Thomas Newsome

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The Redomestication of Wolves

Our paper “Making a new dog?” was published today in the journal BioScience, it is free to view and has been selected as Editor’s choice for the forthcoming April issue.

Below is a copy of the press release prepared by BioScience.

It has generated some news stories already, including a feature piece in Science titled “Are some wolves being ‘redomesticated’ into dogs?

Press Release by BioScience:

On landscapes around the world, environmental change is bringing people and large carnivores together—but the union is not without its problems. Human–wildlife conflict is on the rise as development continues unabated and apex predators begin to reoccupy their former ranges. Further complicating matters, many of these species are now reliant on anthropogenic, or human foods, including livestock, livestock and other ungulate carcasses, and garbage.

Writing in BioScience, Thomas Newsome, of Deakin University and the University of Sydney, and his colleagues use gray wolves and other large predators as case studies to explore the effects of anthropogenic foods. They find numerous instances of species’ changing their social structures, movements, and behavior to acquire human-provisioned resources. For instance, in central Iran, gray wolves’ diets consist almost entirely of farmed chickens, domestic goats, and garbage.

Other instances of these phenomena abound. In a similar case in Australia, dingoes gained access to anthropogenic foods from a waste facility. The result, according to the authors, was “decreased home-range areas and movements, larger group sizes, and altered dietary preferences to the extent that they filled a similar dietary niche to domestic dogs.” Moreover, wrote the authors, “the population of subsidized dingoes was a genetically distinct cluster,” which may portend future speciation events. Hybridization among similar predator species may also contribute to evolutionary divergence: “Anthropogenic resources in human-modified environments could increase the probability of non-aggressive contact” between species. According to the authors, “If extant wolves continue to increase their reliance on anthropogenic foods, we should expect to observe evidence of dietary niche differentiation and, over time, the development of genetic structure that could signal incipient speciation.”

Wolves’ use of anthropogenic food could have serious implications for wider conservation efforts, as well. In particular, Newsome and his colleagues raise concerns about whether wolf reintroduction and recolonisation programs will meet ecosystem-restoration goals in human-modified systems. Managers will need to consider “how broadly insights into the role played by wolves gleaned from protected areas such as Yellowstone can be applied in areas that have been greatly modified by humans,” say the authors.

Newsome and his colleagues call for further research—in particular, “studies showing the niche characteristics and population structure of wolves in areas where human influence is pervasive and heavy reliance on human foods has been documented.” Through such studies, they argue that “we might be able to ask whether heavy reliance of anthropogenic subsidies can act as a driver of evolutionary divergence and, potentially, provide the makings of a new dog.”

DogDomestication

A conceptual model describing the role of anthropogenic foods in the hypothesized original wolf domestication pathway (left) and possible evolutionary divergence (right) due to behavioral and genetic differentiation. Silhouettes are courtesy of Phylopic (Tracy A. Heath).

 

 

Fourth Book Review

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Rob Wallis from the Office of the Deputy Vice-Chancellor (Research & Innovation), the Federation University Australia, recently reviewed our book “The Red Kangaroo in Central Australia; an early account by A.E. Newsome”.

The review was published in the February 2017 issue of The Victorian Naturalist.

A copy of the review is provided below:

“Alan Newsome was one of Australia’s great naturalists and also a leading scientist whose early work focused on the biology of the Red Kangaroo Osphranter rufus. His work on the species began in 1957 and, unbeknown to his family, he had been preparing a book on his research which the publisher (Collins) was expecting to be completed in 1975. However, like so many things in people’s busy lives, it got put aside; why it was never completed remains a mystery. In 2010 his son Thomas discovered the manuscript in a box of materials his father had left behind in his son’s Canberra garage and, after a thorough read of it, Thomas decided to edit it for publication. I suspect Alan intended this book to be primarily an account of the biology of the Red Kangaroo, elucidated by his field work. If readers treat it as such, they will be somewhat disappointed as there have been many more accounts of kangaroo biology published recently that are much more up-to-date and complete. Indeed, this journal has published reviews of such books.

What makes this book a fascinating read, however, is the description of how this pioneer of ecological research went about his work. As the preface notes:

It is rare for an ecologist to write reflectively and personally about the experience of discovery, especially during the early stages of a career … I suspect it is also because few early career scientists have a journey that results in the kind of pioneering discoveries that Alan’s did (p. xx).

