Abstracts of Recently Published Papers on Wildlife and Habitat Conservation
We selected a range of new scientific, peer-reviewed papers and thesis submissions. Scan the abstracts for an overview. Links to the original papers are provided. Check also additions to the Conservation Frontlines library for more recent material.
A rare 300-kilometer dispersal by an adult male white-tailed deer. 2021. Remington J. Moll, Jon T. McRoberts, Joshua J. Millspaugh, Kevyn H. Wiskirchen, Jason A. Sumners, Jason L. Isabelle, Barbara J. Keller & Robert A. Montgomery. Ecology and Evolution. 2021; 00:1–11. https://doi.org/10.1002/ece3.7354
Abstract: Despite the key roles that dispersal plays in individual animal fitness and meta-population gene flow, it remains one of the least understood behaviors in many species. In large mammalian herbivores, dispersals might span long distances and thereby influence landscape-level ecological processes, such as infectious disease spread. Here, we describe and analyze an exceptional long-distance dispersal by an adult white-tailed deer (Odocoileus virginianus) in the central United States. We also conducted a literature survey to compare the dispersal to previous studies. This dispersal was remarkable for its length, duration, and the life history stage of the dispersing individual. Dispersal is typical of juvenile deer seeking to establish postnatal home ranges, but this dispersal was undertaken by an adult male (age = 3.5). This individual dispersed ~300 km over a 22-day period by moving, on average, 13.6 km/day and achieving a straight-line distance of ~215 km, which was ~174 km longer than any other distance recorded for an adult male deer in our literature survey. During the dispersal, which occurred during the hunting season, the individual crossed a major river seven times, an interstate highway, a railroad, and eight state highways. Movements during the dispersal were faster (mean = 568.1 m/h) and more directional than those during stationary home range periods before and after the dispersal (mean = 56.9 m/h). Likewise, movements during the dispersal were faster (mean = 847.8 m/h) and more directional at night than during the day (mean = 166.4 m/h), when the individual frequently sheltered in forest cover. This natural history event highlights the unpredictable nature of dispersal and has important implications for landscape-level processes such as chronic wasting disease transmission in cervids. More broadly, our study underscores how integrating natural history observations with modern technology holds promise for understanding potentially high impact but rarely recorded ecological events.
The need for a more inclusive science of elephant conservation. 2020. Lin Cassidy and Jonathan Salerno. Conservation Letters 2020;13:e12717. https://doi.org/10.1111/conl.12717
Abstract: Largely absent from the current scientific dialog is recognition of which voices should contribute to decisions on the future of Africa’s elephants, particularly those living in the Kavango‐Zambezi Transfrontier Conservation Area. We argue that elephant conservation policy must take into account the voices of the people bearing the cost of living with wildlife, as well as the nations with the responsibility of hosting elephant populations. Southern African elephant conservation is a ‘wicked problem’, which is best addressed through small wins approaches. Specifically, research on changes in local political and governance dynamics resulting from community conservation programs is needed, to identify new modalities for community level engagement. Additionally, research into policy implications, as well as seasonal resource needs of humans and wildlife, from zoning and corridor development to facilitate landscape level movement is needed. A modular approach to research for ensuring functional social–ecological landscapes within the KAZA context could help sustain both wildlife and communities in the region.
