Structure, function and resilience of avian communities in tropical ecosystems

Lead Research Organisation: University of Oxford
Department Name: Zoology


The study of biodiversity and its role in natural ecosystems is an urgent priority because the Earth is facing unprecedentedly rapid changes in climate and land-use. These changes will be felt most acutely in tropical regions, not only because they are set to experience the biggest increase in human population, habitat loss and economic development, but also because they support the vast majority of species (>80%), many with small ranges and narrow climatic limits, making them vulnerable to extinction. However, partly because of a research bias towards temperate systems, we have a very incomplete understanding of how range shifts and extinctions will affect ecosystem structure and resilience in tropical regions.

Of all tropical biodiversity, vertebrates are the iconic figureheads for conservation. They are central to a range of key ecosystem processes, such as seed dispersal, pollination and predation. The importance of understanding the forces underpinning the structure, function and resilience of their communities is clear, yet the answers remain elusive because of the difficulty of surveying vertebrates. In addition, the coverage of molecular data for vertebrates has until very recently been incomplete.

In this project, we will capitalise on new high-resolution datasets for the best-known group of tropical vertebrates - birds - to test ecological theory at contrasting spatial scales using community phylogenetic approaches. We will use site-based faunal lists gathered throughout the Neotropics in recent decades. We will also use plot-based community and abundance data collected through fieldwork across an elevational gradient in the tropical Andes. These datasets will be coupled with information about ecological niches and functional traits for each species. In all cases analyses will be framed by newly available species-level phylogenies, which have the power to reveal the structure of evolutionary relationships between community members, and uncover the way niches and traits have evolved through time. This will help us to compare communities from sites with differing levels of habitat degradation and fragmentation.

To manage ecosystems effectively we need to understand the mechanisms governing responses to change, and how these changes are likely to influence the ecological function and resilience of communities over time. The main goals of this research are to understand (1) how species from a regional pool are assembled into local communities, (2) how the phylogenetic structure and ecological function of communities varies in relation to climate and human impacts, and (3) how we can apply insights from (1) and (2) to improve methods for ecological forecasting under various global change scenarios. The results will provide a more complete understanding of the forces shaping and regulating biological communities worldwide, and enhance our ability to predict the consequences of environmental change, particularly in tropical systems.

Planned Impact

The UK government, scientists and many national and international NGOs have specific interest in improved understanding of the ecological and evolutionary processes determining range limits and abundance of vertebrates, as well as the implications that those processes have for ecosystem function. This knowledge is a key step to developing effective strategies for managing biodiversity in the context of global change.
Scientists and NGOs will benefit from new information about factors determining the distribution and abundance of species in tropical regions (the epicentre of the current extinction crisis). The results will enable refinement of predictive models of tropical species distributions. They will also help to clarify the extent to which environmental changes impact on ecosystem functioning, and in particular on key ecosystem processes-such as seed dispersal and pollination-that feed into long-term stability and resilience. In addition, they will provide the first information about population density and community interactions for hundreds of tropical bird species, which will directly support IUCN conservation status assessments, and strategic assessments of biodiversity risk.
Policy makers and private sector will benefit from some of the same resources, and from improved methods for mapping and predicting patterns of biodiversity, and long-term ecosystem resilience, aspects with useful applications for channelling Reduced Emissions from Deforestation and Degradation (REDD) and carbon market funding.
Public sector will benefit from high-quality information about environmental science in high-profile ecosystems (Andean and Amazonian forests, the world's most diverse terrestrial biomes).
We will exchange knowledge with scientists via symposia, seminars and meetings, and by publication of peer-reviewed articles, including submissions to top-rank journals. Applications have already been submitted for a symposium titled "Competition and the structure of avian communities" for the Neotropical Ornithology Congress in Cusco, Nov 2011. Five speakers (including project staff) have been arranged, and all relevant parties associated with the Andean transect study are attending.
To engage users from science, NGOs and the private sector, we will run a 2-day meeting co-hosted by the Biodiversity Institute (Zoology Dept., Oxford University) and the Oxford Centre for Tropical Forests (OCTF). All project members will attend, along with members of the Andes Biodiversity & Ecosystem Research Group (ABERG), members of key NGOs, and researchers studying the dynamics of biodiversity in relation to environmental change. We will invite private-sector carbon companies with an interest in channelling carbon offset funding or other carbon finance mechanisms to maximise benefits to biodiversity conservation (e.g. REDD++). The results communicated during the meeting will form the basis for a publication about global change and tropical ecosystems, with the longer-term goal of spearheading collaborative interactions in a global network of studies (mainly UK- and US-based) focused on questions about global change and the management of biodiversity and ecosystem services. We will also exchange knowledge with NGOs directly via our close professional links with RSPB, BirdLife International, IUCN and CI.
To engage with the public sector, we will produce at least one mainstream article and at least one television report of our research. We will also update & develop the ABERG website to provide a range of educational materials for public download, including information about our study plots, and relevant images and sound files. To deliver useful outputs to scientists, as well as to a wider audience, all project data will be accessible through the ABERG website portal, as will printable colour webguides of Andean birds (partly to train fieldworkers and support long-term monitoring programmes, but also useful to the public).


10 25 50
Description 1. Specialisation to narrow ecological niches promotes diversification in tropical animals. This helps to explain the latitudinal diversity gradient, and indicates that specialised species have a greater 'speciation potential' particularly in the tropics, i.e. they are likely to produce more species in future.
2. Phylogenetic models reveal that ecologically similar species are unable to co-occur until millions of years after speciation.
3. Competition between species increases after habitat fragmentation, driving some species to extinction.
4. Secondary forests play a greater role in maintaining biodiversity and ecological processes when they are situated adjacent to extensive primary forest.
5. Land sparing agriculture maintains higher levels of functional diversity than land sharing.
Exploitation Route Finding (1) focuses conservation attention on species with specialised ecological niches, particularly those with large ranges not otherwise considered priorities for conservation.

