New wildlife bridge in the Netherlands


This 5 February 2015 video is about the new wildlife bridge Laarderhoogt in the Netherlands.

Today, 7 February 2015, this wildlife bridge had its official inauguration.

The bridge, near Crailoo, crosses tha A1 highway and the Naarderstraat road. It makes it possible for animals to move between the Westerheide and Laarderheide nature reserves. This should help rare species like pine marten and sand lizard.

Humans can cross now between the two nature reserves as well.

World’s smallest monitor lizard discovery in Australia


This video says about itself:

24 March 2014

Sir David Attenborough narrates a documentary about the life and crimes of Africa’s most notorious raider the monitor lizard. To feed its monster appetite, it will steal from under the noses of humans, lions and crocodiles, but with its criminal lifestyle comes extreme danger. The Nile Monitor is Africa’s largest lizard and most notorious ‘raider’ – its ultimate challenge is to steal the heavily guarded eggs and young of the Nile crocodile – can this expert thief pull it off?

From daily The Guardian in Britain:

Newly discovered Dampier peninsula goanna to go on display at WA Museum

The lizard, which grows to a maximum length of 23cm, is the world’s smallest and newest addition to the genus that includes monitors and Komodo dragons

Tuesday 30 December 2014 07.36 GMT

A newly discovered species of reptile, the Dampier peninsula goanna, has gone on display at the Western Australian Museum. The lizard is the world’s smallest addition to the Varanus genus, the family that also includes monitors and Komodo dragons.

The lizard on display, a female named Pokey, may look ordinary to the untrained eye but for scientists she’s an evolutionary marvel.

Unlike her relatives, who are often large and found over a widespread area of Australia, Pokey and her fellow Dampier peninsula goannas are found only on the peninsula north of Broome and Derby in Western Australia’s Kimberley region. The species is quite tiny, growing to a maximum 23cm in length and weighing only 16 grams.

WA Museum’s reptile expert, Dr Paul Doughty, said the discovery of the Dampier peninsula goanna was significant because it is a new species.

Doughty said this goanna diverged from its closest living relative – the short-tailed monitor – about six to seven million years ago, about the same time humans and chimpanzees split off from their common ancestor.

Museum visitors will be able to observe her small head, tiny legs, stretchy body and short tail, which Doughty described as a “funky” shape for a goanna.

See also here.

Colourful new lizard species discovery in India


This video says about itself:

In Rajasthan, India, a 15-year-old boy called Navratan Harsh or ‘lizard boy’ lets lizards crawl all over his face.

From Wildlife Extra:

New species of gecko lizard has been found in Central India

A new species of gecko lizard has been discovered in the Satpura Hill ranges in Central India by four researchers.

The new species has been named Eublepharis satpuraensis after the location in which it was found in, reports The Asian Age.

The lizard belongs to the family of leopard geckos, which are some of the least studied lizards in India.

The gecko was located while researchers Zeeshan A Mirza, Rajesh V Sanap, David Raju, Atish Gawai and Prathamesh Ghadekar were studying amphibians in the region.

“The first picture of this species came to me in 2009 from Melghat Tiger Reserve,” said Mr Mirza, who is currently doing his research at Bengaluru’s National Centre for Biological Sciences.

“Later a few more pictures followed which led us to Satpura Hills, where we discovered the new gecko,”

The specimens of adult male and female were found in the Satpura Tiger Reserve, Madhya Pradesh, and juveniles were collected from Amravati district.

The species were collected near the boulders, rocky outcrops and burrows mostly in the nights.

The paper also states that the geckos are nocturnal and secretive in nature. At the slightest disturbance, the species retreats.

The scientific description of this new species is here.

See also photo here.

Dutch reptiles use life-saving tunnel


This video is about reptiles in France and Tunisia.

In 2009, herpetologists designed a special wildlife corridor for reptiles and amphibians, a ‘herpetoduct‘ for nature reserve Elspeetsche Heide in the Netherlands.

