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Michel A, Johnson JR, Szeligowski R, Ritchie EG, Sih A. Integrating sensory ecology and predator-prey theory to understand animal responses to fire. Ecol Lett 2023; 26:1050-1070. [PMID: 37349260 DOI: 10.1111/ele.14231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 01/11/2023] [Accepted: 02/10/2023] [Indexed: 06/24/2023]
Abstract
Fire regimes are changing dramatically worldwide due to climate change, habitat conversion, and the suppression of Indigenous landscape management. Although there has been extensive work on plant responses to fire, including their adaptations to withstand fire and long-term effects of fire on plant communities, less is known about animal responses to fire. Ecologists lack a conceptual framework for understanding behavioural responses to fire, which can hinder wildlife conservation and management. Here, we integrate cue-response sensory ecology and predator-prey theory to predict and explain variation in if, when and how animals react to approaching fire. Inspired by the literature on prey responses to predation risk, this framework considers both fire-naïve and fire-adapted animals and follows three key steps: vigilance, cue detection and response. We draw from theory on vigilance tradeoffs, signal detection, speed-accuracy tradeoffs, fear generalization, neophobia and adaptive dispersal. We discuss how evolutionary history with fire, but also other selective pressures, such as predation risk, should influence animal behavioural responses to fire. We conclude by providing guidance for empiricists and outlining potential conservation applications.
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Affiliation(s)
- Alice Michel
- Animal Behavior Graduate Group, University of California, Davis, California, USA
| | - Jacob R Johnson
- Animal Behavior Graduate Group, University of California, Davis, California, USA
| | - Richard Szeligowski
- Department of Environmental Science & Policy, University of California, Davis, California, USA
| | - Euan G Ritchie
- School of Life and Environmental Sciences, Centre for Integrative Ecology, Deakin University, Burwood, Victoria, Australia
| | - Andrew Sih
- Department of Environmental Science & Policy, University of California, Davis, California, USA
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2
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Nimmo DG, Carthey AJR, Jolly CJ, Blumstein DT. Welcome to the Pyrocene: Animal survival in the age of megafire. GLOBAL CHANGE BIOLOGY 2021; 27:5684-5693. [PMID: 34404117 DOI: 10.1111/gcb.15834] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 06/11/2021] [Accepted: 07/17/2021] [Indexed: 06/13/2023]
Abstract
Planet Earth is entering the age of megafire, pushing ecosystems to their limits and beyond. While fire causes mortality of animals across vast portions of the globe, scientists are only beginning to consider fire as an evolutionary force in animal ecology. Here, we generate a series of hypotheses regarding animal responses to fire by adopting insights from the predator-prey literature. Fire is a lethal threat; thus, there is likely strong selection for animals to recognize the olfactory, auditory, and visual cues of fire, and deploy fire avoidance behaviours that maximize survival probability. If fire defences are costly, it follows that intraspecific variation in fire avoidance behaviours should correspond with variation in fire behaviour and regimes. Species and populations inhabiting ecosystems that rarely experience fire may lack these traits, placing 'fire naive' populations and species at enhanced extinction risk as the distribution of fire extends into new ecosystem types. We outline a research agenda to understand behavioural responses to fire and to identify conservation interventions that could be used to overcome fire naivety.