Using very‐high‐resolution satellite imagery and deep learning to detect and count African elephants in heterogeneous landscapes. 2020.Isla Duporge, Olga Isupova, Steven Reece, David W. Macdonald & Tiejun Wang. https://doi.org/10.1002/rse2.195
Abstract: Satellites allow large‐scale surveys to be conducted in short time periods with repeat surveys possible at intervals of <24 h. Very‐high‐resolution satellite imagery has been successfully used to detect and count a number of wildlife species in open, homogeneous landscapes and seascapes where target animals have a strong contrast with their environment. However, no research to date has detected animals in complex heterogeneous environments or detected elephants from space using very‐high‐resolution satellite imagery and deep learning. In this study, we apply a Convolution Neural Network (CNN) model to automatically detect and count African elephants in a woodland savanna ecosystem in South Africa. We use WorldView‐3 and 4 satellite data –the highest resolution satellite imagery commercially available. We train and test the model on 11 images from 2014 to 2019. We compare the performance accuracy of the CNN against human accuracy. Additionally, we apply the model on a coarser resolution satellite image (GeoEye‐1) captured in Kenya, without any additional training data, to test if the algorithm can generalize to an elephant population outside of the training area. Our results show that the CNN performs with high accuracy, comparable to human detection capabilities. The detection accuracy (i.e., F2 score) of the CNN models was 0.78 in heterogeneous areas and 0.73 in homogenous areas. This compares with the detection accuracy of the human labels with an averaged F2 score 0.77 in heterogeneous areas and 0.80 in homogenous areas. The CNN model can generalize to detect elephants in a different geographical location and from a lower resolution satellite. Our study demonstrates the feasibility of applying state‐of‐the‐art satellite remote sensing and deep learning technologies for detecting and counting African elephants in heterogeneous landscapes. The study showcases the feasibility of using high resolution satellite imagery as a promising new wildlife surveying technique. Through creation of a customized training dataset and application of a Convolutional Neural Network, we have automated the detection of elephants in satellite imagery with accuracy as high as human detection capabilities. The success of the model to detect elephants outside of the training data site demonstrates the generalizability of the technique.
Ecological Effects of Wolves in Anthropogenic Landscapes: The Potential for Trophic Cascades Is Context-Dependent. 2021. Giorgia Ausilio, Håkan Sand, Johan Månsson, Karen Marie Mathisen and Camilla Wikenros. Front. Ecol. Evol. 8:577963. doi:10.3389/fevo.2020.577963.
Abstract: In recent years, large predators have made a comeback across large parts of Europe. However, little is known about the impact that recolonizing predators may have on ecosystems with high degrees of anthropogenic influence. In Scandinavia, wolves (Canis lupus) now inhabit areas affected by intense forestry practices and their main prey, moose (Alces alces), are exposed to significant human hunting pressure. We used long-term datasets to investigate whether the return of wolves has affected moose distribution (i.e., presence and abundance) as well as browsing damage (i.e., presence and intensity) by moose on Scots pine (Pinus sylvestris). We found that the probability of moose presence and abundance increased with time since wolf territory establishment and was higher inside wolf territories than outside. Additionally, the probability of browsing damage was also higher inside wolf territories compared to outside, but wolf occurrence had no effect on browsing damage intensity. We suggest two possible underlying mechanisms behind these results: (1) wolves might select to establish territories in areas with higher moose abundance, increasing their probability of encounters, and/or (2) hunters within wolf territories reduce the number of harvested moose to compensate for wolf predation. This study highlights that the return of large predators to landscapes with strong anthropogenic influence may result in alternative effects than those described in studies on trophic cascades located in protected areas.
Food System Impacts on Biodiversity Loss: Three levers for food system transformation in support of nature. 2021. Tim G. Benton, Carling Bieg, Helen Harwatt, Roshan Pudasaini and Laura Wellesley. Chatham House, The Royal Institute of International Affairs, 2021.
Summary: This paper explores the role of the global food system as the principal driver of accelerating biodiversity loss. It explains how food production is degrading or destroying natural habitats and contributing to species extinction. The paper outlines the challenges and trade-offs involved in redesigning food systems to restore biodiversity and/or prevent further biodiversity loss and presents recommendations for action. The paper introduces three ‘levers’ for reducing pressures on land and creating a more sustainable food system. The first is to change dietary patterns to reduce food demand and encourage more plant-based diets. The second is to protect and set aside land for nature, whether through re-establishing native ecosystems on spared farmland or integrating pockets of natural habitat into farmland. The third is to shift to more sustainable farming. All three levers will be needed for food system redesign to succeed. Our recommendations for action are based around a series of major summits and conferences on food systems, climate, biological diversity, nutrition and related areas scheduled in 2021. These offer a unique opportunity for a ‘food systems approach’ to become embedded in international policy processes.
