This video is about two fighting slow worms.
Marleen Komduur Ter Apel filmed these lizards in the Netherlands in May 2014.
This video is about two fighting slow worms.
Marleen Komduur Ter Apel filmed these lizards in the Netherlands in May 2014.
This video is called Reptile Classification Project – Biology.
By John M. Regan:
Herping The Kingdom of Saudi Arabia
Imagine a land with lizards so large and numerous that you can spot them from a speeding car as they pop up from their burrows. A country where lizards are so prevalent that they scatter away from your approaching footsteps like a school of lakeside minnows. If this tickles your lacertilian fancy, then you owe it to yourself to visit Saudi Arabia, a place where lizards rule.
If only that would be literally true; then, there would not be those beheadings.
Herping the Kingdom of Saudi Arabia
The largest country in the Middle East, the Kingdom of Saudi Arabia is a huge chunk of desert about one-fifth the size of the United States. It is bordered on the north by Iraq and Iran; Yemen and Oman round out its southern tip. To the east and west sit the strategic waterways of the Persian Gulf and the Red Sea. Ruled by King Abdullah, son of the first Saudi king, Saudi Arabia is truly a monarchy. The country is a predominately harsh desert with no running waterways or large permanent bodies of water. Summer temperatures regularly exceed 120 degrees Fahrenheit, and barely 2 percent of the country is arable. Yet with 20 percent of the world’s proven oil reserves, it is a country of enormous geopolitical and economic importance.
There are at least 100 lizard species in Saudi Arabia, many perhaps unknown in the west. The Saudis are not known as great naturalists, and species identification is a challenge. Geckos of almost pure white emerge at night, and big pot-bellied geckos haunt wadi caves. Large desert monitors prowl the land as well. For any reptile enthusiast, Saudi Arabia is a potential treasure trove. …
For sightseeing and herping in the Riyadh area, two locations are in the absolute must-see category: Thumamah and the Tuwayq Mountains. Thumamah is a Saudi national park that is an intriguing complex of cliffs, deep wadis and hidden valleys. In addition to being fertile herping grounds, Thumamah is a fossil hunter’s dream. Entire hillsides are comprised of the fossilized remains of coral, shells and sponges. Plush Bedouin-style tents are available for overnight stays. The Tuwayq Mountains, also known as the “Edge of the World,” is an astounding ridge of desert cliffs that stop abruptly and overlook a desert plain that seems to go on to infinity. …
The Riyadh Escarpment, a dramatic curving line of spectacular desert cliffs, runs from north to south along the west side of the city. The scenery is stunning and the fauna in the area is just as dazzling. A single day’s outing reveals everything from camel spiders to baboons. Wolves and hyenas prowl; owls, falcons and eagles soar. Reptiles abound.
The Lizards of Saudi Arabia
But lizards rule. Geckos colored from shades of pink to white run about inside and outside of homes, and they inhabit every crack and crevice of backyards by the dozens. In the desert, the supremacy of lizards is even more evident. In fact, the lizard population is so large that a dedicated observer can soon learn to gauge the temperature of the day simply by identifying the species of lizard that happens to be out at a particular time. It is as though the lizards have taken over the role of rodents in this austere climate.
Geckos and agamids boast the largest variety of species, with the nod toward sheer numbers going to the geckos. Agamids, however, hold the size title. The largest and most famous of the Saudi agamids is the Egyptian uromastyx (Uromastyx aegyptia), also known as the dhub. With an adult length of 2 feet and a hefty 7- to 10-pound weight, the Egyptian uromastyx is the largest lizard species in Saudi and the most well known. They have long been a favorite at the Saudi dinner table. Bedouin desert dwellers are experts at smoking the reptiles out of their den and making a snack out of the lizard’s tail.
Those countless years of hunting have made the Egyptian uromastyx a very wary animal. Despite their size and squat appearance, they are extraordinarily fast and race to their burrow at the first inkling of danger. Catching one in the open is not an easy task. Finding them, however, is hardly a challenge. As the morning heat rises to about 90 degrees — cool by Saudi standards — the Egyptian uromastyx begin to emerge. They are so large and their burrows so distinctive that they are easy to see even when you’re rolling along at a moderate speed in a car. Their resemblance to prairie dogs is remarkable. Like prairie dogs, they are plant eaters. These stout lizards normally exhibit a dull desert-beige color, but in the spring, females display their finery and show off a beautiful variation of vivid yellow-and-black mating colors.
Another large agamid is Agama blandfordi. Bearing a marked resemblance in color and body type to bearded lizards, A. blandfordi reaches 10 inches in length and is just as noticeable a part of the desert landscape as the Egyptian uromastyx. Yet unlike the easily spooked Egyptian uro, these agamids are extraordinarily approachable. Their distinctive profiles grace exposed rocks, dirt mounds and scrub brushes as they calmly bask during the hottest part of the desert day. Perhaps this is the key to their approachability — they simply aren’t used to seeing other living things stirring in this heat. Photographing an A. blandfordi is as easy as driving your vehicle up to its basking rock and clicking the shutter. They can be approached on foot just as easily.
Although A. blandfordi initially appears as a lizard-shaped extension of light-gray rock, a closer look reveals unique wavy patterns of long, dark bands that run the entire length of the animal’s body. At the base of the lizard’s tail, the stripes are interrupted by brown-gray bands. The legs and feet, right down to the animal’s claws, also display this classic camouflage strategy.
