Dr Jake Bicknell
Dr Jake Bicknell is a conservation scientist broadly interested in conservation of biodiversity throughout the globe and across taxonomic groups. Much of his work focuses on degraded tropical forests, primarily in Guyana and Borneo, but he has also conducted research across Europe, Africa and central America.
Dr Jake Bicknell is a member of the Durrell Institute of Conservation and Ecology.
Environmental change in tropical forests
- Species and assemblage responses to logging (reduced-impact logging in particular), conversion (for palm oil, mining etc), habitat fragmentation, climate change and urbanisation.
- Focus on vertebrates, in particular birds and mammals, but also fish and invertebrates such as dung beetles.
- Habitat restoration, in particular forest restoration following conversion or degradation, and the role of seed dispersers in aiding restoration (especially birds).
- Relationships between biodiversity and the provision of ecosystem services, particularly carbon in forests.
Conservation practice and policy
- Conservation planning, implementation and protected area development.
- Land-use planning to mitigate the impacts of habitat change on biodiversity. Dr Bicknell has recently focused on riparian buffers in palm oil plantations.
- Human wellbeing benefits derived from experiencing biodiversity in tropical cities.
- Environmental change in relationship to infrastructure development, and how to minimise impacts to biodiversity.
- Reconciling food production with biodiversity conservation in tropical areas.
- Bioacoustics and their use in assessing biodiversity responses to land-use change.
- The role of local communities in conserving tropical forests.
- All things conservation-related in Guyana.
- DI303: Survey and Monitoring for Biodiversity
- DI538: Data Analysis for Conservation Biologists
- DI505: Conceptual Frameworks in Conservation Science
A scholarship is currently available to work with Dr Bicknell on the project 'After the gold rush: vertebrate communities in abandoned gold mines and implications for restoration'. Further details can be found here.
Current PhD students
- Jessica Fisher (co-supervised with Professor Zoe Davies, Professor Jay Mistry and Damian Fernandes): The benefits people derive from interacting with biodiversity in urban Guyana (ESRC).
- Natalie Yoh (co-supervised with Dr Matthew Struebig): Monitoring responses of tropical vertebrates to land-use change using acoustic technologies (NERC).
Dr Bicknell is available to provide commentary on issues related to land-use change in tropical forests, particularly regarding forestry and mining, and the conservation of biodiversity.
Gardner, Charlie J., Jake E. Bicknell, William Baldwin-Cantello, Matthew J. Struebig, and Zoe G. Davies. 2019. “Quantifying the Impacts of Defaunation on Natural Forest Regeneration in a Global Meta-Analysis”. Nature Communications. Nature. doi:10.1038/s41467-019-12539-1.Intact forests provide diverse and irreplaceable ecosystem services that are critical to human well-being, such as carbon storage to mitigate climate change. However, the ecosystem functions that underpin these services are highly dependent on the woody vegetation-animal interactions occurring within forests. While vertebrate defaunation is of growing policy concern, the effects of vertebrate loss on natural forest regeneration have yet to be quantified globally. Here we conduct a meta-analysis to assess the direction and magnitude of defaunation impacts on forests. We demonstrate that real-world defaunation caused by hunting and habitat fragmentation leads to reduced forest regeneration, although manipulation experiments provide contrasting findings. The extirpation of primates and birds cause the greatest declines in forest regeneration, emphasising their key role in maintaining carbon stores, and the need for national and international climate change and conservation strategies to protect forests from defaunation fronts as well as deforestation fronts.
Padfield, Rory, Sune Hansen, Zoe G. Davies, Albrecht Ehrensperger, Eleanor M. Slade, Stephanie Evers, Effie Papargyropoulou, Cécile Bessou, Norhayati Abdullah, Susan Page, Marc Ancrenaz, Paul Aplin, Dzulkafli S Balqis, Holly Barclay, Darshanaa Chellaiah, Sonal choudhary, Samantha Conway, Sarah Cook, Alison Copeland, Ahimsa Camposarceiz, Nicolas Deere, Simon Mitchell, Simon Drew, David Gilvear, Ross Gray, Tobias Haller, Amelia S Hood, Lee K. Huat, Nhat Huynh, Nagulendran Kangayatkarasu, Lian Pin Koh, Sananth Kumaran, Robin A. Hee Lim, Yeong K. Loong, Jennifer M. Lucey, Sarah H. Luke, Marvin Montefrio, Katherine Mullin, Anand Nainar, Anna Nekaris, Vincent Nijman, Matheus nunes, Siti Nurhidayu, Patrick O’Reilly, Chong L. Puan, Nadine Ruppert, Hengky Salim, Greetje Schouten, Anne Tallontire, Thomas Smith, Hsiao-Hang Tao, Mun H Tham, Helena Varkkey, Jamie Wadey, Catherine Yule, Badrul Azhar, Alexender Sayok, Charles S. Vairappan, Jake E. Bicknell, and Matthew J. Struebig. 2019. “Co-Producing a Research Agenda for Sustainable Palm Oil”. Frontiers in Forests and Global Change. Frontiers Media. doi:10.3389/ffgc.2019.00013.The rise of palm oil as the world’s most consumed vegetable oil has coincided with exponential growth in palm oil research
activity. Bibliometric analysis of research outputs reveals a distinct imbalance in the type of research being undertaken, notably a
disproportionate focus on biofuel and engineering topics. Recognising the expansion of oil palm agriculture across the tropics and
the increasing awareness of environmental, social and economic impacts, we seek to re-orient the existing research agenda
towards one that addresses the most fundamental and urgent questions defined by the palm oil stakeholder community. Following
consultation with 659 stakeholders from 38 countries, including palm oil growers, government agencies, non-governmental
organisations and researchers, the highest priority research questions were identified within 13 themes. The resulting 279
questions, including 26 ranked as top priority, reveal a diversity of environmental and social research challenges facing the
industry, ranging from the ecological and ecosystem impacts of production, to the livelihoods of plantation workers and smallholder
communities. Analysis of the knowledge type produced from these questions underscores a clear need for fundamental science
programmes, and studies that involve the consultation of non-academic stakeholders to develop ‘transformative’ solutions to the
oil palm sector. Stakeholders were most aligned in their choice of priority questions across the themes of policy and certification
related themes, and differed the most in environmental feedback, technology and smallholder related themes. Our
recommendations include improved regional academic leadership and coordination, greater engagement with private and public
stakeholders of Africa, and Central and South America, and enhanced collaborative efforts with researchers in the major
consuming countries of India and China.
