Should government allow 25,000 cattle to starve or does it allow them to graze (until the next wet season) in protected nature reserves where they will certainly damage the natural environment? If this is an accurate way of posing the issues – I am unsure that the choices are as stark as this* – there is a real ethical dilemma. Economists tend to see these choices as involving choices at the margin whereas conservationists tend to emphasise the principle that nature reserves should be for nature. In addition, the decision to allow grazing creates a precedent for implementing the same actions in the future. In the link the RSPCA is listed as a pressure group favouring grazing – hardly surprising given their ambivalent attitudes towards nature and their attitudes toward the feral cats-type issues.
I reserve my judgment on the broad question posed – my biases are towards the views of the conservationists – but would be interested to learn the views of others. Crucial question: how damaging is the grazing? Should nature be assigned priority over human-raised animal populations?
* Is an alternative to cull the drought-endangered cattle? This would be the standard (and probably optimal) approach to drought were there no reserve-grazing options and the initial allocation of land between conservation and agricultural uses is not biased against agricultural interests. The sometimes-cited argument that cattle-grazing will remove combustible material in nature reserves is dubious.