Frogs mating, and the bats danger


This video says about itself:

Risky Ripples

23 Jan 2014

When a male túngara frog serenades female frogs from a pond, he creates watery ripples that make him easier to target by rivals and predators such as bats. A túngara frog will stop calling if it sees a bat overhead, but ripples continue moving for several seconds after the call ceases. In the study, published Jan. 23, 2014 in the journal Science, researchers found evidence that bats use echolocation — a natural form of sonar — to detect these ripples and home in on a frog. The discovery sheds light on an ongoing evolutionary arms race between frogs and bats. Video by Wouter Halfwerk.

From The Why Files:

Menacing mating game: Frogs fear bats!

23 January 2014

Like any foolish fellow, the túngara frog lives and loves dangerously. To those in the tropical-bio-biz, it’s old news that this resident of shallow ponds ranging from Venezuela to Central Mexico is prey to frog-eating bats.

That croaking mating call makes a great target for the flying mammals with an appetite for frogs’ legs. But now we hear another reason why life is hard for the feckless frog.

In a study released today, scientists revealed that the croaking frog sends two separate signals to the bats: First, the mating call, which deters competing males while attracting females — and those hungry bats.

But the frogs power their croak by inflating and deflating an enormous air sac, which forms ripples on the pond that survive even after the frog chokes off its croaks after seeing a bat against the night sky

To test the interaction between the bats and frogs, first author Wouter Halfwerk of Leiden University in The Netherlands set up an experiment in Panama, using artificial frogs to simulate the appropriate sound, with or without ripples

Halfwerk and co-author Michael Ryan, professor of zoology at the University of Texas, found that bats would attack in response to the mating call alone, but the attacks increased 36 percent when ripples accompanied the soundtrack.

Frogs croak, and then croak!

This makes life difficult for the frogs, Ryan notes. To reproduce, they must call. “The males can stop calling, but they can’t take these ripples back, so the danger of calling extends for a few seconds. It’s amazing that bats are able to figure this out.”

The tests were held in darkness, so the bats must have been using their sonar — echolocation — to find the pattern of ripples.

The mating call is primarily to attract females, but it also shouts “Keep away!” to other males, and the competition doubled their “I’m here too!” responses when ripples followed the croaks. “If you look when they are calling, the frogs are spaced out,” Ryan says. “If another male is too close, they start to make aggressive calls, and sometimes they fight; I have seen them kill each other.”

Ryan, who first noticed the frog-bat system as a graduate student in the 1980s studying with bat biologist Merlin Tuttle, notes, “We have known for a long time that the bats can find the frogs.” The new study, however, is the first to show how waves created when the frog sounds off affects bats — and other frogs.

Now that they know that competing males are more responsive when ripples are present, the researchers plan to see how females act with and without ripples.

Live to love, but love to live!

If the bats have “cracked the code” of the frogs behavior, turning a mating move into a death dance, that could be shaping frog behavior. “We know frogs prefer calling under cover, compared to out in the open,” says Ryan. Not only do bats have trouble flying to the sheltered frogs, but they may also have difficulty detecting ripples with echolocation in the brush.

We mused: the frogs, like certain guys we could name, allow mating to trump everything, even mortal danger. “Through the entire animal kingdom — there are exceptions — but most of the attributes that make an animal sexy or beautiful can be very costly. Men die before women in part because testosterone has a negative effect on the immune system.”

Every time an animal communicates, it creates a disturbance in the environment, and that’s especially true for the “look-at-me” mating messages. “The question I have,” Ryan adds, “is how many of these incidental things that we animals do become fodder for another animal that is looking to parasitize, to lay eggs” or grab dinner?

Do some showboating, and a biological big brother may be bugging your channel, Ryan says. “Males have to make themselves more conspicuous to females; to call louder, to wear brighter colors, do fancy dances. But all of this also makes them more conspicuous to predators.”

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Giant armadillo ecology, new discoveries


This video is called In Search of a Giant Armadillo.

From Wildlife Extra:

Giant Armadillos found to be ecosystem engineer

Secretive species gives shelter to other creatures

November 2013: A South American project into the little-known giant armadillo has unearthed the mysterious creature’s role as ecosystem engineers, giving housing and shelter to others.

The species is so enigmatic that the first ever photograph of one was taken just two years ago, with an automated camera trap capturing the first giant armadillo young earlier this year.

