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Young HS, McCauley FO, Micheli F, Dunbar RB, McCauley DJ. Shortened food chain length in a fished versus unfished coral reef. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2024; 34:e3002. [PMID: 38840322 DOI: 10.1002/eap.3002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 02/23/2024] [Accepted: 04/09/2024] [Indexed: 06/07/2024]
Abstract
Direct exploitation through fishing is driving dramatic declines of wildlife populations in ocean environments, particularly for predatory and large-bodied taxa. Despite wide recognition of this pattern and well-established consequences of such trophic downgrading on ecosystem function, there have been few empirical studies examining the effects of fishing on whole system trophic architecture. Understanding these kinds of structural impacts is especially important in coral reef ecosystems-often heavily fished and facing multiple stressors. Given the often high dietary flexibility and numerous functional redundancies in diverse ecosystems such as coral reefs, it is important to establish whether web architecture is strongly impacted by fishing pressure or whether it might be resilient, at least to moderate-intensity pressure. To examine this question, we used a combination of bulk and compound-specific stable isotope analyses measured across a range of predatory and low-trophic-level consumers between two coral reef ecosystems that differed with respect to fishing pressure but otherwise remained largely similar. We found that even in a high-diversity system with relatively modest fishing pressure, there were strong reductions in the trophic position (TP) of the three highest TP consumers examined in the fished system but no effects on the TP of lower-level consumers. We saw no evidence that this shortening of the affected food webs was being driven by changes in basal resource consumption, for example, through changes in the spatial location of foraging by consumers. Instead, this likely reflected internal changes in food web architecture, suggesting that even in diverse systems and with relatively modest pressure, human harvest causes significant compressions in food chain length. This observed shortening of these food webs may have many important emergent ecological consequences for the functioning of ecosystems impacted by fishing or hunting. Such important structural shifts may be widespread but unnoticed by traditional surveys. This insight may also be useful for applied ecosystem managers grappling with choices about the relative importance of protection for remote and pristine areas and the value of strict no-take areas to protect not just the raw constituents of systems affected by fishing and hunting but also the health and functionality of whole systems.
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Affiliation(s)
- Hillary S Young
- Department of Ecology, Evolution and Marine Biology, UC Santa Barbara, Santa Barbara, California, USA
| | | | - Fiorenza Micheli
- Oceans Department, Hopkins Marine Station, and Stanford Center for Ocean Solutions, Stanford University, Pacific Grove, California, USA
| | - Robert B Dunbar
- Oceans Department and Earth Systems Science, Stanford University, Pacific Grove, California, USA
| | - Douglas J McCauley
- Department of Ecology, Evolution and Marine Biology, UC Santa Barbara, Santa Barbara, California, USA
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2
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Toszogyova A, Smyčka J, Storch D. Mathematical biases in the calculation of the Living Planet Index lead to overestimation of vertebrate population decline. Nat Commun 2024; 15:5295. [PMID: 38906876 PMCID: PMC11192898 DOI: 10.1038/s41467-024-49070-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 05/22/2024] [Indexed: 06/23/2024] Open
Abstract
The Living Planet Index (LPI) measures the average change in population size of vertebrate species over recent decades and has been repeatedly used to assess the changing state of nature. The LPI indicates that vertebrate populations have decreased by almost 70% over the last 50 years. This is in striking contrast with current studies based on the same population time series data that show that increasing and decreasing populations are balanced on average. Here, we examine the methodological pipeline of calculating the LPI to search for the source of this discrepancy. We find that the calculation of the LPI is biased by several mathematical issues which impose an imbalance between detected increasing and decreasing trends and overestimate population declines. Rather than indicating that vertebrate populations do not substantially change, our findings imply that we need better measures for providing a balanced picture of current biodiversity changes. We also show some modifications to improve the reliability of the LPI.
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Affiliation(s)
- Anna Toszogyova
- Center for Theoretical Study, Charles University & Czech Academy of Sciences, CZ-110 00, Prague, Czech Republic.
