Climate Change Vulnerability & Adaptation

Coordinators

Dr Rob Simmons
Dr Phoebe Barnard (Birds & Environmental Change Partnership, SANBI)

Research team

Dr Res Altwegg (Postdoctoral Fellow, Avian Demography Unit, UCT and Global Change & Biodiversity Programme, SANBI), Mr Mark Anderson (Northern Cape Department of Tourism, Environment & Conservation), Mr Bernard Coetzee (PhD student, Stellenbosch University and Global Change & Biodiversity Programme, SANBI), Dr Richard Dean (PFIAO), Dr Barend Erasmus (University of the Witwatersrand), Professor Brian Huntley (Durham University), Dr Guy Midgley (Global Change & Biodiversity Programme, SANBI), Mr Thabiso Mokotjomela (PhD student, Stellenbosch University and Global Change & Biodiversity Programme, SANBI), Dr Jeff Price (California State University at Chico, USA), Dr Terry Root (Stanford University, USA), Dr Clelia Sirami (postdoctoral fellow, Global Change & Biodiversity Programme, SANBI), Professor Les Underhill (Avian Demography Unit, UCT).

Overview

Phoebe Barnard and young colleagues ringing passerines in central Namibia (Photo: Rob Simmons)

There are few greater challenges facing biodiversity today than that posed by anthropogenic climate change. While barely six years ago, climate change was still regarded as a peripheral and controversial issue, the international scientific consensus on its magnitude, causes and types of consequences is now virtually complete. Climate change impacts on southern African biodiversity are expected to be highly significant. Africa is widely accepted to be the continent most vulnerable to climate change and least equipped to adapt to it. Nonetheless, its biodiversity science community lags badly behind those of the northern hemisphere and Australia in understanding these impacts.

Even more worryingly, climate change impacts are increasingly understood to be exacerbated by other global change drivers, such as land use change, biotic invasion and desertification. These other drivers have already significantly altered southern African ecosystems, and the ways in which they compound the impacts of climate change are complex and often difficult to predict in detail. The magnitude and pace of these problems demands a concerted research response, coupled to concrete tools for conservation planners, policy policymakers and habitat managers.

Together with the South African National Biodiversity Institute’s (SANBI’s) Birds and Environmental Change Partnership, based in the Global Change and Biodiversity Programme at Kirstenbosch, the PFIAO has thus established a programme focusing on the vulnerability of bird species to climate change, and other drivers of environmental change which worsen its impacts. The scientific research work is done jointly by the PFIAO, Avian Demography Unit of UCT, and SANBI, with international partners. The policy and planning translation is undertaken mainly by SANBI with partners’ inputs.

Key themes and questions

It is critical that conservation management responses to climate change are focused, well-informed by solid research, achievable and cost-efficient. Our approach therefore relies on a hierarchy of questions, from basic to applied.

Which species are most vulnerable, and why?

Which ecological, behavioural and life history traits influence birds’ vulnerability to range changes? Our initial analysis of six species predicted an average 40% range loss, but only one species, Blue Swallow Hirundo atrocaerulea, is currently on South Africa’s Red Data List. We use demographic and spatial models to analyse long-term datasets, and will establish new long-term studies of carefully chosen species. Drs Wilfried Thuiller and Res Altwegg are developing advanced bioclimatic envelope and demographic modeling techniques, which we will combine in more sensitive analyses.

How do differences in vulnerability affect populations?

Large-scale range shifts on their own are a very incomplete way of understanding impacts. We need to establish how populations are affected in detail – which individuals or age classes suffer most and why; how breeding, migration and other activities are affected; and whether normal activities carry increased costs (e.g. energetics) and risks (e.g. predation) for individuals as the climate changes. This work is constrained by the availability of long-term population datasets, but a series of collaborative manuscripts is emerging.

What are the risks for threatened, small and peripheral populations?

Cape Sugarbird - proteoid interactions: one of many relationships to be affected by climate change...? (Photo: I. Grastveit & S. Byrkjeland)

In a series of planned analyses, we will look in particular at threatened and restricted-range species, including montane endemics, species mutualists such as pollinators, and Red Data species to analyse impacts on these birds and the species which depend on them. Cape sugarbirds Promerops cafer and proteas, particularly along their range limits, are an example of this. Considerable new fieldwork is needed to address this effectively.

The potential influence of climate change on southern African vultures and passerines. Recent surveys of two threatened mountain-dwelling vultures (Bearded Gypaetus barbatus and Cape Vulture Gyps coprotheres) suggest that factors other than poisons and habitat change may help explain population declines. We tested the hypotheses that climate change would negatively influence lower-latitude colonies before higher ones, lower-altitude sites before higher ones, and north-facing cliffs before south-facing ones. All predictions were supported for both species. In Lesotho, low-altitude sites are being abandoned and birds are retreating to high-altitude sites. Colonies in Namibia and Zimbabwe have gone extinct as breeding colonies in the last 2 decades when temperatures have climbed most rapidly. Behavioural observations of birds on north-facing cliffs also indicate widespread shading of chicks.

Further BIOTA-funded studies by Rob Simmons will assess the relative impact of climate and habitat change on Namibian passerines across a rainfall gradient.

How can conservation planning, policy and management respond to these challenges?

Finally, in work led by SANBI, the results of climate change research will be increasingly fed into the science-policy interface – through uptake of data in State of the Environment (SoE) reports, biodiversity indicators, and contributions to species and habitat management planning. Although this component is still in its infancy, long-term datasets and large-scale projects (such as the 2nd Southern African Bird Atlas Project and its successors) which can inform public policy are being secured financially by SANBI. The goal is to track southern Africa’s bird species over time and space and provide baselines and snapshots of environmental change. Such work is badly needed to shape and strengthen appropriate conservation strategies for the future.