It is a tunnel under the N310 motorway and a bicycle track, preventing crossing animals from being killed by traffic.

Research at various times in 2012-2014 proves much wildlife, especially lizards, use the tunnel. 16 viviparous lizards used the tunnel. Once, even at least five young viviparous lizards were born in the tunnel. Other species: four sand lizards; one slow worm; two adders; one moor frog; one European toad; one Alpine newt. Also, one smooth snake was seen.

Results of the research were published in the Zeitschrift für Feldherpetologie.

How some snakes became venomous, new research


This video is called The Evolution of Venom – Who is The Most Poisonous? [Full Documentary]

From the University of Texas at Arlington in the USA today:

Team proposes new model for snake venom evolution

17 hours ago

Technology that can map out the genes at work in a snake or lizard‘s mouth has, in many cases, changed the way scientists define an animal as venomous. If oral glands show expression of some of the 20 gene families associated with “venom toxins,” that species gets the venomous label.

But, a new study from The University of Texas at Arlington challenges that practice, while also developing a new model for how snake venoms came to be. The work, which is being published in the journal Molecular Biology and Evolution, is based on a painstaking analysis comparing groups of related genes or “gene families” in tissue from different parts of the Burmese python, or Python molurus bivittatus.

A team led by assistant professor of biology Todd Castoe and including researchers from Colorado and the United Kingdom found similar levels of these so-called toxic gene families in python oral glands and in tissue from the python brain, liver, stomach and several other organs. Scientists say those findings demonstrate much about the functions of genes before they evolved into venoms. It also shows that just the expression of genes related to venom toxins in oral glands of snakes and lizards isn’t enough information to close the book on whether something is venomous.

“Research on venom is widespread because of its obvious importance to treating and understanding snakebite, as well as the potential of venoms to be used as drugs, but, up until now, everything was focused in the , where venom is produced before it is injected,” Castoe said. “There was no examination of what’s happening in other parts of the snake’s body. This is the first study to have used the genome to look at the rest of that picture.”

Learning more about venom evolution could help scientists develop better anti-venoms and contribute to knowledge about gene evolution in humans.

Castoe said that with an uptick in genetic analysis capabilities, scientists are finding more evidence for a long-held theory. That theory says highly toxic venom proteins were evolutionarily “born” from non-toxic genes, which have other ordinary jobs around the body, such as regulation of cellular functions or digestion of food.

“These results demonstrate that genes or transcripts which were previously interpreted as ‘toxin genes’ are instead most likely housekeeping genes, involved in the more mundane maintenance of normal metabolism of many tissues,” said Stephen Mackessy, a co-author on the study and biology professor at the University of Northern Colorado. “Our results also suggest that instead of a single ancient origin, venom and venom-delivery systems most likely evolved independently in several distinct lineages of reptiles.”

Castoe was lead author on a 2013 study that mapped the genome of the Burmese python. Pythons are not considered venomous even though they have some of the same genes that have evolved into very toxic venoms in other species. The difference is, in highly venomous snakes, such as rattlesnakes or cobras, the venom gene families have expanded to make many copies of those shared genes, and some of these copies have evolved into genes that produce highly toxic venom proteins.

“The non-venomous python diverged from the snake evolutionary tree prior to this massive expansion and re-working of venom gene families. Therefore, the python represents a window into what a snake looked like before venom evolved,” Castoe said. “Studying it helps to paint a picture of how these gene families present in many vertebrates, including humans, evolved into deadly toxin encoding genes.”

Jacobo Reyes-Velasco, a graduate student from Castoe’s lab, is lead author on the new paper. In addition to Castoe and Mackessy, other co-authors are: Daren Card, Audra Andrew, Kyle Shaney, Richard Adams and Drew Schield, all from the UT Arlington Department of Biology; and Nicholas Casewell, of the Liverpool School of Tropical Medicine.

