How to mitigate the harm caused by veganism?

As the production of animal protein is less efficient than plant-based protein, vegans use less agricultural land than omnivores. If everyone went vegan, a land area almost the size of the North and South American continent is no longer needed for agriculture. If this agricultural land is turned back into natural habitats such as forests, a huge number of extra wild animals will be born. But there is a lot of wild animal suffering from hunger, disease, predation, parasitism, injuries, fires, cold,… Most wild animals die prematurely, which can indicate that they have a negative welfare overall.[1] Hence, by freeing up agricultural land, vegans cause harm (to wild animals). How much harm is cause by adopting a vegan diet, and how can vegans mitigate this harm?

First, how much agricultural land is used by an average omnivore and an average vegan (based on average western data)? The table below shows the hectares of land used by one person. (All data are obtained by Gemini.) An omnivore uses three times as much agricultural land as a vegan, mostly due to the extra grazing land.

The 0,11 hectare cropland used by an omnivore is used to produce feed crops for farmed animals. Roughly one third of the feed-cropland is used to feed chickens (broiler and laying hens), a quarter to feed cows.

An hectare of cropland can produce enough food to feed roughly 2000 broiler chickens, 30 pigs and 3 cows per year. An hectare of grazing land can sustain roughly one cow per year.

Next to the farmed animals, we also have to consider the wild animals. In a forest or grazing land without large grazers, more than 2000 wild vertebrate animals (mammals, birds, amphibians, reptiles) can be born per hectare per year. That is five times higher than on cropland.

With the above data, we can calculate the number of vertebrate land animals that are born each year and whose birth is determined by the food choice of one human. 

An average omnivore, eating an average western omnivorous diet, causes the birth of 55 farmed animals. Those farmed animals mostly have a negative welfare as intense as the positive welfare of a human, according to a survey of people in Belgium. Next to the farmed animals, on the cropland and grazing land indirectly used by the omnivore, 265 wild vertebrate animals are born each year. Those wild animals my have a welfare around zero (according to the abovementioned survey), but they may also have a negative welfare (according to many experts).

A vegan does not cause the birth of farmed animals, but if the freed up agricultural land is turned into forest, 465 wild vertebrate animals are born each year in that forest. In other words: the choice of the vegan to let the agricultural land be turned into forest land, causes 200 extra births of wild animals each year. 

In total, an omnivore brings about the birth of 320 vertebrate animals per year, on the land area used for livestock agriculture, whereas a vegan brings about the birth of 465 animals per year on the same land area. If wild animals have zero welfare on average, the vegan doesn’t cause animal harms: the vegan doesn’t cause the existence of animals with a negative welfare, whereas the omnivore causes the existence of a few dozen farmed animals with a negative welfare. However, if the wild animals have a negative welfare as intense as the negative welfare of farmed animals, the vegan causes 45% more animal suffering than the omnivore. 

How can the vegan mitigate this harm caused to wild animals? By choosing for ecosystems that have the lowest wild animal birth and mortality rates, i.e. natural habitat where animals have higher average life spans and lower fertility rates. These can be grasslands with large herbivores such as horses. On grazing land with large herbivores, fewer wild vertebrate animals are born than in forests. Wildlife fertility control might be an additional measure to decrease the fertility rates of small, highly reproductive animals. If the freed up agricultural land is turned into grassland with wild roaming horses and donkeys, the vegan brings about the birth of 295 wild animals on that grassland. If these wild animals would have a negative welfare equal to the welfare of farmed animals, the vegan would still cause the existence of fewer negative-welfare animals than the omnivore. Hence, the vegan causes less animal harm than the omnivore. 

This also sheds a new light on the “What about crop deaths?” argument against veganism. Vegan agriculture kills wild animals on cropland. But if those wild animals have neutral or negative welfare (i.e. with lives not worth living), their deaths are neutral or good, as their deaths decrease the populations of wild animals with neutral or negative welfare.

Note: for simplicity, invertebrates are not considered: assume invertebrate animals have zero welfare on average.

Conclusion: vegans might cause the existence of more animals with a negative welfare than omnivores. To mitigate this harm caused to wild animals by vegans, vegans should make sure that the freed up agricultural land is turned into grassland with large herbivores (or more generally: natural habitat with animals that have the lowest fertility rates), and promote wildlife fertility control to reduce populations of small, highly reproductive animals. 

[1] Consider for example a country like Afghanistan, where less than 1 in 10 children die, and people have on average a well-being of 1,4 on the Cantril scale from 0 to 10, which is lower than the neutral point of 2,5. In contrast, in nature, more than 9 out of 10 juveniles die prematurely. If welfare negatively correlates with premature death rate, wild animals most likely have negative welfare on average.