The 2019–2020 megafires in Australia brought a tragic loss of human life and the most dramatic loss of habitat for threatened species and devastation of ecological communities in postcolonial ...history. What must be done now to keep impacted species from extinction? What can be done to avoid a repeat of the impacts of such devastating bushfires? Here, we describe hard-won lessons that may also be of global relevance.
Animal mortality during fire Jolly, Chris J.; Dickman, Chris R.; Doherty, Tim S. ...
Global change biology,
March 2022, Letnik:
28, Številka:
6
Journal Article
Recenzirano
Earth's rapidly warming climate is propelling us towards an increasingly fire‐prone future. Currently, knowledge of the extent and characteristics of animal mortality rates during fire remains ...rudimentary, hindering our ability to predict how animal populations may be impacted in the future. To address this knowledge gap, we conducted a global systematic review of the direct effects of fire on animal mortality rates, based on studies that unequivocally determined the fate of animals during fire. From 31 studies spanning 1984–2020, we extracted data on the direct impacts of fire on the mortality of 31 species from 23 families. From these studies, there were 43 instances where direct effects were measured by reporting animal survival from pre‐ to post‐fire. Most studies were conducted in North America (52%) and Oceania (42%), focused largely on mammals (53%) and reptiles (30%), and reported mostly on animal survival in planned (82%) and/or low severity (70%) fires. We found no studies from Asia, Europe or South America. Although there were insufficient data to conduct a formal meta‐analysis, we tested the effect of fire type, fire severity, fire regime, animal body mass, ecological attributes and class on survival. Only fire severity affected animal mortality, with a higher proportion of animals being killed by high than low severity fires. Recent catastrophic fires across the globe have drawn attention to the plight of animals exposed to wildfire. Yet, our systematic review suggests that a relatively low proportion of animals (mean predicted mortality 95% CI = 3% 1%–9%) are killed during fire. However, our review also underscores how little we currently know about the direct effects of fire on animal mortality, and highlights the critical need to understand the effects of high severity fire on animal populations.
Our understanding of animal mortality rates during fire is rudimentary. Here, we conducted a global systematic review of the direct effects of fire on animal mortality rates. From 31 studies spanning 1984–2020, we extracted data on the direct impacts of fire on the mortality of 31 species from 23 families. Our systematic review suggests that a relatively low proportion of animals (3% 1%–9%) are killed during fire. However, our review also underscores how little we currently know about the direct effects of fire on animal mortality, and highlights the critical need to understand the effects of high severity fire on animal populations.
One of the key gaps in understanding the impacts of predation by small mammalian predators on prey is how habitat structure affects the hunting success of small predators, such as feral cats. These ...effects are poorly understood due to the difficulty of observing actual hunting behaviours. We attached collar-mounted video cameras to feral cats living in a tropical savanna environment in northern Australia, and measured variation in hunting success among different microhabitats (open areas, dense grass and complex rocks). From 89 hours of footage, we recorded 101 hunting events, of which 32 were successful. Of these kills, 28% were not eaten. Hunting success was highly dependent on microhabitat structure surrounding prey, increasing from 17% in habitats with dense grass or complex rocks to 70% in open areas. This research shows that habitat structure has a profound influence on the impacts of small predators on their prey. This has broad implications for management of vegetation and disturbance processes (like fire and grazing) in areas where feral cats threaten native fauna. Maintaining complex vegetation cover can reduce predation rates of small prey species from feral cat predation.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Fire has shaped ecological communities worldwide for millennia, but impacts of fire on individual species are often poorly understood. We performed a meta‐analysis to predict which traits, habitat, ...or study variables and fire characteristics affect how mammal species respond to fire. We modeled effect sizes of measures of population abundance or occupancy as a function of various combinations of these traits and variables with phylogenetic least squares regression. Nine of 115 modeled species (7.83%) returned statistically significant effect sizes, suggesting most mammals are resilient to fire. The top‐ranked model predicted a negative impact of fire on species with lower reproductive rates, regardless of fire type (estimate = –0.68), a positive impact of burrowing in prescribed fires (estimate = 1.46) but not wildfires, and a positive impact of average fire return interval for wildfires (estimate = 0.93) but not prescribed fires. If a species’ International Union for Conservation of Nature Red List assessment includes fire as a known or possible threat, the species was predicted to respond negatively to wildfire relative to prescribed fire (estimate = –2.84). These findings provide evidence of experts’ abilities to predict whether fire is a threat to a mammal species and the ability of managers to meet the needs of fire‐threatened species through prescribed fire. Where empirical data are lacking, our methods provide a basis for predicting mammal responses to fire and thus can guide conservation actions or interventions in species or communities.
