Dragonflies, sea urchins, birds of Terschelling island


Migrant hawker male, 21 September 2019

After 20 September 2019 on Terschelling island came 21 September. We walked from West-Terschelling to the North Sea coast. We saw migrant hawker dragonflies. We heard a jay.

A carrion crow on a meadow.

On a bush, a willow emerald damselfly.

Birch bolete fungi along the footpath.

Two kestrels hovering, and driving a sparrowhawk away.

A bit further, a buzzard flying.

Reed bunting female, 21 September 2019

As we approached the last sand dunes separating us from the beach, this female reed bunting.

Sand dunes, Terschelling 21 September 2019

The final sand dunes were steep; but still, we could see the sea already.

Atlantic jackknife clam shells, Terschelling, 21 Sepember 2019

On the beach, many Atlantic jackknife clam shells.

Also, many dead small shore crabs. Also some, bigger, brown crabs.

Two common gulls.

Sea urchins, Terschelling, 21 September 2019

Also, sea urchins on the beach.

Serpent stars, Terschelling 21 September 2019

And, among the Atlantic jackknife clams, some serpent stars.

Stay tuned, as there will be more on 21 September 2019 on Terschelling on this blog!

Belgian climate strikers-yellow vests together against repression


This 12 October 2019 Voice of America video about Belgium says about itself:

Police Make Mass Arrests in Brussels During Climate Protest

Belgian police arrested large numbers of climate protesters in Brussels, Saturday, October 12, as mass demonstrations by the Extinction Rebellion group entered a sixth day.

Dozens of arrests were made while demonstrators gathered around a pink boat, with at least one climate activist using a bike lock to attach himself to the vessel. Police officers at the scene used heavy-duty cutting tools to remove the lock from around the man’s neck before arresting him.

Earlier in the day activists staged a protest next to the gardens of the Royal Palace calling on the King to declare a climate emergency. (Reuters)

Translated from Belgian daily Het Nieuwsblad, 15 October 2019:

Climate truants and Yellow Vests now want to demonstrate together against police violence

By Cedric Lagast

Brussels – The “Students for Climate” and the Yellow Vests want to come together on Monday in Brussels to protest against police violence. The reason is not only the tear gas incident last Saturday, but also the arrest of 350 Yellow Vests on election Sunday.

United Against Police Violence“. Under that name, eight organizations are announcing a rally in the capital on Monday. They want to go to the Brussels Grand Place, where the city council meeting should start at that time.

“We have taken the initiative and have invited a number of other groups,” says Yuni Mertens of Students For Climate. He refers to an incident last Saturday, in which a handcuffed man still got pepper spray in his face during a protest by climate movement Extinction Rebellion.

“After the shocking images, we felt it was necessary to raise this issue,” says Mertens. “We cannot accept this in a democratic constitutional state such as Belgium. This issue is not new. Many groups and minorities do experience this repression. We want to raise the issue of police violence in general. That is why we also let those other groups speak about their experience with the police, which is never mediatised.”

Together with Yellow Vests

Remarkably, one of those other groups is the Yellow Vests. …

On Facebook, reference is made to the arrest of 350 Yellow Vests on 26 May, the day of the elections.

“During an announced and peaceful demonstration, to demand more social justice, the Yellow Vests were preventively arrested.”

“We are organizing a standing, peaceful demonstration as close as possible to the Brussels city hall where the city council is taking place on Monday,” says Mertens. “We ask the mayor to treat non-violent demonstrators also non-violently in the future.”

Mayor must decide

“We have received a request today, Tuesday,” confirms police spokeswoman Ilse Van De Keere. … It is Mayor Philippe Close who must ultimately decide whether the demonstration can go ahead.”

Why mammal ancestors became nocturnal


This April 2017 video says about itself:

Genetics Used To Pinpoint When Early Mammals Became Nocturnal

Using genetic analysis of modern species, researchers have confirmed what has long been assumed to be the case – the early mammals that evolved when dinosaurs were roaming the land became nocturnal early on, most likely to avoid the reptiles that were snacking on them.

“This method is like using the genome as a fossil record, and with it we’ve shown when genes involved in night vision appear”, says Liz Hadly, co-author of the study published in Scientific Reports, in a statement.