| | - Jan Smyčka
- Center for Theoretical Study, Charles University & Czech Academy of Sciences, CZ-110 00, Prague, Czech Republic
| | - David Storch
- Center for Theoretical Study, Charles University & Czech Academy of Sciences, CZ-110 00, Prague, Czech Republic
- Department of Ecology, Faculty of Science, Charles University, CZ-128 44, Prague, Czech Republic
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3
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Lamb CT, Williams S, Boutin S, Bridger M, Cichowski D, Cornhill K, DeMars C, Dickie M, Ernst B, Ford A, Gillingham MP, Greene L, Heard DC, Hebblewhite M, Hervieux D, Klaczek M, McLellan BN, McNay RS, Neufeld L, Nobert B, Nowak JJ, Pelletier A, Reid A, Roberts AM, Russell M, Seip D, Seip C, Shores C, Steenweg R, White S, Wittmer HU, Wong M, Zimmerman KL, Serrouya R. Effectiveness of population-based recovery actions for threatened southern mountain caribou. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2024; 34:e2965. [PMID: 38629596 DOI: 10.1002/eap.2965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 10/12/2023] [Accepted: 12/20/2023] [Indexed: 06/04/2024]
Abstract
Habitat loss is affecting many species, including the southern mountain caribou (Rangifer tarandus caribou) population in western North America. Over the last half century, this threatened caribou population's range and abundance have dramatically contracted. An integrated population model was used to analyze 51 years (1973-2023) of demographic data from 40 southern mountain caribou subpopulations to assess the effectiveness of population-based recovery actions at increasing population growth. Reducing potential limiting factors on threatened caribou populations offered a rare opportunity to identify the causes of decline and assess methods of recovery. Southern mountain caribou abundance declined by 51% between 1991 and 2023, and 37% of subpopulations were functionally extirpated. Wolf reduction was the only recovery action that consistently increased population growth when applied in isolation, and combinations of wolf reductions with maternal penning or supplemental feeding provided rapid growth but were applied to only four subpopulations. As of 2023, recovery actions have increased the abundance of southern mountain caribou by 52%, compared to a simulation with no interventions. When predation pressure was reduced, rapid population growth was observed, even under contemporary climate change and high levels of habitat loss. Unless predation is reduced, caribou subpopulations will continue to be extirpated well before habitat conservation and restoration can become effective.
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Affiliation(s)
- Clayton T Lamb
- Wildlife Science Center, Biodiversity Pathways, Kelowna, British Columbia, Canada
- Department of Biology, University of British Columbia, Kelowna, British Columbia, Canada
| | - Sara Williams
- Wildlife Biology Program, University of Montana, Missoula, Montana, USA
| | - Stan Boutin
- Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Michael Bridger
- Ministry of Water, Land and Resource Stewardship, Government of British Columbia, Victoria, British Columbia, Canada
| | | | - Kristina Cornhill
- Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Craig DeMars
- Wildlife Science Center, Biodiversity Pathways, Kelowna, British Columbia, Canada
| | - Melanie Dickie
- Wildlife Science Center, Biodiversity Pathways, Kelowna, British Columbia, Canada
- Department of Biology, University of British Columbia, Kelowna, British Columbia, Canada
| | - Bevan Ernst
- Ministry of Water, Land and Resource Stewardship, Government of British Columbia, Victoria, British Columbia, Canada
| | - Adam Ford
- Wildlife Science Center, Biodiversity Pathways, Kelowna, British Columbia, Canada
- Department of Biology, University of British Columbia, Kelowna, British Columbia, Canada
| | - Michael P Gillingham
- Ecosystem Science and Management, University of Northern British Columbia, Prince George, British Columbia, Canada
| | - Laura Greene
- Ministry of Water, Land and Resource Stewardship, Government of British Columbia, Victoria, British Columbia, Canada
| | - Douglas C Heard
- Tithonus Wildlife Research, Prince George, British Columbia, Canada
| | - Mark Hebblewhite
- Wildlife Biology Program, University of Montana, Missoula, Montana, USA
| | - Dave Hervieux
- Alberta Environment and Protected Areas, Government of Alberta, Grande Prairie, Alberta, Canada
| | - Mike Klaczek
- Ministry of Forests, Government of British Columbia, Victoria, British Columbia, Canada
| | - Bruce N McLellan
- International Union for the Conservation of Nature Bear Specialist Group, D'Arcy, British Columbia, Canada
| | - R Scott McNay
- Wildlife Infometrics Inc., Mackenzie, British Columbia, Canada
| | | | - Barry Nobert
- Alberta Environment and Protected Areas, Government of Alberta, Grande Prairie, Alberta, Canada
| | | | - Agnès Pelletier
- Ministry of Water, Land and Resource Stewardship, Government of British Columbia, Victoria, British Columbia, Canada
| | - Aaron Reid
- Ministry of Water, Land and Resource Stewardship, Government of British Columbia, Victoria, British Columbia, Canada
| | - Anne-Marie Roberts
- Ministry of Water, Land and Resource Stewardship, Government of British Columbia, Victoria, British Columbia, Canada
| | - Mike Russell
- Alberta Environment and Protected Areas, Government of Alberta, Grande Prairie, Alberta, Canada
| | - Dale Seip
- Ministry of Environment, Government of British Columbia, Fort St. John, British Columbia, Canada
| | - Caroline Seip
- Alberta Environment and Protected Areas, Government of Alberta, Grande Prairie, Alberta, Canada