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Affiliation(s)
- Dale G Nimmo
- Institute of Land, Water and Society, School of Agricultural, Environmental and Veterinary Sciences, Charles Sturt University, Albury, New South Wales, Australia
| | - Alexandra J R Carthey
- Department of Biological Sciences, Macquarie University, North Ryde, New South Wales, Australia
| | - Chris J Jolly
- Institute of Land, Water and Society, School of Agricultural, Environmental and Veterinary Sciences, Charles Sturt University, Albury, New South Wales, Australia
| | - Daniel T Blumstein
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California, USA
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3
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Nowack J, Turbill C. Survivable hypothermia or torpor in a wild-living rat: rare insights broaden our understanding of endothermic physiology. J Comp Physiol B 2021; 192:183-192. [PMID: 34668054 PMCID: PMC8817056 DOI: 10.1007/s00360-021-01416-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 09/08/2021] [Accepted: 10/03/2021] [Indexed: 12/16/2022]
Abstract
Maintaining a high and stable body temperature as observed in endothermic mammals and birds is energetically costly. Thus, it is not surprising that we discover more and more heterothermic species that can reduce their energetic needs during energetic bottlenecks through the use of torpor. However, not all heterothermic animals use torpor on a regular basis. Torpor may also be important to an individual’s probability of survival, and hence fitness, when used infrequently. We here report the observation of a single, ~ 5.5 h long hypothermic bout with a decrease in body temperature by 12 °C in the native Australian bush rat (Rattus fuscipes). Our data suggest that bush rats are able to rewarm from a body temperature of 24 °C, albeit with a rewarming rate lower than that expected on the basis of their body mass. Heterothermy, i.e. the ability to withstand and overcome periods of reduced body temperature, is assumed to be an evolutionarily ancestral (plesiomorphic) trait. We thus argue that such rare hypothermic events in species that otherwise appear to be strictly homeothermic could be heterothermic rudiments, i.e. a less derived form of torpor with limited capacity for rewarming. Importantly, observations of rare and extreme thermoregulatory responses by wild animals are more likely to be discovered with long-term data sets and may not only provide valuable insight about the physiological capability of a population, but can also help us to understand the constraints and evolutionary pathways of different phenologies.
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Affiliation(s)
- Julia Nowack
- Hawkesbury Institute for the Environment and School of Science, Western Sydney University, Richmond, NSW, Australia. .,School of Biological and Environmental Sciences, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, UK.
| | - Christopher Turbill
- Hawkesbury Institute for the Environment and School of Science, Western Sydney University, Richmond, NSW, Australia
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Stawski C, Geiser F. Growing Up in a Changing Climate: How Temperature Affects the Development of Morphological, Behavioral and Physiological Traits of a Marsupial Mammal. Front Physiol 2020; 11:49. [PMID: 32116761 PMCID: PMC7028820 DOI: 10.3389/fphys.2020.00049] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 01/21/2020] [Indexed: 01/14/2023] Open
Abstract
Climate change is likely to affect many mammalian phenotypes, yet little is known whether and how phenotypic plasticity is involved in responding to thermal challenges during mammalian development. We investigated the effect of continuous cold or warm exposure during development on morphological, behavioral, and functional variables of yellow-footed antechinus (Antechinus flavipes), a semelparous Australian marsupial mammal. Captive-bred young were exposed to two ambient temperatures (T a ), cold (17°C) or warm (25°C), once weaned. Treatments were reversed and metabolic rate (MR) measurements repeated after 2 months. We measured body mass weekly, activity continuously, and MRs over a range of T a once they were adults. Growth rate was similar in both groups, but was faster in males. Antechinus in the warm group were initially more active than the cold group and decreased activity when exposed to cold, whereas the cold group increased activity when exposed to warm. Interestingly, females changed their night-time activity when T a was changed, whereas males changed their daytime activity. MRs were originally lower in the warm group in comparison to the cold group for both sexes and increased slightly for females, but not for males, after being exposed to cold. After exposure to warm T a , the MRs of the cold group decreased significantly over the entire T a -range for both sexes. Our results reveal that temperatures experienced during development can influence behavioral and physiological traits in antechinus. Such phenotypic plasticity is vital for a species that within 1 year is dependent on a single breeding event and experiences a complete population turnover.