Alan Newsome’s research dispelled many myths and incorrect claims about Red Kangaroos. His blend of acute observational skills of a naturalist combined with rigorous scientific examination helped answer these questions:

…why were red kangaroos so abundant on open plains and creeks during droughts, and more so on some than others? Where did they disappear to after rain? Why did they sometimes congregate to form large mobs? What did they eat and did they compete severely or at all with cattle and sheep? How did kangaroos foul pastures as claimed? How could 5 to 10 shooters work one 500 km2 plain 50 km north of Alice Springs night after night in the 1950s without making an impression on numbers? Their breeding would seem to be prodigious for such to happen. So what were the reproductive processes, and what ensured reproductive success?…..Why did kangaroos appear to be more numerous on cattle country than land never stocked? Was it due to stock waters man has made? If so, why were kangaroos so rarely seen at water? Had kangaroos always been so numerous? (pp. 9–10).

For so many questions to be answered in such a slim book is remarkable, especially when they are explained so clearly and logically!

Explorers’ accounts of Central Australia suggest the Red Kangaroo was quite rare before European exploitation of the environment. Yet Newsome observed huge mobs—one of about 1500 animals south of Alice Springs. These massive changes in numbers reflect significant environmental change—change that Newsome also noted had deleterious effects on small to medium sized fauna, which was facing extirpation. His observations and suggested explanations make interesting reading.

Thomas Newsome notes his father rated his paper ‘The Eco-Mythology of the Red Kangaroo in Central Australia’ published in 1980 as his favourite, yet the manuscript proved very difficult to get accepted and remains infrequently cited. Fortunately it is reproduced in full in the book. I found it fascinating in demonstrating Indigenous myths that turned out to be based on sound ecological knowledge. Newsome’s work was prescient—today we should recognise the value of Indigenous knowledge as a sound basis for ecological research and that proper management of our natural assets are best achieved by a blend of Indigenous wisdom with scientific work.

During Newsome’s 16 field trips to the centre between 1959 and 1962 he shot 2000 Red Kangaroos! That was the way in those days—even small mammals were usually caught using break-back traps! I wonder how such research propositions would have fared in today’s environment where work must be approved by independent animal ethic committees?

This is an important book which needs to be read in the context of when it was written and when the research was carried out. In his foreword, Hugh Tyndale-Biscoe believes this book rates with other natural history classics such as Ratcliffe’s Flying Fox and Drifting Sand, Frith’s The Mallee Fowl: the bird that makes an incubator and Rolls’ They All Ran Wild. This may be an exaggeration (it is a slim volume) but certainly field naturalists will enjoy reading about the early journey Newsome took in his field work career.

References
Frith HJ (1962) The Mallee Fowl: the bird that makes an incubator. (Angus and Robertson: Sydney)
Ratcliffe F (1938) Flying Fox and drifting sand. (Chatto and Windus: London)
Rolls EC (1969) They all ran wild: the story of pests on the land in Australia. (Angus and Robertson: Sydney)”

Thanks Rob for the review.

Golden jackal expansion in Europe

In a recent paper we explored whether the expansion of golden jackal populations in Europe is linked to the widespread extirpation of the grey wolf.

Below is a copy of the abstract and you can view the open access paper HERE

Abstract

Top-down suppression by apex predators can limit the abundance and spatial distribution of mesopredators. However, this phenomenon has not been studied over long time periods in human-dominated landscapes, where the strength of this process might be limited. Here, we used a multi-scale approach to analyse interactions between two canids in the human-dominated landscapes of Europe. We tested the hypothesis that the range expansion of golden jackals (Canis aureus) was triggered by intensive persecution and resulting decline of the apex predator, the grey wolf (Canis lupus). To do so, we (1) reviewed literature to reconstruct the historic changes in the distribution and abundance of the two canid species on the continental scale, (2) analysed hunting data patterns for both species in Bulgaria and Serbia, and (3) surveyed jackal persistence in eight study areas that became re-colonized by territorial wolves. The observed trends were generally consistent with the predictions of the mesopredator release hypothesis and supported the existence of top-down suppression by wolves on jackals. We observed inverse patterns of relative abundance and distribution for both canid species at various spatial scales. In most (seven out of eight) cases of wolf re-colonization of jackal territories, jackals disappeared or were displaced out or to the periphery of the newly established wolf home-ranges. We suggest that wolf extermination could be the key driver that enabled the expansion of jackals throughout Europe. Our results also indicate that top-down suppression may be weakened where wolves are intensively persecuted by humans or occur at reduced densities in human-dominated landscapes, which has important management implications and warrants further research.

 

WolfJackalAbundance

Schematic reconstruction  of the relative population dynamics of grey wolves (grey line) and golden jackals (black line) in central and southeastern Europe since 1800

 

 

 

Research Update – Dingo Reintroduction

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The dingo. Source Bobby Tamayo.

In a recent paper and opinion piece in The Conversation it was argued that the case for dingo reintroduction (e.g. see HERE) in Australia is weak.