Modelos de las respuestas de los mamíferos a los incendios basados en las características de la especie
Resumen
Durante milenios, los incendios han moldeado a las comunidades ecológicas en todo el mundo y aun así conocemos muy poco sobre el impacto que tienen sobre cada especie. Realizamos un metaanálisis para predecir cuáles características, hábitat o variable de estudio en conjunto con las características del incendio afectan la respuesta de los mamíferos ante este fenómeno. Usamos para modelar los tamaños del efecto de las medidas de la abundancia poblacional o la ocupación como función de varias combinaciones de estas características y variables mediante una regresión filogenética por mínimos cuadrados. Nueve de las 115 especies modeladas (7.83%) devolvieron tamaños del efecto con importancia estadística, lo que sugiere que la mayoría de los mamíferos son resilientes a los incendios. El modelo mejor clasificado pronosticó un impacto negativo de los incendios sobre las especies con tasas reproductivas más bajas, sin importar el tipo de incendio (estimado = ‐0.68); un impacto positivo de las madrigueras durante las quemas prescritas (estimado = 1.46) pero no durante los incendios forestales; y un impacto positivo del intervalo promedio de rendimiento del incendio para los incendios forestales (estimado = 0.93) pero no para las quemas prescritas. Si la valoración de una especie en la Lista Roja de la Unión Internacional para la Conservación de la Naturaleza incluye a los incendios como una amenaza conocida o posible, pronosticamos que la especie respondería negativamente a los incendios forestales con relación a la quema prescrita (estimado = ‐2.84). Estos hallazgos proporcionan evidencia de la habilidad que tienen los expertos para predecir si los incendios son una amenaza para los mamíferos y la habilidad de los gestores para cumplir con las necesidades de las especies amenazadas por incendios por medio de las quemas prescritas. En caso de que falte información empírica, nuestros métodos proporcionan una base para predecir las respuestas de los mamíferos a los incendios y así orientar a las acciones o intervenciones de conservación para una especie o comunidad.
【摘要】
几千年来, 火灾塑造了全球的生态群落, 但火灾对单个物种的影响往往尚不清楚。本研究通过荟萃分析预测了影响哺乳动物响应火灾的物种特征、栖息地或研究变量和火灾特征。我们用系统发育最小二乘回归法模拟了种群丰度或占域率作为这些特征和变量各种组合的函数的效应量。在我们分析的 115 个物种中, 有 9 个 (7.83%) 物种可以得到具有统计学意义的效应量, 这表明大多数哺乳动物面对火灾都具有恢复力。排名第一的模型预测火灾对繁殖率较低的物种有负面影响, 且与火灾类型无关 (估计值为−0.68), 计划火烧对穴居动物有积极影响 (估计值为1.46), 但野火没有;野火对平均火灾间隔有积极影响 (估计值=0.93), 但计划火烧没有。如果一个物种的《国际自然保护联盟红色名录》评估中将火灾作为已知或可能的威胁, 则预测结果中该物种对野火相对于计划火烧有负面响应 (估计值为−2.84) 。这些发现证明专家有能力预测火灾是否对哺乳动物物种构成威胁, 以及管理者有能力通过计划火烧满足受火灾威胁的物种的需求。在缺乏经验数据的情况下, 我们的方法可以为预测哺乳动物对火灾的响应提供基础, 从而指导物种或群落的保护行动或干预措施。【翻译: 胡怡思; 审校: 聂永刚】
Intensification of fires and grazing by large herbivores has caused population declines in small vertebrates in many ecosystems worldwide. Impacts are rarely direct, and usually appear driven via ...indirect pathways, such as changes to predator-prey dynamics. Fire events and grazing may improve habitat and/or hunting success for the predators of small mammals, however, such impacts have not been documented. To test for such an interaction, we investigated fine-scale habitat selection by feral cats in relation to fire, grazing and small-mammal abundance. Our study was conducted in north-western Australia, where small mammal populations are sensitive to changes in fire and grazing management. We deployed GPS collars on 32 cats in landscapes with contrasting fire and grazing treatments. Fine-scale habitat selection was determined using discrete choice modelling of cat movements. We found that cats selected areas with open grass cover, including heavily-grazed areas. They strongly selected for areas recently burnt by intense fires, but only in habitats that typically support high abundance of small mammals. Intense fires and grazing by introduced herbivores created conditions that are favoured by cats, probably because their hunting success is improved. This mechanism could explain why, in northern Australia, impacts of feral cats on small mammals might have increased. Our results suggest the impact of feral cats could be reduced in most ecosystems by maximising grass cover, minimising the incidence of intense fires, and reducing grazing by large herbivores.