Colombia is home to large variety of animals and plants, partly due to the very different geographic features in the country’s landscapes, like the Andes and the Amazon, creating a myriad of habitats for species to live in. And while the Amazonian rainforest is renowned for its spectacular diversity of life, the lesser known cloud forests of the Andes rival this rainforest in biodiversity. The Andean part of Colombia and surrounding countries like Brazil, Ecuador and Venezuela, might even be the place with the highest amphibian diversity in the world and is definitely a hotspot in terms of amphibian species. No surprise then that two new frog species have been recently found in these Andean cloud forests in Colombia. Though certainly not the only new species that have been identified recently in this region, their ‘discovery’ is remarkable, because these species had been known to science longer, but after careful examination they have received the status of ‘new species’ .
Credit: Luis A. Mazariegos
Darwin’s frogs are aptly named, because they provide a wonderful example of evolutionary adaptation, blending in into their habitat of the leaf litter, with their body plan resembling a leaf. Unfortunately one of the two species, the northern Darwin’s frog (Rhinoderma rufum) hasn’t been seen since 1980 and a recent survey had no luck in finding any individuals, although its vast distribution in the past gives some reason for hope. The southern Darwin’s frog (Rhinoderma darwinii) has declined severely in numbers and its distribution throughout its range is now patchy with small population sizes. A study that appeared in PLOS One last week has shed some light on the dwindling numbers of these enigmatic animals. These species are both presumed to be yet another victim of the chytrid fungus that has been held responsible for decimating amphibian populations worldwide. A team of researchers led by Claudio Soto-Azat of the Universidad Andres Bello in Santiago and the Zoological Society of London (ZSL) found this out by conducting an analysis on dead and living specimens of the Darwin’s frogs and on other anuran (frog and toad) species living in their vicinity that might be carriers of the disease. Their results showed a high prevalence of the chytrid fungus in areas where the Darwin’s frogs have undergone dramatic declines.
Southern Darwin’s frog (Rhinoderma darwinii)
Credit: Claudio Soto-Azat
That men can be easily distracted by any hint at sex, especially when communicated by attractive women, is no surprise to us humans. More surprising is that this male preoccupation with sex might be used by female frogs as well to mislead male frogs and enhance their own fitness (the number of surviving offspring). This seems to be the case with females of the green poison frog (Dendrobates auratus). Because whenever a male frog with whom she recently mated, tries to indulge himself into the habit of promiscuous mating, the female will try keep him from it. She does so by leading him to believe she too wants to mate with him, seducing him and then after courting him for some time, blowing him off.
Green poison frog (Dendrobates auratus)
In Costa Rica a viable breeding population of a critically endangered harlequin toad species has recently been discovered. The beautifully colored harlequin toad Atelopus varius, was presumed to be extirpated from Costa Rica with only populations of the species remaining in the western part of Panama. Due to intense survey efforts after discovery of the population in 2008 in a private reserve within La Amistad Biosphere Reserve, it has been determined that more than 200 individuals of this species are surviving and that breeding very likely occurs. Because more than 90% of harlequin toad species, endemic to the Americas, are threatened and more than 75% of species is even critically endangered, it is very important that a previously unknown population of a harlequin toad species has been discovered.
A three week expedition in the south of Suriname has led to the discovery of 60 new species, including a chocolate-colored frog named the’ cocoa frog’. The expedition also turned up five other potentially new frog species, among them a poison dart frog. Recently, another poison dart frog had been discovered not far away in the Iwokrama Mountians in Central Guyana. This part of the Amazon and Suriname in particular is home to relatively pristine and untouched forests and biodiversity seems to be still thriving there.
And now a bit of history. Famously, the Dutch traded to the British their colony of New Amsterdam for the South American colony of Suriname. More historically correct, in the treaty of Breda (1667) the Dutch and the British agreed that they would both keep hold of the areas they had conquered in the Second Anglo-Dutch war. And that meant that the Dutch were now in charge in Suriname and the British ruled over New Amsterdam. This event is often quoted to state how foolish the Dutch had been to give away New Amsterdam that would later grow up to be New York or the ‘Big Apple’. One of the most famous cities in the world with millions of inhabitants and a very important economical center. What if they would have never given up on New Amsterdam. This in contrast to Suriname that still seems underdeveloped and has even today just over half a million inhabitants.
Scientists believe the so-called ‘cocoa’ frog is new to science. Photo by: Conservation International.
As I wrote some months earlier the Fire salamander has made a dramatic decline in the Netherlands and might be lost for my country forever if nothing is done to save it. Luckily there are people who are looking after this enigmatic species and live individuals have been caught in the wild to reproduce and eventually repopulate the Dutch woods. Repopulation is still an option, because the habitat is still there and so habitat destruction was not the agent of decline in this case. Scientists were puzzled by the sudden decline of the species, especially because they didn’t find any signs of the feared chytridiomycosis caused by the fungus Batrachochytrium dendrobatidis. Now after extensive research by the University of Gent the verdict is in and it doesn’t look good: a new fungus has been identified as the cause of the decline of the Fire salamander population. So this means there is a new sheriff in town and one that seems as lethal as the old one. The particular bad news is that this new species of fungus, Batrachochytrium salamandrivorans (referring to its quality of ‘eating’ salamanders) fills a different ecological niche, because it thrives at lower temperatures than the dendrobatidis one. So while Batrachochytrium dendrobatidis is mostly active in the tropics, although it has been found in the Netherlands as well, in the more temperate zones a similar disease posing a similar threat now has been identified. It is thought by the discoverers of the disease that it might have been responsible for more amphibian deaths than just the Dutch Fire salamanders, but until now there was no way of identifying this disease. For both chytrid species researchers now have found a cure, but this unfortunately doesn’t protect the animals from subsequent infections. So it is very important to discover the source of this new chytrid species, to eradicate it if possible and to stop the further spread of these fungal pathogens.