| | - Carolyn Shores
- Ministry of Water, Land and Resource Stewardship, Government of British Columbia, Victoria, British Columbia, Canada
| | - Robin Steenweg
- Canadian Wildlife Service, Environment and Climate Change Canada, Kelowna, British Columbia, Canada
| | - Shane White
- Ministry of Forests, Government of British Columbia, Victoria, British Columbia, Canada
| | - Heiko U Wittmer
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Mark Wong
- Ministry of Water, Land and Resource Stewardship, Government of British Columbia, Victoria, British Columbia, Canada
| | - Kathryn L Zimmerman
- Ministry of Water, Land and Resource Stewardship, Government of British Columbia, Victoria, British Columbia, Canada
| | - Robert Serrouya
- Wildlife Science Center, Biodiversity Pathways, Kelowna, British Columbia, Canada
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4
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Callaghan CT, Santini L, Spake R, Bowler DE. Population abundance estimates in conservation and biodiversity research. Trends Ecol Evol 2024; 39:515-523. [PMID: 38508923 DOI: 10.1016/j.tree.2024.01.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 01/24/2024] [Accepted: 01/29/2024] [Indexed: 03/22/2024]
Abstract
Measuring and tracking biodiversity from local to global scales is challenging due to its multifaceted nature and the range of metrics used to describe spatial and temporal patterns. Abundance can be used to describe how a population changes across space and time, but it can be measured in different ways, with consequences for the interpretation and communication of spatiotemporal patterns. We differentiate between relative and absolute abundance, and discuss the advantages and disadvantages of each for biodiversity monitoring, conservation, and ecological research. We highlight when absolute abundance can be advantageous and should be prioritized in biodiversity monitoring and research, and conclude by providing avenues for future research directions to better assess the necessity of absolute abundance in biodiversity monitoring.
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Affiliation(s)
- Corey T Callaghan
- Department of Wildlife Ecology and Conservation, Fort Lauderdale Research and Education Center, University of Florida, Davie, FL 33314-7719, USA.
| | - Luca Santini
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, Rome, Italy
| | - Rebecca Spake
- School of Biological Sciences, University of Reading, Reading RG6 6AS, UK
| | - Diana E Bowler
- UK Centre for Ecology and Hydrology, Wallingford, OX10 8BB, UK
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5
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Greenspoon L, Rosenberg Y, Meiri S, Roll U, Noor E, Milo R. Reply to Santini et al.: Total population reports are necessary for global biomass estimation of wild mammals. Proc Natl Acad Sci U S A 2024; 121:e2316314121. [PMID: 38227657 PMCID: PMC10823233 DOI: 10.1073/pnas.2316314121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2024] Open
Affiliation(s)
- Lior Greenspoon
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Yuval Rosenberg
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Shai Meiri
- School of Zoology, Tel-Aviv University, Tel-Aviv6997801, Israel
- The Steinhardt Museum of Natural History, Tel Aviv University, Tel-Aviv6997801, Israel
| | - Uri Roll
- Mitrani Department of Desert Ecology, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, 8499000, Israel
| | - Elad Noor
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Ron Milo
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, 76100 Rehovot, Israel
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6
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Dornelas M, Chase JM, Gotelli NJ, Magurran AE, McGill BJ, Antão LH, Blowes SA, Daskalova GN, Leung B, Martins IS, Moyes F, Myers-Smith IH, Thomas CD, Vellend M. Looking back on biodiversity change: lessons for the road ahead. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220199. [PMID: 37246380 PMCID: PMC10225864 DOI: 10.1098/rstb.2022.0199] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 03/24/2023] [Indexed: 05/30/2023] Open
Abstract
Estimating biodiversity change across the planet in the context of widespread human modification is a critical challenge. Here, we review how biodiversity has changed in recent decades across scales and taxonomic groups, focusing on four diversity metrics: species richness, temporal turnover, spatial beta-diversity and abundance. At local scales, change across all metrics includes many examples of both increases and declines and tends to be centred around zero, but with higher prevalence of declining trends in beta-diversity (increasing similarity in composition across space or biotic homogenization) and abundance. The exception to this pattern is temporal turnover, with changes in species composition through time observed in most local assemblages. Less is known about change at regional scales, although several studies suggest that increases in richness are more prevalent than declines. Change at the global scale is the hardest to estimate accurately, but most studies suggest extinction rates are probably outpacing speciation rates, although both are elevated. Recognizing this variability is essential to accurately portray how biodiversity change is unfolding, and highlights how much remains unknown about the magnitude and direction of multiple biodiversity metrics at different scales. Reducing these blind spots is essential to allow appropriate management actions to be deployed. This article is part of the theme issue 'Detecting and attributing the causes of biodiversity change: needs, gaps and solutions'.