From the University of Chicago Press Journals in the USA:

Did early mammals turn to night life to protect their sperm?

October 15, 2019

Humans are diurnal — we are active in the day and sleep at night. But diurnalism is by far the exception rather [than] the rule in mammals. About 250-230 million years ago, the mammalian ancestors, called the therapsids, became exclusively nocturnal, and stayed so until the demise of the dinosaurs 66 million years ago. All of our mammal ancestors lived in the dark for about 200 [million] years, and the majority still do to this day. Humans are, essentially, nocturnal animals that have reverted back to living in the sun.

There has been much speculation about why the therapsids became nocturnal. The traditional argument is that the archosauriforms and the dinosaurs became ecologically dominant during the Triassic. To avoid being eaten by the multitude of new carnivorous reptiles, the archaic mammals, it is argued, fled into the dark, where reptiles had yet to dominate. In a new paper, “Obligatory nocturnalism in Triassic archaic mammals: Preservation of sperm quality?”, Barry G. Lovegrove proposes a simple, new, alternative hypothesis based purely upon physiological constraints.

The therapsids were becoming rapidly endothermic (producing more of their own internal heat through metabolism) to fuel new energy demands and to defend the consequent elevated body temperature, especially as they got smaller during the Triassic. And herein lies a problem. As their body temperature started to approach that of the air, around 93.2°F (34°C), they would not have been able to offload excessive heat generated by being active during the day without losing vast amounts of body water through evaporative cooling, such as by sweating or panting.

Archaic mammals did not have scrotums, in which the testes are kept cool, and if there had not been a way to keep sperm cool, quality would have declined through the accumulation of free radicals with the increases in temperature during sperm maturation. By becoming active during the cooler nights, these mammals were able to preserve sperm quality. A nocturnal lifestyle could solve this problem, now that they were “warm-blooded,” with the newly acquired thermoregulatory toolkit to cope with the cooler night air.

The colour yellow in ancient Egypt


This January 2018 video says about itself:

The world’s first artificial pigment, Egyptian blue, may help scientists prevent forgery and even save lives.

From the University of Southern Denmark:

Discovered: Unknown yellow colors from antiquity

October 15, 2019

Summary: Antique artefacts have been studied by chemists, revealing a hitherto unknown use of yellow in Ancient Egypt

Archaeologists have long known that artefacts from the Antiquity were far more colorful than one would think when looking at the bright white statues and temples, left behind for today.

The statues and buildings only appear white today because the colors have degraded over time. Initially, lots of colors were in use.

This was also true for King Apries I‘s palace in Ancient Egypt. This palace was situated in the Nile Delta, and from here King Apries ruled from 589 to approx. 568 BC.

Fragments of the palace are today kept at the Glyptoteket Museum in Copenhagen, and recently they have been the focus of a collaboration between archaeologists from Glyptoteket, the British Museum, the University of Pisa and a chemist from the University of Southern Denmark.

“We are interested in learning more about the use of pigments, binders and the techniques associated with using them in the Antuquity. It has an obvious relevance for art historians, but it can also tell us about how different cultures in the Mediterranean and the Near East exchanged materials and knowledge and thus connected,” says Cecilie Brøns, classical archaeologist at Glyptoteket.

With this in mind, the archaeologists have worked with professor of archaeometry Kaare Lund Rasmussen from the University of Southern Denmark.

Professor Rasmussen is an expert in conducting advanced chemical analyzes of archaeological objects. Among other things, he has examined the beard of renaissance astronomer Tycho Brahe, Italian monk skeletons, medieval syphilis-infested bones, sacred relics and the Dead Sea Scrolls.

For this project he has taken samples of the palace fragments to learn more about the pigments and binders used.

The project has resulted in two scientific articles, the last one just been published. They can both be found in the journal Heritage Science.

“We have discovered no less than two pigments whose use in Antiquity has hitherto been completely unknown,” says Kaare Lund Rasmussen.

These are lead-antimonate yellow and lead-tin yellow. Both are naturally occurring mineral pigments.

“We do not know whether the two pigments were commonly available or rare. Future chemical studies of other antiquity artefacts may shed more light,” he says.

