Poison frog colours, new research

This 2013 video from French Guiana is called Dendrobates tinctorius in its natural habitat.

From the University of Jyväskylä – Jyväskylän yliopisto in Finland:

Toxic frogs with weak defenses persist in the gene pool alongside stronger competitors

A multi-national team of evolutionary biologists shows that diversity exists even when expecting otherwise

September 2, 2019

Diversity is a hallmark of life and it shows up in unexpected places. A multi-national team of evolutionary biologists investigated how two types of poison frog co-exist when we expect only one. Their innovative study uncovers conditions where diversity flourishes against the odds, and offers new perspectives on chemical defense. The project was a collaboration between the University of Jyvaskylä, the University of Mississippi, Centre national de la recherche scientifique (CNRS) and John Carroll University. The findings were published in the Proceedings of the National Academy of Sciences (PNAS) on September 2nd 2019.

Many creatures carry warning colors that signal toxicity, such as wasps with yellow bands. The Dyeing Poison Frog (Dendrobates tinctorius) of French Guiana also has yellow stripes to keep predators away, but some have white stripes instead. This is an anomaly of evolution because predators learn to avoid warning colors through bad experience, and rare warning colors are harder to learn.

The team headed by Doctors Bibiana Rojas from University of Jyvaskyla and J.P Lawrence from the University of California Irvine propose evolutionary explanations for how nature allows rare warnings to persist.

Firstly, rare or weak signals can persist under the protection of stronger signals. The researchers show that predators learn to avoid more distasteful yellow frogs and generalize this avoidance to white frogs. Although the stronger defenses of yellow frogs should allow them to out-compete the whites over time, genomic analysis revealed that the population of white frogs is genetically separate from the yellows. Thus, diversity can exist within a single population (due to generalized learning) and between different populations (due to genetic isolation).

New methods to measure chemical defence were developed

The initial experiments were modest in scope, but strange results inspired the researchers to develop new methods.

“We faced the difficulty of not having an established method to quantify predator reaction to the chemical defenses. However, that difficulty turned into one of the biggest assets of our study, as we eventually succeeded at developing a method,” says Doctor Bibiana Rojas from University of Jyvaskyla.

The new method improves the ecological relevance and precision of measuring predator-prey interactions. Past studies have assumed that toxicity is everything, and measure it by injecting mice with defensive chemicals. But prey survival and evolution depends on whether they are eaten or spat out, not the blood chemistry of their predators. Thus, the researchers used skin extracts mixed with oats to get a separate measure of distastefulness. They show that toxicity and distastefulness are better considered independently.

“The biggest surprise came from the fact that the frogs [with] higher amount of toxins in their skin are not necessarily the ones that birds find most distasteful. This finding challenges previous assumptions that most toxic equals most unpalatable,” says Rojas.

Poison dart frogs’ colours, also camouflage

This 2016 terrarium video says about itself:

Dendrobates tinctorius ‘Powder Blue’ Calling.

Male dart frog vocalizing while female (barely seen) climbs the glass attempting to get to him.

From the University of Bristol in England:

Bright warning colors on poison dart frogs also act as camouflage

June 4, 2018

Poison dart frogs are well known for their deadly toxins and bright colours, which have made them a classic example of warning coloration.

The Dyeing Dart Frog, for example, is highly toxic and warns its predators with a bright yellow-and-black pattern.

However, new research led by scientists at the University of Bristol has revealed that the colour pattern does more than simply signal “danger.” Counterintuitively, it also works as camouflage.

Lead author, Jim Barnett completed this research, published today in the journal Proceedings of the National Academy of Sciences, while studying for a PhD at Bristol. He is now based at McGill University in Canada.

He said: “Effective as warning signals are, it’s not necessarily the best strategy to be maximally conspicuous.

Certain predators have evolved tolerance of toxins that would be deadly for humans, and some individual predators may have not encountered the warning signal prey before (a dangerous mistake for the predator, but also for the frog).

“So, colour patterns that could be distinctive close-up, but work as camouflage from a distance, would provide a clear advantage.”

Combining fieldwork in the jungles of French Guiana, computational modelling, and laboratory visual search experiments, Barnett and colleagues from the University of Bristol’s School of Biological Sciences and the School of Experimental Psychology investigated how the Dyeing Dart Frog uses its colours to balance the benefits of effective warning signals with the advantages of concealment.