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Affiliation(s)
- Maria Dornelas
- Centre for Biological Diversity, University of St Andrews, St Andrews KY16 9TH, UK
- Guia Marine Laboratory, MARE, Faculdade de Ciencias da Universidade de Lisboa, Cascais 2750-374, Portugal
- Leverhulme Centre for Anthropocene Biodiversity, Department of Biology, University of York, Wentworth Way, York YO10 5DD, UK
| | - Jonathan M. Chase
- German Centre for Integrative Biodiversity Research (iDiv), Halle-Jena-Leipzig 04103, Germany
- Department of Computer Sciences, Martin Luther University, Halle-Wittenberg 06099, Germany
| | | | - Anne E Magurran
- Centre for Biological Diversity, University of St Andrews, St Andrews KY16 9TH, UK
| | - Brian J McGill
- School of Biology and Ecology and Mitchell Center for Sustainability Solutions, University of Maine, Orono, ME, USA
| | - Laura H. Antão
- Research Centre for Ecological Change, Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki,Finland
| | - Shane A. Blowes
- German Centre for Integrative Biodiversity Research (iDiv), Halle-Jena-Leipzig 04103, Germany
- Department of Computer Sciences, Martin Luther University, Halle-Wittenberg 06099, Germany
| | - Gergana N. Daskalova
- International Institute for Applied Systems Analysis (IIASA), Laxenburg 2361, Austria
| | - Brian Leung
- Department of Biology, McGill University, Montreal, Canada H3A 1B1
| | - Inês S. Martins
- Centre for Biological Diversity, University of St Andrews, St Andrews KY16 9TH, UK
- Leverhulme Centre for Anthropocene Biodiversity, Department of Biology, University of York, Wentworth Way, York YO10 5DD, UK
| | - Faye Moyes
- Centre for Biological Diversity, University of St Andrews, St Andrews KY16 9TH, UK
| | | | - Chris D Thomas
- Leverhulme Centre for Anthropocene Biodiversity, Department of Biology, University of York, Wentworth Way, York YO10 5DD, UK
| | - Mark Vellend
- Leverhulme Centre for Anthropocene Biodiversity, Department of Biology, University of York, Wentworth Way, York YO10 5DD, UK
- Département de biologie, Université de Sherbrooke, Québec, Canada J1K 2R1
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7
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Gregory RD, Eaton MA, Burfield IJ, Grice PV, Howard C, Klvaňová A, Noble D, Šilarová E, Staneva A, Stephens PA, Willis SG, Woodward ID, Burns F. Drivers of the changing abundance of European birds at two spatial scales. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220198. [PMID: 37246375 DOI: 10.1098/rstb.2022.0198] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 01/16/2023] [Indexed: 05/30/2023] Open
Abstract
Detecting biodiversity change and identifying its causes is challenging because biodiversity is multifaceted and temporal data often contain bias. Here, we model temporal change in species' abundance and biomass by using extensive data describing the population sizes and trends of native breeding birds in the United Kingdom (UK) and the European Union (EU). In addition, we explore how species' population trends vary with species' traits. We demonstrate significant change in the bird assemblages of the UK and EU, with substantial reductions in overall bird abundance and losses concentrated in a relatively small number of abundant and smaller sized species. By contrast, rarer and larger birds had generally fared better. Simultaneously, overall avian biomass had increased very slightly in the UK and was stable in the EU, indicating a change in community structure. Abundance trends across species were positively correlated with species' body mass and with trends in climate suitability, and varied with species' abundance, migration strategy and niche associations linked to diet. Our work highlights how changes in biodiversity cannot be captured easily by a single number; care is required when measuring and interpreting biodiversity change given that different metrics can provide very different insights. This article is part of the theme issue 'Detecting and attributing the causes of biodiversity change: needs, gaps and solutions'.
