Abundance estimation of unmarked animals based on camera‐trap data

Conservation Biology, Journal Year: 2020, Volume and Issue: 35(1), P. 88 - 100

Published: April 16, 2020

The rapid improvement of camera traps in recent decades has revolutionized biodiversity monitoring. Despite clear applications conservation science, have seldom been used to model the abundance unmarked animal populations. We sought summarize challenges facing estimation animals, compile an overview existing analytical frameworks, and provide guidance for practitioners seeking a suitable method. When records multiple detections animal, one cannot determine whether images represent mobile individuals or single individual repeatedly entering viewshed. Furthermore, movement obfuscates definition sampling area and, as result, which estimate corresponds. Recognizing these challenges, we identified 6 approaches reviewed 927 camera-trap studies published from 2014 2019 assess use prevalence each Only about 5% any abundance-estimation methods identified. Most estimated local covariate relationships rather than predicting density over broader areas. Next, approach, compiled data requirements, assumptions, advantages, disadvantages help navigate landscape methods. appropriate method, should evaluate life history focal taxa, carefully define frame, consider what types collection are possible. challenge estimating populations persists; although exist, no method is optimal under all circumstances. As frameworks continue evolve animals becomes increasingly common, will become even more important informing decision-making.Estimación de la Abundancia Animales No Marcados con Base en Datos Cámaras Trampa Resumen La rápida mejoría las cámaras trampa décadas recientes ha revolucionado el monitoreo biodiversidad. A pesar su clara aplicación ciencias conservación, han sido utilizadas pocas veces para modelar abundancia poblaciones animales marcados. Buscamos resumir los retos que enfrenta estimación marcados, compilar una perspectiva general marcos analíticos trabajo existentes y proporcionar guía aquellos practicantes buscan un método adecuado. Cuando cámara registra múltiples detecciones se puede determinar si imágenes representan diferentes individuos movimiento o solo individuo entra repetidamente zona visión cámara. Sumado esto, ofusca definición del área muestreo y, como resultado, cual corresponde estimado abundancia. Después reconocer estos retos, identificamos seis estrategias analíticas revisamos estudios publicados entre evaluar uso prevalencia cada método. Solamente usó cualquiera métodos identificamos. mayoría estimaron relaciones covarianza lugar predecir densidad lo largo áreas más amplias. Después, estrategia analítica, recopilamos requerimientos datos, suposiciones, ventajas desventajas ayudar navegar paisaje busquen apropiado deberán historia vida taxón focal, definir cuidadosamente marco considerar cuáles tipos recolección datos son posibles. El reto estimar marcados persiste; aunque existan muchos métodos, hay único óptimo cumpla todas circunstancias. Mientras sigan evolucionando sea vez común, serán todavía importantes informar toma decisiones conservación.近几十年来红外相机陷阱技术的快速发展已经彻底改变了生物多样性监测的现状。尽管红外相机陷阱法在动物保护科学中有明确的应用, 但它很少被用来模拟无标记动物的种群数量。本研究旨在总结无标记动物的丰度估计所面临的挑战, 总结现有的分析框架并为寻求合适方法的实践者提供指导意见。当红外相机多次记录到无标记的动物时, 人们无法确定这些图像代表的是多个个体还是一个重复进入相机拍摄范围的个体。此外, 动物的运动导致不能清晰地划定采样区域, 因此也模糊了所对应区域的丰度估计。面对这些挑战, 我们确定了六种分析方法, 并综述了 年至 年发表的 项红外相机陷阱研究, 以评估每种方法的使用情况和流行程度。结果发现, 只有约 的研究使用了至少一种我们确定的丰度估计方法。这些研究大多是估计局部丰度或协变量关系, 而不是预测更大范围内的动物丰度或密度。接下来, 我们总结了每种分析方法的数据需求、假设、优点和缺点, 以帮助实践者了解丰度估计方法的总体情况。实践者在寻找合适的方法时, 应评估研究所关注类群的生活史, 谨慎地确定采样范围, 并考虑可能收集到的数据类型。无标记动物的种群数量估计仍面临挑战, 虽然已存在多种方法, 但没有一种方法对于所有红外相机陷阱数据都是最优的。随着分析框架的不断发展和对无标记动物数量估计变得越来越普遍, 红外相机陷阱法在为指导保护决策中也将更加重要。【翻译: 胡怡思; 审校: 聂永刚】.

