
Christopher Ian MacgregorAustralian National University | ANU · Fenner School of Environment & Society
Christopher Ian Macgregor
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83
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Introduction
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October 1998 - present
Publications
Publications (83)
Long-term ecological monitoring is crucial to understanding the complex dynamics of ecosystems, communities, and populations. Despite this, monitoring data are lacking or rare for the vast majority of biodiversity. Here we report the results of 19 years (2003–2022) of continuous annual monitoring of reptile species at Booderee National Park (BNP) o...
Co-occurring species often overlap in their use of resources and can interact in complex ways. However, shifts in environmental conditions or resource availability can lead to changes in patterns of species co-occurrence, which may be exacerbated by global escalation of human disturbances to ecosystems, including conservation-directed interventions...
Dense ground cover and understory can be important as diurnal shelter for terrestrial mammals. Fire can lead to the short-term removal of much of this shelter. Here, we report on the shelter site selection of the Southern Brown Bandicoot Isoodon obesulus obesulus and Long-nosed Bandicoot Perameles nasuta eight months after a wildfire. We analysed t...
Fire and herbivores alter vegetation structure and function. Future fire activity is predicted to increase, and quantifying changes in vegetation communities arising from post-fire herbivory is needed to better manage natural environments. We investigated the effects of post-fire herbivory on understory plant communities in a coastal eucalypt fores...
Fire can have marked impacts on biodiversity and on ecosystem condition. However, it is the sequence of multiple fires over a prolonged period of time which can have the most marked effects on biodiversity and on ecosystem condition. A good understanding of these effects comes from long-term studies. In this article we outline some of the key persp...
Management of fire and fire regimes is an important part of reserve management. In Australia, fire is used as a management tool to protect human infrastructure and cultural and natural assets. It is also used in reserve management to reduce fuel loads and promote the regrowth of fire-dependent vegetation. Many vertebrate species depend upon the nat...
Reintroduction and translocation are widely employed actions in restoration ecology. The broad aim of these activities is to re-establish populations in places where they formerly existed. However, the success of re-establishment efforts in terms of responses to key ecosystem processes such as natural disturbances like fires has rarely been quantif...
Knowledge of animal responses to fire is fundamental to wildlife management in fire-prone ecosystems. Fire can influence the occurrence of large herbivores by altering the structure and composition of vegetation. However, how fire affects herbivore occurrence in many ecosystems is poorly understood. Large herbivores may be attracted to burnt areas...
Over two field seasons during 2014-15, 35 long-nosed potoroos (Potorous tridactylus) were captured in state forests in South Eastern New South Wales for translocation to Booderee National Park, Jervis Bay Territory, Australia. Animals were anesthetized for physical examination and collection of samples to assess general health and screen for select...
• Theories of dispersal and senescence (or aging) predict that dispersal, and ongoing survival and body condition, are influenced by evolutionary drivers, along with intrinsic and extrinsic factors. Such theories are relevant to translocations of animals where high mortality, loss of body condition, and dispersal beyond the area of release are comm...
Translocated captive-bred predators are less skilled at hunting than wild-born predators and more prone to starvation post-release. Foraging in an unfamiliar environment presents many further risks to translocated animals. Knowledge of the diet and foraging behaviour of translocated animals is therefore an important consideration of reintroductions...
Modelling the occupancy of species is a key part of the discipline of ecology, with particular efforts often focused on identifying which environmental, vegetation and other factors influence why a given species occurs where it does. Here, based on data gathered between 2003 and 2016, we developed models of the environmental, terrain and vegetation...
Reintroductions are increasingly being used to restore species and ecosystems. However, chances of successful establishment are often low. Key to improving success is careful consideration of threats, threat mitigation, monitoring and subsequent improvement to management. We demonstrate this planning, implementation and review process using the rei...
Effective control of an invasive species is frequently used to infer positive outcomes for the broader ecosystem. In many situations, whether the removal of an invasive plant is of net benefit to biodiversity is poorly assessed. We undertook a 10-year study on the effects of invasive shrub management (bitou bush, Chrysanthemoides monilifera ssp. ro...
Reintroducing a species to an ecosystem can have significant impacts on the recipient ecological community. Although reintroductions can have striking and positive outcomes, they also carry risks; many well‐intentioned conservation actions have had surprising and unsatisfactory outcomes. A range of network‐based mathematical methods has been develo...