Bicknell, Jake E., Murray B. Collins, Rob S.A. Pickles, Niall P. McCann, Curtis R. Bernard, Damian J. Fernandes, Mark G.R. Miller, Samantha M. James, Aiesha U. Williams, Matthew J. Struebig, Zoe G. Davies, and Robert J. Smith. 2017. “Designing Protected Area Networks That Translate International Conservation Commitments into National Action”. Biological Conservation. Elsevier. doi:10.1016/j.biocon.2017.08.024.Most countries have committed to protect 17% of their terrestrial area by 2020 through Aichi Target 11 of the Convention on Biological Diversity, with a focus on protecting areas of particular importance for biodiversity. This means national-scale spatial conservation prioritisations are needed to help meet this target and guide broader conservation and land-use policy development. However, to ensure these assessments are adopted by policy makers, they must also consider national priorities. This situation is exemplified by Guyana, a corner of Amazonia that couples high biodiversity with low economic development. In recent years activities that threaten biodiversity conservation have increased, and consequently, protected areas are evermore critical to achieving the Aichi targets. Here we undertake a cost-effective approach to protected area planning in Guyana that accounts for in-country conditions. To do this we conducted a stakeholder-led spatial conservation prioritisation based on meeting targets for 17 vegetation types and 329 vertebrate species, while minimising opportunity costs for forestry, mining, agriculture and urbanisation. Our analysis identifies 3 million
Hudson, Lawrence N., Tim Newbold, Sara Contu, Samantha L. L. Hill, Igor Lysenko, Adriana De Palma, Helen R. P. Phillips, Tamera I. Alhusseini, Felicity E. Bedford, Dominic J. Bennett, Hollie Booth, Victoria J. Burton, Charlotte W. T. Chng, Argyrios Choimes, David L. P. Correia, Julie Day, Susy Echeverría-Londoño, Susan R. Emerson, Di Gao, Morgan Garon, Michelle L. K. Harrison, Daniel J. Ingram, Martin Jung, Victoria Kemp, Lucinda Kirkpatrick, Callum D. Martin, Yuan Pan, Gwilym D. Pask-Hale, Edwin L. Pynegar, Alexandra N. Robinson, Katia Sanchez-Ortiz, Rebecca A. Senior, Benno I. Simmons, Hannah J. White, Hanbin Zhang, Job Aben, Stefan Abrahamczyk, Gilbert B. Adum, Virginia Aguilar-Barquero, Marcelo A. Aizen, Belén Albertos, E. L. Alcala, Maria del Mar Alguacil, Audrey Alignier, Marc Ancrenaz, Alan N. Andersen, Enrique Arbeláez-Cortés, Inge Armbrecht, Víctor Arroyo-Rodríguez, Tom Aumann, Jan C. Axmacher, Badrul Azhar, Adrián B. Azpiroz, Lander Baeten, Adama Bakayoko, András Báldi, John E. Banks, Sharad K. Baral, Jos Barlow, Barbara I. P. Barratt, Lurdes Barrico, Paola Bartolommei, Diane M. Barton, Yves Basset, Péter Batáry, Adam J. Bates, Bruno Baur, Erin M. Bayne, Pedro Beja, Suzan Benedick, Åke Berg, Henry Bernard, Nicholas J. Berry, Dinesh Bhatt, Jake E. Bicknell, Jochen H. Bihn, Robin J. Blake, Kadiri S. Bobo, Roberto Bóçon, Teun Boekhout, Katrin Böhning-Gaese, Kevin J. Bonham, Paulo A. V. Borges, Sérgio H. Borges, Céline Boutin, Jérémy Bouyer, Cibele Bragagnolo, Jodi S. Brandt, Francis Q. Brearley, Isabel Brito, Vicenç Bros, Jörg Brunet, Grzegorz Buczkowski, Christopher M. Buddle, Rob Bugter, Erika Buscardo, Jörn Buse, Jimmy Cabra-García, Nilton C. Cáceres, Nicolette L. Cagle, María Calviño-Cancela, Sydney A. Cameron, Eliana M. Cancello, Rut Caparrós, Pedro Cardoso, Dan Carpenter, Tiago F. Carrijo, Anelena L. Carvalho, Camila R. Cassano, Helena Castro, Alejandro A. Castro-Luna, Cerda B. Rolando, Alexis Cerezo, Kim Alan Chapman, Matthieu Chauvat, Morten Christensen, Francis M. Clarke, Daniel F.R. Cleary, Giorgio