Wild animal suffering is the suffering experienced by nonhuman animals in nature through causes such as disease, injury, starvation, natural disasters, and killings by other animals. Wild animal suffering has historically been discussed in the context of philosophy of religion as an instance of the problem of evil. More recently, a number of academics have considered the suspected scope of the problem from a secular standpoint as a general moral issue, one that humans might be able to take action towards preventing.
There is considerable disagreement around this latter point, as many believe that human intervention in nature would be either unethical, unfeasible, or both.
In his autobiography, Charles Darwin acknowledged that the existence of extensive suffering in nature was fully compatible with the workings of natural selection, yet maintained that pleasure was the main driver of fitness-increasing behavior in organisms. Evolutionary biologist Richard Dawkins challenged Darwin's claim in his book River Out of Eden, wherein he argued that wild animal suffering must be extensive due to the interplay of the following evolutionary mechanisms:
The total amount of suffering per year in the natural world is beyond all decent contemplation. During the minute that it takes me to compose this sentence, thousands of animals are being eaten alive, many others are running for their lives, whimpering with fear, others are slowly being devoured from within by rasping parasites, thousands of all kinds are dying of starvation, thirst, and disease. It must be so. If there ever is a time of plenty, this very fact will automatically lead to an increase in the population until the natural state of starvation and misery is restored.
Building on this, others have argued that the prevalence of r-selected animals in the wild indicates that the average life of a wild animal is likely to be very short and end in a painful death. According to this view, the average life of a wild animal should thus contain more suffering than happiness, since a painful death would outweigh any short-lived moments of happiness in their short lives.
In Bambi or Bessie: Are Wild Animals Happier? Christie Wilcox argues that wild animals do not appear to be happier than domestic animals, based on findings of wild animals having greater levels of cortisol and elevated stress responses relative to domestic animals. Additionally, unlike domestic animals, animals in the wild do not have some of their needs provided for them by human caretakers. Welfare economist Yew-Kwang Ng has written that evolutionary dynamics can lead to animal welfare which is worse than necessary for a given population equilibrium.
In sober truth, nearly all the things which men are hanged or imprisoned for doing to one another, are nature's every day performances. [...] The phrases which ascribe perfection to the course of nature can only be considered as the exaggerations of poetic or devotional feeling, not intended to stand the test of a sober examination. No one, either religious or irreligious, believes that the hurtful agencies of nature, considered as a whole, promote good purposes, in any other way than by inciting human rational creatures to rise up and struggle against them. [...] Whatsoever, in nature, gives indication of beneficent design proves this beneficence to be armed only with limited power; and the duty of man is to cooperate with the beneficent powers, not by imitating, but by perpetually striving to amend, the course of nature - and bringing that part of it over which we can exercise control more nearly into conformity with a high standard of justice and goodness.
The English writer and naturalist Henry Stephens Salt wrote an entire chapter on the plight of wild animals, 'The Case of Wild Animals', in his 1894 book Animals' Rights: Considered in Relation to Social Progress. Salt wrote that:
It is of the utmost importance to emphasize the fact that, whatever the legal fiction may have been, or may still be, the rights of animals are not morally dependent on the so-called rights of property; it is not to owned animals merely that we must extend our sympathy and protection. [...] To take advantage of the sufferings of animals, whether wild or tame, for the gratification of sport, or gluttony, or fashion, is quite incompatible with any possible assertion of animals' rights.
Salt argued that humans are justified in killing wild animals in self-defense, but that "[...] we are not justified in unnecessarily killing—still less in torturing—any harmless beings whatsoever." He argues that this applies to insects as well: "We are unable to give life, and therefore ought not to take it away from the meanest insect without sufficient reason.'"
In 1991, the environmental philosopher Arne Naess critiqued what he termed the "cult of nature" of contemporary and historical attitudes of indifference towards suffering in nature. He argued that we should confront the reality of the wilderness and that we should be prepared to disturb natural processes when feasible to relieve suffering.
Holmes Rolston III argues that only unnatural animal suffering is a morally bad thing and that humans do not have a duty to intervene in natural cases. He celebrates carnivores in nature because of the significant ecological role they play. Others have argued that the reason that humans have a duty to protect other humans from predation is because humans are part of the cultural world rather than the natural world and so different rules apply to them in these situations. Others argue that prey animals are fulfilling their natural function, and thus flourishing, when they are preyed upon or otherwise die, since this allows natural selection to work.
That people would also be obliged to intervene in nature has been used as a reductio ad absurdum against the position that animals have rights. This is because, if animals such as prey animals did have rights, people would be obliged to intervene in nature to protect them, but this is claimed to be absurd. An objection to this argument is that people do not see intervening in the natural world to save other people from predation as absurd and so this could be seen to involve treating non-human animals differently in this situation without justification.
Some theorists have reflected on whether we should accept the harms that animals suffer in nature or try to do something to mitigate them. The moral basis for interventions aimed at reducing wild animal suffering can be rights-based or welfare-based. From a rights-based perspective, if animals have a moral right to life or bodily integrity, intervention may be required to prevent such rights from being violated by other animals.
From a welfare-based perspective, a requirement to intervene may arise insofar as it is possible to prevent some of the suffering experienced by wild animals without causing even more suffering. Advocates of intervention in nature argue that nonintervention is inconsistent with either of these approaches. Some proposed courses of action include removing predators from wild areas, refraining from reintroducing predators, providing medical care to sick or injured animals, and rescuing wild animals from natural disasters.
A common objection to intervening in nature is that it would be impractical, either because of the amount of work involved, or because the complexity of ecosystems would make it difficult to know whether or not an intervention would be net beneficial on balance. Aaron Simmons argues that we should not intervene to save animals in nature because doing so would result in unintended consequences such as damaging the ecosystem, interfering with human projects, or resulting more animal deaths overall. Philosopher Peter Singer has argued that intervention in nature would be justified if one could be reasonably confident that this would greatly reduce wild animal suffering and death in the long run. In practice, however, Singer cautions against interfering with ecosystems because he fears that doing so would cause more harm than good.
Other authors dispute Singer's empirical claim about the likely consequences of intervening in the natural world, and argue that some types of intervention can be expected to produce good consequences overall. Economist Tyler Cowen cites examples of animal species whose extinction is not generally regarded as having been on balance bad for the world. Cowen also notes that, insofar as humans are already intervening in nature, the relevant practical question is not whether we should intervene at all, but what particular forms of intervention we should favor. Philosopher Oscar Horta similarly writes that there are already many cases in which we intervene in nature for other reasons, such as for human interest in nature and environmental preservation as something valuable in their own rights. Likewise, moral philosopher Jeff McMahan argues that, since humans "are already causing massive, precipitate changes in the natural world," we should favor those changes that would promote the survival "of herbivorous rather than carnivorous species."
Peter Vallentyne suggests that, while humans should not eliminate predators in nature, they can intervene to help prey in more limited ways. In the same way that we help humans in need when the cost to us is small, we might help some wild animals at least in limited circumstances.
It has been argued that the common environmentalist goal of preserving the natural order is not in line with the goal of looking after the welfare of sentient animals. It has been further argued that they conflict in different cases. Examples include environmentalists supporting hunting invasive species for population control while animal rights advocates oppose it; animal rights advocates arguing for the extinction or reengineering of carnivores or r strategist species while deep ecologists defend their right to be and flourish as they are; animal rights advocates defending the reduction of wildlife areas or arguing against their expansion out of concern that most animal suffering takes place in them while environmentalists want to safeguard and expand the wild.