Professor Jonathan Webb, Discipline Leader Environmental Science

Jonathan's research interests

I have broad research interests in ecology, wildlife management, conservation biology, behavioural ecology, and invasive species. I am particularly interested in the ecology and behaviour of lizards and snakes, but I've worked on mammals, birds, and arachnids. I  teach Wildlife Ecology and Wildlife Field Techniques: Animal Handling and Survey Methods at the University of Technology Sydney. When I'm not teaching, writing, or doing field biology, I enjoy bush walking, nature photography, growing edible plants, surfing and mountain bike riding. I currently have space in my group for keen PhD and Masters students. If you're interested in joining my lab then please email me.
Current students
Reannan Honey, PhD student

I am investigating habitat restoration for hollow dependent fauna. In Australia, over 300 native vertebrate species use tree hollows, however, hollows are being depleted through native silviculture, firewood collection, rural dieback, grazing, and clearing. To offset this loss, nest boxes are typically used. However the effectiveness of nest boxes is vigorously debated. Therefore, I am investigating if artificial hollows are a better alternative. Artificial hollows are created by removing a faceplate from the tree, removing the internal heartwood, making an entrance hole, and then returning the faceplate. There is currently very little research on artificial hollows and I hope to close some of the knowledge gaps on them. To do this, I am investigating over 500 artificial hollows that have been created across NSW from Sydney to Dubbo. I spend most of my time climbing trees, looking inside hollows and installing cameras and data loggers. I am also investigating population changes and hollow use by arboreal mammals including Brushtail Possums (Trichosurus vulpecula), Sugar Gliders (Petaurus breviceps) and Squirrel Gliders (Petaurus norfolcensis). I hope that my research can change the way we treat hollows and create better restoration strategies in the future.
Yingyod Lapwong, PhD student

I am studying the behavior of the invasive Asian House Gecko (Hemidactylus frenatus), one of the world’s most successful invaders. This species has been found on all continents, except for Antarctica. Asian house geckos can disrupt ecosystems by competing with native species, acting as a vector for parasites and diseases, and interfering with food webs. In addition, the geckos can become a nuisance to households, as they often attain high densities in urban areas. However, the factors that have helped this species become so successful are largely unknown. To shed light on this question, I will be studying the behavior of Asian house geckos in their native range, and in invaded areas outside of their native range, to see whether there has been selection for particular behavioral traits in newly invaded areas.
Hall of fame
Naomi Indigo, PhD, completed 2020

Naomi undertook an extremely ambitious project working with the Australian Wildlife Conservancy at Mornington Wildlife Sanctuary that aimed to prevent northern quoll populations from going extinct. To do this, Naomi developed a toad-aversion sausage that she aerially deployed ahead of the toad invasion front to train wild quolls not to eat cane toads. Naomi was fortunate to be able to work in some amazing country, though it was a logistically challenging place to work as summer temperatures regularly top 46° C! Naomi's results have been promising, and she found that a high proportion of wild quolls will consume toad-aversion sausages. However, she also found that the timing of bait delivery was crucial for training wild quolls to become toad-averse. Naomi remains optimistic that this novel technique will help to conserve one of our most iconic predators in the face of the invasion of toxic cane toads.

Theja Hemamali, PhD, completed 2019

Theja investigated whether egg laying reptiles can adapt to rapidly warming climates. Currently, we do not know how climate warming will affect rock dwelling reptiles in south eastern Australia. Theja used a combination of laboratory and field experiments to determine how developmental temperatures will affect the behaviour and morphology of hatchling lizards. In the laboratory, Theje measured how incubation temperatures affected offspring learning ability and locomotor performance.  In the field, Theja used mark-recapture techniques to determine which offspring traits are subject to natural selection in the wild. Her research answered some fundamental questions in evolutionary ecology, and also increased our understanding of how climate warming may influence the persistence of rock-dwelling reptiles in south-eastern Australia.




Santiago Cuartas, MSc, Completed 2019

Santiago studied the thermal ecology of nest site selection in lizards. The objectives of his project were to understand the cues that females use when selecting nests sites, and to measure geographic variation in nest temperatures across species ranges. Santiago used this information to model the effects of climate change on nest temperatures in order to understand how species may be affected by climate change and habitat fragmentation in future. His research involved lots of hiking in remote national parks and a lot of crawling and searching inside crevices for communal egg laying sites. By measuring nest site variation across broad geographic distances, Santiago helped to elucidate how gecko populations may respond to latitudinal and temporal shifts in climate.




Hélène Defendini, internship student 2018, Agrocampus Ouest, France

Hélène spent six months doing an internship in our lab. For her project, Hélène investigated whether photo identification methods could be used to accurately identify individuals of the velvet gecko Amalosia lesueurii. This technique is less invasive than traditional toe-clipping, and could provide an alternative method for identifying geckos. In the field, Hélène photographed the geckos’ dorsal surface and eyes, and she then processed the pictures using the software I3S Interactive  Individual  Identification  System. By comparing iris and dorsal pattern photos, Helene was able to evaluate which photographs were most accurate for identifying individuals. She also created a photographic database for velvet geckos that will be used to estimate some demographic parameters from analysis of mark-recapture data.