Colombo, Stuart P. Connop, Michael D. Craig, Leopoldo Cruz-López, Saul A. Cunningham, Biagio D’Aniello, Neil D’Cruze, Pedro Giovâni da Silva, Martin Dallimer, Emmanuel Danquah, Ben Darvill, Jens Dauber, Adrian L. V. Davis, Jeff Dawson, Claudio de Sassi, Benoit de Thoisy, Olivier Deheuvels, Alain Dejean, Jean-Louis Devineau, Tim Diekötter, Jignasu V. Dolia, Erwin Domínguez, Yamileth Dominguez-Haydar, Silvia Dorn, Isabel Draper, Niels Dreber, Bertrand Dumont, Simon G. Dures, Mats Dynesius, Lars Edenius, Paul Eggleton, Felix Eigenbrod, Zoltán Elek, Martin H. Entling, Karen J. Esler, Ricardo F. de Lima, Aisyah Faruk, Nina Farwig, Tom M. Fayle, Antonio Felicioli, Annika M. Felton, Roderick J. Fensham, Ignacio C. Fernandez, Catarina C. Ferreira, Gentile F. Ficetola, Cristina Fiera, Bruno K. C. Filgueiras, Hüseyin K. F?r?nc?o?lu, David Flaspohler, Andreas Floren, Steven J. Fonte, Anne Fournier, Robert E. Fowler, Markus Franzén, Lauchlan H. Fraser, Gabriella M. Fredriksson, Geraldo B. Freire, Tiago L. M. Frizzo, Daisuke Fukuda, Dario Furlani, René Gaigher, Jörg U. Ganzhorn, Karla P. García, Juan C. Garcia-R, Jenni G. Garden, Ricardo Garilleti, Bao-Ming Ge, Benoit Gendreau-Berthiaume, Philippa J. Gerard, Carla Gheler-Costa, Benjamin Gilbert, Paolo Giordani, Simonetta Giordano, Carly Golodets, Laurens G. L. Gomes, Rachelle K. Gould, Dave Goulson, Aaron D. Gove, Laurent Granjon, Ingo Grass, Claudia L. Gray, James Grogan, Weibin Gu, Moisès Guardiola, Nihara R. Gunawardene, Alvaro G. Gutierrez, Doris L. Gutiérrez-Lamus, Daniela H. Haarmeyer, Mick E. Hanley, Thor Hanson, Nor R. Hashim, Shombe N. Hassan, Richard G. Hatfield, Joseph E. Hawes, Matt W. Hayward, Christian Hébert, Alvin J. Helden, John-André Henden, Philipp Henschel, Lionel Hernández, James P. Herrera, Farina Herrmann, Felix Herzog, Diego Higuera-Diaz, Branko Hilje, Hubert Höfer, Anke Hoffmann, Finbarr G. Horgan, Elisabeth Hornung, Roland Horváth, Kristoffer Hylander, Paola Isaacs-Cubides, Hiroaki Ishida, Masahiro Ishitani, Carmen T. Jacobs, Víctor J. Jaramillo, Birgit Jauker, F. Jiménez Hernández, McKenzie F. Johnson, Virat Jolli, Mats Jonsell, S. Nur Juliani, Thomas S. Jung, Vena Kapoor, Heike Kappes, Vassiliki Kati, Eric Katovai, Klaus Kellner, Michael Kessler, Kathryn R. Kirby, Andrew M. Kittle, Mairi E. Knight, Eva Knop, Florian Kohler, Matti Koivula, Annette Kolb, Mouhamadou Kone, Ádám K?rösi, Jochen Krauss, Ajith Kumar, Raman Kumar, David J. Kurz, Alex S. Kutt, Thibault Lachat, Victoria Lantschner, Francisco Lara, Jesse R. Lasky, Steven C. Latta, William F. Laurance, Patrick Lavelle, Violette Le Féon, Gretchen LeBuhn, Jean-Philippe Légaré, Valérie Lehouck, María V. Lencinas, Pia E. Lentini, Susan G. Letcher, Qi Li, Simon A. Litchwark, Nick A. Littlewood, Yunhui Liu, Nancy Lo-Man-Hung, Carlos A. López-Quintero, Mounir Louhaichi, Gabor L. Lövei, Manuel Esteban Lucas-Borja, Victor H. Luja, Matthew S. Luskin, M Cristina MacSwiney G, Kaoru Maeto, Tibor Magura, Neil Aldrin Mallari, Louise A. Malone, Patrick K. Malonza, Jagoba Malumbres-Olarte, Salvador Mandujano, Inger E. Måren, Erika Marin-Spiotta, Charles J. Marsh, E. J. P. Marshall, Eliana Martínez, Guillermo Martínez Pastur, David Moreno Mateos, Margaret M. Mayfield, Vicente Mazimpaka, Jennifer L. McCarthy, Kyle P. McCarthy, Quinn S. McFrederick, Sean McNamara, Nagore G. Medina, Rafael Medina, Jose L. Mena, Estefania Mico, Grzegorz Mikusinski, Jeffrey C. Milder, James R. Miller, Daniel R. Miranda-Esquivel, Melinda L. Moir, Carolina L. Morales, Mary N. Muchane, Muchai Muchane, Sonja Mudri-Stojnic, A. Nur Munira, Antonio Muoñz-Alonso, B. F. Munyekenye, Robin