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.
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.
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.
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.”
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.
The National Hurricane Center has forecasted “unsurvivable storm surge” from Hurricane #Laura in parts of Louisiana and Texas. Do NOT underestimate this storm.
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).
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.
The river is full when rainfall is low because the water is controlled for navigation.
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.
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
Lake Mead at Hoover Dam, 1998 (photo from Wikimedia Commons)
Lake Mead at Hoover Dam, 2015 (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.
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.
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.
You might hear about fancy mating dances done by birds in the tropics. Piping Plovers have one too! Goose stepping (tattooing) is a courtship dance done by the male right before copulation. The female rejects or accepts this dance! ? Video by Plover Lovers pic.twitter.com/0zyKH54fgW
— Ontario Piping Plover Conservation Program (@ontarioplovers) July 3, 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.
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.
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.
Sometimes the perch can swim.
(photos from Wikimedia Commons; video from Love Nature on YouTube)
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.
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.
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.
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!