Consequences of recreational hunting for biodiversity conservation and livelihoods. 2021. Enrico Di Minin, Hayley S. Clements, Ricardo A. Correia, Gonzalo Cortés-Capano, Christoph Fink, Anna Haukka, Anna Hausmann, Ritwik Kulkarni & Corey J.A. Bradshaw. One Earth, Volume 4, Issue 2, P238-253, February 19, 2021. doi: 10.1016/j.oneear.2021.01.014
Summary: The widespread activity of recreational hunting is proposed as a means of conserving nature and supporting livelihoods. However, recreational hunting—especially trophy hunting—has come under increasing scrutiny based on ethical concerns and the arguments that it can threaten species and fail to contribute meaningfully to local livelihoods. We provide an overview of the peer-reviewed literature on recreational hunting of terrestrial birds and mammals between 1953 and 2020 (>1,000 papers). The most-studied species are large mammals from North America, Europe, and Africa. While there is extensive research on species’ ecology to inform sustainable hunting practices, there is comparably little research on the role of local perceptions and institutions in determining socioeconomic and conservation outcomes. Evidence is lacking to answer the pressing questions of where and how hunting contributes to just and sustainable conservation efforts. We outline an agenda to build this evidence base through research that recognizes diverse social-ecological contexts.
Identifying priority areas for restoring mountain ungulates in the Caucasus ecoregion. 2020. Tobias Kuemmerle, Hendrik Bluhm, Arash Ghoddousi, Marine Arakelyan, Elshad Askerov, Benjamin Bleyhl, Mamikon Ghasabian, Alexander Gavashelishvili, Aurel Heidelberg, Alexander Malkhasyan, Karen Manvelyan, Mahmood Soofi, Yuriy Yarovenko, Paul Weinberg and Nugzar Zazanashvili. Conservation Science and Practice. September 2020. DOI: 10.1111/csp2.276
Abstract: Mountain ungulates around the world have been decimated to small, fragmented populations. Restoring these species often is limited by inadequate information on where suitable habitat is found, and which restoration measures would help to increase and link existing populations. We developed an approach to spatially target threat-specific restoration actions and demonstrate it for bezoar goats (Capra aegagrus) in the Caucasus. Using a large occurrence dataset, we identified suitable habitat patches and evaluate them in terms of connectivity, protection status, and competition with other mountain ungulates. We found extant bezoar goat populations to be highly isolated, yet with widespread areas of suitable, unoccupied habitat between them. Many unoccupied habitat patches were well-connected to extant populations, were at least partly protected, and have low potential for competition with other Capra species. This signals substantial pressure on bezoar goats, likely due to poaching, which currently prevents natural recolonization. Our study shows how restoration planning is possible in the face of multiple threats and scarce data. For bezoar goats in the Caucasus, we pinpoint priority patches for specific restoration measures, including reintroductions and anti-poaching action. We highlight that many patches would benefit from multiple interventions and that transboundary restoration planning is needed, a situation likely similar for many mountain ungulates around the world.
PARKS. The International Journal of Protected Areas and Conservation, Volume 27 (Special Issue on COVID‐19 and Protected and Conserved Areas). 2021. Edited by Adrian Phillips and Brent A. Mitchell, IUCN World Commission on Protected Areas, IUCN WCPA (2021)., Gland, Switzerland. ISSN 2411-2119 (Online), ISSN 0960-233X (Print). DOI.10.2305/IUCN.CH.2021PARKS-27SI.en
Abstract: This special issue of PARKS is devoted to the impact and implications of COVID-19 on the world’s protected and conserved areas. It describes how 11 peer reviewed papers and 14 essays have brought together the knowledge and findings of numerous experts from all parts of the world, supported by several wide-ranging surveys. The resulting global synthesis of experience answers some key questions: why did the pandemic occur? what has it meant for protected and conserved areas, and the people that depend on them? what were the underlying reasons for the disaster we now face? and how can we avoid this happening again? We applaud the international effort to combat the disease but suggest that humanity urgently needs to devote as much effort to addressing the root causes of the pandemic—our fractured relationship to nature. Unless we repair it, humanity will face consequences even worse than this pandemic.