They found that, despite being highly conspicuous at close range, the particular colours and their arrangement allow the pattern to blend together to form background-matching camouflage when viewed from a distance.

The frog’s pattern, therefore, allows it to get the best of both worlds: high fidelity camouflage until a predator discovers it, at which point its bright, highly salient, warning signal becomes clear.

Co-author Professor Innes Cuthill from the University of Bristol added: “How many other animals use ‘distance-dependent coloration’ to balance competing evolutionary pressures is yet to be explored.

“Being able to signal when close to a would-be mate, whilst remaining inconspicuous to more distant predators would seem beneficial. So too for human applications such as military camouflage, where recognition by allies is as important as concealment from foes. Also, signage that only need be clear at the distance where the information is needed, but might be distracting if detected earlier.”

French Macron wants destructive gold mining in French Guiana

This 2016 video is called Wildlife of French Guiana.

As this blog reported, there are grave economic and social problems in the French colonyOverseas Department‘ French Guiana, and workers have a general strike to protest.

Now, French ‘centrist’ (and militarist) presidential candidate Macron has a plan which he claims will miraculously solve the economic and social problems of French Guiana.

He wants to give Canadian mining corporations Columbus Gold and Nordgold permission to start the big Montagne d’Or gold mine in French Guiana.

Macron and gold mining pollution in French Guiana

This sarcastic French cartoon is called Macron on his way (‘en marche’, also the name of Macron’s political party) to energy transition (away from climate changing CO2, as promised in the Paris climate agreement). ‘Columbus Gold [mining in French Guiana] will be the spearhead of ‘responsible’ mining!’ Macron says.

Alex Anfruns interviewed Patrick Monier, the president of French Guiana’s environmental organisation Maiouri Nature Guyane on this.

Monier points out that the planned mine is in the middle of Amazon rainforest, right next to a nature reserve. It will violate the Paris climate agreement and gravely damage biodiversity in French Guiana. Gold mining uses poisonous cyanide and mercury.

About half of French Guianan young people are unemployed. And mining won’t give them jobs, as the mining industry in French Guiana imports 90% of its workforce from (cheaper) Brazil and to a lesser extent Suriname.

The local people (Native Americans and Maroons, offspring of slaves who fled from the French colonial plantations) were not consulted about the gold mining plans. They oppose them.

On 22 February 2017, 22 French pro-environment organisations appealed to the French government to immediately stop the Montagne d’Or mining plans.

You can oppose these plans as well by sending an email to contact-guyane@isf-systext.fr.

You can also sign an Internet petition, in French, against the destructive gold mining plans; here.

Or you can sign a petition in English: here.

Montagne d'Or plan

French Guiana strikers reject PS government’s offer: here.

French Elections: Alt-Right, Total and Gold Mines, the Story Behind the Candidates’ Environmental Policies: here.

General strike in French Guiana

This video from France says about itself:

French Guiana: ‘A powder keg abandoned by the state’

FRENCH PAPERS – Mon. 27.03.17: The situation in French Guiana is making headlines. The overseas territory in South America has seen social unrest over the past week and there are calls for a general strike today. Meanwhile, less than a month before round one, many French people still don’t know who to vote for in the upcoming presidential elections.

By Kumaran Ira:

General strike declared in French Guyana

27 March 2017

A few weeks before the French presidential elections, French Guyana is paralyzed by a general strike. Strikes and road blockades have been ongoing for a week in this French overseas department in South America, bordering Brazil, based on demands on health, education, economy, security and housing.

Protests by health care, transport and energy workers are demanding jobs, pay increases and improvements to the quality of public services. After a week of strikes and demonstrations, largely launched independently of the union bureaucracy, the 37 unions gathered in the Union of Guyanese Workers (UTG) union federation voted to hold a general strike starting today.

At the same time, significant protest movements are mobilizing farmers and agricultural labourers in solidarity with the workers. In recent days, they have set up dozens of roadblocks that control strategic intersections in several cities, including the entrances to the cities of Cayenne, Kourou, Rémire-Montjoly and Saint-Laurent du Maroni.