The Fire salamander. Copyright: Wikipedia
Here follows the more lengthy article from Mongabay.com on this discovery: (more…)
As we have seen in an earlier contribution here on my blog, poison dart frogs are in general beautifully colored creatures of a somewhat dangerous nature due to the poison they carry in their skin. There are more than 175 species of poison dart frogs known to science and last week a press release from the German Senckenberg Gesellschaft für Naturforschung announced the discovery of a new posion dart species, Allobates amissibilis. The species’ Latin name, amissibilis, translates as ‘that may be lost’ and refers to the location where the species has been discovered, the Iwokrama Mountains in Central Guyana, which was the stage for Sir Arthur Conan Doyle’s book ‘The Lost World’. Scientists were working on a project in this region, investigating the impact of planned ecotourism development on Atelopus hoogmoedi, a Harlequin toad, and by chance stumbled upon this new species of frog. Happy to see that we are still expanding our knowledge of the natural world and these beautiful frogs in particular.
Allobates amissibilis Credit: M. Hoelting and R. Ernst/Senckenberg
Here follows the article from Mongabay.com giving more details on this discovery: (more…)
This summer one of the most powerful men alive today, president Obama, spoke out very clearly his opinion on climate change and the human role in it: “The planet is warming. Human activity is contributing to it”. He added to that, pointing his arrows at the climate change skeptics, “we don’t have time for a meeting of the Flat Earth society”. Such a clear statement from the political leader of the USA is good news, because much time has been wasted on the question whether climate change is real and less time has therefore remained for solving the issue. The USA is one of the biggest CO2-contributors and is home to the most fanatic climate change skeptics. At least Obama’s words suggest that the political powers that be in the USA are acknowledging the problem of CO2-pollution and subsequent global warming. Moreover, they are willing to put their words into actions since they have launched an energy policy plan in which significant cuts on CO2-emissions are proposed. Needless to say, that this isn’t a done deal, because Obama still has to overcome the resistance from the Republican party and the lobby from the energy sector. For here it suffices to say that Obama’s intention to change the status quo is already a positive step forward. How much imminent action is needed, became clear at the end of September, when the IPCC presented a new report on climate change. U.S. Secretary of State, John Kerry summed up the conclusions of the report: “Boil down the IPCC report and here’s what you find: climate change is real, it’s happening now, human beings are the cause of this transformation, and only action by human beings can save the world from its worst impacts”. Not much to add here.
Climate change likelty has had a large impact on the Panamanian golden frog (Atelopus zeteki) Credit: DPAPE/FLICKR
Although I do not want this blog turning into a bad news show or a rewriting of the Apocalypse, I draw my inspiration from current events and these events are not unfolding favorably for many amphibian species.
Last month I read an article on the species in the Caribbean that seem to be in even greater peril than species in the rest of the world. Some 80 percent of the species in the Dominican Republic, Cuba and Jamaica and even 90 percent of the species in Puerto Rico are in danger of extinction. One major reason for this is that habitats have been degraded severely in these countries and that most species only are seen in small habitats on just one island.
Coqui or Common Coqui (Eleutherodactylus coqui) at a tropical forest in Patillas, Puerto Rico. Credit: Ricardo Arduengo
If you ever would be so happy to stumble upon a golden poison frog in the wild, chances are you are more enticed by this creature than frightened of it. With a Latin name like ‘terribilis’, referring to how terrifying this creature is, you might expect to see a more ferocious animal. However it definitely has earned its Latin name considering it is the most poisonous animal on earth. Therefore, it would be very wise not to touch it; the skin of one frog contains enough poison to kill 20 grown men. Its toxicity has proved to be a very useful feature for indigenous people living in the western part of Colombia: these people load their blowguns with darts that are made toxic by simply rubbing them against the backs of living golden poison frogs. This custom is very neatly described by Myers et al. in a lengthy article announcing the discovery of the species in 1978. Why it is so toxic and where it derives its toxicity from is still up for debate: long it was believed that ants in their diet were the primary source of the alkaloids that make up the poison, however the source now most likely is a small beetle that is part of the species’ diet. I will leave the debate with this and will focus now on conservation efforts, because unfortunately, even being the most poisonous animal on earth has not safeguarded this species from humanity’s march up on the Olympus. For it is our species that is continuously extending its sphere of influence over the earth and thereby leaving less and less habitat for other species to occupy. With its global population declining the golden poison frog, like many other amphibians, seems to have a grim future ahead.
The golden poison frog.
Credit: © Fundación ProAves – www.proaves.org