Endangered lizard conservation in California, USA


This 2014 video from the USA is called Blunt-nosed leopard lizard, endangered species project.

From the University of California – Davis in the USA:

Detection dogs and DNA on the trail of endangered lizards

Noninvasive scat sampling could strengthen reptile conservation

October 30, 2019

Detection dogs trained to sniff out the scat of an endangered lizard in California’s San Joaquin Valley, combined with genetic species identification, could represent a new noninvasive sampling technique for lizard conservation worldwide. That is according to a study published today from the University of California, Davis, in partnership with the nonprofit Working Dogs for Conservation, U.S. Geological Survey and the U.S. Bureau of Land Management.

Scientists have used trained conservation dogs to locate scat and collect DNA samples for everything from bears and foxes to gorillas and whales. But the technique had not been used for reptiles until this study, for which scientists developed a novel approach to identify the presence of the blunt-nosed leopard lizard in the Panoche Hills Recreation Area and Carrizo Plain National Monument, both managed by BLM.

They developed new methods to recover DNA from feces and genetically identify lizard species in the same area. The study, published in the Journal of Wildlife Management, is a proof of concept for a host of reptiles.

“So many reptilian species have been hit so hard,” said lead author Mark Statham, an associate researcher with the Mammalian Ecology and Conservation Unit of the UC Davis School of Veterinary Medicine. “A large proportion of them are endangered or threatened. This is a really valuable way for people to be able to survey them.”

NO DIRECT CONTACT NEEDED

Current methods for surveying lizard species typically rely on live capture or visual surveys. Scat sampling allows biologists to study elusive, rare or dangerous animals without the need for direct contact. In addition to informing about the presence, habitat and genetics of an animal, scat can also be analyzed to inform researchers about diet, hormones, parasites and other health factors.

Using the new method, the authors genetically identified specific species for 78 percent of the 327 samples collected by dog-handler teams across four years. Most (82 percent) of those identified were confirmed as being from blunt-nosed leopard lizards.

To meet regulatory monitoring requirements, more research is needed to assess the viability of using detection dogs to recover usable DNA at larger scales. But the research highlights the broad potential this method holds for surveying and monitoring reptiles.

Study co-authors include Deborah A. Woollett, Alice Whitelaw and Ngaio L. Richards of Working Dogs for Conservation; Susan Fresquez, Jerene Pfeiffer and Benjamin Sacks from UC Davis School of Veterinary Medicine; Jonathan Richmond from the U.S. Geological Survey; and Michael F. Westphal of the U.S. Bureau of Land Management.

Funding was provided by the Bureau of Land Management.

Female sand lizard digs tunnel


This video shows a female sand lizard digging a tunnel to lay her eggs in.

The eggs will be at 10 centimeter under the ground, and the sun’s heat will develop them.

Laura van Ewijk in the Netherlands made this video.

Indian red-wattled lapwings and monitor lizard


This 4 October 2019 video from India says about itself:

Asian Lapwings Attempt to Scare Off a Lizard

A group of red-wattled lapwings are confronting an Indian monitor lizard that has stumbled on their nest. With little regard for their safety, they puff themselves up in the hope of scaring the predator away.

Komodo dragons’ armour to defend themselves


This video says about itself:

The Last Kingdom of Dragons – film about Komodo by Living Zoology film studio

Komodo national park is the last place on Earth ruled by dragons. Matej and Zuzana Dolinay, authors of an unusual natural documentary, will present an insight into the life of amazing creatures living on small and remote islands in Indonesia.

From the University of Texas at Austin in the USA:

Elaborate Komodo dragon armor defends against other dragons

September 12, 2019

Just beneath their scales, Komodo dragons wear a suit of armor made of tiny bones. These bones cover the dragons from head to tail, creating a “chain mail” that protects the giant predators. However, the armor raises a question: What does the world’s largest lizard — the dominant predator in its natural habitat — need protection from?

After scanning Komodo dragon specimens with high-powered X-rays, researchers at The University of Texas at Austin think they have an answer: other Komodo dragons.

Jessica Maisano, a scientist in the UT Jackson School of Geosciences, led the research, which was published Sept.10 in the journal The Anatomical Record. Her co-authors are Christopher Bell, a professor in the Jackson School; Travis Laduc, an assistant professor in the UT College of Natural Sciences; and Diane Barber, the curator of cold-blooded animals at the Fort Worth Zoo.

The scientists came to their conclusion by using computed tomography (CT) technology to look inside and digitally reconstruct the skeletons of two deceased dragon specimens — one adult and one baby. The adult was well-equipped with armor, but it was completely absent in the baby. It’s a finding that suggests that the bony plates don’t appear until adulthood. And the only thing adult dragons need protection from is other dragons.

“Young komodo dragons spend quite a bit of time in trees, and when they’re large enough to come out of the trees, that’s when they start getting in arguments with members of their own species,” Bell said. “That would be a time when extra armor would help.”