Understanding the genetic diversity of a population is important for understanding population persistence and extinction risk. The long-nosed bandicoot (Perameles nasuta) was once regarded as common throughout its range, but it is unknown whether it is at risk of decline and the genetic diversity in this species has not been assessed. We evaluated...
Booderee National Park is located in Jervis Bay in south-eastern Australia, around 200 km south of Sydney on the New South Wales coast between Nowra
and Ulladulla. A major monitoring program began in Booderee National Park in 2003, which encompassed a range of vertebrate groups including mammals, birds, reptiles and frogs, as well as native vegetat...
A major monitoring program began in Booderee National Park in 2003, which encompassed a range of vertebrate groups including mammals, birds, reptiles and frogs, as well as native vegetation. Fifteen-years of monitoring has now revealed a major ecological surprise: localised collapses of populations of some of the park’s mammal species and the drama...
Context
Reintroductions can be an effective means of re-establishing locally extinct or declining faunal populations. However, incomplete knowledge of variables influencing survival and establishment can limit successful outcomes.
Aim
We aimed to examine the factors (e.g. sex, body mass, release order) influencing the survival, dispersal, home ran...
The conventional approach to conserving threatened biota is to identify drivers of decline, instigate actions to mitigate threatening processes, and monitor interventions to test their effectiveness and ensure target species recover. In Australia, predation by introduced predators is a threatening process for many native mammals. Here we report the...
Question
Do the effects of fire regimes on plant species richness and composition differ among floristically similar vegetation types?
Location
Booderee National Park, south‐eastern Australia.
Methods
We completed floristic surveys of 87 sites in Sydney Coastal dry sclerophyll vegetation, where fire history records have been maintained for over 5...
Aim
To quantify how frogs in terrestrial environments respond to recurrent fire, and to what extent this is mediated by isolation from breeding sites or vegetation structure.
Location
Jervis Bay, south‐eastern Australia.
Methods
We used data from 8 years of pitfall trapping, collected via a random stratified design, to quantify frog occurrence at...
Management guidelines for many fire-prone ecosystems highlight the importance of maintaining a variable mosaic of fire histories for biodiversity conservation. Managers are encouraged to aim for fire mosaics that are temporally and spatially dynamic, include all successional states of vegetation, and also include variation in the underlying “invisi...
Military training areas (MTAs) cover 6% of the earth's land surface, but the impact on biodiversity of weapons use in MTAs remains largely unknown. We quantified the effects of military training on vertebrates in a 5-year study at Beecroft Weapons Range in south-eastern Australia by contrasting the occurrence of birds, mammals and reptiles between...
Fire is a major ecological process in many ecosystems worldwide. We sought to identify which attributes of fire regimes affect temporal change in the presence and abundance of Australian native mammals. Our detailed study was underpinned by time series data on 11 mammal species at 97 long-term sites in southeastern Australia between 2003 and 2013....
Fire is a major ecological process in many ecosystems worldwide. We sought to identify which attributes of fire regimes affect temporal change in the presence and abundance of Australian native mammals. Our detailed study was underpinned by time series data on 11 mammal species at 97 long-term sites in southeastern Australia between 2003 and 2013....
Context
Biodiversity studies often require wildlife researchers to survey multiple species across taxonomic classes. To detect terrestrial squamate and mammal species, often multiple labour-intensive survey techniques are required. Camera traps appear to be more effective and cost-efficient than labour-intensive methods for detecting some mammal sp...
Context: Multiple ecological drivers generate spatial patterns in species’ distributions. Changes to natural disturbance regimes can place early successional habitat specialists at an increased risk of extinction by altering landscape patterns of habitat suitability. Objectives: We developed a series of hypotheses to evaluate the effects of landsca...
QuestionsDoes browsing by large herbivores affect forest understorey diversity by modifying assemblage dominance? Does fire interact with browsing to affect forest understorey diversity? Does this interaction occur via a numerically mediated or functionally moderated pathway?LocationBooderee National Park, Jervis Bay Territory, south-eastern Austra...
Invasive plant management is often justified in terms of conservation goals, yet progress is rarely assessed against these broader goals, instead focussing on short-term reductions of the invader as a measure of success. Key questions commonly remain unanswered including whether invader removal reverses invader impacts and whether management itself...