Researchers led by Dr Arnaud Desbiez, the Royal Zoological Society of Scotland’s regional coordinator for Latin America, have now discovered the armadillos dig deep burrows which provide new habitats and resources for many other animals. Camera traps in the Brazilian Pantanal have photographed at least 24 different species using their burrows as either a thermal refuge, shelter against predators, feeding ground or resting spot.

Dr Desbiez said: “It’s amazing to see such a secretive species which occurs at such low densities can play such an important role within the ecological community.”

Alfred Wallace’s South American butterflies rediscovered by English schoolgirl


This video is called Alfred Russel Wallace Pt1.

From the BBC:

10 September 2013 Last updated at 02:03 GMT

‘Priceless’ butterflies found at Oxford museum

By Sean Coughlan, BBC News education correspondent

An A-level student on work experience at an Oxford museum has found rare examples of butterflies lost since the 19th Century.

Athena Martin with some of the butterflies in the collection

Athena Martin, aged 17, has found butterfly specimens described as “priceless” by the Oxford University Museum of Natural History.

They had been brought back from South America by a Victorian naturalist.

Many of the butterflies were thought lost at sea in the 1850s.

Ms Martin’s discoveries came during the summer when she was taking part in a science-related work experience project.

Lost at sea

The school girl, who wants to study zoology at university, found and identified butterflies collected by the naturalist Alfred Russel Wallace.

They had been buried away in more than 3,000 separate drawers of butterflies at the museum.

Painstakingly going through the collection turned up more than 300 of Wallace’s butterflies.

The biggest find made by the work experience student was a butterfly called Dismorphia, brought from the Amazon and which had remained undiscovered and unacknowledged within the museum since the end of the 19th Century.

The confusion over Wallace’s collection had been caused by a fire breaking out on his ship when he was bringing back specimens from South America in 1852 – and it had been believed that most of his butterfly collection had been lost.

“The re-discovered Amazonian specimen in particular is a significant find in terms of the history of science and natural history collecting in the 19th Century,” says Dr James Hogan of the Hope Entomological Collections, which are based at the museum.

Dutch book on Wallace: here.

Peru rainforest plants research, video


This video says about itself:

Patricia’s Story: TEAM Network and the Vegetation Protocol – Conservation International (CI)

9 July 2013

Patricia Alvarez travels two days by boat to measure more than 7,000 trees and vines in the remote, intact core of Peru‘s Manú National Park. Her work is part of the TEAM Network, a global web of field stations that provide an early warning system for loss of biodiversity in tropical forests. The vegetation protocol followed by Patricia and her fellow TEAM scientists is used to calculate biomass and carbon stocks on a global scale.

This story is the second in a series that will follow three TEAM scientists on three different continents monitoring ground dwelling animals, vegetation and climate.

Watch Badru’s Story: http://youtu.be/Y-SJjJ3ZfP4.

Learn more about the Tropical Ecology Assessment and Monitoring Network:

http://www.teamnetwork.org

Native American dogs’ Asian origins


This video is called Dogs 101: Chihuahua.

From KTH The Royal Institute of Technology in Sweden:

Asian origins of native American dogs confirmed

10 July 2013 KTH The Royal Institute of Technology

Once thought to have been extinct, native American dogs are on the contrary thriving, according to a recent study that links these breeds to ancient Asia.

The arrival of Europeans in the Americas has generally been assumed to have led to the extinction of indigenous dog breeds; but a comprehensive genetic study has found that the original population of native American dogs has been almost completely preserved, says Peter Savolainen, a researcher in evolutionary genetics at KTH Royal Institute of Technology in Stockholm.

In fact, American dog breeds trace their ancestry to ancient Asia, Savolainen says. These native breeds have 30 percent or less modern replacement by European dogs, he says.

“Our results confirm that American dogs are a remaining part of the indigenous American culture, which underscores the importance of preserving these populations,” he says.

Savolainen’s research group, in cooperation with colleagues in Portugal, compared mitochondrial DNA from Asian and European dogs, ancient American archaeological samples, and American dog breeds, including Chihuahuas, Peruvian hairless dogs and Arctic sled dogs.

They traced the American dogs’ ancestry back to East Asian and Siberian dogs, and also found direct relations between ancient American dogs and modern breeds.

