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Doherty TS, Bohórquez Fandiño DF, Watchorn DJ, Legge SM, Dickman CR. Experimentally testing animal responses to prescribed fire size and severity. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2024; 38:e14231. [PMID: 38111980 DOI: 10.1111/cobi.14231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 09/23/2023] [Accepted: 10/04/2023] [Indexed: 12/20/2023]
Abstract
Deserts are often highly biodiverse and provide important habitats for many threatened species. Fire is a dominant disturbance in deserts, and prescribed burning is increasingly being used by conservation managers and Indigenous peoples to mitigate the damaging effects of climate change, invasive plants, and land-use change. The size, severity, and patchiness of fires can affect how animals respond to fire. However, there are almost no studies examining such burn characteristics in desert environments, which precludes the use of such information in conservation planning. Using a before-after control-impact approach with 20 sampling sites, we studied the outcomes of 10 prescribed burns of varying size (5-267 ha), severity, and patchiness to identify which variables best predicted changes in small mammal and reptile species richness and abundance. Three of the 13 species showed a clear response to fire. Captures increased for 2 species (1 mammal, 1 reptile) and decreased for 1 species (a reptile) as the proportional area burned around traps increased. Two other mammal species showed weaker positive responses to fire. Total burn size and burn patchiness were not influential predictors for any species. Changes in capture rates occurred only at sites with the largest and most severe burns. No fire-related changes in capture rates were observed where fires were small and very patchy. Our results suggest that there may be thresholds of fire size or fire severity that trigger responses to fire, which has consequences for management programs underpinned by the patch mosaic burning paradigm. The prescribed burns we studied, which are typical in scale and intensity across many desert regions, facilitated the presence of some taxa and are unlikely to have widespread or persistent negative impacts on small mammal or reptile communities in this ecosystem provided that long unburned habitat harboring threatened species is protected.
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Affiliation(s)
- Tim S Doherty
- School of Life and Environmental Sciences, The University of Sydney, Camperdown, New South Wales, Australia
| | - Daniel F Bohórquez Fandiño
- School of Life and Environmental Sciences, The University of Sydney, Camperdown, New South Wales, Australia
| | - Darcy J Watchorn
- School of Life and Environmental Sciences, The University of Sydney, Camperdown, New South Wales, Australia
- School of Life and Environmental Sciences (Burwood campus), Deakin University, Waurn Ponds, Victoria, Australia
| | - Sarah M Legge
- Research Institute of Environment and Livelihoods, Charles Darwin University, Casuarina, Northern Territory, Australia
- Fenner School of Society and the Environment, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Chris R Dickman
- School of Life and Environmental Sciences, The University of Sydney, Camperdown, New South Wales, Australia
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Watchorn DJ, Doherty TS, Wilson BA, Garkaklis MJ, Driscoll DA. How do invasive predators and their native prey respond to prescribed fire? Ecol Evol 2024; 14:e11450. [PMID: 38783847 PMCID: PMC11112300 DOI: 10.1002/ece3.11450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 04/30/2024] [Accepted: 05/07/2024] [Indexed: 05/25/2024] Open
Abstract
Fire shapes animal communities by altering resource availability and species interactions, including between predators and prey. In Australia, there is particular concern that two highly damaging invasive predators, the feral cat (Felis catus) and European red fox (Vulpes vulpes), increase their activity in recently burnt areas and exert greater predation pressure on the native prey due to their increased exposure. We tested how prescribed fire occurrence and extent, along with fire history, vegetation, topography, and distance to anthropogenic features (towns and farms), affected the activity (detection frequency) of cats, foxes, and the native mammal community in south-eastern Australia. We used camera traps to quantify mammal activity before and after a prescribed burn and statistically tested how the fire interacted with these habitat variables to affect mammal activity. We found little evidence that the prescribed fire influenced the activity of cats and foxes and no evidence of an effect on kangaroo or small mammal (<800 g) activity. Medium-sized mammals (800-2000 g) were negatively associated with prescribed fire extent, suggesting that prescribed fire has a negative impact on these species in the short term. The lack of a clear activity increase from cats and foxes is likely a positive outcome from a fire management perspective. However, we highlight that their response is likely dependent upon factors like fire size, severity, and prey availability. Future experiments should incorporate GPS-trackers to record fine-scale movements of cats and foxes in temperate ecosystems immediately before and after prescribed fire to best inform management within protected areas.