Naidoo, A. Naithani, Michiko Nakagawa, Akihiro Nakamura, Yoshihiro Nakashima, Shoji Naoe, Guiomar Nates-Parra, Dario A. Navarrete Gutierrez, Luis Navarro-Iriarte, Paul K. Ndang’ang’a, Eike L. Neuschulz, Jacqueline T. Ngai, Violaine Nicolas, Sven G. Nilsson, Norbertas Noreika, Olivia Norfolk, Jorge Ari Noriega, David A. Norton, Nicole M. Nöske, A. Justin Nowakowski, Catherine Numa, Niall O’Dea, Patrick J. O’Farrell, William Oduro, Sabine Oertli, Caleb Ofori-Boateng, Christopher Omamoke Oke, Vicencio Oostra, Lynne M. Osgathorpe, Samuel Eduardo Otavo, Navendu V. Page, Juan Paritsis, Alejandro Parra-H, Luke Parry, Guy Pe’er, Peter B. Pearman, Nicolás Pelegrin, Raphaël Pélissier, Carlos A. Peres, Pablo L. Peri, Anna S. Persson, Theodora Petanidou, Marcell K. Peters, Rohan S. Pethiyagoda, Ben Phalan, T. Keith Philips, Finn C. Pillsbury, Jimmy Pincheira-Ulbrich, Eduardo Pineda, Joan Pino, Jaime Pizarro-Araya, A. J. Plumptre, Santiago L. Poggio, Natalia Politi, Pere Pons, Katja Poveda, Eileen F. Power, Steven J. Presley, Vânia Proença, Marino Quaranta, Carolina Quintero, Romina Rader, B. R. Ramesh, Martha P. Ramirez-Pinilla, Jai Ranganathan, Claus Rasmussen, Nicola A. Redpath-Downing, J. Leighton Reid, Yana T. Reis, José M. Rey Benayas, Juan Carlos Rey-Velasco, Chevonne Reynolds, Danilo Bandini Ribeiro, Miriam H. Richards, Barbara A. Richardson, Michael J. Richardson, Rodrigo Macip Ríos, Richard Robinson, Carolina A. Robles, Jörg Römbke, Luz Piedad Romero-Duque, Matthias Rös, Loreta Rosselli, Stephen J. Rossiter, Dana S. Roth, T’ai H. Roulston, Laurent Rousseau, André V. Rubio, Jean-Claude Ruel, Jonathan P. Sadler, Szabolcs Sáfián, Romeo A. Saldaña-Vázquez, Katerina Sam, Ulrika Samnegård, Joana Santana, Xavier Santos, Jade Savage, Nancy A. Schellhorn, Menno Schilthuizen, Ute Schmiedel, Christine B. Schmitt, Nicole L. Schon, Christof Schüepp, Katharina Schumann, Oliver Schweiger, Dawn M. Scott, Kenneth A. Scott, Jodi L. Sedlock, Steven S. Seefeldt, Ghazala Shahabuddin, Graeme Shannon, Douglas Sheil, Frederick H. Sheldon, Eyal Shochat, Stefan J. Siebert, Fernando A. B. Silva, Javier A. Simonetti, Eleanor M. Slade, Jo Smith, Allan H. Smith-Pardo, Navjot S. Sodhi, Eduardo J. Somarriba, Ramón A. Sosa, Grimaldo Soto Quiroga, Martin-Hugues St-Laurent, Brian M. Starzomski, Constanti Stefanescu, Ingolf Steffan-Dewenter, Philip C. Stouffer, Jane C. Stout, Ayron M. Strauch, Matthew J. Struebig, Zhimin Su, Marcela Suarez-Rubio, Shinji Sugiura, Keith S. Summerville, Yik-Hei Sung, Hari Sutrisno, Jens-Christian Svenning, Tiit Teder, Caragh G. Threlfall, Anu Tiitsaar, Jacqui H. Todd, Rebecca K. Tonietto, Ignasi Torre, Béla Tóthmérész, Teja Tscharntke, Edgar C. Turner, Jason M. Tylianakis, Marcio Uehara-Prado, Nicolas Urbina-Cardona, Denis Vallan, Adam J. Vanbergen, Heraldo L. Vasconcelos, Kiril Vassilev, Hans A. F. Verboven, Maria João Verdasca, José R. Verdú, Carlos H. Vergara, Pablo M. Vergara, Jort Verhulst, Massimiliano Virgilio, Lien Van Vu, Edward M. Waite, Tony R. Walker, Hua-Feng Wang, Yanping Wang, James I. Watling, Britta Weller, Konstans Wells, Catrin Westphal, Edward D. Wiafe, Christopher D. Williams, Michael R. Willig, John C. Z. Woinarski, Jan H. D. Wolf, Volkmar Wolters, Ben A. Woodcock, Jihua Wu, Joseph M. Wunderle, Yuichi Yamaura, Satoko Yoshikura, Douglas W. Yu, Andrey S. Zaitsev, Juliane Zeidler, Fasheng Zou, Ben Collen, Rob M. Ewers, Georgina M. Mace, Drew W. Purves, Jörn P. W. Scharlemann, and Andy Purvis. 2016. “The Database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) Project”. Ecology and Evolution. Wiley. doi:10.1002/ece3.2579.The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.