Dr. Buddhi Dayananda, PhD, completed 2016

Buddhi studied how climate warming will affect populations of the velvet gecko, Amalosia lesueurii. Prior to Buddhi's research, we did not know how warming would affect gecko populations in south eastern Australia. Buddhi used a combination of modelling, laboratory experiments, and field mark-recapture studies to determine how increases in temperature are likely to affect populations of rock-dwelling reptiles. Buddhi found that nest temperatures are likely to increase under climate warming, and such increases will produce smaller offspring, with poor cognitive abilities, and these hatchlings are less likely to survive their first year in the wild. Buddhi's research has been published in Global Change Biology and Biology Letters.
Dr. Teigan Cremona, PhD, completed 2015

Teigan investigated whether conditioned taste aversion could reduce the impacts of cane toads on northern quolls Dasyurus hallucatus. Northern quolls were once widespread across northern Australia, but populations crashed after the arrival of toxic cane toads. Quolls can't tolerate toad toxins, and they die after attacking or mouthing large toads. We developed a novel solution to this problem, which involved feeding quolls a small dead toad coated with a nausea inducing chemical. These 'toad smart' quolls became ill, but subsequently refused to attack live toads. In 2010 we reintroduced these ‘toad smart’ quolls to Kakadu National Park. Teigan showed that some ‘toad smart’ females survived long-term and reproduced, and their offspring also survived.By radio-tracking juvenile quolls, Teigan discovered that independent juveniles forage with their mothers at night, suggesting that social learning might be involved in the acquisition of toad avoidance. Teigan's work was published in Animal Conservation and Conservation Genetics. Teigan is currently a postdoctoral research fellow at Charles Darwin University.
Reannan Honey, Honours, 2016

Reannan studied the effects of  incubation temperatures on the morphology, performance, and survival of velvet geckos. Reannan was particularly interested in the role of developmental temperatures in shaping the cognitive abilities of baby lizards. To investigate how incubation temperatures influence cognition, Reannan used a Y maze apparatus to measure how quickly lizards could remember the location of 'safe' shelters during an attack by a simulated predator. Reannan was awarded a first class Honours for her research, and she is currently doing a PhD at UTS.
Scott Penfold, Honours 2016

Scott investigated competitive interactions between spiders, ants, lizards and snakes on rock outcrops in the Sydney region. Scott explored whether native ants could exclude target species from using restored habitats. He discovered that the artificial rocks used to restore degraded rock outcrops are also very attractive to ants of the genera Campanotus, Polyrachis and Iridomyrmex, which construct large nests under rocks. These aggressive ants prevented other rock-dwelling animals, such as velvet geckos, flat rock spiders, and even snakes – from using the artificial rocks. Most worrying, Scott found that ant domination of artificial rocks has increased steadily over time, leaving fewer vacant rocks for target animals (geckos and snakes). Thus, future rock restoration projects may need to consider designing artificial rocks that are attractive to reptiles, but which are less attractive to ants.
Caitlin Austin, Honours, 2014

Caitlin is particularly interested in conservation biology and the use of non-invasive methods to monitor Australia’s wildlife. Caitlin did her honours project at Mornington Wildlife Sanctuary, in the Kimberly, WA, in collaboration with Dr Katherine Tuft from the Australian Wildlife Conservancy. Caitlin developed a robust methodology for estimating population size of northern quolls using camera traps. Caitlin was awarded First Class Honours for her research, and she published her paper in Australian Mammalogy. Caitlin is currently doing a PhD on kangaroos with Daniel Ramp.
Sarah Gray, Honours, 2014

Sarah investigated whether increases in nest temperatures affect the behaviour of velvet geckos, a nocturnal crevice-nesting species that is potentially at risk from climate change. Sarah incubated eggs at cycling temperatures to mimic current and future nest temperatures, and then released her hatchlings in the field. Sarah discovered that incubation temperatures not only affect offspring size, shape, and running speed, but also have significant effects on the lizards' short-term survival. Sarah was awarded a First Class Honours for her research, and her paper was published in Global Change Biology.
Libby Dwyer, Honours, 2013

Libby investigated how fire regimes affect small mammal assemblages in Yengo National Park. Libby chose some very rough terrain for her field project, and she spent long hours Elliot trapping small mammals in patches with different fire histories. Libby found strong effects of fire on two species of Antechinus, suggesting that fire frequency influences mammal assemblages in south-eastern Australia. Libby has excellent field and managerial skills, and after graduating she worked as a manager for Kleinfelder Australia before moving to Canada to take up a position with Hydro One.