Lizards Prefer to Poop on the Largest Rock They Can Find-Conspicuous toilet spots may help Dalmatian wall lizards communicate. - via Herp Digest

Simon Baeckens knows when he's in a good spot for catching lizards. It's when he sees the largest, most prominent rocks are crowned in poop.

"It's not like I'm a poop researcher or anything," he clarified. Baeckens, an evolutionary biologist at the University of Antwerp in Belgium, studies the pheromones and physical traits of lizards in the family Lacertidae, also known as wall lizards, which are native to Europe, Africa and Asia. But after years of collecting lizards from the wild, it was clear to him that his research subjects did not choose their toilets randomly.

Previous studies have indicated that wall lizards use their feces to communicate. Males will avoid areas where another male has defecated, suggesting that lizard droppings may function as a "keep out" sign. Wall lizards can also glean information from the scent of other lizards' feces.

Baeckens suspected that lizards might be deliberately leaving their "signals" in places where other lizards could easily see and smell them. But it's also possible that lizards like big rocks for other reasons, and their waste placement is a side effect of where they spend their time. For example, big rocks might provide the warmest sunning spots or the best view to watch for predators.

To partially control for such factors, Baeckens and his colleagues collected 90 Dalmatian wall lizards from Croatia and housed them alone in identical enclosures. Each enclosure contained a small rock, a medium rock, and a large rock, all of which were the same temperature.

Eighty percent of the lizards defecated primarily on the biggest rock, the researchers reported in the journal Behavioural Processes. "There's almost no feces on the smallest or the medium-sized rock," said Baeckens. The findings held true for males and females and for lizards from three separate populations. It's not yet possible to be sure of the lizards' motivations, said Baeckens. Still, the study lends weight to the idea that large rocks serve as poop display sites.

Wall lizard becomes accustomed to humans and stops hiding

 Date: March 27, 2017

Source: FECYT - Spanish Foundation for Science and Technology

Habituating to predators or fleeing and hiding are tactics that vary between species. Scientists from two research centres in Italy and Spain have observed that adult male common wall lizards sharing their living spaces with humans become accustomed to them and hide less when humans approach them. Yellow lizards were the most "daring."

Humans have an increasing presence in different species' natural habitats. For this reason, scientists are investing much time in studying wild animals' capacity to tolerate these disturbances. Lizards are an appropriate model for research into this subject, as they can be found in high densities in many environments and are relatively easy to observe in the field and handle in laboratories.

Scientists from the Eco-Ethology group of the University of Pavia (Italy) and the National Museum of Natural History (CSIC) in Spain used the lizards to analyse their reactions to attacks by human predators and the strategies they adopt, depending on the local risk level. To do this, they simulated human attacks on two populations in completely different settings: rural and urban habitats.

"The species we used in the study was the common wall lizard (Podarcis muralis). The main aim was to detect the possible influence of urbanisation on their antipredator response in terms of activity, time spent hidden in refuges after attacks and habituation to predators after repeated attacks," Sinc was told by Jose Martín of the Spanish National Museum of Natural History and co-author of the paper, published in the journal Animal Behaviour.

The findings show that urban lizards spend less time in their refuges following simulations of predator attacks and that the become habituated, as their successive hiding times decreased faster than those of the rural lizards. This detail suggests different levels of caution against potential predators. 

Continued 

Human introductions create opportunities for intra-specific hybridization in an alien lizard - via Herp Digest