The arguments focused on two key points:

    1. That dingo reintroduction proposals have been inspired largely by the reintroduction of wolves into Yellowstone National Park.
    2. That unstable climates in Australia will make if difficult for dingoes to exert strong effects on ecosystems via trophic cascades.

(see here for a definition of a trophic cascade, and below for an example of a dingo-induced trophic cascade).

In a paper published in the journal Food Webs, we responded to these criticisms and argued that (1) the case for dingo reintroduction has never been solely based on the reintroduction of wolves into Yellowstone National Park, and (2) that the climatic circumstances under which dingoes can provide net positive effects on ecosystems via trophic cascades are those that typically prevail in Australia.

We concluded that the case for dingo reintroduction in Australia remains strong, and urge managers and decision makers to consider the mounting evidence that dingoes can have positive effects on ecosystems before deciding whether or not to reintroduce dingoes into ecosystems where they have been extirpated by humans.

 

dingoeffects_2

A dingo-induced trophic cascade (solid arrows).

If dingoes suppress large herbivores (e.g. kangaroos and emus), then grass and herb biomass is expected to increase. If dingoes suppress lower order predators (e.g. foxes and cats), then numbers of small mammals (e.g. mice), reptiles (e.g. goannas), and birds (e.g. parrots) are expected to increase. Invertebrates also may respond to improved vegetation conditions and contribute to soil quality. However, the strength of all interactions may be influenced by the extent of rainfall and fires (hashed arrows). Numbers represent the predicted sequence of events based on trophic cascade theory.

 

Research Update – Feral Cats

FeralCat4

Since my last post I have been a co-author on two research papers on feral cats.

1. Legge S, et al (including Newsome TM) (2017) Enumerating a continental-scale threat: how many feral cats are in Australia? (Biological Conservation

In this paper we found that feral cats cover over 99.8% of Australia’s land area, including almost 80% of the area of our islands.

“Australia’s total feral cat population fluctuates between 2.1 million when times are lean, up to 6.3 million when widespread rain results in plenty of available prey,” explains the lead author Dr Sarah Legge from The University of Queensland.

Furthermore, cat densities were found to be the same both inside and outside conservation reserves, such as National Parks, showing that declaring protected areas alone is not enough to safeguard our native wildlife.

This paper has now become the most heavily ‘e-cited’ paper in the journal Biological Conservation. 

A full summary of the media generated can be found HERE

 

2. Molsher R, Newsome AE, Newsome TM, Dickman CR (2017) Mesopredator management: effects of red fox control on the abundance, diet and use of space by feral cats (PLOS ONE)

In this paper we investigated interactions between red foxes and feral cats in south-eastern Australia.

We used a fox-removal experiment to assess whether foxes affect cat abundance, diet, home-range and habitat use.

The results provide little indication that cats responded numerically to the fox removal, but suggest that the fox affects some aspects of cat resource use. In particular, where foxes were removed cats increased their consumption of invertebrates and carrion, decreased their home range size and foraged more in open habitats.

The results suggest that fox control programs could lead to changes in the way that cats interact with co-occurring prey, and that some prey may become more vulnerable to cat predation in open habitats after foxes have been removed.

The paper was featured in the NRM Research and Innovation Network weekly updates.

 

 

New paper on red fox home-range sizes

Our paper “Short-term tracking of three red foxes in the Simpson Desert reveals large home-range sizes” was recently published in Australian Mammalogy.
A copy of the abstract is below and you can view the paper HERE.
“The red fox (Vulpes vulpes) is probably the most intensively studied introduced predator in Australia, but little is known about its movements in arid areas. Here, we report on the home-range sizes of one male and two female red foxes that were tracked for 2–8 months using collars fitted with ARGOS transmitters in the Simpson Desert, central Australia. Based on the 100% Minimum Convex Polygon method, home-range sizes were 5723 ha, 50 158 ha, and 12 481 ha, respectively. Based on the 95% kernel contour method, home-range sizes were 3930 ha, 26 954 ha, and 12 142 ha, respectively. These home-range sizes are much larger than any recorded previously from elsewhere in Australia, suggesting that red foxes in the Simpson Desert need to roam over extensive areas to find enough resources to meet their energetic needs. Given that predation by red foxes poses a key threat to many small and medium-sized native mammals, we suggest that red fox control operations may need to be undertaken at very large spatial scales to be effective in arid areas.”
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Co-author Emma Spencer releasing one of the red foxes tracked in the study.