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Affiliation(s)
- Darcy J. Watchorn
- School of Life and Environmental Sciences (Burwood Campus)Deakin UniversityGeelongVictoriaAustralia
| | - Tim S. Doherty
- School of Life and Environmental SciencesThe University of SydneySydneyNew South WalesAustralia
- Biodiversity and Conservation ScienceDepartment of Biodiversity, Conservation and AttractionsWoodvaleWestern AustraliaAustralia
| | - Barbara A. Wilson
- School of Life and Environmental Sciences (Burwood Campus)Deakin UniversityGeelongVictoriaAustralia
| | | | - Don A. Driscoll
- School of Life and Environmental Sciences (Burwood Campus)Deakin UniversityGeelongVictoriaAustralia
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Doherty TS, Geary WL, Jolly CJ, Macdonald KJ, Miritis V, Watchorn DJ, Cherry MJ, Conner LM, González TM, Legge SM, Ritchie EG, Stawski C, Dickman CR. Fire as a driver and mediator of predator-prey interactions. Biol Rev Camb Philos Soc 2022; 97:1539-1558. [PMID: 35320881 PMCID: PMC9546118 DOI: 10.1111/brv.12853] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 03/15/2022] [Accepted: 03/16/2022] [Indexed: 01/08/2023]
Abstract
Both fire and predators have strong influences on the population dynamics and behaviour of animals, and the effects of predators may either be strengthened or weakened by fire. However, knowledge of how fire drives or mediates predator–prey interactions is fragmented and has not been synthesised. Here, we review and synthesise knowledge of how fire influences predator and prey behaviour and interactions. We develop a conceptual model based on predator–prey theory and empirical examples to address four key questions: (i) how and why do predators respond to fire; (ii) how and why does prey vulnerability change post‐fire; (iii) what mechanisms do prey use to reduce predation risk post‐fire; and (iv) what are the outcomes of predator–fire interactions for prey populations? We then discuss these findings in the context of wildlife conservation and ecosystem management before outlining priorities for future research. Fire‐induced changes in vegetation structure, resource availability, and animal behaviour influence predator–prey encounter rates, the amount of time prey are vulnerable during an encounter, and the conditional probability of prey death given an encounter. How a predator responds to fire depends on fire characteristics (e.g. season, severity), their hunting behaviour (ambush or pursuit predator), movement behaviour, territoriality, and intra‐guild dynamics. Prey species that rely on habitat structure for avoiding predation often experience increased predation rates and lower survival in recently burnt areas. By contrast, some prey species benefit from the opening up of habitat after fire because it makes it easier to detect predators and to modify their behaviour appropriately. Reduced prey body condition after fire can increase predation risk either through impaired ability to escape predators, or increased need to forage in risky areas due to being energetically stressed. To reduce risk of predation in the post‐fire environment, prey may change their habitat use, increase sheltering behaviour, change their movement behaviour, or use camouflage through cryptic colouring and background matching. Field experiments and population viability modelling show instances where fire either amplifies or does not amplify the impacts of predators on prey populations, and vice versa. In some instances, intense and sustained post‐fire predation may lead to local extinctions of prey populations. Human disruption of fire regimes is impacting faunal communities, with consequences for predator and prey behaviour and population dynamics. Key areas for future research include: capturing data continuously before, during and after fires; teasing out the relative importance of changes in visibility and shelter availability in different contexts; documenting changes in acoustic and olfactory cues for both predators and prey; addressing taxonomic and geographic biases in the literature; and predicting and testing how changes in fire‐regime characteristics reshape predator–prey interactions. Understanding and managing the consequences for predator–prey communities will be critical for effective ecosystem management and species conservation in this era of global change.
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Affiliation(s)
- Tim S Doherty
- School of Life and Environmental Sciences, Heydon-Laurence Building A08, The University of Sydney, Sydney, NSW, 2006, Australia
| | - William L Geary
- Biodiversity Strategy and Knowledge Branch, Biodiversity Division, Department of Environment, Land, Water and Planning, 8 Nicholson Street, East Melbourne, VIC, 3002, Australia.,Centre for Integrative Ecology, School of Life and Environmental Sciences (Burwood Campus), Deakin University, 75 Pigdons Road, Waurn Ponds, VIC, 3216, Australia
| | - Chris J Jolly
- School of Agricultural, Environmental and Veterinary Sciences, Charles Sturt University, Gungalman Drive, Albury, NSW, 2640, Australia.,School of Natural Sciences, G17, Macquarie University, 205B Culloden Road, Macquarie Park, NSW, 2109, Australia
| | - Kristina J Macdonald
- Centre for Integrative Ecology, School of Life and Environmental Sciences (Burwood Campus), Deakin University, 75 Pigdons Road, Waurn Ponds, VIC, 3216, Australia
| | - Vivianna Miritis
- School of Life and Environmental Sciences, Heydon-Laurence Building A08, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Darcy J Watchorn
- Centre for Integrative Ecology, School of Life and Environmental Sciences (Burwood Campus), Deakin University, 75 Pigdons Road, Waurn Ponds, VIC, 3216, Australia
| | - Michael J Cherry
- Caesar Kleberg Wildlife Research Institute, Texas A&M University-Kingsville, 700 University Boulevard, MSC 218, Kingsville, TX, 78363, U.S.A
| | - L Mike Conner
- The Jones Center at Ichauway, 3988 Jones Center Drive, Newton, GA, 39870, U.S.A
| | - Tania Marisol González
- Laboratorio de Ecología del Paisaje y Modelación de Ecosistemas ECOLMOD, Departamento de Biología, Facultad de Ciencias, Universidad Nacional de Colombia, Edificio 421, Bogotá, 111321, Colombia
| | - Sarah M Legge
- Fenner School of Environment & Society, The Australian National University, Linnaeus Way, Canberra, ACT, 2601, Australia.,Centre for Biodiversity Conservation Science, University of Queensland, Level 5 Goddard Building, St Lucia, QLD, 4072, Australia
| | - Euan G Ritchie
- Centre for Integrative Ecology, School of Life and Environmental Sciences (Burwood Campus), Deakin University, 75 Pigdons Road, Waurn Ponds, VIC, 3216, Australia
| | - Clare Stawski
- Department of Biology, Norwegian University of Science and Technology, Trondheim, NO-7491, Norway.,School of Science, Technology and Engineering, University of the Sunshine Coast, Maroochydore DC, QLD, 4558, Australia
| | - Chris R Dickman
- School of Life and Environmental Sciences, Heydon-Laurence Building A08, The University of Sydney, Sydney, NSW, 2006, Australia
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