Forty years later, the research study is the longest-running lizard study in the southern hemisphere. And Bull– in addition to generations of other researchers– have discovered amazing things about this unassuming little reptile.
” One of the greatest things Bull discovered was that sleepy lizards are monogamous,” states Mike Gardner, a researcher at Flinders University and Bulls ultimate successor..
Drowsy lizards can live for as much as 50 years, and they spend much of their lives alone. Each spring, they reunite with their partners to mate, after an extended courtship. These partnerships can last for years; one set of lizards in the research study was still together after 27 years..
1 of 3A male drowsy lizard safeguarding his female parter with a mouth-gaping screen. © Michael Gardner2 of 3A male sleepy lizard follows his partner throughout a road. © Michael Gardner.
3 of 3A sleepy lizard pair. © Gerrut Norval.
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Nearly everything we know about drowsy lizards comes from a research task out of Flinders University in South Australia. In the early 1980s, scientist Mike Bull set out to study two types of tick that parasitize drowsy lizards. Drowsy lizards can live for up to 50 years, and they spend much of their lives alone. © Michael Gardner2 of 3A male drowsy lizard follows his partner across a road. After reuniting with their partners, drowsy lizards court for up to 8 weeks prior to breeding.
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” We can follow individuals for 40 years,” he says. “Ive captured lizards that were [first] marked in 1987, and its just fantastic to have the same lizard just doing its thing out there for all this time.”.
After bothering my little lizard for a couple of more photos, I pick it up and bring it throughout the roadway, far from the speeding tires of 4-wheel drives. We gaze at one another, and it strikes me that we could effectively be the exact same age. And after that it rotates and turns off into the scrub searching for flowers, bob-tail waggling with each action.
Thats one remarkable little lizard..
A drowsy lizard on a road in South Australia. © Michael Gardner.
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I wonder out loud, squinting at the dark, elongate shape in the center of the red dirt track. A tree root?
As we slow down, I acknowledge the unusual shape from my childhood days seeing Steve Irwin man-handle reptiles. “Oh my god, its a drowsy lizard.”.
My boots struck the dirt before my partner can stop the car, red dust rippling in through the open door as I destroy the roadway.
The lizard stops and gives me the side-eye. I kneel down to take a photo, and after that, as if on cue, it opens its mouth wide, splays an undulating, navy-blue tongue, and lunges towards my lense..
This drowsy lizard isnt all that drowsy..
Drowsy, Stumpy-tailed, Two-headed, Pinecone.
Depending upon where you remain in Australia, the species understood as Tiliqua rugosa may be called by any one of its colorful typical names: shingleback, bobtail, two-headed lizard, boggi, stumpy-tailed lizard, pinecone lizard, and, naturally, the drowsy lizard. These lizards are in fact a type of skink, related to Australias other blue-tongued skinks..
Sleepy lizards arent small: they can grow up to 12 inches long and have a chunky, wedge-shaped head, thick scales, and tiny legs that stand out from either side of their body. Perhaps their most significant feature is their short, thick tail, which includes fat reserves to assist the lizard endure severe dry spells. (It also looks precisely like the lizards head, which might help confuse predators.).
Sleepy lizards consume plants and flowers, like this a thread iris (Moraea setifolia). © Gerrut Norval.
Drowsy lizard scales vary in color, from cream to yellow to a dark, chocolate brown. Glinting in the sunshine, they offer the lizard a wet-looking appearance, like a piece of scrap metal or– as my partner kept in mind with glee– a comically large turd..
Drowsy lizards are found throughout semi-arid environments across the southern half of Australia, up into main Queensland. Each lizard has a house series of between 7 and 22 acres. They spend the night sheltering under plants or in logs and burrows, emerging in the early morning to bask in the sun. Then they triggered to forage for flowers, plants, snails, insects, and sometimes carrion..
When threatened, drowsy lizards open their mouths in a large, enormous gape and flick their tongue in an attempt to frighten predators, which include dingos, cats, foxes, birds of prey, and snakes.
Drowsy lizards will mouth-gape at possible predators. © Michael Gardner.