Herbivory and fire are two disturbances that often co-occur, but studies of their interactive effects are rare outside of grassland ecosystems. We experimentally tested the interactive effects of prescribed fire and macropod herbivory on forest understory vegetation and its vertebrate fauna. Fire and herbivory interacted synergistically to affect f...
Ecological theory predicts that species with narrow niche requirements (habitat specialists) are more vulnerable to anthropocentric disturbances than those with broad niche requirements (habitat generalists). Hence, understanding a species ecological niche and guild membership would serve as a valuable management tool for providing a priori assessm...
Access to nest sites is critical to species survival and habitat suitability for most faunal species worldwide. We report on nest-site selection and use by the long-nosed bandicoot (Perameles nasuta) following a wildfire in late 2003. Thirty-eight bandicoots were tracked to 213 nests. The number of nests, frequency of nest use, nest range, nest siz...
Ecogeographical rules help explain spatial and temporal patterns in intraspecific body size. However, many of these rules, when applied to ectothermic organisms such as reptiles, are controversial and require further investigation. To explore factors that influence body size in reptiles, we performed a heuristic study to examine body size variation...
Background/Question/Methods
Ascertaining mammal and reptile diversity at a site has traditionally required researchers to employ a variety of data collection techniques due to vast differences in morphology and behaviour within and between taxonomic groups. Developing new methods, or improving the effectiveness of existing methods, has preoccupie...
Many animal taxa respond strongly to spatial and temporal variation in vegetation structure and floristic composition, suggesting that changes in vegetation could be a cheap and readily observable surrogate for changes in animal assemblages. Yet there is considerable uncertainty about how different taxa respond to vegetation over time, potentially...
Ecological theory predicting the impact of fire on ecological communities is typically focused on post-disturbance recovery processes or on disturbance-diversity dynamics. Yet the established relationship between vegetation structure and animal diversity could provide a foundation to predict the short-term effects of fire on biodiversity, but has r...
Booderee National Park at Jervis Bay, 200km south of Sydney, attracts over 450,000 visitors each year. The park has many special features, including dramatic wave cut platforms and sea caves, some of the whitest beach sands in Australia, and very high densities of native predators such as the Powerful Owl and the Diamond Python. This book outlines...
Over-abundance of native herbivores is a problem in many forests worldwide. The abundance of native macropod wallabies is extremely high at Booderee National Park (BNP) in south-eastern Australia. This has occurred because of the reduction of exotic predators through an intensive baiting program, coupled with the absence of other predators. The hig...
Understanding how animals use available habitat and how disturbance events such as fire influence habitat use is crucial to wildlife management. Relationships between home-range size of long-nosed bandicoots (Perameles nasuta) and vegetation type and fire effects on food availability and vegetation cover were explored. Home ranges and movement of P...
A large-scale biodiversity monitoring program examining the response of herpetofauna to the Australian Government's Environmental Stewardship Program is taking place in south-eastern Australia within the critically endangered Box Gum Grassy Woodland vegetation community. Field surveys involve counting reptiles in areas under Environmental Stewardsh...
Species that specialize in disturbed habitats may have considerably different dispersal strategies than those adapted to more stable environments. However, little is known of the dispersal patterns and population structure of such species. This information is important for conservation because many postfire specialists are at risk from anthropogeni...
A 10‐year science–management partnership has focussed on three key issues within Booderee National Park in eastern Australia: the impacts of fire on native biota, the response of vertebrates to feral animal control and the control of Bitou Bush. What has been achieved to date and what are the partnership's key ingredients?
At Booderee National Park, south-eastern Australia, the intensive control of the introduced red fox (Vulpes vulpes) resulted in a major increase in the abundance of a browsing macropod, the swamp wallaby (Wallabia bicolor). This has led to a major decrease in the abundance and biomass of a range of palatable plant species. Fox control has also star...
Do sites managed under an agri-environment scheme support significantly more biodiversity than sites managed in accordance with traditional agricultural practices? This is a key question underpinning agri-environment schemes worldwide, including one that we report on here that has been established in south-eastern Australia. To address this questio...
Two large-scale, long-term biodiversity monitoring programs examining vertebrate responses to habitat fragmentation and landscape change in agricultural landscapes are taking place in the Murray Catchment Management Area of New South Wales, south-eastern Australia. Field surveys involve counting reptiles under a range of management conditions and a...