Rivett, Skye, Jake E. Bicknell, and Zoe G. Davies. 2016. “Effect of Reduced-Impact Logging on Seedling Recruitment in a Neotropical Forest”. Forest Ecology and Management. Elsevier Science B.V., Amsterdam. doi:10.1016/j.foreco.2016.02.022.Seedling growth and survival are critical for tropical rainforest regeneration. Alterations to natural disturbance regimes, such as those brought about by logging, have the potential to shift relative species abundances and the community composition of forests, resulting in population declines for commercially valuable species. Timber operations therefore need to minimise such changes if long-term sustainability is to be achieved within the industry. Reduced-impact logging (RIL) has been promoted widely as an alternative management strategy to conventional selective logging, as it employs practices that decrease the negative impacts of logging within forests. However, the long-term sustainability of RIL, including the influence it has on the regeneration of species targeted for timber extraction, is still uncertain. Here we undertake a comparative study in Iwokrama forest, Guyana, examining seedling densities of four commercially valuable and two pioneer tree species in unlogged, 1.5 years and 4.5 years postharvest forest plots to ascertain how seedling regeneration is effected by RIL. We find that RIL had either a neutral or positive impact on the density of seedlings of timber species when compared to unlogged forest, with pioneer species densities remaining unaffected. We conclude that the forestry practices associated with RIL have little effect on the natural regeneration rates of key commercially valuable tree species in logged neotropical forests.
Bicknell, Jake E., David L.A. Gaveau, Zoe G. Davies, and Matthew J. Struebig. 2015. “Saving Logged Tropical Forests: Closing Roads Will Bring Immediate Benefits”. Frontiers in Ecology and the Environment. doi:doi:10.1890/15.WB.001.
Bicknell, Jake E., Matthew J. Struebig, and Zoe G. Davies. 2015. “Reconciling Timber Extraction With Biodiversity Conservation in Tropical Forests Using Reduced-Impact Logging”. Journal of Applied Ecology. Wiley. doi:10.1111/1365-2664.12391.Over 20% of the world's tropical forests have been selectively logged, and large expanses are allocated for future timber extraction. Reduced-impact logging (RIL) is being promoted as best practice forestry that increases sustainability and lowers CO2 emissions from logging, by reducing collateral damage associated with timber extraction. RIL is also expected to minimize the impacts of selective logging on biodiversity, although this is yet to be thoroughly tested.
We undertake the most comprehensive study to date to investigate the biodiversity impacts of RIL across multiple taxonomic groups. We quantified birds, bats and large mammal assemblage structures, using a before-after control-impact (BACI) design across 20 sample sites over a 5-year period. Faunal surveys utilized point counts, mist nets and line transects and yielded >250 species. We examined assemblage responses to logging, as well as partitions of feeding guild and strata (understorey vs. canopy), and then tested for relationships with logging intensity to assess the primary determinants of community composition.
Community analysis revealed little effect of RIL on overall assemblages, as structure and composition were similar before and after logging, and between logging and control sites. Variation in bird assemblages was explained by natural rates of change over time, and not logging intensity. However, when partitioned by feeding guild and strata, the frugivorous and canopy bird ensembles changed as a result of RIL, although the latter was also associated with change over time. Bats exhibited variable changes post-logging that were not related to logging, whereas large mammals showed no change at all.
Indicator species analysis and correlations with logging intensities revealed that some species exhibited idiosyncratic responses to RIL, whilst abundance change of most others was associated with time.
Synthesis and applications. Our study demonstrates the relatively benign effect of reduced-impact logging (RIL) on birds, bats and large mammals in a neotropical forest context, and therefore, we propose that forest managers should improve timber extraction techniques more widely. If RIL is extensively adopted, forestry concessions could represent sizeable and important additions to the global conservation estate – over 4 million km2.