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Affiliation(s)
- Richard D Gregory
- RSPB Centre for Conservation Science, Sandy, Befordshire SG19 2DL, UK
- Centre for Biodiversity and Environment Research, Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK
| | | | - Ian J Burfield
- BirdLife International, Cambridge, Cambridgeshire CB2 3QZ, UK
| | - Philip V Grice
- Chief Scientist Directorate, Natural England, Peterborough PE2 8YY, UK
| | - Christine Howard
- Conservation Ecology Group, Department of Biosciences, Durham University, South Road, Durham, County Durham DH1 3LE, UK
| | - Alena Klvaňová
- Czech Society for Ornithology, 150 00 Prague 5, Czech Republic
| | - David Noble
- British Trust for Ornithology, The Nunnery, Thetford, Norfolk IP24 2PU, UK
| | - Eva Šilarová
- Czech Society for Ornithology, 150 00 Prague 5, Czech Republic
| | - Anna Staneva
- BirdLife International, Cambridge, Cambridgeshire CB2 3QZ, UK
| | - Philip A Stephens
- Conservation Ecology Group, Department of Biosciences, Durham University, South Road, Durham, County Durham DH1 3LE, UK
| | - Stephen G Willis
- Conservation Ecology Group, Department of Biosciences, Durham University, South Road, Durham, County Durham DH1 3LE, UK
| | - Ian D Woodward
- British Trust for Ornithology, The Nunnery, Thetford, Norfolk IP24 2PU, UK
| | - Fiona Burns
- RSPB Centre for Conservation Science, Cambridge CB2 3QZ, UK
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8
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Chen X, Pu H, He Y, Lai M, Zhang D, Chen J, Pu H. An Efficient Method for Monitoring Birds Based on Object Detection and Multi-Object Tracking Networks. Animals (Basel) 2023; 13:ani13101713. [PMID: 37238144 DOI: 10.3390/ani13101713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 05/14/2023] [Accepted: 05/16/2023] [Indexed: 05/28/2023] Open
Abstract
To protect birds, it is crucial to identify their species and determine their population across different regions. However, currently, bird monitoring methods mainly rely on manual techniques, such as point counts conducted by researchers and ornithologists in the field. This method can sometimes be inefficient, prone to errors, and have limitations, which may not always be conducive to bird conservation efforts. In this paper, we propose an efficient method for wetland bird monitoring based on object detection and multi-object tracking networks. First, we construct a manually annotated dataset for bird species detection, annotating the entire body and head of each bird separately, comprising 3737 bird images. We also built a new dataset containing 11,139 complete, individual bird images for the multi-object tracking task. Second, we perform comparative experiments using a state-of-the-art batch of object detection networks, and the results demonstrated that the YOLOv7 network, trained with a dataset labeling the entire body of the bird, was the most effective method. To enhance YOLOv7 performance, we added three GAM modules on the head side of the YOLOv7 to minimize information diffusion and amplify global interaction representations and utilized Alpha-IoU loss to achieve more accurate bounding box regression. The experimental results revealed that the improved method offers greater accuracy, with mAP@0.5 improving to 0.951 and mAP@0.5:0.95 improving to 0.815. Then, we send the detection information to DeepSORT for bird tracking and classification counting. Finally, we use the area counting method to count according to the species of birds to obtain information about flock distribution. The method described in this paper effectively addresses the monitoring challenges in bird conservation.
