David Pearson

• B. Nat Res (Hons) G.Dip.Ab St. MSc PhD
• Principal Research Scientist at Dept of Biodiversity Conservation and Attractions

Black-flanked rock-wallabies (Petrogale lateralis lateralis) exist in small and isolated populations across Western Australia, making them highly susceptible to loss of genetic diversity and increased extinction risk. Conservation translocations are frequently implemented to improve threatened species population sizes with ongoing monitoring requir...

Comparative studies of mortality in the wild are necessary to understand the evolution of aging; yet, ectothermic tetrapods are underrepresented in this comparative landscape, despite their suitability for testing evolutionary hypotheses. We present a study of aging rates and longevity across wild tetrapod ectotherms, using data from 107 population...

Rock-wallabies (Petrogale spp.) are one of Australia’s most speciose genera of mammals, irregularly distributed across much of the continent and its offshore islands. The 25 taxa in the genus Petrogale (17 species and 8 subspecies) have specialised ecological requirements that render them vulnerable to numerous threats. Many rock-wallaby population...

Understanding how animal populations respond to environmental factors is critical because large-scale environmental processes (e.g., habitat fragmentation, climate change) are impacting ecosystems at unprecedented rates. On an overgrazed floodplain in north-western Australia, a native rodent (Pale Field Rat, Rattus tunneyi ) constructs its burrows...

It is increasingly recognised that intertaxon hybridisation is more common in vertebrates than previously thought. However, recent hybridisation has rarely been reported from wild marsupials, with only three instances of first generation (F1) hybrids reported, all in macropodids. In the 1990s a chromosomally anomalous population of black-footed roc...

Our ecological studies on large varanid lizards in a remote region of tropical Australia reveal a direct benefit to collaboration with local indigenous people. Although they worked together, in pairs, western scientists and indigenous rangers found lizards with different behavioral phenotypes (“personalities”). The resultant broader sampling of the...

Black-flanked rock-wallabies (Petrogale lateralis lateralis) were thought to be locally extinct in Kalbarri National Park, Western Australia, until 2015 when a pair were photographed in the Murchison River gorge. Subsequent searches failed to locate any other populations and, in combination with previous surveys, suggest that these animals were the...

The invasion of a toxic prey type can differentially affect closely related predator species. In Australia, the invasive Cane Toad (Rhinella marina) kills native anurophagous predators that cannot tolerate the toad’s toxins; but predators that are physiologically resistant (i.e., belong to lineages that entered Australia recently from Asia, where t...

To identify cost-effective ways to control invasive species, we need to evaluate alternative methods. The invasion of tropical Australia by cane toads (Rhinella marina) has killed many native predators, prompting efforts to cull adult toads. We analyzed a dataset on > 17,500 toads killed by government-employed teams from 2005 to 2008, using a range...

In many animal populations, individuals exhibit repeatable behavioral traits across a range of contexts, and similarly, individuals differ in ecological traits such as habitat use, home range sizes, growth rates, and mating success. However, links between an individual's positions on behavioral vs. ecological axes of variation remain relatively uns...

La plupart des travaux sur dimorphisme sexuel (DS) sont limités aux adultes, l’ontogénèse n’a pas été prise en compte. Les serpents présentent une croissance continue, une maturité relativement tardive, une morphologie simplifiée et un grand recouvrement de taille entre les sexes. Ce sont de bons modèles pour examiner les ontogénétiques du DS. Avec...

The near-pristine continental-shelf islands along the remote and rugged Kimberley coast of north-western Australia are important natural refuges that have been isolated from many of the threatening processes affecting the adjacent mainland. Between 2007 and 2014, 27 of the largest of these islands were sampled for non-volant mammals, bats, reptiles...

In an ecosystem under simultaneous threat from multiple alien species, one invader may buffer the impact of another. Our surveys on a remote floodplain in the Kimberley region of north western Australia show that invasive chinee apple trees (Ziziphus mauritiana) provide critical refuge habitat for native rodents (pale field rats, Rattus tunneyi). F...

