Ecological and life‐history traits may say little about birds’ vulnerability to high‐amplitude climatic fluctuations

Abstract

Species-specific 'resistance' to impacts, such as accelerated climate change, and 'resilience' (if pressures are released), have important implications for long-term persistence. There have been some reports that species' traits may be related to resistance and resilience. We sought to determine whether guild membership, ecological versatility or life-history traits of woodland birds were related to species' resistance and resilience in the face of high-amplitude climatic fluctuations over two decades. There were four extensive survey programmes in temperate woodlands in Victoria, Australia, spanning the longest, most intense drought on record in the region (Big Dry: 1996-2010), a short, intense wet period (Big Wet: 2010-2012) and a return to very dry conditions (post-Big Wet: 2012-2016). We used species-specific reporting rates (RRs) to identify species having low resistance to the Big Dry, high resilience (recovery) during the Big Wet and low resistance over the whole survey period (1996-2016). Species falling into these three groups were compared with species not showing those responses, and the contrasting groups evaluated for systematic differences in ecological and life-history traits. Neither ecological nor life-history traits accounted for much variation in the three contrasts, suggesting that Big Dry-and overall-resistant species and Big Wet-resilient species were not coherent subsets of the terrestrial avifaunas. Given that species' traits were not related to vulnerability or to immunity from climatic pressures, we probably need to concentrate on species directly rather than groups defined by common life-history or ecological traits. Moreover, it almost certainly will be more useful to focus conservation management on reducing pervasive, manageable pressures (e.g. natural resource extraction, land-use change, reductions of greenhouse gas emissions), which is likely to provide assemblage-wide benefits for birds and other taxa.

Underlying trends confound estimates of fish population responses to river discharge

“…Large‐scale disturbances can synchronise population dynamics, both spatially and temporally, resulting in similar trends in functionally distinct species (Keitt, 2008). A similar disconnect between life history and species' responses was observed in birds surveyed over the same period in south‐eastern Australia (Mac Nally et al., 2020). We stress that similar responses to discharge attributes under extreme conditions is not evidence that these species will respond similarly to less extreme discharge conditions.…”

“…Largescale disturbances can synchronise population dynamics, both spatially and temporally, resulting in similar trends in functionally distinct species (Keitt, 2008). A similar disconnect between life history and species' responses was observed in birds surveyed over the same period in south-eastern Australia (Mac Nally et al, 2020).…”

Does life history mediate discharge as a driver of multi‐decadal changes in populations of freshwater fish?

“…Such knowledge will likely be equally as useful in other systems (although it is important to note that ecological and life history traits may not always predict how groups of species respond to environmental change; Mac Nally et al. 2020). For example, development mode dictates how different frog species respond to deforestation, and in turn, which restoration strategy will be most suitable (Becker et al.…”