The paper is titled “Expression of Venom Gene Homologs in Diverse Python Tissues Suggests a New Model for the Evolution of Snake Venom.” It is available online here.

The research team looked at 24 gene families that are shared by pythons, cobras, rattlesnakes and Gila monsters, and associated with venom. The traditional view of venom evolution has been that a core venom system developed at one point in the evolution of snakes and lizards, referred to as the Toxicofera, and that the evolution of highly venomous snakes, known as caenophidian snakes, came afterward. But little explanation has been given for why evolution picked just 24 genes to make into highly toxic venom-encoding genes, from the 25,000 or so possible.

“We believe that this work will provide an important baseline for future studies by venom researchers to better understand the processes that resulted in the mixture of toxic molecules that we observe in venom, and to define which molecules are of greatest importance for killing prey and causing pathology in human snakebite victims,” Casewell said.

When they looked at the python, the team found several common characteristics among the venom-related gene families that differed from other genes. Compared with other python gene families, venom are “expressed at lower levels overall, expressed at moderate-high levels in fewer tissues and show among the highest variation in expression level across tissues,” Castoe said.

“Evolution seems to have chosen what genes to evolve into venoms based on where they were expressed (or turned on), and at what levels they were expressed,” Castoe said.

Based on their data, the new paper presents a model with three steps for venom evolution. First, these potentially venomous genes end up in the oral gland by default, because they are expressed in low but consistent ways throughout the body. Then, because of natural selection on this expression in the oral gland being beneficial, tissues in the mouth begin expressing those genes in higher levels than in other parts of the body. Finally, as the venom evolves to become more toxic, the expression of those genes in other organs is decreased to limit potentially harmful effects of secreting such toxins in other body tissues.

The team calls its new model the Stepwise Intermediate Nearly Neutral Evolutionary Recruitment, or SINNER, model. They say differing venom levels in snakes and other animals could be traced to the variability of where different species, or different genes within a species, are along the continuum between the beginning and end of the SINNER model.

Castoe said the next step in the research would be to examine the genome of highly venomous snakes to see if the SINNER model bears out. For now, he and the rest of the team hope that their findings about the presence of venom-related in other parts of the python change some thinking on what species are labeled as venomous.

“What is a venom and what species are venomous will take a lot more evidence to convince people now,” Castoe said. “It provides a brand new perspective on what we should think of when we look at those oral glands.”

How grass snakes changed from protective deities to Satan


This video says about itself:

This young grass snake was sleeping with slow worms.

From Environment and History, Volume 20, Number 3:

The Grass Snake and the Basilisk: From Pre-Christian Protective House God to the Antichrist

Abstract:

The grass snake owes its far northern distribution in Europe to the production and hoarding of dung from stock breeding. Dung heaps appear to be perfect breeding sites that surpass ‘natural’ reproduction sites in quality. Here we point out that the grass snake‘s dependency on manure goes back to Neolithic times and that it had a reciprocal cultural effect.

Moreover, the positive influence of humans on the species not only resulted from physical opportunities offered by agriculture, but also from the fact that grass snakes were considered to be chthonic deities not to be harmed.

The conversion of Europe to Christianity, however, marked the turning of the cultural tide for the species. From being a divine creature originally, the grass snake evolved into the number one symbol of the Anti-Christ: the basilisk.

In spite of the subsequent witch-hunt motivated by Christian belief, the overall historical human influence on the species was certainly not detrimental as regarded geographical distribution opportunities. This historical perspective on grass snake-human relationships adds to the discussion of whether nature conservation is better served by a strategy of land sparing or of land sharing.

It also makes clear not only that co-dependency of species is a matter of mutual biophysical advantages but that metaphysical considerations may also play a role. In this case it leads to the conclusion that bringing back the grass snake into our direct everyday surroundings is both favourable to the grass snake and reinstates the species in our own cultural environment.