A dozen roadblocks and strike action are paralyzing the Cayenne airport. A Paris-Cayenne Air France flight had to head back to Paris after four hours flight time when the General Directorate of Civil Aviation (DGAC) radioed that it could not land in Cayenne airport due to a shortage of staff.

Striking electricity workers, Kourou hospital workers, and workers of the Endel corporation have blockaded the entrance to the Guyana space centre in Kourou. They were thus able to prevent the launching of the Ariane 5 rocket, the heart of Guyana’s economy, scheduled for March 21. “Due to a social movement, it was impossible to carry out the transfer operations of the launcher of the Final Assembly Structure (BAF) towards the launch area scheduled for today,” Ariane-Space declared in a statement.

Strikers also blocked the commercial port, the local authorities, the police prefecture and major roadways. Farmers are blockading the Agricultural Directorate’s buildings. Guyana’s schools, junior high schools and high schools have been closed by the authorities “until further notice.” University students are reportedly joining the protests.

The strike reflects deep social anger that is building among workers and oppressed social layers after five years of austerity under the Socialist Party (PS) government of President François Hollande. In this department of 200,000 people, 22 percent of workers (18,000 people) are jobless. Youth aged 15 to 24, who make up 46 percent of the unemployed, are the worst hit.

Speaking to France-Info, Senator for Guyana Antoine Karam said there was in Guyana “more insecurity than in the major cities inside France itself.” He added, “nearly 30 percent of the population does not have access to either drinkable water or to electricity, but on the other hand we have a space station.”

He also pointed to “murder, and armed robbery” in Guyana, claiming, “People will carry out murder for 20 euros, a jewel or a mobile phone.”

Guyanese people underscored their deep disappointment with the Hollande administration and the French government. Hollande promised a Pact for the Future of Guyana, which is still not signed.

Maud, 29, a teacher at Saint-Laurent-du-Maroni, told RMC: “Everyone has had it. People feel that no one ever talks about them, but that the situation is truly catastrophic. The Guyanese people have the impression that they have been abandoned by metropolitan France. They do not feel they are treated equally as compared to other departments.”

A month before the presidential elections, which are taking place amid explosive social anger in France, the PS government will seek to rapidly end the strike in the overseas department, before it triggers solidarity protests and strikes inside metropolitan France.

A billion stars, new information

This video, recorded in French Guiana, says about itself:

19 December 2013

Watch a replay of ESA’s billion-star surveyor Gaia lift off.

Today, the European Space Agency is presenting the first results of their Gaia satellite mission:

“From more than a billion stars we will finally get the exact position, brightness and distance from the earth“, says [Dutch astronomer] Nelemans.

Anna Frebel digs a young universe. Stellar archaeologist has turned up stars from the second generation ever to form. By Christopher Crockett, 11:05am, September 21, 2016: here.

French Guiana archaeological discoveries

This 2010 BBC video says about itself:

11 August 2010

Michelle Jana Chan explores the heritage of Suriname before crossing the Maroni River into French Guiana.

Translated from Leiden University in the Netherlands, 25 August 2015:

Original inhabitants of French Guiana were not nomads

Archaeologically, French Guiana is still largely unexplored. “The work is hard,” says Martijn van den Bel, “but all you find is brand new. For example, that Indians really lived in the so-called virgin forest.” PhD on September 2.

Finds from unknown epoch

Van den Bel focused on the period from 3000 BC. until the present time. He discovered that French Guiana had already residents then and also that these Indians were not so primitive. He and his colleagues found shards which could be reconstructed into open, round bowls of 30 cm high with powdered quartz stone mixed into the baking clay. They can be dated to the Early Ceramic period (2500 BC.). “There was nothing known about that time,” says Van den Bel.

Parts of the Amazon previously thought to have been almost uninhabited were really home to thriving populations of up to a million people, new research shows: here.

Wildlife in French colonies threatened

This June 2017 video says about itself:

Operation Acteon & Gambier, French Polynesia

Some of world’s rarest birds rebound on Pacific islands cleared of invasive predators Five remote Pacific islands are once again safe havens for four of our world’s rarest bird species following the success of one of the most ambitious island restoration projects ever implemented.

Just two years after ambitious efforts by a team of international conservation organisations to rid French Polynesia’s Acteon & Gambier island groups of invasive mammals began, five of six targeted islands are now confirmed as predator-free—a ground-breaking one thousand hectares in total. Early signs already indicate that rare birds found nowhere else in the world (endemic) and other native plants and animals are recovering as the remote islands return to their former glory.