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Extinctions typically have ecological drivers, such as habitat loss. However, extinction events are also influenced by policy and management settings that may be antithetical to biodiversity ...conservation, inadequate to prevent extinction, insufficiently resourced, or poorly implemented. Three endemic Australian vertebrate species—the Christmas Island pipistrelle (Pipistrellus murrayi), Bramble Cay melomys (Melomys tuhicob), and Christmas Island forest skink (Emoia mtivitatis)—became extinct from 2009 to 2014. All 3 extinctions were predictable and probably preventable. We sought to identify the policy, management, research, and other shortcomings that contributed to their extinctions or failed to prevent them. These included a lack within national environmental legislation and policy of explicit commitment to the prevention of avoidable extinctions, lack of explicit accountability, inadequate resources for conservation (particularly for species not considered charismatic or not of high taxonomic distinctiveness), inadequate biosecurity, a slow and inadequate process for listing species as threatened, recovery planning that failed to consider the need for emergency response, inability of researchers to identify major threatening factors, lack of public engagement and involvement in conservation decisions, and limited advocacy. From these 3 cases, we recommend: environmental policy explicitly seeks to prevent extinction of any species and provides a clear chain of accountability and an explicit requirement for public inquiry following any extinction; implementation of a timely and comprehensive process for listing species as threatened and for recovery planning; reservation alone not be assumed sufficient to maintain species; enhancement of biosecurity measures; allocation of sufficient resources to undertake actions necessary to prevent extinction; monitoring be considered a pivotal component of the conservation response; research provides timely identification of factors responsible for decline and of the risk of extinction; effective dissemination of research results; advocacy by an informed public for the recovery of threatened species; and public involvement in governance of the recovery process. These recommendations should be applicable broadly to reduce the likelihood and incidence of extinctions. Las extinciones tienen comúnmente conductores ecológicos, como la pérdida de hábitat. Sin embargo, los eventos de extinción también tienen influencia de la política y los ambientes de manejo que pueden ser anti-éticos para la conservación de la biodiversidad, inadecuados para prevenir la extinción, tener fondos insuficientes o estar implementados pobremente. Tres especies de vertebrados endémicos de Australia - el murciélago de Isla Navidad (Pipistrellus murrayi), el melomys de Cayo Bramble (Melomys rubicola) y el eslizón de bosque de Isla Navidad (Emoia nativitatis) - se extinguieron entre 2009 y 2014. Las tres extinciones fueron predecibles y probablemente prevenibles. Buscamos identificar la política, la administración, la investigación y otros defectos que contribuyeron a su extinción o que fallaron en prevenirlas. Los factores que contribuyeron a estas extinciones incluyen la carencia de un compromiso explícito con la prevención de las extinciones evitables dentro de la legislación ambiental nacional y la política, la carencia de una responsabilidad explícita, los recursos inadecuados para la conservación (particularmente para las especies que no son consideradas carismáticas o que no tienen una diferencia taxonómica alta), la bioseguridad inadecuada, el proceso lento e inadecuado para enlistar a las especies como amenazadas, la planeación de la recuperación que falló en considerar la necesidad de una respuesta de emergencia, la incapacidad de los investigadores de identificar factores de amenaza mayores, la falta de un compromiso público y la participación en las decisiones de conservación, y la defensa limitada. A partir de estos tres casos de extinción recomendamos una política ambiental que busque explícitamente prevenir la extinción de cualquier especie y que proporcione una cadena entendible de responsabilidad y un requerimiento