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Designing studies of predation risk for improved inference in carnivore-ungulate systems

Biological Conservation, Journal Year: 2019, Volume and Issue: 232, P. 194 - 207

Published: Feb. 16, 2019

Quantifying both the lethal and non-lethal (or “risk”) effects of predation has emerged as a major research focus in carnivore-ungulate systems. While numerous studies have examined risk recent decades, lack standardization approaches impeded progress field. We provide an overview five study design considerations involved assessing responses prey systems, highlighting how different choices can impact strength scope inference. First, we stress importance distinguishing measures (probability being killed) from (costs antipredator behaviors response to risk). Second, recommend explicit consideration spatial temporal scales using standardized framework facilitate cross-study comparisons. Third, ungulates use visual, auditory, olfactory sensory pathways evaluate risk. Experiments that manipulate signals (e.g., auditory playbacks or application predator scent) be powerful approaches, but dosages types cues need carefully considered. Fourth, usually face threats multiple predators simultaneously, highlight potential for remote cameras structural equation modeling help address this challenge. Fifth, emerging technologies may substantially improve our ability assess discuss several promising technologies, such animal-borne video, unmanned aerial vehicles, physiological sensors. conclude with general recommendations design, which utility conservation management

Language: Английский

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Indigenous‐led research on traditional territories highlights the impacts of forestry harvest practices on culturally important plants

Earth stewardship., Journal Year: 2025, Volume and Issue: 2(1)

Published: Feb. 1, 2025

Abstract Indigenous knowledge and governance are critical to successful conservation Peoples' ability live sustainably on their lands. However, various industrial land use practices impact the value traditional resources these lands provide. Here, we evaluated effects of harvest, glyphosate application, fire 51 edible medicinal plant species identified by Peoples in western boreal forest Canada, a landscape rapid industrialized change. We collected vegetation data between 2007 2020 used linear models machine learning model richness abundance species. Glyphosate application harvest best explained Despite our models' indication that were higher harvested treated study sites, detailed qualitative based local suggest forestry negatively impacted plants. Importantly, plants areas with unsuitable for human consumption exhibited abnormal color flavor presentations. Concerns over access increasingly important as impacts continue expand globally. Thus, hope this Indigenous‐led design leveraging both quantitative can result partnerships better reflect environmental concerns Peoples.

Language: Английский

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Density‐dependent space use affects interpretation of camera trap detection rates

Ecology and Evolution, Journal Year: 2019, Volume and Issue: 9(24), P. 14031 - 14041

Published: Nov. 22, 2019

Abstract Camera traps (CTs) are an increasingly popular tool for wildlife survey and monitoring. Estimating relative abundance in unmarked species is often done using detection rate as index of abundance, which assumes that has a positive linear relationship with true abundance. This assumption may be violated if movement behavior varies density, but the degree to density‐dependent across taxa unclear. The potential confounding population‐level indices by would depend on how regularly, what magnitude, home‐range size vary density. We conducted systematic review meta‐analysis quantify relationships between rate, size, terrestrial mammalian taxa. then simulated animal movements CT sampling test effect contrasting scenarios indices. Overall, were negatively correlated density positively one another. strength varied significantly populations. In simulations, rates related underestimated change, particularly slower moving small home ranges. situations where space use changes markedly we estimate up thirty percent change missed due movement, making trend estimation more difficult. common remains constant densities therefore wide range mammal species. When studying rates, researchers managers should explicitly consider such reflect both movement. Practitioners interpreting camera aware observed differences biased low Further information or methods do not assumptions density‐independent required make robust inferences population trends.

Language: Английский

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Response of wildlife communities to human activities in the distribution area of the North China Leopard

Global Ecology and Conservation, Journal Year: 2024, Volume and Issue: 51, P. e02872 - e02872

Published: March 1, 2024

Currently, human activities are among the most important factors affecting distribution of wildlife, and conservationists around world working to uncover true impact on wildlife. With rapid disappearance tigers wolves in North China recent decades, leopards have become only top predators. However, responses including leopards, leopard areas remain unknown. This study systematically quantified disturbance village distance as gradient variables measure intensity activities, community threshold analysis was used analyze response wildlife communities area. The results showed that had effects community. There were different thresholds for 19 species, activities. findings show reasonable control activity according (0.14 times/day) may be beneficial result will help clarify role umbrella species conservation. ecological can provide reliable development scientific management policies

Language: Английский

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Mammal seismic line use varies with restoration: Applying habitat restoration to species at risk conservation in a working landscape

Biological Conservation, Journal Year: 2019, Volume and Issue: 241, P. 108295 - 108295