From BirdLife:

Protecting birds in ‘tropical’ Europe

By Sanya Khetani-Shah, Mon, 13/07/2015 – 11:46

Given the nature protection laws in the EU (the Birds Directive and the Habitats Directive), it’s easy to believe that all European territories are well protected. But ironically, its overseas territories and départements, often teeming with biodiversity, are not covered by the EU’s environmental law framework. As a result, they are plagued by problems of invasive alien species, loss of habitat and extinction of endemic species.

Réunion Island, Martinique and French Guiana (all French overseas départements) are perfect examples. The Ligue pour la Protection des Oiseaux (LPO), BirdLife’s Partner in France, has been working there with local ornithological partners to save endangered birds like Réunion Cuckooshrike (or Tuit Tuit) and the Guianan Cock-of-the-rock (Le Coq de Roche Orange) through their five-year Life+Cap DOM programme, which concluded in a seminar in Paris on June 30-July 1 this year. This was the first Life+ project involving the creation of a network of local ornithological NGOs and the protection of fauna in the French overseas entities.


Réunion Cuckooshrike has been listed as Critically Endangered since 2008. Their numbers had dropped drastically due to predation by black rats, an invasive species that thrives on picnic remains. When the Life+ project began in 2010, there were only 27 pairs of the species in the world, all present in the Roche-Écrite Nature Reserve (now part of the Réunion National Park).

On islands like Réunion, species evolved without any predators or pathogenic agents, which left them particularly vulnerable to introduced predators. The extinction rate of bird species in Réunion is over 50%, and more than half the extinctions of island bird species are caused by the introduction of new predators.

Manual rat eradication in the core area of this site in the park, carried out all year round, with the Société d’Etudes Ornithologiques de La Réunion (SEOR), the Réunion National Park and the National Forestry Commission, led to the number of birds increasing to 40 pairs in 2015, with over 92% of eggs laid successfully fledging chicks. The species’ breeding area has also been increasing by about 9% per year.

Voluntary rescue rangers

Réunion Marsh-harrier or ‘Papangue’ is the only bird of prey breeding and endemic to the Réunion Island. It is the last raptor nesting on the island. With less than 200 pairs remaining, it is an Endangered species. But despite this status, for years it has been killed illegally or kept in cages. Since it flies at a low altitude while hunting, it is prone to fatal collisions with electric cables. Feeding on rats poisoned by rodenticides also contributes to deaths.

To protect the species, not only were frameworks put into place after consultation with national and regional authorities, but a group of 77 volunteers – the Papangue SOS Brigade – was formed in 2012 to monitor the numbers of the species at three sites, report any hurt or poisoned bird, and create awareness among the local farmers, residents and veterinarians to the issue.

Orange is the new red

In French Guiana, the limited nesting sites of the striking Guianan Cock-of-the-rock are threatened because of their economic viability: gold mining, logging, poaching and illegal animal trade, and unregulated wildlife tourism.

Since the species is fruit-eating and primarily inhabits forests with caves, the Groupe d’Etude et de Protection des Oiseaux en Guyane is working with local tour operators and mining companies to provide information about the most sensitive areas for the Cock-of-the-rock.  Tour operators have also been informed about the vulnerability of the species to visitor disturbance. Visitor tracks have been reoriented to enhance the viewing of the Cocks at their lek (breeding display site) and a hide put up to reduce disturbance by tourists.

Read more about the project, and view videos on Lifecapdom.org.

French fascist politician jailed for calling black minister chimpanzee

National Front politicians Marine Le Pen and Anne-Sophie Leclere, French parliamentary election poster

From daily The Independent in Britain:

Former Front National candidate jailed for calling black minister a chimpanzee

John Lichfield

Wednesday 16 July 2014

In the severest sentence of its kind ever handed down in France, a former far-right local politician has been sentenced to nine months in prison for comparing a black cabinet minister to a chimpanzee.

Anne-Sophie Leclère, a senior Front National municipal candidate in northern France, posted adjacent images on Facebook of a female chimpanzee and the justice minister, Christiane Taubira. The first image was labelled “at 18 months old” and the second “now”.

