(a) Conceptual diagram showing how the three components of climate change vulnerability, namely sensitivity, exposure and low adaptive capacity describe four distinct categories of climate change vulnerable species, each with particular implications for conservation prioritisation and strategic planning.

Foden et al. (2013)

Ecologists are increasingly using large-scale modelling of species’ distributions in order to forecast the impacts of climate change on biodiversity (Thuiller 2007). Such models can produce sobering predictions: for example, 15–37% of species are likely to be ‘committed to extinction’ by 2050 according to one such study (Thomas et al. 2004). However, bioclimatic models rely on broad assumptions and rarely take into account species-specific biological traits.

The degree to which species will be impacted by climate change depends on their inherent sensitivity and ability to adapt, as well as the degree to which they are exposed to changes in climate. Species’ sensitivity and adaptive capacity depends on a suite of taxon-specific biological and ecological traits. BirdLife has collaborated with the International Union for Conservation of Nature (IUCN) and others to develop a novel approach to identifying those species most at risk from climate change, and applied this to all the world’s birds (Foden et al. 2013). Between a quarter and a half of all bird species may have traits that make them particularly vulnerable to climate change. Up to 83% of those bird species identified as highly vulnerable to climate change are not yet considered threatened on the IUCN Red List. Similarly in a recent study in North America, less than 1% of climatically threatened or vulnerable bird species were also found on the Red List (Langham et al. 2015). This is of concern, as it indicates that these species may not yet be the focus of conservation efforts.

Certain taxonomic groups are shown to be particularly sensitive, including seabirds within the Diomedeidae (albatrosses), Spheniscidae (penguins), Procellariidae, Pelecanoididae and Hydrobatidae (petrels and shearwaters) families and Neotropical forest-dependent passerines such as Thamnophilidae (antbirds), Formicariidae (antthrushes and antpittas) and Pipridae (manakins).

Similarly high levels of climate-change susceptibility were identified for amphibians and warm water reef-building corals, suggesting that climate change is likely to have a profound impact not just on birds, but on global biodiversity as a whole.

Species that are ‘highly climate change vulnerable’ (1), being sensitive exposed and of low adaptive capacity, are of greatest concern. They are the first priority for monitoring responses to climate change and for assessment of the interventions needed to support them. ‘Potential adapters’ (2) are sensitive and exposed (but high adaptive capacity) species that may be able to mitigate negative climate change impacts by dispersal or microevolution, although close monitoring is needed to verify this. ‘Potential persisters’ (3) have low adaptive capacity and are exposed (but are not sensitive) so may be able to withstand climate change in situ by themselves, but again, monitoring is needed to ensure that the assumptions about insensitivity are realized in practice. Finally, species of ‘high latent risk’ (4) have low adaptive capacity and are sensitive (but are not exposed). Althogh not of immediate concern if climate change projections and emissions scenarios are accurate, they could become climate change vulnerable if exposed beyond selected time frames (e.g., 2050).

(b) Number of bird species falling into these four categories, plus those that score highly for just one component of climate change vulnerability, or none.

Foden et al. (2013)

Certain taxonomic groups are shown to be particularly sensitive, including seabirds within the Diomedeidae (albatrosses), Spheniscidae (penguins), Procellariidae, Pelecanoididae and Hydrobatidae (petrels and shearwaters) families and Neotropical forest-dependent passerines such as Thamnophilidae (antbirds), Formicariidae (antthrushes and antpittas) and Pipridae (manakins).

Similarly high levels of climate-change susceptibility were identified for amphibians and warm water reef-building corals, suggesting that climate change is likely to have a profound impact not just on birds, but on global biodiversity as a whole.

Species that are ‘highly climate change vulnerable’ (1), being sensitive exposed and of low adaptive capacity, are of greatest concern. They are the first priority for monitoring responses to climate change and for assessment of the interventions needed to support them. ‘Potential adapters’ (2) are sensitive and exposed (but high adaptive capacity) species that may be able to mitigate negative climate change impacts by dispersal or microevolution, although close monitoring is needed to verify this. ‘Potential persisters’ (3) have low adaptive capacity and are exposed (but are not sensitive) so may be able to withstand climate change in situ by themselves, but again, monitoring is needed to ensure that the assumptions about insensitivity are realized in practice. Finally, species of ‘high latent risk’ (4) have low adaptive capacity and are sensitive (but are not exposed). Although not of immediate concern if climate change projections and emissions scenarios are accurate, they could become climate change vulnerable if exposed beyond selected time frames (e.g., 2050).

This case study is taken from ‘The Messengers: What birds tell us about threats from climate change and solutions for nature and people’. To download the report in full click here.