Lead-antimonate yellow and lead-tin yellow have so far only been found in paintings dating to the Middle Ages or younger than that. The oldest known use of lead-tin yellow is in European paintings from ca. 1300 AD. The oldest known use of lead-antimonate yellow is from the beginning of the 16th century AD.

Analyzing binders is more difficult than analyzing pigments. Pigments are inorganic and do not deteriorate as easily as most binders which are organic and therefore deteriorate faster.

Nevertheless, Kaare Lund Rasmussen’s Italian colleagues from Professor Maria Perla Colombini’s research group at the University of Pisa managed to find traces of two binders, namely rubber and animal glue.

The rubber is probably tapped from an acacia tree and served as a solvent for powdered pigment. Rubber was widely used as a binder, and it has also been found on stone columns in the Karnak Temple and murals in Queen Nefertite‘s tomb.

Animal glue was also commonly available. It was made by boiling animal parts, in particular the hides and bones, in water to a gel-like mass which could be dried and pulverized. When needed, the powder was stirred with warm water and ready to use.

The researchers also found these color pigments:

  • Calcite (white).
  • Gypsum (white).
  • Egyptian Blue (a synthetic pigment, invented in the 3rd millennium BC)
  • Atacamite (green).
  • Hematite (red).
  • Orpiment (golden yellow).

20 ancient coffins discovered in Luxor, Egypt: here.

Two new porcelain crab species discovery


This April 2018 video says about itself:

Species Corner – Porcelain crab in a symbiotic relationship with a bubble-tip anemone

The Porcelain Crab is common throughout the tropical oceans of the world, and has a flat, round body with two large front claws. They are brown and orange in coloration with bright blue spots. These crabs have a pair of front arms called maxillipeds, which have ends that are feather-like in appearance. They use these appendages to filter the water for any passing food. They are peaceful and interesting invertebrates for the marine aquarium..

From the Smithsonian Tropical Research Institute:

Two new porcelain crab species discovered

October 15, 2019

Summary: Two new symbiotic porcelain crab species have been described. One of them, from the South China Sea of Vietnam, inhabits the compact tube-like shelters built by the polychaete worm with other organisms. The other inhabits the intertidal vermetid snail formations in the Colombian Caribbean.

Two new porcelain crab species have been described in the ZooKeys journal by scientists from the Smithsonian Tropical Research Institute (STRI) and the Institut fur Tierokologie und Spezielle Zoologie der Justus-Liebig-Universitat Giessen. One of the new species, Polyonyx socialis, was discovered in the South China Sea of Vietnam. The other, Petrolisthes virgilius, has a new identity, after initially being taken for a similar-looking species — Petrolisthes tonsorius — four decades ago in the Colombian Caribbean.

Porcelain crabs belong to a highly diverse family of marine crustaceans, distributed in the shallow waters of oceans worldwide. They also are known as “false crabs”, because they evolved a crab-like form independently of true crabs. A relatively large number of porcelain crab species are symbiotic with other organisms, allowing scientists to tell a story of a long-time relationship between species from distantly related taxa.

“Most porcelain crabs live on the hard substrates of shallow waters like the surface of corals or rocks overgrown by algae, microbes and decaying material,” said STRI research associate Alexandra Hiller, co-author of the papers. “Others live as symbionts of invertebrates like sponges, anemones, sea urchins, polychaete worms and other crustaceans.”

The two recently described species are examples of these symbiotic porcelain crabs. P. socialis derives its name from the Latin word for “social” because it was found living with other organisms — including the larger porcelain crab species, Polyonyx heok — in the compact tube-like shelters built by the polychaete worm Chaetopterus sp. Its broad, flat walking legs and claw-bearing extremities appear to have been adapted for living tightly-attached to the worm tube walls and avoid being perceived as an obstacle for the other organisms.

Although initially mistaken for P. tonsorius in the 1970s, the uncommon colors and atypical habitat of P. virgilius — intertidal vermetid snail formations in the Colombian Caribbean — led the scientists to corroborate through genetic analyses that it was a new species. As a symbiont, P. virgilius has evolved in tight association to its distinctive surroundings: a reef-like microhabitat exposed to wave action and consisting of snail shells cemented to each other and to a hard substrate.

Despite the relatively high number of known symbiotic porcelain crab species, such as P. socialis and P. virgilius, the researchers believe this aspect of their ecology could hinder their long-term survival, particularly in the shallow-water ecosystems where they typically occur. These habitats are often more vulnerable to climate change, ocean acidification and contamination.