Egyptian uromastyx excepted, this nonchalance in the presence of humans seems to be the case with many of the agamid species in the area. The smaller and much prettier spotted toad-headed agama (Phrynocephalus maculatus) prefers rocky landscapes in more moderate heat. These slender lizards often sit very still and allow the photographer to belly crawl all around while snapping close-up after close-up.
On the other end of the size scale are a number of small, American-anole-shaped lizards that inhabit a variety of desert niches. The delicately designed Hadramaut sand lizard (Mesalina adramitana) stretches out to just 2 inches. This diminutive reptile is a marvelous example of adaptation to extreme conditions. They are most common in areas of small, pancake-shaped rocks devoid of vegetation or anything approaching moisture. No bigger than a medium-sized dragonfly, this little lizard comes out at nearly the height of midday heat. Fast and perfectly camouflaged in sandy beige, it is a difficult animal to spot. At first you think the heat and bland terrain are playing tricks on your eyes. Eventually you realize that those tiny, light-brown flickers in your peripheral vision are actually this small lizard. The obvious food source for the sand lizard is small insects, while there are several Saudi scorpions that will just as easily make a meal out of the sand lizard.
This video is called Convergent evolution of anole lizards.
By Bob Yirka:
Study shows human impact on biodiversity on islands based on amount of trade
19 hours ago
(Phys.org) — A trio of researchers looking to test the idea of island biogeography have found a real world example that seems to both upend the traditional tenets upon which the science is based and confirm them at the same time. In their paper published in the journal Nature, Matthew Helmus of Vrije Universiteit in the Netherlands, Luke Mahler of the University of California and Jonathan Losos of Harvard University describe their study of anoles (a type of lizard) in the Caribbean Islands and how new data shows the ways humans have impacted the means by which the tiny color changing creatures migrate.
The science of island biogeography took off back in 1969, when ecologists Robert MacArthur and E. O. Wilson essentially sterilized a few very small islands and then monitored them to see how long and in which ways they would recover. Their study cemented the idea that island biodiversity is based on two major principles. The first is that the bigger an island is the more diversity it can support. The second is that the more remote an island is the less diverse it will be because other species have so much difficulty getting to it.
If humans weren’t around, it’s likely the original model would persist, but because they do, the principles have to be modified. That’s because people engage in shipping which living creatures can use to migrate. In this new study, the researchers looked at anoles as a barometer of sorts—traditional theory suggests there should be more species of them on larger islands, and more of them in general. Smaller islands on the other hand should have less, or none at all if they are too far away for migrants to reach.
This new study entailed cataloguing anoles by number and species throughout the Caribbean Islands and then comparing what they found to the traditional model. Doing so showed the original model failed miserably—but it also showed why. Because distance is no longer a factor in the equation (due to so much shipping), anoles are free to migrate to wherever they wish. The researchers found that in the newly updated model, island size still dictates population density, but now economic isolation is more of a factor. As one example, they note that diversity is limited on the Cuban islands, due to the trade embargo imposed by the United States. Much smaller Trinidad, on the other hand, which has a robust trade association with other nations throughout the area, has as many of the lizards and species as the island seems capable of supporting.
Translated from the Dutch RAVON herpetologists:
Wednesday, September 17th, 2014
During the renovation of a railway line in Maastricht in 2008 the wall lizard was taken into account. For those lizards, very rare in the Netherlands then there more than 20 drystone walls were built. Since then, the population is closely monitored annually by RAVON. This monitoring showed until recently that there was a slow recovery. However, the reproductive success was lower than people hoped. But the counts of this late summer bring good news. This year, more newborn wall lizards are crawling around than ever before!
Protecting vulnerable populations
The wall lizard lives in the Netherlands originally only in Maastricht. Here live a few hundred to under a thousand animals. That may seem like a lot, but on the northern edge of its range, in an isolated habitat this species in our country is very vulnerable.
This is another video about that iguana species.
The SOS iguana website started today to help save them.
This is a wall lizard video from Italy.
Lizard discovered on Texel – 26-08-14
There are no lizards on Texel. So, Texel man Hans van Garderen looked surprised when he found one in his home in Den Burg town. The animal was missing part of his tail, but looked healthy overall. He sent pictures of his special discovery to Ecomare biologist Pierre Bonnet. To find out which type it was precisely, Bonnet asked experts in the field of reptiles. According to RAVON staff member Annemarie van Diepenbeek it’s probably a young wall lizard.
Wall lizards are found in rocky environments in France and neighboring countries in southern Europe. In the Netherlands this species lives in one place, in Maastricht. Texel is not a suitable habitat for a wall lizard. They love a stony environment and not all that sand! Sand lizards do live on Terschelling and Vlieland, and on Terschelling, also the viviparous lizard. These species would also be able to live on Texel, but then you would expect them in the dunes, not in a house in Den Burg!
Alone or more of them
To find out whether this is a lone adventurer or whether there might be a population living on the island, Pierre advised Hans to also look in the garden. Among the stones he turned were there plenty of smooth newts, but no lizards. How the wall lizard came to Den Burg is unknown. It was probably taken along by people accidentally. Maybe it hitched a ride from a French campsite.