Third Book Review

RedKangBook
Nancy Cushing from the School of Humanities and Social Science, University of Newcastle, recently reviewed our book “The Red Kangaroo in Central Australia; an early account by A.E. Newsome”.
The review was published in the journal Historical Records of Australian Science.
A copy of the review is provided below, and the original version can be viewed HERE.
      “The Red Kangaroo in Central Australia is a son’s tribute to his father but also a younger scientist’s homage to a pioneer. Discovered amongst former CSIRO ecologist Alan Newsome’s papers three years after his death in 2007, the unfinished text had been intended for publication in the mid-1970s. While others have advanced understandings of the red kangaroo in the intervening period, the lasting contribution of this slim volume lies in its lively account of the methods, attitudes and lived experience of a field ecologist working in Arrente country north of Alice Springs from the late 1950s to the early 1970s.
      When he first joined the Northern Territory’s Animal Industry Branch in 1957, Newsome was just 22 years old, with a freshly minted Bachelor of Science from the University of Queensland. Directed to investigate the red kangaroo (then Macropus rufus, now Osphranter rufus) as a pest to the pastoral industry, he was well aware that he had a lot to learn and listened carefully to kangaroo hunters, cattlemen and Indigenous elders. Newsome studied the red kangaroo intensively through the 1960s, applying careful scientific methods and a good measure of  seat-of-the-pants improvisation. Aerial surveys, days spent observing soaks and the post-mortem examination of some 2000 carcases built up Newsome’s deep knowledge of his subject.
      Beginning with an historical introduction, the book is organized into seven chapters that place the red kangaroo in its physical setting of the Central Australian landform, climate and vegetation. It then considers the species’ distribution and numbers, its highly adapted reproductive processes, food preferences and water sources, and group behaviour (labelled ‘Sociology’).
      Chapter 2, addressing climate, is now of greater interest than when it was first drafted. Although unaware of the El Niño phenomenon, Newsome produced evidence of cycles of wetter and dryer years back to 1892, including the record dry he himself witnessed between 1958 and 1965. He furthermore made the link between drought and interracial violence that is now being explored by historians.
      By tracking kangaroo populations through this cycle, in Chapter 3 Newsome addressed his employer’s concerns about competition with sheep and cattle. Red kangaroos had expanded their range as new dams and bores allowed more individuals to survive times of drought, and the consumption of long dry grasses by introduced livestock encouraged the sprouting of the green grass needed by kangaroos. Newsome solved some of the riddles of kangaroo populations, showing that while they preferred to live in mulga scrub, mobs moved onto open plains during drought. Thus they created an impression of increasing numbers just when cattlemen were most troubled by their presence—and also when successful reproduction fell to near zero.
      In Chapters 4 and 5, on physiology and diet, Newsome described his methods and findings in sufficient detail to satisfy other ecologists, but with an immediacy that also readily engages the non-specialist. Comparisons with better-known animals make the distinctive adaptations of the red kangaroo to their arid environment stand out, including the reflective pale red fur that lessens the heating effect of the sun. Even with these attributes, Newsome concluded that red kangaroos lived at the limits of their capacity for survival in Central Australia, with numbers kept in check by regular droughts.
      For historians, the human as well as human–animal relations described by Newsome are of great interest. His book portrays a strikingly masculine world in which not a single female name is recorded. Unnamed Aboriginal women do appear in the text, voiceless in comparison with their male counterparts with whom Newsome hunted and prepared kangaroo for consumption. He acknowledged the long shared history of Arrente people and red kangaroos and described his own research into this relationship, informed by the contemporary work of anthropologist Ted Strehlow. In his 1980 Mankind article, reprinted in full in the final chapter, ‘Ecomythology’, Newsome made a case that the stories told by Aboriginal elders had an underlying ecological rationale, with dreaming tracks crossing habitats most favoured by red kangaroos and restrictions on hunting at dreaming sites reducing pressure on populations. That Indigenous people have a deep environmental knowledge that is embedded in traditional stories, is now widely understood but was then only just being recognized in the wider society. According to his son, this was Newsome’s least cited article but the one of which he was most proud.
      Thomas Newsome was well placed to serve as his father’s editor: he is also an ecologist who has worked in the Alice Springs area. He rounded out incomplete chapters and inserted tables, charts and photographs from other pieces of Alan’s work, also adding a foreword, maps and explanatory notes. In the absence of a conclusion, an afterword would have been welcome, to explore how Newsome’s research was received, its impact and longevity. This could have been supported by suggestions for further reading in ecological and anthropological texts that have advanced or challenged his findings.
      The Red Kangaroo in Central Australia is an engaging and informative book that draws the reader into the world of a curious ecologist. Seeking answers to questions that had practical applications at the time, they hold even greater layers of significance now.”
Thanks Nancy for the review.