:30am

Mixed Up Ducks

Mixed up ducks in Germany (photo from Wikimedia Commons)

One of the challenges of city birding is identifying the mixed up ducks not found in any field guide. These “mutt ducks” are the hybrids of mallards paired with escaped domestic ducks.

It’s easy for domestic ducks to hybridize with mallards because nearly all of them(*) are descended from mallards (Anas platyrhynchos).

Mallard cross with a domestic duck (photo from Wikimedia Commons)

Mallards hybridize with wild ducks, too, as shown in this a mallard X gadwall mix.

Mallard X gadwall hybrid Brewer’s duck (photo from Wikimedia Commons)

Some ornithologists worry that mallards will hybridize their closest relatives — American black ducks, Mexican ducks and mottled ducks — out of existence, as in this mallard X Mexican duck mix.

Mallard X Mexican duck hybrid (photo from Wikimedia Commons)

But perhaps they’re forgetting how recently those species evolved from mallards. The Mexican duck (Anas diazi) that occurs in Mexico and the U.S. Southwest was thought to be a subspecies of mallard until 1957.

Mallards are just working on creating new species. 😉

Read more about mixed up ducks in this vintage article: Ugly Ducks

(*) Some domestic ducks are descended from Muscovy ducks.

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

Disappearing into Thin Air

  • Lake Mead at Hoover Dam, 1998 (photo from Wikimedia Commons)

It’s hard to remember what we worried about before the coronavirus, but long term water crises provoked by climate change are still chugging along in the U.S. West. The most troubling of these is looming at the Colorado River, the water source for over 40 million people.

Many of the seven western states in the Colorado River watershed are suffering under severe to extreme drought. Of course it affects the river.

U.S. Drought Monitor map as of 28 July 2020,

But drought is not the only factor. A study published last February found that 20% of the river flow has been lost to the albedo effect in a period of 20 years.

Albedo is a reflectivity measure of various surfaces as they reflect sunlight back into space. Snow and ice have high albedo, bare ground and trees have low albedo. Melting snow and ice expose low albedo ground so the temperature rises. As the temperature rises more snow and ice melt. This climate change feedback loop is affecting the Colorado River.

The two photos at top span 22 years on the Colorado River at Lake Mead where Hoover Dam holds back the river. The amount of water in the lake is highly controlled by upstream dams but about 20% of that “bathtub ring” can be attributed to the albedo effect.

The river is disappearing into thin air.

(photos from Wikimedia Commons. Colorado River watershed map from, drought map from

Piping Plovers Dance For Love

Piping plover at West Meadow Beach, NY (photo from Wikimedia Commons)

7 July 2020

For such a tiny shorebird, male piping plovers (Charadrius melodus) have an elaborate courtship dance. The best part of it — the “tattoo” — was tweeted last Friday by the Ontario Piping Plover Conservation Program.

There’s more to the dance than that. In the run-up to copulation the male

  • Calls to his mate while scraping a nest in the sand, tossing away twigs and debris.
  • Approaches her in a low gliding crouch with his head below the horizontal.
  • Pauses near her, raises his head up high and beats a tattoo with his feet, faster and faster, closer and closer.
  • When he’s ready he mounts, still moving his feet up and down while on her back. He may stay in this position without copulating for more than a minute.
  • After or during copulation he may grab her by the nape of the neck. Though this looks vicious she doesn’t seem to mind.
  • And then they walk away and preen.

You can see all of these behaviors in this longer video from Montrose Beach, Illinois.

If all goes well, the dance results in some very cute baby birds.

Piping plover chick at West Meadow Beach, NY (photo from Wikimedia Commons)

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

Loons Have Unexpected Relatives

Common loon family, 2009 (photo by Kim Steininger)

1 July 2020:

If like me you owned a field guide at the turn of the century you remember that loons were the first bird in the book. Ornithologists placed them there because they thought loons were the oldest evolved bird in North America but DNA sequencing changed all that. In 2020 loons are near the middle of the tree and they have unexpected relatives.

In this July 2019 phylogenetic supertree I’ve circled loons and their relatives in blue. Notice that they aren’t related to ducks at all. Ducks are related to chickens.

Phylogenomic supertree of birds, a clockwise spiral from oldest to newest, circle and text added (image from MDPI, July 2019)

Here’s a closer look at the blue section showing that loons (Gaviiformes) stand alone after they split from a common ancestor of penguins, tubenoses, storks, cormorants and pelicans.

Here some of the loons’ unexpected relatives.

Penguins (Sphenisciformes) include king penguins (Aptenodytes patagonicus).

King penguins at Salisbury Plain (photo from Wikimedia Commons)

Tubenoses (Procellariiformes) include the wandering albatross (Diomedea exulans).

Storks (Ciconiiformes) include the white stork (Ciconia ciconia) that nests on roofs in Europe.