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Affiliation(s)
- Clare Stawski
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW, Australia.,Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Fritz Geiser
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW, Australia
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5
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He T, Lamont BB, Pausas JG. Fire as a key driver of Earth's biodiversity. Biol Rev Camb Philos Soc 2019; 94:1983-2010. [PMID: 31298472 DOI: 10.1111/brv.12544] [Citation(s) in RCA: 108] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 06/19/2019] [Accepted: 06/21/2019] [Indexed: 12/21/2022]
Abstract
Many terrestrial ecosystems are fire prone, such that their composition and structure are largely due to their fire regime. Regions subject to regular fire have exceptionally high levels of species richness and endemism, and fire has been proposed as a major driver of their diversity, within the context of climate, resource availability and environmental heterogeneity. However, current fire-management practices rarely take into account the ecological and evolutionary roles of fire in maintaining biodiversity. Here, we focus on the mechanisms that enable fire to act as a major ecological and evolutionary force that promotes and maintains biodiversity over numerous spatiotemporal scales. From an ecological perspective, the vegetation, topography and local weather conditions during a fire generate a landscape with spatial and temporal variation in fire-related patches (pyrodiversity), and these produce the biotic and environmental heterogeneity that drives biodiversity across local and regional scales. There have been few empirical tests of the proposition that 'pyrodiversity begets biodiversity' but we show that biodiversity should peak at moderately high levels of pyrodiversity. Overall species richness is greatest immediately after fire and declines monotonically over time, with postfire successional pathways dictated by animal habitat preferences and varying lifespans among resident plants. Theory and data support the 'intermediate disturbance hypothesis' when mean patch species diversity is correlated with mean fire intervals. Postfire persistence, recruitment and immigration allow species with different life histories to coexist. From an evolutionary perspective, fire drives population turnover and diversification by promoting a wide range of adaptive responses to particular fire regimes. Among 39 comparisons, the number of species in 26 fire-prone lineages is much higher than that in their non-fire-prone sister lineages. Fire and its byproducts may have direct mutagenic effects, producing novel genotypes that can lead to trait innovation and even speciation. A paradigm shift aimed at restoring biodiversity-maintaining fire regimes across broad landscapes is required among the fire research and management communities. This will require ecologists and other professionals to spread the burgeoning fire-science knowledge beyond scientific publications to the broader public, politicians and media.
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Affiliation(s)
- Tianhua He
- School of Molecular and Life Sciences, Curtin University, Perth, Australia.,College of Science, Health, Engineering and Education, Murdoch University, Murdoch, Australia
| | - Byron B Lamont
- School of Molecular and Life Sciences, Curtin University, Perth, Australia
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Geiser F, Stawski C, Doty AC, Cooper CE, Nowack J. A burning question: what are the risks and benefits of mammalian torpor during and after fires? CONSERVATION PHYSIOLOGY 2018; 6:coy057. [PMID: 30323932 PMCID: PMC6181253 DOI: 10.1093/conphys/coy057] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 08/11/2018] [Accepted: 10/08/2018] [Indexed: 06/08/2023]
Abstract
Although wildfires are increasing globally, available information on how mammals respond behaviourally and physiologically to fires is scant. Despite a large number of ecological studies, often examining animal diversity and abundance before and after fires, the reasons as to why some species perform better than others remain obscure. We examine how especially small mammals, which generally have high rates of energy expenditure and food requirements, deal with fires and post-fire conditions. We evaluate whether mammalian torpor, characterised by substantial reductions in body temperature, metabolic rate and water loss, plays a functional role in survival of mammals impacted by fires. Importantly, torpor permits small mammals to reduce their activity and foraging, and to survive on limited food. Torpid small mammals (marsupials and bats) can respond to smoke and arouse from torpor, which provides them with the possibility to evade direct exposure to fire, although their response is often slowed when ambient temperature is low. Post-fire conditions increase expression of torpor with a concomitant decrease in activity for free-ranging echidnas and small forest-dwelling marsupials, in response to reduced cover and reduced availability of terrestrial insects. Presence of charcoal and ash increases torpor use by captive small marsupials beyond food restriction alone, likely in anticipation of detrimental post-fire conditions. Interestingly, although volant bats use torpor on every day after fires, they respond by decreasing torpor duration, and increasing activity, perhaps because of the decrease in clutter and increase in foraging opportunities due to an increase in aerial insects. Our summary shows that torpor is an important tool for post-fire survival and, although the physiological and behavioural responses of small mammals to fire are complex, they seem to reflect energetic requirements and mode of foraging. We make recommendations on the conditions during management burns that are least likely to impact heterothermic mammals.