40 Years and 14,000+ Lizards.
Almost whatever we understand about sleepy lizards comes from a research job out of Flinders University in South Australia. In the early 1980s, researcher Mike Bull set out to study two types of tick that parasitize drowsy lizards. He established a 25-by-25 kilometer research study website northeast of Adelaide, and got to work capturing lizards.
” That discovery began research study programs all throughout the world to take a look at sociality in reptiles,” states Gardner. “At the time, nobody thought they would have intricate sociality.” And while research on the social lives of lizards is much more robust, thanks to Bulls discovery, drowsy lizards are still the only recognized monogamous reptile on the planet..
After reuniting with their partners, sleepy lizards court for as much as 8 weeks before breeding. Males will follow women throughout this time, rotating close behind them and functioning as a lookout while the females eat plants and flowers. Males stay with their partners after breeding, which takes place earlier for sets that are currently knowledgeable about one another, compared to freshly partnered lizards..
After about 5 months, the female gives birth to between 1 and 4 live young that can be as much as one-third of the mothers size. Baby sleepy lizards are precocial, implying they can look after themselves instantly after birth. They dont scuttle off into the bush straight away. Young stay within their mothers home range for approximately a year, and mother lizards can recognize their young by means of chemical signals..
A female sleepy lizard with her two young. © Michael Gardner.
Lovers and Fighters.
For anybody who questions that a cold-blooded reptile can form a long-lasting bond, consider this: Scientists, consisting of Mike Bull, have recorded sleepy lizards defending their dead partners on multiple occasions, normally after one is eliminated by a lorry..
It would be anthropomorphic (and a bit unscientific) to call this “grief.” Its clear that the lizards are distressed by their partners death, which isnt all that surprising given that drowsy lizards are a long-lived, social, and monogamous types..
Automobiles are a serious risk to drowsy lizards, which arent properly designed for life near roadways: Theyre slow-moving, typically feed on roadside greenery, and have the regrettable practice of freezing when they pick up a risk..
Spotting a sleepy lizard while it crosses the roadway is so typical that its how Gardner and other researchers perform their yearly lizard study. Their research study site is crisscrossed by roads, so they just drive around till they spot a lizard.
A sleepy lizard encountered throughout field studies. © Michael Gardner.
Next, Gardner carries out an assessment that, for absence of a much better term, well call a drowsy lizard character test: He reaches down towards the lizard– as if he were going to pick it up– and tape-records its response. The lizards generally respond in one of three ways: (1) they mouth-gape, trying to frighten this prospective predator, (2) they attempt to run away, or (3) they do, as Gardner says, “definitely nothing.”.
Its rather comparable to the flight, fight, or freeze reactions human beings show when threatened, and Gardner has discovered that the lizards tend to react the very same way each time theyre captured. “They have these little personalities,” he says, “and they have consistent habits in time.”.
Those personalities extend to their romantic relationships. When scientists looked at sleepy lizard collaborations at the Flinders research study site, they found that male drowsy lizards tend to be either “fans” or “fighters.” The less aggressive “enthusiasts” were more attracted to locations with great deals of food and better shelter, which is possibly why they had more success hanging on to their mates for many years. On the other hand, the more aggressive “fighter” males had weaker set bonds with their partners..
Researcher Mike Gardner holds a drowsy lizard. © Rob Miller.
Death, Data, and the Value of Long-Term Research.
Mike Bull ran the sleepy lizard research study project up until 2016, when he died of a cardiovascular disease simply one month after ending up the 35th year of studies. His long time collaborator and field coordinator, Dale Burzacott, died unexpectedly simply a couple of months later on..
Whatever arrived on Gardners desk: the survey, research jobs, monitoring more than 20 college student, and the fight to encourage funders that the job was still rewarding. “I occurred to be in the best area at the correct time to take this on, and Im actually grateful,” says Gardner..
A data photo taken of lizard # 720 throughout the 2021 lizard survey. © Michael Gardner.
You might question: Why keep studying sleepy lizards, after all this time? The mix of a long-running field job on a long-lived animal (thats very simple to capture) is an unusual thing in conservation science. Four years of data allow Gardners and his collaborators throughout the world to ask concerns– about social relationships, speciation, health and genes– that they would otherwise never ever have the ability to address..