“It was especially exciting to find that the Mexican breed, Chihuahua, shared a DNA type uniquely with Mexican pre-Columbian samples,” he says. “This gives conclusive evidence for the Mexican ancestry of the Chihuahua.”

The team also analysed stray dogs, confirming them generally to be runaway European dogs; but in Mexico and Bolivia they identified populations with high proportions of indigenous ancestry.

Savolainen says that the data also suggests that the Carolina Dog, a stray dog population in the U.S., may have an indigenous American origin.

Savolainen works at the Science for Life Laboratory (SciLifeLab www.scilifelab.se), a collaboration involving KTH Royal Institute of Technology, Stockholm University, the Karolinska Institutet and Uppsala University.

America’s first human inhabitants


This video from the USA is called America’s National Treasures: Prehistoric American Indians.

From the Universidad de Barcelona in Spain:

Towards the origin of America’s first settlers

17 April 2013 Universidad de Barcelona

The most supported traditional hypothesis points out that the earliest well-established human culture in the North American continent were the Clovis, a population of hunters who arrived about 13,000 years before present from North-East Asia through the Bering Strait, and scattered over the continent. A new genetic study of South American natives, published on the journal PLOS Genetics, provides scientific evidence to reformulate the traditional model and define new theories of human settlement of the Americas. Professor Daniel Turbón, from the Department of Animal Biology of the University of Barcelona, is one of the authors of this international research, led by Lutz Roewer (Charité – University Medicine, Berlin). Eduardo Arroyo-Pardo and Ana Maria López Parra (Complutense University of Madrid) also sign the paper.

Which was the earliest well-established culture in America?

This new research is based on the analysis of male Y-chromosomal genetic markers in about one thousand individuals, representing 50 tribal South American native populations. According to the authors, the extant genetic structure of South America native populations is largely decoupled from the continent-wide linguistic and geographic relationships. This finding evidences that the initial human settlement of the Americas was not a single migration process —regardless of whether it took place through the Bering Strait—, but rapid peopling, followed by long periods of isolation in small tribal groups.

Profesor Daniel Turbón, expert on molecular and forensic anthropology and the origin and evolution of hominids, states that “Probably, America is one of the most recent examples of human settlement of a large continent. For scientists, it constitutes an excellent laboratory to compare the methodological tools used on genetic and population studies. Even if it has been widely held, the hypothesis of a single migration movement to explain the origin of America’s settlers is a reductionist view which is more and more questioned”.

Studies of Y-chromosomal markers

Authors analyse the genetic variation of every male individual by means of a series of Y-chromosomal genetic markers: to be exact, 919 subjects (91 % of the total) were typed for the 16 most common single nucleotide polymorphisms (SNP) in South America, and for the 17 short tandem repeat (STR) most widely used in forensic anthropology. The analysis of polymorphisms enabled to determine each individual’s geographical origin and to compare these data with other populations from North and Central America.

The research presents also a powerful international database on forensic genetics based on relevant collective studies (with native atomized small populations) developed by the international co-authors. The experts Francesc Bert and Alfons Corellas, both authors of doctoral theses supervised by Professor Daniel Turbón, also represent UB’s participation in the research.

“Nowadays, science is strongly atomized”, affirms Turbón. “On the one hand, many published researches are based on small population samples and use few genetic markers. That prevents us to observe the global scene. On the other hand, there are some macro genetic studies that show a wider scene, but it is difficult to compare them due to methodological reasons. Studies with biological samples are also carried out; samples come from hospitals located at large population centres with a high hybridization level. Native communities, which usually live in a more isolated way, are becoming scarcer”.

Native communities in danger of extinction

The paper published in PLOS Genetics identifies also a lineage which has not been described to date in North and Central American populations: C-M217 (C3*) haplotype, which occur at high frequency in Asia. Moreover, experts detected a Polynesian lineage in Peru.

The international scientific community faces the exciting challenge of discovering the origin of America’s first settlers. This new publication shapes some alternatives to the hypothesis of a single migration movement —which denies any trans-Pacific migration with remarkable effects on population’s genetics— as a model to describe America’s population origin.

“In the future, it would be essential to find an archaeological site which has a continuous archaeological sequence. Furthermore, it would be necessary to develop a complete genetic study of native populations as their danger of extinction is increasing day by day”, concludes Professor Turbón.