Finding (2) radically changes the assumptions of models forecasting the biological impacts of climate change, which generally assume that species ranges can move freely in response to changing climates.

Finding (3) provided information on minimum size requirements for functioning ecosystems in fragmented forests.

Finding (4) provided policy-relevant insights into management of reforestation projects

Finding (5) suggested agricultural land-use practices required to maintain functioning ecosystems.
Sectors Agriculture, Food and Drink,Environment,Culture, Heritage, Museums and Collections

Description The morphometric trait aspects of this research has snowballed into a major international enterprise spanning 70+ museums in ~40 countries. This global consortium is pooling resources into a large trait database which will support efforts to digitise and interlink world museum holdings. The outputs are already being used in educational materials by major museums (serving hundreds of millions of public visitors annually) with many additional initiatives underway based on applying the trait database to environmental policy at organisational, national and international levels. I co-organised a meeting of the global traits consortium in Frankfurt in 2018 and we are running a daylong symposium in USA 2019.
First Year Of Impact 2017
Sector Digital/Communication/Information Technologies (including Software),Education,Culture, Heritage, Museums and Collections
Impact Types Societal,Policy & public services

Description GCRF: Social and Environmental Trade-offs in African Agriculture
Amount £5,630,400 (GBP)
Funding ID ES/P011306/1 
Organisation Economic and Social Research Council 
Sector Public
Country United Kingdom
Start 10/2017 
End 12/2021
Description Human-modified Tropical Forests Programme
Amount £3,200,000 (GBP)
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 01/2014 
End 12/2019
Title Fragmented communities database 
Description Lists of bird species occurring in forest fragments worldwide, generated from literature review. This links with the Global Bird Database to allow tests of functional responses to habitat fragmentation. 
Type Of Material Database/Collection of data 
Year Produced 2013 
Provided To Others? Yes  
Impact Two papers published so far. Bregman et al. 2014 Biological Conservation, and Bregman et al. in press Ecology 
Title Global Bird Database 
Description Large compilation of data for all (>10,000) bird species worldwide covering life history, environmental variables, biometrics, functional traits, etc. 
Type Of Material Database/Collection of data 
Year Produced 2013 
Provided To Others? Yes  
Impact None as yet but several collaborations underway 
Description Collaboration over Amazonian datasets with Jos Barlow, Lancaster 
Organisation Lancaster University
Country United Kingdom 
Sector Academic/University 
PI Contribution Statistical models and methods, additional datasets
Collaborator Contribution Large field-based datasets from long-term landscape-scale research projects
Impact Not yet.
Start Year 2012
Description Collaboration over global datasets with Andrew Meade, Reading 
Organisation University of Reading
Country United Kingdom 
Sector Academic/University 
PI Contribution Large datasets generated by the existing grant are being shared with Andrew Meade.
Collaborator Contribution Andrew Meade is performing large-scale phylogenetic analyses.
Impact No outcomes yet
Start Year 2012
Description Collaboration over global datasets with Walter Jetz, Yale 
Organisation Yale University
Country United States 
Sector Academic/University 
PI Contribution NERC funded work on tropical systems has led to projects tackling similar questions at a global scale in collaboration with biogeography and macroecology experts in Yale, USA (Walter Jetz)
Collaborator Contribution Research input into papers arising from the collaboration
Impact Two research papers: Pigot, A., Jetz, W., Sheard, C., Tobias, J.A. (2018) The macroecological dynamics of species coexistence in birds. Nature Ecology & Evolution 2: 1012-1019. Pigot, A., Tobias, J.A., Jetz, W. (2016) Energetic constraints on species coexistence in birds. PLoS Biology 14: e1002407.
Start Year 2012
Description Collaboration with B10K project 
Organisation Beijing Genomics Institute
Country China 
Sector Academic/University 
PI Contribution Functional traits for the world's birds
Collaborator Contribution Genomes for 10,000 species of birds. Several hundred already compiled. In-kind contribution in terms of sequencing costs are probably vastly underestimated.
Impact None yet, but several on the way
Start Year 2016
Description Collaboration with Helene Morlon 
Organisation École Normale Supérieure, Paris
Country France 
Sector Academic/University 
PI Contribution Functional trait dataset of the world's birds
Collaborator Contribution Technical expertise with unpublished analytical methods
Impact None yet, but 2 major papers in the pipeline
Start Year 2016
Description Collaboration with Luc Lens 
Organisation University of Ghent
Department Department of Biology
Country Belgium 
Sector Academic/University 
PI Contribution Functional traits of African birds
Collaborator Contribution Extensive field survey data from East Africa conducted over a series of years
Impact One publication above; others on the way
Start Year 2016
Description AvoNet consortium workshop 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Workshop to spearhead a global data sharing enterprise
Year(s) Of Engagement Activity 2018
Description Interviews and press releases for international media outlets 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Various interviews and press releases which have led to articles in national and international magazines and newspapers (over 30 outlets).
Most recently articles in The Atlantic (2018), The Daily Mail (2018), The Independent (2019), etc.
Year(s) Of Engagement Activity 2013,2014,2015,2016,2017
Description Public lecture to British Ornithologists' Union 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact A talk to members of a national interest group about findings of the research. The talk has been posted online and is being viewed globally.
Year(s) Of Engagement Activity 2018
Description Radio Interviews 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Interviewed live on the Today programme BBC Radio 4 to talk about my research. Also live-interviewed by Radio Wales and Radio Scotland.
Year(s) Of Engagement Activity 2018