How different are insights based on cross-sectional studies from those of longitudinal investigations? We addressed this question using a detailed case study encompassing a rare suite of inter-connected cross-sectional and longitudinal investigations that have spanned the past two decades and included work on: (1) the decay and collapse of large-ca...
We used isodars to analyse habitat-dependent population regulation by long-nosed bandicoots Perameles nasuta during an irruption and subsequent population crash in three habitats (heath, woodland and forest) at Booderee National Park, south-eastern Australia. Specifically, we aimed to see whether patterns of habitat-dependent population regulation...
Context
Temporal reduction in shelter is an indirect primary impact of fire. Removal of animal refugia has implications for shelter site selection and fidelity – factors that have been largely overlooked in studies of Australian rodent fauna. This information is critical for guiding species conservation and appropriate land management including pre...
A traditional focus in conservation biology has been on rare species as they are often those most at risk of decline or extinction. However, we argue in this paper that some kinds of currently common species also can be susceptible to decline. Those at particular risk are species that are specialized on widespread environmental conditions. Such spe...
Spring et al. (D.A. Spring, M. Bevers, J.O.S. Kennedy, and D. Harley. 2001. Can. J. For. Res. 31: 19922003) recently published a paper on the economics of a nest-box program for the endangered arboreal marsupial, Leadbeater's possum (Gymnobelideus leadbeateri) in southeastern Australian forests. While their paper is a useful one, there are some im...
This book brings together extensive scientific learning on what makes a good farm for biodiversity. Based on thirteen years of intensive research, it breaks the discussion into chapters on key environmental and vegetation assets and then discusses how to make these assets better for biodiversity. The work encompasses information on vertebrates and...
Knowing how species respond to fire regimes is essential for ecologically sustainable management. This axiom raises two important questions: (1) what knowledge is the most important to develop and (2) to what extent can current research methods deliver that knowledge? We identify three areas of required knowledge: (i) a mechanistic understanding of...
Agencies charged with nature conservation and protecting built-assets from fire face a policy dilemma because management that protects assets can have adverse impacts on biodiversity. Although conservation is often a policy goal, protecting built-assets usually takes precedence in fire management implementation. To make decisions that can better ac...
Patterns of avian species richness and assemblage composition may change markedly between and within vegetation types. We compared bird species richness and assemblage composition in cool temperate rainforest and Mountain Ash ( Eucalyptus regnans) forest in the Central Highlands of Victoria, south-eastern Australia. We quantified the effects of the...
Large-scale vegetation clearing accompanying agricultural development has been a major driver of biodiversity loss. Efforts to reverse this problem have often included revegetation, but the value of revegetated areas for biodiversity is poorly known. We addressed aspects of this knowledge gap using a case study in south-eastern Australia. We quanti...
We implemented a replicated before-after-control-impact (BACI) experiment to quantify vertebrate response in native forest
patches to a major change in the surrounding exotic Radiata Pine (Pinus radiata) plantation. We contrasted vertebrate occupancy of patches of native eucalypt forest where the surrounding stands of exotic
Radiata Pine (Pinus rad...
A large-scale, long-term study is being conducted to describe the bird assemblages inhabiting a 6500 ha areaat Booderee National Park, south-eastern Australia. In this paper, we provide a list of birds recorded within rainforest,forest, woodland, shrubland, heathland and sedgeland during surveys conducted each spring between 2003 and 2007. Ofpartic...
A relatively common observation in forest environments has been that gullies support higher species richness and individual abundance than elsewhere in the landscape. We completed a detailed case study of birds to contrast species richness and assemblage composition between gullies and other parts of the topography of landscapes in three closely re...
Use of multiple observers in large-scale bird surveys is often unavoidable. But how significant are observer differences in bird detection? Do observer effects significantly influence inferences about environmental factors on birds? We conducted a field experiment to quantify differences between observers in the detection of birds at Booderee Natio...
Nest box programs have often been established to conserve hollow-dependent fauna but their effectiveness is unknown in many jurisdictions. We examined nest box effectiveness in a 10-year experimental study in the Mountain Ash (Eucalyptus regnans) forests of Victoria (south-eastern Australia) where the paucity of hollow-bearing trees is a significan...