Horsley, Thomas W.B., Jake E. Bicknell, Burton K. Lim, and Loren K. Ammerman. 2015. “Seed Dispersal by Frugivorous Bats in Central Guyana and a Description of Previously Unknown Plant-Animal Interactions”. Acta Chiropterologica. Museum and Institute of Zoology, Polish Academy of Sciences. doi:10.3161/15081109ACC2015.17.2.008.Species of bats in the subfamilies Stenodermatinae and Carolliinae are primarily frugivores, and through the ingestion of fruit and
defecation of seeds, they play a crucial role in their environment through the dispersal of early successional and pioneer plants contributing to reforestation. These ecosystem services provided by frugivorous bats are becoming more critical with time, as anthropogenic habitat destruction continues to rise. The objective of this study was to survey the plant species dispersed by frugivorous bats in a tropical rainforest in Guyana. Fecal samples were taken from captured frugivorous bats and stomach contents were taken from a representative collection. The four most common bats were Artibeus planirostris, A. obscurus, A. lituratus, and Carollia perspicillata, which accounted for 67% of total captures in mist nets set in the forest understory. Twenty plant species were identified in fecal and stomach content samples with the most abundant (Ficus nymphaeifolia, Piper bartlingianum, Cecropia latiloba, and C. sciadophylla) accounting for 60% of the total. Cecropia latiloba, which is an early colonizer of floodplains throughout the Guiana Shield and Amazon River Basin was previously unknown to be bat dispersed. Seven plant species were documented as being dispersed by nine bat species for the first time. These results enhance our understanding of seed dispersal by Neotropical bats, specifically by revealing previously unknown bat/plant relationships.
Bicknell, Jake E., Matthew J. Struebig, David P. Edwards, and Zoe G. Davies. 2014. “Improved Timber Harvest Techniques Maintain Biodiversity in Tropical Forests”. Current Biology. Elsevier. doi:10.1016/j.cub.2014.10.067.Tropical forests are selectively logged at 20 times the rate at which they are cleared, and at least a fifth have already been disturbed in this way. In a recent pan-tropical assessment, Burivalova et al. demonstrate the importance of logging intensity as a driver of biodiversity decline in timber estates. Their analyses reveal that species richness of some taxa could decline by 50% at harvest intensities of 38 m3 ha-1. However, they did not consider the extraction techniques that lead to these intensities. Here, we conduct a complementary meta-analysis of assemblage responses to differing logging practices: conventional logging and reduced-impact logging. We show that biodiversity impacts are markedly less severe in forests that utilise reduced-impact logging, compared to those using conventional methods. While supporting the initial findings of Burivalova et al., we go on to demonstrate that best practice forestry techniques curtail the effects of timber extraction regardless of intensity. Therefore, harvest intensities are not always indicative of actual disturbance levels resulting from logging. Accordingly, forest managers and conservationists should advocate practices that offer reduced collateral damage through best practice extraction methods, such as those used in reduced-impact logging. Large-scale implementation of this approach would lead to improved conservation values in the 4 million km2 of tropical forests that are earmarked for timber extraction.
Bicknell, Jake E., Simon P. Phelps, Richard G. Davies, Darren J. Mann, Matthew J. Struebig, and Zoe G. Davies. 2014. “Dung Beetles As Indicators for Rapid Impact Assessments: Evaluating Best Practice Forestry in the Neotropics”. Ecological Indicators. doi:10.1016/j.ecolind.2014.02.030.Dung beetles (Scarabaeidae: Scarabaeinae) are sensitive to habitat perturbations and are easily studied, making them an ideal taxonomic group with which to evaluate the effects of low-intensity anthropogenic disturbances such as Reduced-Impact Logging. Here we examine the effect of a certified Reduced-Impact Logging operation on dung beetles, and demonstrate their suitability for use in rapid ecological impact studies. We sampled dung beetle assemblages, environmental variables and timber extraction rates across four treatment groups in closed canopy and canopy gaps in logged and unlogged forest in Guyana. Community analysis revealed that logged forest supported a more uniform dung beetle assemblage compared to unlogged forest. Differences in assemblage structure were driven by dissimilarity between closed canopy treatments, as plots in artificial and natural canopy gaps supported comparable assemblages. Indicator analyses were conducted across treatments, using a new approach (CLAM) and two well-established methods (IndVal, SIMPER). Two species respectively were classified as indicators of logged (Hansreia affinis and Eurysternus caribaeus) and unlogged forest (Canthidium aff. centrale and Deltochilum (Calhyboma) carinatum). BIO-ENV analysis demonstrated that tree extraction intensity, bare ground cover, and ground cover by leaf material were key factors influencing dung beetle assemblages. Despite the relatively low-impact of Reduced-Impact Logging reported by previous studies, we find that dung beetles are sensitive to even small changes in environmental conditions as a result of this form of anthropogenic disturbance. As dung beetles are a highly responsive taxonomic group, we illustrate that they represent a valuable taxon that can be used to critically evaluate best practice forestry operations and other disturbance activities, particularly in time constrained studies (e.g., rapid monitoring and environmental impact assessments). However, we recommend the use of multiple indicator analyses to monitor potential changes in assemblage composition, due to a lack of congruence between methods.
Dallimer, Martin, Mark Parnell, Jake E. Bicknell, and M. Melo. 2012. “The Importance of Novel and Agricultural Habitats for the Avifauna of an Oceanic Island”. Journal for Nature Conservation. doi:doi:10.1016/j.jnc.2012.04.001.Conservation management can no longer rely on protecting pristine habitats, but must consider the
wider landscape. This is especially true on oceanic islands where endemic species are believed to be
particularly susceptible to the extinction risks that accompany land conversion. Despite this, there is a
paucity of studies examining how endemic communities on oceanic islands may be distributed across
such human-modified habitats. Taking Príncipe Island in West Africa as a case study, we investigate how
avian communities vary across the habitats (primary forest, secondary forest, agricultural areas) of this
globally important centre of endemism. Here, recent policy reforms aimed at poverty alleviation and
increased food production are rapidly altering the current land-use mosaic. Across all habitats, 27 bird
species were encountered. Survey points in secondary forest and agricultural areas were, on average,
more diverse and held higher overall abundances of birds than those within primary forest. This was
true for both the entire avian assemblage and the endemic species alone. Nevertheless, two IUCN-listed
species were restricted to primary forest, and many other endemics occurred at higher densities within
this habitat. We demonstrate that agricultural areas and novel habitats, such as secondary forest, can
hold high abundances of endemic species and thus have the potential to act as a resource for biodiversity
conservation. A double-stranded approach to conservation is therefore required that both protects the
integrity of the primary forest and controls the rapid changes in agricultural land-use to ensure that it
continues to support a large component of the endemic avifauna.