explícito de la indagación pública después de cualquier extinción; la implementación de un proceso oportuno y comprensible para enlistar a las especies como amenazadas y para la planeación de la recuperación; que no se asuma que la reservación es la única forma de mantener a las especies; el mejoramiento de las medidas de bioseguridad; la asignación de suficientes recursos para llevar a cabo las acciones necesarias para prevenir la extinción; que el monitoreo no sea considerado como un componente crucial de la respuesta a la conservación; que las investigaciones proporcionen la identificación oportuna de los factores responsables de la declinación y del riesgo de extinción; la diseminación efectiva de los resultados de las investigaciones; y la defensa por parte de un público informado para la recuperación de las especies amenazadas; y la participación del público en la gobemanza del proceso de recuperación. Estas recomendaciones deberían ser aplicables de manera general para reducir la probabilidad y la incidencia de las extinciones.
Body condition may predict individual fitness because those in better condition have more resources to allocate towards improving their fitness. However, the hypothesis that condition indices are ...meaningful proxies for fitness has been questioned. Here, we ask if intraspecific variation in condition indices predicts annual reproductive success and survival. We monitored a population of Neochmia phaeton (crimson finch), a sedentary, tropical passerine, for reproductive success and survival over four breeding seasons, and sampled them for commonly used condition indices: mass adjusted for body size, muscle and fat scores, packed cell volume, hemoglobin concentration, total plasma protein, and heterophil to lymphocyte ratio. Our study population is well suited for this research because individuals forage in common areas and do not hold territories such that variation in condition between individuals is not confounded by differences in habitat quality. Furthermore, we controlled for factors that are known to impact condition indices in our study population (e.g., breeding stage) such that we assessed individual condition relative to others in the same context. Condition indices that reflect energy reserves predicted both the probability of an individual fledging young and the number of young produced that survived to independence, but only during some years. Those that were relatively heavy for their body size produced about three times more independent young compared to light individuals. That energy reserves are a meaningful predictor of reproductive success in a sedentary passerine supports the idea that energy reserves are at least sometimes predictors of fitness. However, hematological indices failed to predict reproductive success and none of the indices predicted survival. Therefore, some but not all condition indices may be informative, but because we found that most indices did not predict any component of fitness, we question the ubiquitous interpretation of condition indices as surrogates for individual quality and fitness.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
As with most governments worldwide, Australian governments list threatened species and proffer commitments to recovering them. Yet most of Australia's imperiled species continue to decline or go ...extinct and a contributing cause is inadequate investment in conservation management. However, this has been difficult to evaluate because the extent of funding committed to such recovery in Australia, like in many nations, is opaque. Here, by collating disparate published budget figures of Australian governments, we show that annual spending on targeted threatened species recovery is around U.S.$92m (AU$122m) which is around one tenth of that spent by the U.S. endangered species recovery program, and about 15% of what is needed to avoid extinctions and recover threatened species. Our approach to estimating funding needs for species recovery could be applied in any jurisdiction and could be scaled up to calculate what is needed to achieve international goals for ending the species extinction crisis.
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.
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.