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Affiliation(s)
- Fritz Geiser
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, Australia
| | - Clare Stawski
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, Australia
- Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Anna C Doty
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, Australia
- Department of Biological Sciences, Arkansas State University, Jonesboro, AR, USA
| | - Christine E Cooper
- School of Molecular and Life Sciences, Curtin University, Perth, Western Australia
| | - Julia Nowack
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, Australia
- School of Natural Sciences and Psychology, Liverpool John Moores University, Byrom Street, Liverpool, UK
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7
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Nowack J, Stawski C, Körtner G, Geiser F. Physiological and behavioral responses of an arboreal mammal to smoke and charcoal-ash substrate. Physiol Behav 2018; 184:116-121. [DOI: 10.1016/j.physbeh.2017.11.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 11/08/2017] [Accepted: 11/16/2017] [Indexed: 10/18/2022]
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Geiser F, Stawski C, Wacker CB, Nowack J. Phoenix from the Ashes: Fire, Torpor, and the Evolution of Mammalian Endothermy. Front Physiol 2017; 8:842. [PMID: 29163191 PMCID: PMC5673639 DOI: 10.3389/fphys.2017.00842] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 10/09/2017] [Indexed: 12/02/2022] Open
Affiliation(s)
- Fritz Geiser
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW, Australia
| | - Clare Stawski
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW, Australia
| | - Chris B Wacker
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW, Australia
| | - Julia Nowack
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW, Australia.,Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Vienna, Austria
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Mason ED, Firn J, Hines HB, Baker AM. Plant diversity and structure describe the presence of a new, threatened Australian marsupial within its highly restricted, post-fire habitat. PLoS One 2017; 12:e0182319. [PMID: 28797038 PMCID: PMC5552313 DOI: 10.1371/journal.pone.0182319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 07/16/2017] [Indexed: 11/19/2022] Open
Abstract
Management of critical habitat for threatened species with small ranges requires location-specific, fine-scale survey data. The silver-headed antechinus (Antechinus argentus) is known from only two isolated, fire-prone locations. At least one of these populations, at Kroombit Tops National Park in central-eastern Queensland, Australia, possesses a very small range. Here, we present detailed vegetation species diversity and structure data from three sites comprising the known habitat of A. argentus at Kroombit Tops and relate it to capture data obtained over two years. We found differences in both vegetation and capture data between burnt and unburnt habitat. Leaf litter and grasstrees (Xanthorrhoea johnsonii) were the strongest vegetative predictors for A. argentus capture. The species declined considerably over the two years of the trapping study, and we raise concern for its survival at Kroombit Tops. We suggest that future work should focus on structural vegetative variables (specifically, the diameter and leaf density of grasstree crowns) and relate them to A. argentus occurrence. We also recommend a survey of invertebrate diversity in grasstrees and leaf litter with a comparison to A. argentus prey. The data presented here illustrates how critical detailed monitoring is for planning habitat management and fire regimes, and highlights the utility of a high-resolution approach to habitat mapping. While a traditional approach to fire management contends that pyrodiversity encourages biodiversity, the present study demonstrates that some species prefer long-unburnt habitat. Additionally, in predicting the distribution of rare species like A. argentus, data quality (i.e., spatial resolution) may prevail over data quantity (i.e., number of data).
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Affiliation(s)
- Eugene D. Mason
- Earth, Environmental and Biological Sciences School, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Jennifer Firn
- Earth, Environmental and Biological Sciences School, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Harry B. Hines
- Queensland Museum, South Brisbane, Qld, Australia
- Queensland Parks and Wildlife Service, Department of National Parks, Sport and Racing, Level 19, Brisbane, Queensland, Australia
| | - Andrew M. Baker
- Earth, Environmental and Biological Sciences School, Queensland University of Technology, Brisbane, Queensland, Australia
- Queensland Museum, South Brisbane, Qld, Australia
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10
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Knight K. Charred remains trigger torpor in antechinus survivors. J Exp Biol 2017. [DOI: 10.1242/jeb.154385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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