Bicknell, Jake E., and Carlos A. Peres. 2010. “Vertebrate Population Responses to Reduced-Impact Logging in a Neotropical Forest”. Forest Ecology and Management. Elsevier Science B.V., Amsterdam. doi:doi:10.1016/j.foreco.2010.02.027.Vertebrate population densities were quantified in lowland central Guyana using line-transect censuses at three forest sites subjected to reduced-impact logging (RIL), and three adjacent unlogged sites. We censused a range of forest vertebrate species including large canopy-dwelling and terrestrial birds, three primates, one rodent and one tortoise. Two 4 km transects at each site were repeatedly surveyed during the wet season of 2008 to derive population density estimates on the basis of a cumulative survey effort of 416 km. RIL had ended within 16 months, and sites had been subjected to a mean extraction rate of 3.9 m3 ha?1, equivalent to only 1.1 trees ha?1. Three of the 15 vertebrate species examined here exhibited significantly different abundances at forest RIL sites, two of which were negative. Large frugivores such as primates were less abundant in sites subject to RIL, whereas smaller frugivores, granivores, folivores and insectivores were more common in logged sites. We are unable to reliably distinguish between responses of different taxonomic groups, since robust abundance metrics could only be estimated for four mammal species. Despite this, species traits including dietary guild, body mass, home range size and vertical stratification of forest use are used to explain varying responses. Our findings suggest that responsible reduced-impact logging practices in neotropical forests can be considered as a relatively benign form of forest management that can coexist with the requirements of both local economies and biodiversity conservation. However, our study sites experienced comparably low extraction rates, and detrimental effects such as hunting were low. Our results therefore provide an opportunity to scrutinise the effects of best practice logging systems, though do not necessarily represent typical circumstances across tropical forests.
Bicknell, Jake E., and Christopher Chin. 2007. “Aquarium Fisheries As a Non-Timber Forest Product: Experiences from Conservation through Community Development in North Rupununi District, Guyana”. Conservation Evidence. http://www.conservationevidence.com/individual-study/2269.Deforestation is one of the major global conservation issues. Solutions are being sought to tackle this ongoing
forest loss, including establishment of initiatives to provide new sources of income for local communities that
promote the sustainable use of forests in the interest of biodiversity conservation. One such project ‘Iwokrama’,
demonstrates how tropical forests and associated habitats can be sustainably used. In the central Guyana wetlands of the Rupununi, illegal fishing of arapaima Arapaima gigas, had led to a huge
reduction in its numbers. Iwokrama responded by initiating the Arapaima Management Plan in 2002. This
highlighted the need for another source of local income from fisheries, and a business that undertakes sustainable harvest
of fish for the aquarium trade was developed. Harvesting of a few selected fish species is carried-out by
members of the local community who are paid a daily wage. Fishing methods target individual species to avoid
incidental by-catch. Four species are primarily caught as they are numerous in the Rupununi and are of high trade
value. To ensure ecological and economical sustainability, catch per unit effort is monitored; where this begins to
drop for any given species, harvesting is suspended and the population is allowed to recover before harvesting
resumes. The project has developed into a self-sustaining business, managed by the community themselves. During
2005, the project reached financial sustainability with current profits of over US$3,000 feeding back into local
Watkins, G, W Saul, E Holm, C Watson, D Arjoon, and Jake E. Bicknell. 2005. “The Fish Fauna of the Iwokrama Forest”. Proceedings of the Academy of Natural Sciences of Philadelphia. http://www.jstor.org/discover/10.2307/4065124?uid=3738032&uid=2134&uid=2&uid=70&uid=4&sid=21106200596831.Fishes were collected from the rivers in and around the Iwokrama Forest during January-February and November-December 1997. Four hundred species of fish were recorded from forty families in ten orders. Many of these fishes are newly recorded from Guyana and several are thought to be endemic. The number of species recorded for the area is surprising given the low level of effort and suggests that this area may be particularly important from a fish diversity perspective. This paper focuses on species of particular interest from a management perspective including those considered economically important, rare or endangered. The paper is also the basis for developing fisheries management systems in the Iwokrama Forest and Rupununi Wetlands.
Rice, Charmaine Natasha. 2016. “Abundance, Impacts and Resident Perceptions of Non-Native Common Pheasants (Phasianus Colchicus) in Jersey, UK Channel Islands..”Few species are able to establish themselves in a non-native range and expand their population to
become a wide-ranging invasive. However, for those that are able to, their negative environmental
impacts include widespread predation of native flora and fauna, competition and spread of
parasites and disease. The common pheasant (Phasianus colchicus), a native of central Asia, has
been the subject of introductions for recreational hunting across the globe for hundreds of years.