Amphibian mothers feed young with their skins, new discovery


Young Microcaecilia dermatophaga caecilians eating their mother's skin, photo: Emma Sherratt et al., PLoS ONE

From PLOS ONE:

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

Abstract

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.

Introduction

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].

Lizards endangered by climate change


This video says about itself:

Shining Tree Iguana (Liolaemus nitidus)

* Family: Iguanidae,

* Genus: Liolaemus,

* Species: L. nitidus,

* Phylum: Chordata,

* Class: Reptilia,

* Order: Squamata,

* Type: Reptile,

* Diet: omnivorous

* Average life span in the wild: no data,

* Size: no data,

* Weight: no data,

** Liolaemus nitidus is a species of lizard in the Iguanidae family. It is endemic to Chile.

From Wildlife Extra:

Some lizards particularly vulnerable to climate change

Lizards facing mass extinction

March 2013. Climate change could see dozens of lizard species becoming extinct within the next 50 years, according to new research. The often one-directional evolutionary adaptation of certain lizard species’ reproductive modes could see multiple extinctions as the global temperature increases.

Viviparous lizards at risk

Globally it has been observed that lizards with viviparous reproduction (retention of embryos within the mother’s body) are being threatened by changing weather patterns. The new study suggests that the evolution of this mode of reproduction, which is thought to be a key successful adaptation, could, in fact, be the species’ downfall under global warming.

Dr Daniel Pincheira-Donoso, from the School of Life Sciences at the University of Lincoln (UK), is the lead author of the paper detailing these amazing predictions, published in the scientific journal Global Ecology and Biogeography.

Researchers, including academics from the University of Exeter, investigated the hypothesis that historical invasions of cold climates by Liolaemus lizards – one of the most diverse groups of vertebrates on earth – have only been possible due to their evolution to viviparity (live birth) from oviparity (laying eggs). Remarkably, once these species evolve viviparity, the process is mostly irreversible and they remain restricted to such cold climates.

Viviparous lizards are facing extinction in the next few decades.

By analysing this evolutionary transition in the lizards’ reproductive modes and projecting the future impact of climate change, the scientists discovered that increasing temperatures in the species’ historically cold habitats would result in their areas of distribution being significantly reduced. As a consequence, if global warming continues at the same rate, viviparous lizards are facing extinction in the next few decades.

Dr Daniel Pincheira-Donoso is one of the few people in the world who works on the ecology and evolution of these lizard species. He said: “Lizards’ reproduction is largely linked to climatic temperatures and viviparous species are usually found in cold environments. When reptiles initially moved to colder areas they needed to evolve emergency measures to succeed in these harsh places, and we believe viviparity is one of these key measures. However, this transition is mostly one-directional and unlikely to be reversed. Rapid changes in the environment’s temperature would demand rapid re-adaptations to secure the species’ survival. Through the research we found that over the next 50 years nearly half of the area where these species occur may disappear, causing multiple extinctions due to climate change.”

Overall the conclusion is that although viviparity allowed lizards in the past to invade and adapt to live in cold environments, and was therefore a key trait for evolutionary success, it will now ultimately lead to multiple events of extinction.

Dr Pincheira-Donoso said: “These lizards are one of the most diverse groups of animals, and are able to adapt to remarkably diverse conditions. Unfortunately, a reduction in cold environments will reduce their areas of existence, which means that their successful evolutionary history may turn into a double-edged sword of adaptation. Their extinctions would be an atrocious loss to biodiversity.”

Climate change must not be underestimated

Dr Dave Hodgson, from the University of Exeter, said: “Climate change must not be underestimated as a threat to modern patterns of biodiversity. Our work shows that lizard species which birth live young instead of laying eggs are restricted to cold climates in South America: high in the Andes or towards the South Pole. As the climate warms, we predict that these special lizard species will be forced to move upwards and towards the pole, with an increased risk of extinction.”

The work formed part of Dr Pincheira-Donoso’s post-doctoral work, which was funded by the Leverhulme Trust.

The paper ‘The evolution of viviparity opens opportunities for a lizard radiation but drives it into a climatic cul-de-sac’ is published in the latest issue of the peer-reviewed journal Global Ecology and Biogeography.

Dr Pincheira-Donoso will continue his research at the University of Lincoln by developing projects to investigate the ecology of evolutionary adaptations and its interactions with human-induced climate change.