Conditioned Taste Aversion (CTA) is an adaptive learning mechanism whereby a consumer associates the taste of a certain food with symptoms caused by a toxic substance, and thereafter avoids eating that type of food. Recently, wildlife researchers have employed CTA to discourage native fauna from ingesting toxic cane toads (Rhinella marina Linnaeus,...

In Australia, large native predators are fatally poisoned when they ingest invasive cane toads (Rhinella marina). As a result, the spread of cane toads has caused catastrophic population declines in these predators. Immediately prior to the arrival of toads at a floodplain in the Kimberley region, we induced conditioned taste aversion in free-rangi...

The success of an invasive species can be reduced by biotic resistance from the native fauna. For example, an invader that is eaten by native predators is less likely to thrive than one that is invulnerable. The ability of invasive cane toads (Rhinella marina) to spread through Australia has been attributed to the toad’s potent defensive chemicals...

The ecological impact of an invasive species can depend on the behavioural responses of native fauna to the invader. For example, the greatest risk posed by invasive cane toads (Rhinella marina Bufonidae) in tropical Australia is lethal poisoning of predators that attempt to eat a toad; and thus, a predator's response to a toad determines its vulne...

The Northern Kimberley region in north-western Australia has high biodiversity and conservation values, including a rich herpetofauna with high levels of endemism. To date, the numerous islands off the coast have been little surveyed. We surveyed 24 of the largest islands along the Kimberley coast for reptiles between 2007 and 2010, to improve our...

The islands off the Kimberley coastline of northern Western Australia are among Australia’s most isolated areas. To date, frogs of the Kimberley islands have been a particularly poorly surveyed group owing to the remoteness of the region and the need to conduct surveys during the summer wet season at night when frogs call and are most active. Here,...

Context Invasive species are a leading cause of extinctions, yet predicting their ecological impacts poses a formidable challenge for conservation biologists. When native predators are naïve to invaders, they may lack appropriate behaviours to deal with the invader. In northern Australia, the invasion of the highly toxic cane toad (Rhinella marina)...

Diverse interactions between factors that influence body size complicate the identification of the primary determinants of sexual size dimorphism. Using data from a long-term field study (1997–2009), we examined the contributions of the main proximate factors potentially influencing sexual size dimorphism from birth to adulthood in tiger snakes (No...

The Pilbara region has one of the most diverse reptile assemblages in the world and includes many typical arid zone species as well as many saxicoline endemics. We present the results of a four-year survey of the region during which pitfall trap lines were used to sample 297 quadrats for a total of two weeks in spring and in autumn. The quadrats we...

Long-term studies have revealed population declines in fishes, amphibians, reptiles, birds and mammals. In birds, and particularly amphibians, these declines are a global phenomenon whose causes are often unclear. Among reptiles, snakes are top predators and therefore a decline in their numbers may have serious consequences for the functioning of m...

The spread of cane toads (Bufo marinus) through north-western Australia may threaten populations of endemic camaenid land snails because these snails exhibit restricted geographic distributions, low vagility and ‘slow’ life-histories. We conducted laboratory trials to determine whether toads would consume camaenids if they encountered them, and con...

The shorelines of coral islets are subject to strong anthropogenic pressure, being highly coveted for tourism. These landforms contain unique biotic assemblages but unfortunately are limited in size making them extremely vulnerable to perturbation. Robust information linking habitat structure and species requirements is urgently needed to promote a...

The shorelines of coral islets are subject to strong anthropogenic pressure, being highly coveted for tourism. These landforms contain unique biotic assemblages but unfortunately are limited in size making them extremely vulnerable to perturbation. Robust information linking habitat structure and species requirements is urgently needed to promote a...

Abstract Large predators play important ecological roles, but often are sensitive to habitat changes and thus are early casualties of habitat perturbation. Pythons are among the largest predators in many Australian environments, and hence warrant conservation-orientated research. Carpet pythons (Morelia spilota imbricata) have declined across much...

On a small island off south-western Australia, tiger snakes (Notechis scutatus, Elapidae) continue to survive, feed, grow and reproduce successfully after being blinded by seagulls defending their chicks. We propose two alternative hypotheses to explain this surprising result: either vision is of trivial importance in tiger snake foraging, or the b...