Today, millions of birds are released annually and rural habitats managed to better accommodate
them. These mass introductions have prompted much research regarding the effects of pheasant
populations in areas where they are released at high densities. However, little is known about the
effects of naturalised populations of pheasants in areas where they are neither released nor their
habitat managed. To fill this knowledge gap and to aid management, this study seeks to investigate
the naturalised population of common pheasants on the Bailiwick of Jersey, UK Channel Islands.
Through an extensive programme of field surveys, this research enables a better understanding of
the impacts of this non-native species on native wildlife and agriculture. Distance sampling was
used to provide density and abundance estimates of Jersey's pheasant population and Breeding
Bird Survey data, provided by the British Trust for Ornithology, were also used to investigate
population trends over time. Summer habitat preferences were also investigated and, to
complement these findings and further inform management, an online questionnaire to analyse
local perceptions of pheasants and their impacts was conducted. Pheasant density estimates ranged from 9.5 to 16.6 pheasants per km2, with a total island-wide population of 1011-1780
pheasants. Highest concentrations were seen in the southeast (St. Clement) and northwest (St.
Ouen) of the island and the lowest concentrations in the southwest (St. Brelade), with pheasants
showing a preference for fields that contained shoots, mustard and bare ground. The long-term
data revealed an overall decreasing but oscillating population trend since 2002. Residents of Jersey
perceive pheasants as having negative impacts on farmland birds, herpetofauna and crops, with
some respondents witnessing predation of reptiles and amphibians, all of which are protected
species. Despite this, pheasants are generally well received by residents with the majority 'agreeing'
or 'strongly agreeing' that pheasants add to the appeal of the countryside and that they enjoy
having pheasants in Jersey. Pheasants are also considered to have a positive impact on birds of prey
and are credited for the rise in marsh harrier (Circus aeruginosus) and buzzard (Buteo buteo)
numbers. Arable farmers displayed the most adverse opinions of pheasants and were significantly
more likely to view pheasants as negative for arable crops. The percentages of residents who
believe pheasants should be protected by legislation and those who do not are almost equal.
Specifically, arable farmers were generally in favour of removing pheasant protection, whereas
game shooters polarise this view. The successful management of any invasive species or their
impacts relies on monitoring populations, examining their trends, and understanding their habitat
use. To this end, this study provides the baseline data required for future decisions on pheasant
management by policy makers in Jersey.
Hayes, William M., Jessica C. Fisher, Meshach A. Pierre, Jake E. Bicknell, and Zoe G. Davies. 2019. “Bird Communities across Varying Landcover Types in a Neotropical City”. Biotropica. Wiley.Urbanization poses a serious threat to local biodiversity, yet towns and cities with abundant natural features may harbor important species populations and communities. While the contribution of urban greenspaces to conservation has been demonstrated by numerous studies within temperate regions, few consider the bird communities associated with different landcovers in Neotropical cities. To begin to fill this knowledge gap, we examined how the avifauna of a wetland city in northern Amazonia (Georgetown, Guyana) varied across six urban landcover types (coastal bluespace; urban bluespace; managed greenspace; unmanaged greenspace; dense urban; sparse urban). We measured detections, species richness and a series of ground cover variables that characterized the heterogeneity of each landcover, at 114 locations across the city. We recorded >10% (98) of Guyana’s bird species in Georgetown, including taxa of conservation interest. Avian detections, richness, and community composition differed with landcover type. Indicator species analysis identified 29 species from across dietary guilds, which could be driving community composition. Comparing landcovers, species richness was highest in managed greenspaces and lowest in dense urban areas. The canal network had comparable levels of species richness to greenspaces. The waterways are likely to play a key role in enhancing habitat connectivity as they traverse densely urbanized areas. Both species and landcover information should be integrated into urban land-use planning in the rapidly urbanizing Neotropics to maximize the conservation value of cities. This is imperative in the tropics, where anthropogenic pressures on species are growing significantly, and action needs to be taken to prevent biodiversity collapse.
Gardner, Charlie J., Jake E. Bicknell, William Balwin-Cantello, Matthew J. Struebig, and Zoe G. Davies. “Quantifying the Impacts of Defaunation on Natural Forest 3 Regeneration Worldwide”. Nature Communications. Springer.Intact forests provide diverse and irreplaceable ecosystem services that are critical to human well-being, such as carbon storage to mitigate climate change. However, the ecosystem functions that underpin these services are highly dependent on the woody vegetation-animal interactions occurring within forests. While vertebrate defaunation is of growing policy concern, the effects of vertebrate loss on natural forest regeneration have yet to be quantified globally. Here we conduct a meta-analysis to assess the direction and magnitude of defaunation impacts on forests. We demonstrate that real-world defaunation caused by hunting and habitat fragmentation leads to reduced forest regeneration, although manipulation experiments provide contrasting findings. The extirpation of primates and birds cause the greatest declines in forest regeneration, emphasizing their key role in maintaining carbon stores, and the need for national and international climate change and conservation strategies to protect forests from defaunation fronts as well as deforestation fronts.