Many groups of lizards have bones embedded in their skin called osteoderms. Scientists have known about osteoderms in Komodo dragons since at least the 1920s, when naturalist William D. Burden noted their presence as an impediment to the mass production of dragon leather. But since the skin is the first organ removed when making a skeleton, scientists do not have much information about how they are shaped or arranged inside the skin.

The researchers were able to overcome this issue by examining the dragons at UT’s High-Resolution X-ray Computed Tomography Facility, which is managed by Maisano. The lab’s CT scanners are similar to a clinical CT scanner but use higher-energy X-rays and finer detectors to reveal the interiors of specimens in great detail.

Due to size constraints of the scanner, the researchers only scanned the head of the nearly 9-foot-long adult Komodo dragon, which was donated by the Fort Worth Zoo when it passed away at 19½ years old. The San Antonio Zoo donated the 2-day-old baby specimen.

The CT scans revealed that the osteoderms in the adult Komodo dragon were unique among lizards in both their diversity of shapes and sheer coverage. Whereas the heads of other lizards examined by the researchers for comparison usually had one or two shapes of osteoderms, and sometimes large areas free of them, the Komodo had four distinct shapes and a head almost entirely encased in armor. The only areas lacking osteoderms on the head of the adult Komodo dragon were around the eyes, nostrils, mouth margins and pineal eye, a light-sensing organ on the top of the head.

“We were really blown away when we saw it,” Maisano said. “Most monitor lizards just have these vermiform (worm-shaped) osteoderms, but this guy has four very distinct morphologies, which is very unusual across lizards.”

The adult dragon that the researchers examined was among the oldest known Komodo dragons living in captivity when it died. Maisano said that the advanced age may partially explain its extreme armor; as lizards age, their bones may continue to ossify, adding more and more layers of material, until death. She said that more research on Komodo dragons of different ages can help reveal how their armor develops over time — and may help pinpoint when Komodos first start to prepare for battle with other dragons.

The National Science Foundation funded the research.

Indian lizard’s mating season video


This 3 September 2019 video says about itself:

Lizard Wows Potential Mate with Daring Feats

For the male peninsular rock agama, attracting a mate is all about demonstrating fearlessness. What better way than to perch up high on a rock, in bright-colored skin, risking being spotted by a predator?

Galápagos lava lizards, new research


This 2018 video says about itself:

Lava Lizards are the most abundant reptile in the Galápagos, and they’re among the many species native only to the region.

Video by David Pickar aboard the National Geographic Endeavour II in San Cristobal Island, Galápagos.

From ScienceDaily:

Realistic robots get under Galápagos lizards’ skin

September 4, 2019

Male lava lizards are sensitive to the timing of their opponents’ responses during contest displays, with quicker responses being perceived as more aggressive, a study in Behavioural Ecology and Sociobiology suggests.

To avoid injury from male-to-male contests, some animal species display behaviours such as color changes or sequences of movements that showcase body size and fighting ability. In lizards, one of the most recognised behaviours is the bobbing or pushup display.

Dr David Clark at Alma College, US and colleagues investigated whether lizards would react more quickly and strongly to their opponent’s bobbing display, if that display occurred immediately or with a delay following an initial challenge. The authors used remote-controlled realistic lizard robots made from hand-carved wood, high-resolution photos and latex limbs to simulate an opponent’s reaction to a wild lizards’ display.

The authors positioned lizard robots approximately 1-3m from 20 wild Galápagos Lava Lizards (Microlophus bivitattus) found on the island of San Cristóbal. After provoking an initial response by the native lizard, the researchers remotely activated the lizard robot to respond with a pre-set counter movement either immediately, or after a 30-second delay.

Dr David Clark, the corresponding author of the study said: “We had hypothesized that our Lava Lizard subjects would respond differently if the robot responded immediately to their bobbing display than if the response from the robot was delayed. The results suggest that our hypothesis was correct. We found that an immediate response by the robot stimulated the wild lizard to respond more quickly and significantly more often than when the robot’s response was delayed by 30 seconds.”

The authors suggest that the live lizards may have perceived a rapid response from their robotic contestant as more aggressive than a delayed response. This ability to assess their contestant’s level of aggression may help the lizard size up their competitor and may influence their decision to retreat or instigate a contest, helping them avoid disadvantageous injury.

Dr Clark said: “Ours is the first study to use a lizard robot that interacts with wild subjects in real-time. Previous research in this area has used either pre-recorded video playback or robots with movements set on a “loop”. The findings confirm that realistic robotic stimuli can be used to interact with animals, to communicate with them and even manipulate their behaviour. Our results further our understanding of how lava lizards communicate with each other in their natural habitat.”

The authors say that bobbing display communication in lizards could now be explored further by altering display speeds, bobbing height and the distance between the robot and subject.