Sozos Michaelides, Geoffrey M. While, Celia Bell, Tobias Uller

Biological Invasions

May 2013, Volume 15, Issue 5, pp 1101-1112

Abstract

Introduction of individuals from multiple sources could create opportunities for hybridization between previously isolated lineages, which may impact on the invasion process. Identifying the phylogeographic origin of introduced populations is therefore an important task to further test the causes and consequences of human-mediated translocations. The common wall lizard (Podarcis muralis) shows a strong phylogeographic structure as a result of past isolation in glacial refugia, but it has also been commonly introduced outside of its native range. Here we analysed 655 base pairs (bp) of the cytochrome b sequence from 507 individuals from 23 introduced populations of P. muralis in England. We identified 12 unique haplotypes in the introduced populations that were nested into five native geographically distinct clades with genetic divergences ranging from 2.1 to 5.7 %. Multiple clade origin was common within populations, with a maximum of three different haplotype clades being represented within a single population. The genetic data are consistent with a scenario whereby initial establishment was a result of translocation of animals from their native range, whereas more recent establishment (i.e. since the mid-1980s) is the result of translocations of animals from previously established non-native populations. However, this requires further study. Overall, our results show that human introductions have created substantial opportunities for hybridization between genetically and phenotypically distinct lineages, which may have important consequences for the establishment success and long-term viability of introduced wall lizard population

The mystery of the Mount Laurel lizards solved

The mystery of the Mount Laurel lizards solved

PEG QUANN
Burlington County Times

MOUNT LAUREL - It's a whodunit with a herpetological flair. Little greenish-brown lizards - Italian wall lizards by name - have been scurrying under rocks, porches, and garages in the Mount Laurel area for several years.

But where did they come from?

Rumors suggested that Italian immigrants brought them as pets, or that a Rutgers University student researcher released them.

Then last spring, Russell Burke of Hofstra University on New York's Long Island sent the Burlington County Times a letter. Burke is a biologist with a special interest in herpetology, the study of reptiles and amphibians. He wanted help in his research on the nonnative lizards in Mount Laurel.

Did anyone really know how they got here from the Mediterranean? he asked.

When the paper ran his appeal in a June 25 story, he received several e-mails, including one that appears to have solved the mystery.

A township resident acknowledged that he released about 120 lizards in 1984 to combat a variety of insects seen around his parents' home on Canterbury Road.

"They were released at my parents' house. ... They would eat the spiders, ticks, earwigs. Basically, my thing was control of pests around our house and establishing them in our development," the man said in an interview last week. His name is being withheld because his parents still live in the neighborhood.

He did it "as an experiment ... to help with insects and just out of curiosity, to see if they'd take to our environment."

At the time, he was a 22-year-old former college student with an interest in herpetology. He had kept lizards as pets as a teenager. In reading the "North American Field Guide to Reptiles and Amphibians," he discovered that the wall lizards - good insect eaters that had been brought to the United States by pet suppliers - had already been released or got loose in Philadelphia, New York City and Hempstead, N.Y. He figured they would help reduce the populations of ticks and other insects attracted to the rock gardens his dad had included in landscaping around the family's home.

The former student visited a wholesale amphibian supplier in the Bronx - now out of business - where he saw the imported lizards kept in cages "full of mites." He ordered about three batches of 40 each, glad that he could give the little green and brown reptiles their freedom.

Did the supplier ask why he wanted so many lizards?

"They didn't question me about anything," he said. "I sent in my money."

Once the lizards were set free, they scattered throughout the neighborhood, including setting up residence at the Alice Paul Institute on Hooten Road, where Valerie Buickerood, acting director, said sometimes she can see them near the porch.

"It's hit or miss," she said.

The man didn't release them as a prank, he said. But he didn't inform his parents' neighbors, either.

The new arrivals quickly adapted to the suburban development of colonial and split-level homes. It's a perfect setting for wildlife, with a small stream meandering through the development and woods and farmland surrounding it. The neighborhood is in walking distance to the municipal complex across Mount Laurel Road. Even there, the little lizards have taken up residence. One darted through the shrubbery and stone landscaping along the side of the township building as a visitor went by. Quick as a camera flash, it disappeared under a bush.

"The lizards don't appear to be a problem for the township," Township Manager Jennifer Blumenthal said. "We've had no complaints."

Pat Halbe, township clerk and director of the Paws Farm Nature Center on Hainesport-Mount Laurel Road, said one of the lizards actually seems to know when she's passing by the building's doorway.