Anne-Sophie Leclere and her racist comparison

Challenged about the images in a TV documentary last year, Ms Leclère, 33, said: “On the whole I would rather see (Ms Taubira) in the branches of a tree than see her in the government.” She was rapidly expelled from the FN as part of a drive by its leader, Marine Le Pen to clean up the party.

The Front National was nonetheless – to its fury – also found guilty late on Tuesday of inciting racial hatred by a court at Cayenne, in Guyane in the French West Indies. The FN was fined €30,000. Ms Leclère, from Rethel in the Ardennes on the Franco-Belgian border, was given a nine months’ jail sentence, fined Euros 50,000 and banned from politics for five years.

Both the FN and Ms Leclère have appealed.

FN leaders attacked the judgement as a “judicial ambush” “immoral” and “politically biased”. They complained about the fact that the case had been heard in Guyane – Ms Taubira’s birthplace and an overseas part of France which has an overwhelmingly black population.

“Clearly, in the court in Cayenne, the normal rules do not apply,” the FN said in a statement. “These incredible violations of our legal system must be vigorously denounced.”

The judgement was also criticised by some – not all – centre right politcians but welcomed by the centre-left government and by anti-racist pressure groups.

The government spokesman Stéphane Le Foll, said that he was not going to “judge the judgement” but the attack on Christiane Taubira was “perfectly revolting, unacceptable… and a racist act.”

The lobby group SOS-Racisme said that the court’s ruling should be a landmark in public attitudes to the FN, which topped the poll in the French part of the European elections in May. “This party, whose driving force is hatred of others, can no longer pretend to discover that its election candidates are racist or anti-semitic each time that a controversy like this arises,” the group said.

Ms Leclère was the head of an FN candidates’ list for municipal election in Rethel in Ardennes when she was interviewed for a TV documentary last October. She was [a]sked about her Facebook posting comparing Ms Taubira to a chimpanzee. She said it was a “joke” and “not racist” but she would rather see Ms Taubiura in a tree than in the cabinet.

The FN expelled her from the party, describing her as an “error of casting”. Several similar incidents involving FN municipal candidates followed.

Ms Taubira, 62, is a brilliant academic and lawyer turned politician who has risen from deep poverty in Guyana to one of the top two or three posts in French government. She is detested on the hard right of French politics for pushing through a law legalising same-sex marriage last year.

Soon after Ms Leclère’s attack on her on Facebook, Ms Taubira was greeted by anti-gay marriage protesters on a visit to Angers in central France. They included children carrying “bananas for the monkey.”

Amphibian mothers feed young with their skins, new discovery

This video says about itself:

Why Do These Babies Eat Their Mother’s Skin?

6 May 2015

Legless amphibians, called caecilians, have a very strange way of feeding their young.


A New Species of Skin-Feeding Caecilian and the First Report of Reproductive Mode in Microcaecilia (Amphibia: Gymnophiona: Siphonopidae)

Mark Wilkinson, Emma Sherratt, Fausto Starace, David J. Gower


A new species of siphonopid caecilian, Microcaecilia dermatophaga sp. nov., is described based on nine specimens from French Guiana. The new species is the first new caecilian to be described from French Guiana for more than 150 years. It differs from all other Microcaecilia in having fewer secondary annular grooves and/or in lacking a transverse groove on the dorsum of the first collar. Observations of oviparity and of extended parental care in M. dermatophaga are the first reproductive mode data for any species of the genus. Microcaecilia dermatophaga is the third species, and represents the third genus, for which there has been direct observation of young animals feeding on the skin of their attending mother. The species is named for this maternal dermatophagy, which is hypothesised to be characteristic of the Siphonopidae.


Kupfer et al. [1] discovered a novel form of extended parental care in the oviparous African herpelid caecilian Boulengerula taitanus in which altricial hatchlings feed upon the modified and lipid-rich outer layer of the skin of their attending mothers using a specialised deciduous juvenile dentition.

Subsequently, Wilkinson et al. [2] reported the putatively homologous behaviour and associated morphological and physiological features of maternal dermatophagy in a second species of caecilian, the Neotropical siphonopid Siphonops annulatus. Because these two species of skin-feeding caecilians are not particularly closely related and represent lineages that have been separated for more than 100 million years, Wilkinson et al. [2] suggested that skin feeding was a relatively ancient trait and predicted that it would prove to be more widespread among caecilians.