White storks on nest, Germany (photo from Wikimedia Commons)

Cormorants and allies (Suliformes) include the northern gannet (Morus bassanus) and the double-crested cormorant (Phalacrocorax auritus).

Northern gannet, Bonaventure Island, Canada (photo from Wikimedia Commons)

Double-crested cormorants visit Pittsburgh in the non-breeding season.

A double-crested cormorant with ring-billed gulls, Duck Hollow, Pittsburgh January 2020 (photo by Jim McCollum)

Pelicans (Pelicaniformes) include the brown pelican (Pelecanus occidentalis) we see at the beach and in flight along the coast.

Brown pelicans, one with mouth open, North Carolina (photo from Wikimedia Commons)
Brown pelican in flight, California (photo from Wikimedia Commons)

So when you see a loon on a northern lake this summer, remember his unexpected relatives.

(photos by Kim Steininger, Jim McCollum and from Wikimedia Commons. Phylogentic supertree from MDPI, July 2019)

Hover and Perch

Pied kingfisher, composite of one diving (photo from Wikimedia Commons)

The pied kingfisher (Ceryle rudis), native to Africa and Asia, is nearly as big as our belted kingfisher but he has a unique trait. He’s the largest bird able to hover in place without help from the wind.

The image above is a composite of three photos: a single pied kingfisher diving for the water. The video below (which is missing audio in the middle) shows a parent hovering and his daughter working on her dive.

When pied kingfishers aren’t hovering they hunt from a perch.

Two pied kingfishers watching for fish (photo from Wikimedia Commons)

Sometimes the perch can swim.

Pied kingfisher perched on a hippopotamus (photo from Wikimedia Commons)

(photos from Wikimedia Commons; video from Love Nature on YouTube)

Baby Birds Jump Into Life

Merganser chick contemplates his launch (screenshot from PBS NATURE video)

Across Pennsylvania breeding birds are hatching eggs and feeding young. As the nestlings grow the nests become crowded, a sure sign that the babies will leave soon.

Baby birds in hollow trees have an amazing way of leaving the nest: they climb up the inside of the hole and jump! This is true of chickadees, screech-owls, woodpeckers and wood ducks. But ducklings have no flight feathers and they jump away. That’s OK, they’re built for it.

This 3.5 minute PBS NATURE video shows a family of common mergansers (Mergus merganser) taking the plunge.

Though the video doesn’t show it, the ducklings waddle to the water where their mother calls and waits for them.

(screenshot and video from PBS NATURE)

Great Blue Herons Are Nesting

Great blue heron at Allegheny Islands rookery, 22 March 2020 (photo by Jim McCollum)

Great blue herons nest colonially near creeks, rivers, lakes and wetlands. As soon as they return to Pennsylvania they gather at their rookeries, usually located in sycamores. We have at least three rookeries in or near Allegheny County.

Northeast of Pittsburgh: On 22 March Jim McCollum went to Barking Slopes to see the island rookery above Lock and Dam #3 on the Allegheny River. This island is so close to the dam that it’s inaccessible but the rookery is visible after a mile-long hike at Barking Slopes. A much easier place to view it is on the Cheswick side of the river from the Harmar House parking lot on Freeport Road. There are more than 40 nests at this site.

Great blue heron rookery at Allegheny Islands as seen from Barking Slopes, 22 March 2020 (photo by Jim McCollum)

Northwest of Pittsburgh: On 6 April, Dick Rhoton and his wife visited a rookery near Sewickley, PA, described below with photos.

Last Monday Nellie and I made our almost yearly trip to see what was happening with the blue herons rookery north on the red belt from 65 (just past Sewickley (turn at the high tension wires and go until you see the cement plant on the left and the asphalt plant on the right- park here and then walk up the road for 1/4 mile or so). 

This year we counted 30 to 35 nests east of the road and almost all were occupied with sitting herons. 

— email from Dick Rhoton , 8 April 2020
Heron rookery near Sewickley, PA, 6 Apr 2020 (photo by Dick Rhoton)
Heron rookery near Sewickley, PA, 6 Apr 2020 (photo by Dick Rhoton)

South of Pittsburgh: There’s an easy-to-see rookery above a wetland between I-79 and the parking lot to the left of DDI headquarters on Washington Pike in Bridgeville, PA. Donna Foyle reports that at least 21 nests are visible from the I-79 edge of the parking lot.

If you decide to view a rookery remember to stand 6-feet away from other folks you encounter and, per Governor Wolf’s stay-at-home COVID-19 outdoor guidance, please limit your trip to a 15 minute drive from home. To make that possible, I’ve described locations in three directions.

p.s. The COVID-19 shutdown gives us an unparalleled opportunity to document spring in our own neighborhoods. In a “normal” spring I’d be traveling all over the place and ignoring the wonders of home. Instead I’m seeing changes in Schenley Park and visiting nearby hotspots such as Duck Hollow. This is a great time to keep a Nature Journal!

(photos by Jim McCollum and Dick Rhoton)