Prueba experimental de la respuesta animal al tamaño y gravedad de los incendios controlados
Resumen
Los desiertos suelen contar con mucha biodiversidad y proporcionar hábitats importantes para una variedad de especies amenazadas. El fuego es una perturbación que domina en los desiertos, y los incendios controlados cada vez se usan más por los gestores de la conservación y los pueblos indígenas para mitigar los efectos dañinos del cambio climático, las plantas invasoras y el cambio de uso de suelo. El tamaño, gravedad y fragmentación de los incendios pueden afectar cómo los animales responden al fuego. Sin embargo, casi no existen estudios que analicen dichas características de la quema en los ambientes desérticos, lo que excluye a dicha información de la planeación de la conservación. Usamos una estrategia de antes‐después del control‐impacto en 20 sitios de muestreo para estudiar los resultados de diez incendios controlados de diferentes tamaños (5–267 ha), gravedad y fragmentación para identificar cuáles variables pronostican mejor los cambios en la riqueza de especies y abundancia de mamíferos pequeños y reptiles. Tres de las 13 especies mostraron una respuesta clara al incendio. Las capturas incrementaron en dos especies (una de mamífero y una de reptil) y disminuyeron en una especie (un reptil) conforme incrementó el área proporcional incendiada alrededor de las trampas. Otras dos especies de mamíferos mostraron respuestas positivas más débiles ante el fuego. El tamaño total y la fragmentación del incendio no fueron influyentes sobre los pronosticadores de cualquier especie. Los cambios en las tasas de captura ocurrieron solamente en los sitios con los incendios más graves y grandes. No observamos cambios relacionados al incendio en las tasas de captura en donde los incendios fueron pequeños y muy fragmentados. Nuestros resultados sugieren que podría haber umbrales del tamaño o gravedad del incendio que provocan las respuestas al fuego, lo que tiene consecuencias para los programas de manejo sustentados en el paradigma del mosaico de fragmentos del incendio. Los incendios controlados que estudiamos, que son típicos en escala e intensidad en muchas regiones desérticas, facilitaron la presencia de algunos taxones y no tuvieron probabilidad de tener un impacto negativo extenso o persistente sobre las comunidades de mamíferos pequeños y reptiles en este ecosistema, siempre y cuando se proteja el hábitat que lleva mucho tiempo sin incendios y en donde viven las especies amenazadas.
【摘要】
沙漠通常具有较高的生物多样性, 为许多濒危物种提供了重要栖息地。火烧是沙漠中最主要的干扰因素, 而保护管理者和原住民正越来越多地使用策略烧除来减缓气候变化、入侵植物和土地利用变化的破坏性影响。烧除的规模大小、严重程度和斑块性会影响动物对其响应。然而, 几乎没有研究分析过沙漠中这些火烧特征, 因此无法为保护规划提供信息。我们在20个取样点采用前后对照影响的方法, 研究了10次不同规模(5‐267公顷)、不同严重程度和不同斑块性的策略烧除结果, 以确定哪些变量能够最好地预测小型哺乳动物和爬行动物物种丰富度和丰度的变化。结果表明, 13个物种中有3种火烧有明显的响应。随着研究位点附近燃烧面积比例的增加, 2个物种(1种哺乳动物和1种爬行动物)被诱捕器捕获的概率增加, 而1个物种(爬行动物)的捕获率降低。另外2种哺乳动物则对火烧有较弱的积极响应。总燃烧面积和燃烧斑块性对所有物种都没有明显影响。仅在燃烧规模最大、程度最严重的位点出现了动物捕获率的变化;而在燃烧面积较小且分布非常分散的位点, 动物捕获率没有出现与火烧相关的变化。我们的研究结果表明, 动物如何响应火烧可能存在燃烧规模或严重程度方面的触发阈值, 这对以斑块镶嵌式燃烧范例为基础的管理计划具有影响。我们所研究的策略烧除的规模和强度在许多沙漠地区都很典型, 它有利于一些类群的存在, 且不太可能对这一生态系统中的小型哺乳动物或爬行动物群落产生广泛或持续的负面影响, 前提是长期未被烧毁的受威胁物种栖息地得到保护。【翻译: 胡怡思; 审校: 聂永刚】
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