Savanna birds show surprising vulnerability to climate change

Dr April Reside of James Cook University has just spent several years studying birds that live in Australia's tropical savannas, with an eye to assessing their potential vulnerability to climate change.  You don't have to be a bird-lover to find some of her conclusions alarming.

  Cry for help... the Papuan Frogmouth is vulnerable to climate change.

Cry for help... the Papuan Frogmouth is vulnerable to climate change.

When it comes to species being vulnerable to climate change, many people think of polar bears -- or other species that are highly specialized to local conditions.

A lot of research has focused, for example, on mountain-top endemics -- species reliant on cool, misty mountains whose habitat could shrink and collapse with rising temperatures.

Fewer people are thinking about widespread, generalist, common species -- why would they be of concern?

Many birds in the Australian tropical savannas are widespread generalists.  This is probably because they are adapted to highly variable conditions, and need to continually travel about to find the next source of food –- usually flowering trees or pulses of insects after recent rains.

  Vast expanses of northern Australia are dominated by tropical savannas.

Vast expanses of northern Australia are dominated by tropical savannas.

Such ephemeral food sources might become increasingly rare or thin on the ground if conditions get tougher with climate change.  So, these widespread generalist species might be more vulnerable to climate change than many have expected.

I investigated the vulnerability of 243 bird species found in Australian tropical savannas to climate change.  To do this I incorporating a range of different factors: their sensitivity to fire, their dietary breadth, their range size, and their abundance.

I also incorporated the amount of suitable climate space each species was likely to have by the year 2085, under a severe climate-change scenario.

  The critically endangered Golden-shouldered Parrot is another big worry  (image from Karl Seddon, http://webgram.co/karlseddon).

The critically endangered Golden-shouldered Parrot is another big worry (image from Karl Seddon, http://webgram.co/karlseddon).

I found that many savanna species that are restricted to the Cape York Peninsula are particularly vulnerable to climate change.  Alarmingly, this includes endangered Golden-shouldered Parrot and the endangered Buff-breasted Buttonquail.

However, some species that occur across the northern savannas might actually benefit from climate change -- at least if rainfall changes as some projections indicate.

We will have to keep monitoring the species, particularly those that are already declining and likely to be severely impacted by climate change. 

A key strategy is to devise plans of how to intervene if necessary.  To do that, we might have to make tough choices in the future.  For instance, might some species have a better chance of persisting in zoos than in the wild?  Might major changes in burning, grazing, or land-clearing practices -- possibly putting us as odds with powerful agricultural interests -- become necessary?

My in-depth work on savanna birds shows me that we can't worry just about polar bears or specialized moutaintop species.  We also need to fret about lots of other wildlife in which climate change could make their battered and dwindling populations even more vulnerable to severe stresses in the future.