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Affiliation(s)
- Xian Chen
- College of Information Engineering, Sichuan Agricultural University, Ya'an 625000, China
| | - Hongli Pu
- College of Information Engineering, Sichuan Agricultural University, Ya'an 625000, China
| | - Yihui He
- College of Information Engineering, Sichuan Agricultural University, Ya'an 625000, China
| | - Mengzhen Lai
- College of Information Engineering, Sichuan Agricultural University, Ya'an 625000, China
| | - Daike Zhang
- College of Information Engineering, Sichuan Agricultural University, Ya'an 625000, China
| | - Junyang Chen
- College of Information Engineering, Sichuan Agricultural University, Ya'an 625000, China
| | - Haibo Pu
- College of Information Engineering, Sichuan Agricultural University, Ya'an 625000, China
- Ya'an Digital Agricultural Engineering Technology Research Center, Ya'an 625000, China
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9
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Tulloch AIT, Jackson MV, Bayraktarov E, Carey AR, Correa-Gomez DF, Driessen M, Gynther IC, Hardie M, Moseby K, Joseph L, Preece H, Suarez-Castro AF, Stuart S, Woinarski JCZ, Possingham HP. Effects of different management strategies on long-term trends of Australian threatened and near-threatened mammals. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2023; 37:e14032. [PMID: 36349543 DOI: 10.1111/cobi.14032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 08/16/2022] [Accepted: 10/25/2022] [Indexed: 06/16/2023]
Abstract
Monitoring is critical to assess management effectiveness, but broadscale systematic assessments of monitoring to evaluate and improve recovery efforts are lacking. We compiled 1808 time series from 71 threatened and near-threatened terrestrial and volant mammal species and subspecies in Australia (48% of all threatened mammal taxa) to compare relative trends of populations subject to different management strategies. We adapted the Living Planet Index to develop the Threatened Species Index for Australian Mammals and track aggregate trends for all sampled threatened mammal populations and for small (<35 g), medium (35-5500 g), and large mammals (>5500 g) from 2000 to 2017. Unmanaged populations (42 taxa) declined by 63% on average; unmanaged small mammals exhibited the greatest declines (96%). Populations of 17 taxa in havens (islands and fenced areas that excluded or eliminated introduced red foxes [Vulpes vulpes] and domestic cats [Felis catus]) increased by 680%. Outside havens, populations undergoing sustained predator baiting initially declined by 75% but subsequently increased to 47% of their abundance in 2000. At sites where predators were not excluded or baited but other actions (e.g., fire management, introduced herbivore control) occurred, populations of small and medium mammals declined faster, but large mammals declined more slowly, than unmanaged populations. Only 13% of taxa had data for both unmanaged and managed populations; index comparisons for this subset showed that taxa with populations increasing inside havens declined outside havens but taxa with populations subject to predator baiting outside havens declined more slowly than populations with no management and then increased, whereas unmanaged populations continued to decline. More comprehensive and improved monitoring (particularly encompassing poorly represented management actions and taxonomic groups like bats and small mammals) is required to understand whether and where management has worked. Improved implementation of management for threats other than predation is critical to recover Australia's threatened mammals.
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Affiliation(s)
- Ayesha I T Tulloch
- School of Biology and Environmental Science, Queensland University of Technology, Brisbane, Queensland, Australia
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
- Centre for Biodiversity and Conservation Science, The University of Queensland, St. Lucia, Queensland, Australia
| | - Micha V Jackson
- Centre for Biodiversity and Conservation Science, The University of Queensland, St. Lucia, Queensland, Australia
| | - Elisa Bayraktarov
- Centre for Biodiversity and Conservation Science, The University of Queensland, St. Lucia, Queensland, Australia
- Research, Specialised and Data Foundations, Digital Solutions, Griffith University, Nathan, Queensland, Australia
| | - Alexander R Carey
- Saving our Species Program, Department of the Environment, Sydney, New South Wales, Australia
- Research Institute for the Environment and Livelihoods, Charles Darwin University, Casuarina, Northern Territory, Australia
| | - Diego F Correa-Gomez
- Centre for Biodiversity and Conservation Science, The University of Queensland, St. Lucia, Queensland, Australia
| | - Michael Driessen
- Conservation Science Section, Natural Resources and Environment Tasmania, Hobart, Tasmania, Australia
| | - Ian C Gynther
- Department of Environment and Science, Moggill, Queensland, Australia
- Biodiversity and Geosciences Program, Queensland Museum, South Brisbane, Queensland, Australia
| | - Mel Hardie
- Department of Environment, Land, Water and Planning, Melbourne, Victoria, Australia
| | - Katherine Moseby
- Arid Recovery, Roxby Downs, South Australia, Australia
- School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Liana Joseph
- Australian Wildlife Conservancy, Subiaco East, Western Australia, Australia
| | - Harriet Preece
- Department of Environment and Science, Dutton Park, Queensland, Australia
| | - Andrés Felipe Suarez-Castro
- Centre for Biodiversity and Conservation Science, The University of Queensland, St. Lucia, Queensland, Australia
- Australian Rivers Institute, Griffith University, Nathan, Queensland, Australia
| | - Stephanie Stuart
- Saving our Species Program, Department of the Environment, Sydney, New South Wales, Australia
| | - John C Z Woinarski
- Research Institute for the Environment and Livelihoods, Charles Darwin University, Casuarina, Northern Territory, Australia
| | - Hugh P Possingham
- Centre for Biodiversity and Conservation Science, The University of Queensland, St. Lucia, Queensland, Australia
- The Nature Conservancy, Arlington, Virginia, USA
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10
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We need to talk about nonprobability samples. Trends Ecol Evol 2023; 38:521-531. [PMID: 36775795 DOI: 10.1016/j.tree.2023.01.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 01/13/2023] [Accepted: 01/17/2023] [Indexed: 02/12/2023]
Abstract
In most circumstances, probability sampling is the only way to ensure unbiased inference about population quantities where a complete census is not possible. As we enter the era of 'big data', however, nonprobability samples, whose sampling mechanisms are unknown, are undergoing a renaissance. We explain why the use of nonprobability samples can lead to spurious conclusions, and why seemingly large nonprobability samples can be (effectively) very small. We also review some recent controversies surrounding the use of nonprobability samples in biodiversity monitoring. These points notwithstanding, we argue that nonprobability samples can be useful, provided that their limitations are assessed, mitigated where possible and clearly communicated. Ecologists can learn much from other disciplines on each of these fronts.