“Symbiotic species are thought to be more vulnerable to environmental challenges than free-living organisms,” said Prof. Dr. Bernd Werding, from the Institut fur Tierokologie und Spezielle Zoologie der Justus-Liebig-Universitat Giessen, and co-author of the studies. “Their fate depends on the fate of their host, which may also be affected by local and global conditions and abrupt changes.”

Corals fight back against global warming


This 2013 video is about Cladocora caespitosa coral in the Mediterranean.

From the University of Barcelona in Spain:

Survival strategy found in living corals which was only seen in fossil records

October 15, 2019

Some corals can recover after massive mortality episodes caused by the water temperature rise. This survival mechanism in the marine environment -known as rejuvenation- had only been described in some fossil corals so far. A new study published in the journal Science Advances reveals the first scientific evidence of the rejuvenation phenomenon in vivo in Cladocora caespitosa coral colonies, in the marine reserve in Columbrets, in the coast of Castellón (Spain).

The authors of the study are the experts Diego Kersting and Cristina Linares, from the Department of Evolutionary Biology, Ecology and Environmental Sciences from the Faculty of Biology and the Biodiversity Research Institute (IRBio) of the University of Barcelona.

Heatwaves, more and more common in Mediterranean

The Mediterranean Sea is one of the most affected areas by climate change and the increase of heatwaves. “We are used to hear and read on the general impacts related to the climate change, but we rarely get news on the life recovery after impacts related to global warming,” says Diego Kersting, first author of the article and researcher at the Free University of Berlin (Germany).

Since 2002, Kersting and Linares have been monitoring 250 coral colonies of Cladocora caespitosa in the marine reserve in Columbrets, an area for studies on the effects of climate change on the marine environment. This coral -the only one able to create reefs in the Mediterranean Sea– is listed as an endangered species, mainly because of the mortalities associated with global warming.

Experts had described that the unusual rise of water temperature in summer was killing many of these Mediterranean coral colonies. For instance, during the summer of 2003, one of the hottest ones, “the 25% of the surface occupied by these corals in Columbrets disappeared due a loss of the colonies,” says the authors of the study.

Some coral polyps survive under extreme conditions

In a Mediterranean Sea with higher and higher temperatures and frequent heatwaves, the survival alarms for these species had already rang. However, the long-run monitoring of the coral in Columbrets revealed a surprising result: some coral colonies that were considered lost years ago show some living parts.

According to the experts, this kind of recuperation was possible thanks to a procedure named rejuvenation. In particular, under stress conditions -for instance, excessive water warming-, some polyps in the coral colonies which are dying are able to become smaller until they can abandon their calcareous skeleton.

In this reduced state, these polyps can survive under extreme conditions which cause the death of the other polyps in the colony. When conditions improve, polyps recover its common size and form a new calcareous skeleton. Afterwards, they reproduce by budding until the dead colony recovers.

A hidden survival strategy

According to the authors, this survival strategy had been unnoticed until now due the external good image the colonies show once they have recovered, which masks the mortality that had taken place before. “The real story of these colonies can only be found if controlled every year, over the years, or if we study the skeleton, since the process leaves characteristic features!, warn Kersting and Linares.

So far, researchers had found signs of this rejuvenation only in Paleozoic corals, which lived hundreds of millions of years ago. Therefore, the results of this study will enable making comparisons between the in vivo observations and the description through the fossils, and therefore knowing the implication of these kinds of survival processes and adaptation in corals.

This discovery provides new perspectives for the survival of the only reef coral in the Mediterranean, which has a slow growth -about 3 mm per year- and a limited ability to create new colonies. “However, it is hard for these mechanisms to balance the serious increase of the frequency and severity of the heatwaves in the Mediterranean, so it is necessary to act urgently in order to slow the causes of climate change, and dedicate enough resources to maintain these monitoring procedures in the long run,” warn the authors.

Threats to coral reefs are everywhere — rising water temperatures, ocean acidification, coral bleaching, fishing and other human activities. But new research shows that 3-D printed coral can provide a structural starter kit for reef organisms and can become part of the landscape as fish and coral build their homes around the artificial coral: here.