Radio-telemetric monitoring of 70 free-ranging carpet pythons (Morelia spilota imbricata) at two sites in south-western Australia provided extensive data on the body temperatures exhibited by these animals. The snake's thermal regimes were affected by season, time of day, location, microhabitat, size and sex, behaviour, and reproductive state. Over...

Sexual dimorphism is usually interpreted in terms of reproductive adaptations, but the degree of sex divergence also may be affected by sex-based niche partitioning. In gape-limited animals like snakes, the degree of sexual dimorphism in body size (SSD) or relative head size can determine the size spectrum of ingestible prey for each sex. Our studi...

Animals resident on small islands provide excellent opportunities to carry out detailed mark- recapture studies. Populations are closed and ecosystems are often simpler than those of mainland sites. These factors enable the study of cryptic species that have otherwise been neglected. Snakes are notable for their secretive nature and, as a result, f...

Unusually among reptiles, Australian carpet pythons (Morelia spilota) display substantial geographic variation in mating systems and sexual size dimorphism. We studied a population of the south-western subspecies (M. s. imbricata) of this widely distributed taxon, on Garden Island near Perth, Western Australia. Our data greatly expand the range of...

Although reptiles of many species are often found in aggregations within retreat sites, there is little quantitative information on the size and composition of such aggregations. Such data may clarify the processes that stimulate aggregation, and that determine patterns of co-occurrence of individuals with respect to sex and body size. We gathered...

We collected 48 Crowned Snakes Elapognathus coronotus on Mondrain lsland, in the Archipelago of the Recherche, in November 1999. Published data on the ecology of E. coronatus are based almost entirely on examination of museum specimens from mainland localities, and differ in several respects from our findings. Mondrain snakes are larger than their...

We collected 48 Crowned Snakes Elapognathus coronatus on Mondrain Island, in the Archipelago of the Recherche, in November 1999. Published data on the ecology of E. coronatus are based almost entirely on examination of museum specimens from mainland localities, and differ in several respects from our findings. Mondrain snakes are larger than their...

MARSUPIAL moles (Notoryctes spp.) remain one of the great enigmas of the Australian fauna. Their occurrence is highly sporadic, resulting in a slow trickle of specimens to Museums at the rate of around 5-15 per decade (Johnson 1995). Their small size, cryptic habits, remote distribution and wariness have led to few reported sightings. In addition,...

Large (to >1 m), diurnally active tiger snakes (Notechis scutatus) are abundant on Carnac Island, near the coast of Western Australia. Our behavioural and mark-recapture studies provide the first ecological data on this population, and reveal a surprising phenomenon. Many adult tiger snakes have had their eyes destroyed, apparently during nest defe...

G-banded metaphase preparations from cultured fibroblasts were used to examine the karyotypes of Petrogale lateralis pearsoni and the West Kimberley (WK) race of P. lateralis. Petrogale lateralis pearsoni was found to retain the ancestral 2n = 22 Petrogale karyotype, while the WK race (2n = 20) was found to be characterized by a 9-10 centric fusion...

Western Australia has five species of rock-wallabies. Petrogale brachyotis, Petrogale burbidgei and Petrogale concinna occur in wet-dry tropical habitats in the Kimberley region. Petrogale rothschildi is a Pilbara region endemic, while Petrogale lateralis has the largest distribution, extending from the south-west Kimberley to islands off the south...

Rock-wallaby populations in central desert regions are insidiously disappearing through a continuing process of local extinctions. Their survival will depend on collaboration between Aboriginal Councils and communities, and conservation agencies. While collaborative survey work to locate rock-wallaby populations has been successful, the next step o...

The black-footed rock-wallaby (Petrogale lateralis) was once widespread and abundant in rock-piles and ranges in the Warburton region of Western Australia. However, by the 1970s a major decline in its distribution and abundance was apparent. Ranges and rock outcrops were searched with local Aboriginal people to document the past and present distrib...