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Cox DTC, Gardner AS, Gaston KJ. Diel niche variation in mammalian declines in the Anthropocene. Sci Rep 2023; 13:1031. [PMID: 36658287 PMCID: PMC9852540 DOI: 10.1038/s41598-023-28104-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 01/12/2023] [Indexed: 01/20/2023] Open
Abstract
Biodiversity is being eroded worldwide. Many human pressures are most forcefully exerted or have greatest effect during a particular period of the day. Therefore when species are physically active (their diel niche) may influence their risk of population decline. We grouped 5032 terrestrial extant mammals by their dominant activity pattern (nocturnal, crepuscular, cathemeral and diurnal), and determine variation in population decline across diel niches. We find an increased risk of population decline in diurnal (52.1% of species), compared to nocturnal (40.1% of species), crepuscular (39.1% of species) and cathemeral (43.0% of species) species, associated with the larger proportion of diurnal mammals that are primates. Those species with declining populations whose activity predominantly coincides with that of humans (cathemeral, diurnal) face an increased number of anthropogenic threats than those principally active at night, with diurnal species more likely to be declining from harvesting. Across much of the land surface habitat loss is the predominant driver of population decline, however, harvesting is a greater threat to day-active species in sub-Saharan Africa and mainland tropical Asia, associated with declines in megafauna and arboreal foragers. Deepening understanding of diel variation in anthropogenic pressures and resulting population declines will help target conservation actions.
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Affiliation(s)
- Daniel T C Cox
- Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall, TR10 9FE, UK.
| | - Alexandra S Gardner
- Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall, TR10 9FE, UK
| | - Kevin J Gaston
- Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall, TR10 9FE, UK
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Albaladejo‐Robles G, Böhm M, Newbold T. Species life-history strategies affect population responses to temperature and land-cover changes. GLOBAL CHANGE BIOLOGY 2023; 29:97-109. [PMID: 36250232 PMCID: PMC10092366 DOI: 10.1111/gcb.16454] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 07/24/2022] [Accepted: 08/27/2022] [Indexed: 06/01/2023]
Abstract
Human-induced environmental changes have a direct impact on species populations, with some species experiencing declines while others display population growth. Understanding why and how species populations respond differently to environmental changes is fundamental to mitigate and predict future biodiversity changes. Theoretically, species life-history strategies are key determinants shaping the response of populations to environmental impacts. Despite this, the association between species life histories and the response of populations to environmental changes has not been tested. In this study, we analysed the effects of recent land-cover and temperature changes on rates of population change of 1,072 populations recorded in the Living Planet Database. We selected populations with at least 5 yearly consecutive records (after imputation of missing population estimates) between 1992 and 2016, and for which we achieved high population imputation accuracy (in the cases where missing values had to be imputed). These populations were distributed across 553 different locations and included 461 terrestrial amniote vertebrate species (273 birds, 137 mammals, and 51 reptiles) with different life-history strategies. We showed that populations of fast-lived species inhabiting areas that have experienced recent expansion of cropland or bare soil present positive populations trends on average, whereas slow-lived species display negative population trends. Although these findings support previous hypotheses that fast-lived species are better adapted to recover their populations after an environmental perturbation, the sensitivity analysis revealed that model outcomes are strongly influenced by the addition or exclusion of populations with extreme rates of change. Therefore, the results should be interpreted with caution. With climate and land-use changes likely to increase in the future, establishing clear links between species characteristics and responses to these threats is fundamental for designing and conducting conservation actions. The results of this study can aid in evaluating population sensitivity, assessing the likely conservation status of species with poor data coverage, and predicting future scenarios of biodiversity change.