The Neotropical siphonopid genus Microcaecilia Taylor, 1968 includes eight previously described nominal species of relatively small caecilians with heavily ossified, stegokrotaphic skulls, and small eyes that are covered with bone [3] which suggest they are dedicated burrowers. Very little is known of their biology and there are no previous reports of the reproductive biology of any Microcaecilia. Here we describe a new species of Microcaecilia from French Guiana. Observations of reproduction in captivity reveal that this is a third caecilian species known from direct observation to practice maternal dermatophagy. The species is identified as a member of the Siphonopidae on the basis of being an oviparous caecilian with imperforate stapes and no inner mandibular teeth, and as a Microcaecilia on the basis of having eyes under bone, tentacular apertures closer to the eyes than the nares, and no diastemata between the vomerine and palatine teeth [4].

More leatherback turtle nests in Florida

This video is called Leatherback Turtles in French Guiana (Dermochelys coriacea).

From ScienceDaily:

Leatherback Sea Turtle Nests Increasing in Florida

(Apr. 4, 2011) — The number of endangered leatherback sea turtle nests at 68 beaches in Florida has increased by 10.2 percent a year since 1979, according to a new Duke University-led study published in the current issue of the journal Ecological Applications.

Some beaches posted annual increases of more than 16 percent, others as low as 3.1 percent.

The population boom of turtle nests in the Sunshine State mirrors trends observed for other Atlantic leatherback sea turtle populations and is “very encouraging news,” says Larry B. Crowder, director of the Duke Center for Marine Conservation. “It suggests that conservation and recovery efforts mandated under the Endangered Species Act are paying off region-wide.”

The growth has likely been fueled in part by improved monitoring and protection of nesting beaches over the last 30 years, Crowder says, but other less benign factors may also be at work.

“Nesting is increasing even where beach protection has not been enhanced,” he says. “Changing ocean conditions linked to climate variability may be altering the marine food web and creating an environment that favors turtles by reducing the number of predators and increasing the abundance of prey, particularly jellyfish.”

With plenty of jellyfish to munch on, breeding-age female leatherbacks may be able to build up fat reserves more quickly, allowing them to nest more frequently, says Kelly Stewart, lead author of the study. Stewart received her Ph.D. from Duke in 2007 and conducted the research on Florida’s leatherback sea turtles as her dissertation research. Crowder was her faculty adviser.

Reduced populations of large predators, including the collapse of shark populations in the northwest Atlantic over the past decade, may be playing an even larger role in the turtle boom by decreasing at-sea mortality rates for juvenile and young adult turtles, she says.

Despite being a small population — scientists estimate fewer than 1,000 leatherbacks nest on Florida beaches — the increases in nest counts there may help achieve objectives of the federal Endangered Species Act-mandated recovery plan, Stewart says.

News for leatherback populations elsewhere is not so encouraging, however. Populations have plummeted at eastern Pacific nesting beaches in Mexico and Costa Rica, which once hosted thousands of female leatherbacks each year. Extirpation, or local extinction of the species, may be imminent on those beaches.

“The good news here is that while most sea turtles continue to decline, some sea turtles are increasing. We need to understand why they are increasing as much as why they are declining so we can transfer this understanding to other at-risk species, like Pacific leatherbacks,” says Crowder.

Stewart, Crowder and their colleagues modeled the 30-year nest counts on Florida beaches using a type of multilevel statistical analysis called Poisson regression, which is frequently used to model counts affected by multiple, often random, factors.

Nest counts are the most reliable way of assessing trends in sea turtle populations because they spend most of their lives in the open ocean, where changes in abundance are difficult to detect.

May 2011: A two-metre leatherback turtle weighing up to 250kg has washed up dead at Eagle Bay in Western Australia in what is one of only a few official records of the species in south-west Australian waters: here.

Bill to expand California’s marine sanctuaries, in leatherback sea turtle habitat, clears another hurdle today: here.

April 2011. Some 150 Olive Ridley turtles died after being trapped in a single net in India. A local official blamed the fishermen from the village of Visakhapatnam for not taking preventive measures. He claimed that the local fishermen used such nets in which the turtles get trapped and dead: here.

Vietnam finally nets legendary turtle for treatment: here.