Published: Nov. 20, 2019

Language: Английский

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Extirpation despite regulation? Environmental assessment and caribou

Conservation Science and Practice, Journal Year: 2020, Volume and Issue: 2(4)

Published: March 14, 2020

Abstract Many caribou populations in Canada face extirpation despite dozens of provincial and federal legislative instruments designed to protect them. How are industrial developments that impact justified permitted governments' commitments protection? Toward an answer, this paper scrutinizes approval process for major projects Canada: environmental assessment (EA). We identify 65 EAs with potentially significant adverse impacts caribou—all but one were approved. The results show most approved on the basis proposed mitigation measures promise render effects “insignificant”; yet effectiveness is largely unknown. Further, several even though insufficient, citing public or national interest. Finally, some projects' rested part scientific claims project area already degraded absent caribou. Based these findings, EA failing caribou, acting as a means by which state licenses pretense protection. failure stems from broader tension within manifests EA: between state's roles promoting economic growth protecting against growth's negative effects. Recognition needs be more central conservation biology.

Language: Английский

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Predator control alters wolf interactions with prey and competitor species over the diel cycle

Oikos, Journal Year: 2022, Volume and Issue: 2022(8)

Published: May 13, 2022

Predator control remains one of the most common strategies for conservation threatened prey species. Despite significant and ongoing efforts to reduce predator populations, little is known about impacts on behaviour interactions target non‐target species following numerical potentially behavioural suppression predators. We used camera‐trap data collected before after an intensive wolf program in northeastern Alberta's boreal forest evaluate changes activity patterns overlap wolves, competitors prey. hypothesized wolves would shift their toward increased nocturnality avoid diurnal efforts, thereby cause a cascade where other maintain temporal segregation from wolves. Wolves shifted into nighttime control, reducing with other, mostly diurnal, members community. Decreases between indicates reduced potential ungulate large competitor may therefore not only release top down regulation competition predators, but also through de‐coupling overlap, effects interactions. Understanding indirect such as both provides insight disruptions top–down associated that shape community structure.

Language: Английский

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Boreal Caribou Can Coexist with Natural but Not Industrial Disturbances

Journal of Wildlife Management, Journal Year: 2020, Volume and Issue: 84(8), P. 1435 - 1444

Published: Aug. 7, 2020

ABSTRACT For species at risk, it is important that demographic models be consistent with our most recent knowledge because alternate model versions can have differing predictions for wildlife and natural resource management. To establish maintain this consistency, we compare predicted values to current or past observations knowledge. When novel predictor information becomes available, testing consistency between modeled observed ensures the best are used robust, evidence‐based, We combine on extent of historical disturbance regimes (industrial fire) an existing predict projected demographics woodland caribou ( Rangifer tarandus ). Exploring 6 simulation experiments across 5 populations in Alberta, Canada, identify relative importance industrial disturbance, fire, population density size growth rate. confirm onset significant declines all began approximately 30 years ago, demonstrate these been consistent, conclude they more likely due from oil gas sector within contemporary ranges than fire regimes. These findings reinforce research cause declines. Testing prescribed recovery paramount assessing declines, projecting trends, refining strategies effective provide a method conducting tests. © 2020 The Authors. Journal Wildlife Management published by Wiley Periodicals LLC behalf Society.

Language: Английский

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Boreal predator co‐occurrences reveal shared use of seismic lines in a working landscape

Ecology and Evolution, Journal Year: 2020, Volume and Issue: 10(3), P. 1678 - 1691

Published: Jan. 30, 2020

Abstract Interspecific interactions are an integral aspect of ecosystem functioning that may be disrupted in increasingly anthropocentric world. Industrial landscape change creates a novel playing field on which these take place, and key question for wildlife managers is whether how species able to coexist such working landscapes. Using camera traps deployed northern Alberta, we surveyed boreal predators determine interspecific affected occurrences black bears ( Ursus americanus ), coyotes Canis latrans lynx Lynx canadensis ) within disturbed by networks seismic lines (corridors cut exploration oil gas reserves). We tested hypotheses across one spatial‐only two spatiotemporal (daily weekly) scales. Specifically, hypothesized (1) avoid competition with the apex predator, gray wolf lupus (2) they each other as intraguild competitors, (3) overlap their prey. All three overlapped wolves at least scale, although models daily weekly scale had substantial unexplained variance. None showed avoidance competitors or These results show patterns predator space use consistent both facilitative shared responses unmeasured ecological cues. Our study provides insight into relation other, highlights management indirectly influence multiple through interactions.

Language: Английский

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