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Affiliation(s)
- Gonzalo Albaladejo‐Robles
- Centre for Biodiversity and Environment Research, Department of Genetics, Evolution and EnvironmentUniversity College LondonLondonUK
- Institute of ZoologyZoological Society of LondonLondonUK
| | - Monika Böhm
- Institute of ZoologyZoological Society of LondonLondonUK
- Global Center for Species SurvivalIndianapolisIndianaUSA
| | - Tim Newbold
- Centre for Biodiversity and Environment Research, Department of Genetics, Evolution and EnvironmentUniversity College LondonLondonUK
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Currie J, Burant JB, Marconi V, Blain SA, Emry S, Hébert K, Xie G, Moore NA, Wang X, Brown A, Grevstad L, McRae L, Mezzini S, Pata P, Freeman R. Assessing the representation of species included within the Canadian Living Planet Index. Facets (Ott) 2022. [DOI: 10.1139/facets-2022-0063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To effectively combat the biodiversity crisis, we need ambitious targets and reliable indicators to accurately track trends and measure conservation impact. In Canada, the Living Planet Index (LPI) has been adapted to produce a national indicator by both World Wildlife Fund-Canada (Canadian Living Planet Index; C-LPI) and Environment and Climate Change Canada (Canadian Species Index) to provide insight into the status of Canadian wildlife, by evaluating temporal trends in vertebrate population abundance. The indicator includes data for just over 50% of Canadian vertebrate species. To assess whether the current dataset is representative of the distribution of life history characteristics of Canadian wildlife, we analyzed the representation of species-specific biotic variables (i.e., body size, trophic level, lifespan) for vertebrates within the C-LPI compared to native vertebrates lacking LPI data. Generally, there was considerable overlap in the distribution of biotic variables for species in the C-LPI compared to native Canadian vertebrate species lacking LPI data. Nevertheless, some differences among distributions were found, driven in large part by discrepancy in the representation of fishes—where the C-LPI included larger-bodied and longer-lived species. We provide recommendations for targeted data collection and additional analyses to further strengthen the applicability, accuracy, and representativity of biodiversity indicators.
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Affiliation(s)
- Jessica Currie
- World Wildlife Fund Canada, 410 Adelaide Street West, Toronto ON M5V 1S8, Canada
| | - Joseph B. Burant
- Department of Biology, McGill University, 1205 Docteur Penfield Avenue, Montreal QC H3A 1B1, Canada
- Département de sciences biologiques, Université de Montréal, 1375 Avenue Thérèse-Lavoie-Roux, Montréal QC H2V 0B3, Canada
- Living Data Project, Canadian Institute of Ecology and Evolution, Vancouver BC V6T 124, Canada
| | - Valentina Marconi
- Indicators and Assessments Unit, Institute of Zoology, Zoological Society of London, Regent’s Park, London NW1 4RY, United Kingdom
- Department of Life Sciences (Silwood Park), Imperial College London, Buckhurst Road, Ascot, Berkshire SL5 7PY, United Kingdom
| | - Stephanie A. Blain
- Department of Zoology and Biodiversity Research Centre, University of British Columbia, 6270 University Boulevard, Vancouver BC V6T 1Z4, Canada
| | - Sandra Emry
- Department of Zoology and Biodiversity Research Centre, University of British Columbia, 6270 University Boulevard, Vancouver BC V6T 1Z4, Canada
| | - Katherine Hébert
- Département de biologie, Université de Sherbrooke, 2500 Boulevard de l’Université, Sherbrooke QC J1K 2R1, Canada
| | - Garland Xie
- Department of Biological Sciences, University of Toronto Scarborough, Toronto ON M1C 1A4, Canada
| | - Nikki A. Moore
- Department of Biology, McGill University, 1205 Docteur Penfield Avenue, Montreal QC H3A 1B1, Canada
| | - Xueqi Wang
- Department of Integrative Biology, University of Guelph, 50 Stone Road East, Guelph ON N1G 2W1, Canada
| | - Andrea Brown
- Department of Biology, McGill University, 1205 Docteur Penfield Avenue, Montreal QC H3A 1B1, Canada
| | - Lara Grevstad
- Department of Geography, University of British Columbia, 2329 West Mall, Vancouver BC V6T 1Z4, Canada
| | - Louise McRae
- Indicators and Assessments Unit, Institute of Zoology, Zoological Society of London, Regent’s Park, London NW1 4RY, United Kingdom
| | - Stefano Mezzini
- Department of Biology, University of British Columbia, 1177 Research Road, Kelowna BC V1V 1V7, Canada
| | - Patrick Pata
- Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, 2207 Main Mall, Vancouver BC V6T 1Z4, Canada
| | - Robin Freeman
- Department of Integrative Biology, University of Guelph, 50 Stone Road East, Guelph ON N1G 2W1, Canada
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