Amid the current human driven biodiversity crisis and the emergence of SARS‑CoV‑2 (the virus causing COVID-19), the connections between zoonotic viruses and habitat loss have been brought into the public spotlight. However, the linkage between the two issues has already been public knowledge and warned about by ecologists for years (Gibb et al., 2020).
Simply stated, zoonotic viruses are those that have evolved the ability to jump the species barrier, travelling from animals to humans. The emergence of zoonotic viruses is known to be influenced by the increased amount of contact made between humans and animals due to habitat loss. In fact, Dobson et al. (2020) showed that the risk of zoonotic virus transmission is increased for humans in contact with wildlife such as primates and bats; as well as domesticated animals including chickens, and pigs.
The risks for zoonotic disease transmission are compounded by the fact that humans are continuously expanding our environmental footprint. We are constantly destroying habitats to make room for agriculture, housing, and other industries. As such, we are consequently reducing the Earth’s biodiversity and increasing our physical contact with the wildlife that is being forcibly removed from their habitats.
As species die off, a void is left in ecosystems that is then filled by the species that are able to adapt and survive on the newly available resources. Unfortunately, as Tollefson (2020) states, the species filling the void, such as rats and bats, tend to also be the ones most likely hosting the zoonotic viruses.
Recent examples of zoonotic viruses include the avian and swine influenzas; variants of which have increased in recent years. This phenomenon is likely due to the increase in contact between humans and wildlife as our population continues to expand into new areas previously uninhabited by humans (Tollefson, 2020).
References
Dobson, A. P., Pimm, S. L., Hannah, L., Kaufman, L., Ahumada, J. A., Ando, A. W., … & Vale, M. M. (2020). Ecology and economics for pandemic prevention. Science, 369(6502), 379-381.
Gibb, R., Redding, D. W., Chin, K. Q., Donnelly, C. A., Blackburn, T. M., Newbold, T., & Jones, K. E. (2020). Zoonotic host diversity increases in human-dominated ecosystems. Nature, 584(7821), 398-402.
Tollefson, J. (2020). Why deforestation and extinctions make pandemics more likely. Nature, 584(7820), 175-177.
Applied Plant Ecology Winter 2020 