"It's almost like a daily ritual. When I come back from lunch, it runs in front of me," Halbe said.

Some residents have taken a liking to them.

"If they eat mosquitoes, let's breed some more of these little guys," said an online comment on the phillyBurbs.com/bct website, where the story also ran.

Bill Christy, who resides in the Canterbury Road development, isn't so sure about that.

"They're all over the neighborhood," Christy said. "We never knew what they were."

The lizards seem to have set up home under his garage and on a neighbor's property as well.

"I don't want them to get into the house," he said.

"As the years went by, there were reports of more and more in the development," said the former resident who released them. Now he occasionally sees them in his own neighborhood, a mile or so from his parents' home. He knows they are eating insects from the excrement they leave behind.

The New Jersey Department of Environmental Protection is keeping a close watch on the lizards to see how quickly their habitat is spreading. The agency doesn't plan any action against the man who released them.

DEP spokesman Larry Ragonese said the man was young at the time and "seemed more like a kid goofing around." The DEP was grateful that he contacted the agency so it knows where the lizards came from.

"The fact that he stepped forward and let us know how this began - it's a bonus piece of information, so we're not taking any action," Ragonese said.

"Our wildlife people tell us the lizards are harmless. We're encouraging people to let them be. It's better to appreciate them on your driveway than if you put them into an aquarium," he said.

Anyone who has a problem with the lizards should try to "gently" remove their nest from their property, Ragonese said.

While the state considers them harmless and without local predators, Burke is concerned if their range of habitat expands. The lizards may have been spotted as far as 10 miles away. Burke is tracking their potential locations from the e-mails he has received from area residents. If possible, he'd like residents to take photos of the quick-moving reptiles.

In Southampton, a couple who moved here from California e-mailed Burke to say they've seen the lizards fighting in the trees in their yard.

Have the lizards affected the insect population?

While the man who released them thinks they have, Burke said, "These lizards probably do nothing to reduce pest insect populations."

He thinks they eventually will interact with native lizards, including two skink species and the fence lizards found in rural areas not far from Mount Laurel and which are common in the Pine Barrens.

"As the wall lizards spread, they will eventually come into contact with the native lizards and competition will occur. The wall lizards are not live-bearers; they lay eggs. The idea that the released lizards had mites is a little scary. Those mites can easily jump to native reptiles; however, they are not in any way dangerous to humans," Burke said.

"The scientific community's view of the release (deliberate or accidental) of animals and plants into new places has changed over the years," Burke wrote in a Hofstra publication. "In the past, amateur and professional scientists often actively promoted the introduction of foreign species into new habitats. + In more recent years, the list of introductions with disastrous results has grown. Invasive species are now recognized as one of the most important cause of native species' endangerment and extinction."

As a species, the wall lizard is known to adapt quickly to different regions. When introduced on an island in the Mediterranean, it developed a new digestive feature to help it eat greenery in just 36 years, according to University of Massachusetts biologist Duncan Irschick in an article in Science Daily. In Italy and other Mediterranean regions, they are known to live in stone crevices and walls. And they like to be near people.

Here, they've also adapted to living in wooden structures. A population of them was discovered in Philadelphia in the 1930s nesting in the railroad ties along train tracks in West Philadelphia. But a fire in the 1960s may have destroyed that group, said Ned Gilmore of the Academy of Natural Sciences in Philadelphia.

Burke said the lizards near Hofstra survive the New York winters by burrowing underground. He'd like to know if their South Jersey cousins do the same thing. Since he made his request about the Mount Laurel group, Burke has received feedback from several residents. Anyone who has had contact with the lizards can reach him at biorlb@hofstra.edu.

"This is all very interesting and lots of fun," he noted. "It has definitely been a help to my research."

http://www.phillyburbs.com/news/news_details/article/26/2010/july/11/the-mystery-of-the-mount-laurel-lizards-solved.html