We quantified the post-fire recovery of the endangered Eastern Bristlebird (Dasyornis brachypterus) at Booderee National Park, south-eastern Australia. Occurrence was recorded on 110 sites a year before, and for 3 years after a major unplanned fire in 2003. Although the Eastern Bristlebird is thought to be sensitive to wildfire, data indicated that...
Disturbance is a key ecological process influencing the distribution and abundance of many elements of the earth's biota. Predicting the response of biota to disturbance is therefore important, but it nevertheless remains difficult to make accurate forecasts of response. We tested predictions from disturbance-related theories and concepts in 10 veg...
Plantation development is a significant form of landscape change worldwide. We report findings from a large‐scale longitudinal natural experiment that quantified changes in Australian vertebrates as a former grazing landscape was transformed to one dominated by a radiata pine ( Pinus radiata ) plantation. The study included four main “treatments”:...
Introduction: Novel ecosystems occur when new combinations of species appear within a particular biome due to human activity, environmental change, or impacts of introduced species. Background: Managing the trajectory of ecosystems toward desired outcomes requires an understanding of the means by which they developed. To facilitate this understandi...
Biodiversity conservation on agricultural land is a major issue worldwide. We estimated separate and joint effects of remnant native woodland vegetation and recent tree plantings on birds on farms (approximately 500-1000 ha) in the heavily cleared wheat and sheep belt of southern Australia. Much of the variation (>70%) in bird responses was explain...
Natural disturbances are key processes in the vast majority of ecosystems and a range of ecological theories have been developed in an attempt to predict biotic responses to them. However, empirical support for these theories has been inconsistent and considerable additional work remains to be done to better understand the response of biodiversity...
The management of landscapes for biological conservation and ecologically sustainable natural resource use are crucial global issues. Research for over two decades has resulted in a large literature, yet there is little consensus on the applicability or even the existence of general principles or broad considerations that could guide landscape cons...
The response of terrestrial mammals and arboreal marsupials to past burning history as well as a year prior to, and then for 4 years after, a major wildfire in 2003 at Booderee National Park, Jervis Bay Territory was quantified. The present study encompassed extensive repeated surveys at a set of 109 replicated sites stratified by vegetation type a...
Tree hollows are a key habitat component for a large number of Australian vertebrates and understanding how these resources are used is critical for developing successful management and conservation strategies for particular species or sets of species. Some hollow-using vertebrates are capable of using other kinds of nest sites. The common ringtail...
There are strong links between habitat fragmentation, population size and genetic structure. However, to fully understand the long-term effects of fragmentation on population viability, it is necessary to first understand the relationship between life history traits and genetic characteristics in un-fragmented habitats. This is best done through co...
A large-scale, long-term study of the impacts on vertebrates of landscape change and habitat fragmentationis taking place at Tumut in southern New South Wales, south-eastern Australia. Field surveys focus on counting birdswithin three broad kinds of sites in the study region. These are: (1) A randomized and replicated set of 85 sites inremnants or...
We report reptile and arboreal marsupial responses to vegetation planting and remnant native vegetation in agricultural landscapes in southeastern Australia. We used a hierarchical survey to select 23 landscapes that varied in the amounts of remnant native vegetation and planted native vegetation. We selected two farms within each landscape. In lan...
In this study, we use data drawn from a series of trapping events on four 0.5-ha trapping grids surveyed in the wet eucalypt forests of central Victoria, south-eastern Australia, to identify relationships between capture probabilities and several factors of interest for three species of small mammals that are common throughout the forests of this r...
We describe a non-standard sample design for monitoring the abundance of arboreal marsupials in the montane ash forests of the Central Highlands of Victoria, south-eastern Australia. The survey design is based on overlapping and rotating sampling from a given population of sites—in this case 160 sites, each measuring 1 ha in size. Estimates of popu...
The results are reported of a nest-box study conducted in two locations in the mountain ash (Eucalyptus regnans) forests of the Central Highlands of Victoria (south-eastern Australia) to compare usage of different nest-box designs located at different heights in trees. A total of 96 nest boxes was established using a rigorous experimental design –...
Many landowners are interested in the native animals that live on their farms or once occurred there. In particular they want to know why particular species are present (or absent), what they can do to encourage them to visit, and what they might do to keep them there. Wildlife on Farms outlines the key features of animal habitats—large flowering t...