Eastern meadowlark (photo from

The number astounded me.

“Ninety-six percent of the world’s mammals, by weight, are now humans and their livestock; just four percent are wild.” (From the book The Uninhabitable Earth by David Wallace-Wells, citing the statistic from “The Biomass Distribution on Earth” by Yinon M. Bar-On, et al., published in the Proceedings of the National Academy of the Sciences (June 2018).

I could not accept those counterintuitive figures, observing the number of wildlife species that populate our small farm, so I did some calculations. Even in the decidedly rural state of Iowa where we live, wildlife numbers are dwindling while livestock numbers are growing exponentially. The number of pigs (primarily raised in CAFOs – concentrated animal feeding operations) is 24 million and cattle 3.7 million. There are about 200,000 horses, 160,000 sheep, and 37,000 goats.

Add in the number of humans and the total is about 31.2 million. The human population has been slowly increasing. In 1920 it was 2.4 million, in 2020 a little less than 3.2 million. Except in the metro areas, the state’s population has decreased precipitously; which would seem to be good for wildlife numbers but because of agricultural practices which have denuded the land of habitat for wildlife the effect has been a steady, but steadily steep, decline in wild animals. Pigs now outnumber people in Iowa by a factor of 8-1, which reinforces my contention that we have made a virtually complete transition to industrial agriculture and its sterile soil and polluted waterways. Neither of those factors is conducive to wildlife propagation.

Returning to biomass estimates, Iowa’s livestock – plus humans – accounts for about 7.4 billion pounds of biomass. That is a lot of cottontail rabbits. About three billion of them. I’m not suggesting the state could possibly provide habitat for three billion rabbits, my point is that we, even as a rural state, must be very close to that biomass percentage: 96 percent humans and their livestock, only four percent wild animals.

Because we are dealing with mammalian species, that percentage does not include the state’s poultry. There are about 12 million turkeys (250 million pounds of biomass) and about 68 million chickens (200 million pounds). The Iowa Department of Natural Resources is rather coy about estimates of the number of pheasants in the state, certainly less than 800,000, To match the domestic poultry biomass it would have to be 180 million. More than 400 songbird species make their home in Iowa at least part of the year. To equal the biomass of the state’s poultry numbers there would have to be about 2 billion of them in total.

A farm state, a rural state, a state with less than 3.2 million residents. Imagine, with horror, what minimal percentage of wildlife other parts of the world must support. Even if we consider rats and cockroaches to be part of the fauna, a miniscule portion of the planet’s biomass is part of the ever-shrinking population of wild animals.

Once upon a time, there were four pair of eastern meadowlarks in our hayfield. Now there are none. A global population of eight billion people demands more and more of the world’s resources, and as the Earth becomes warmer and sea levels rise and climate extremes become “normal” weather there will be far fewer resources available. Those resources include the wild animals we have hunted and the wild produce we have harvested.

A dreary, spiritless future. I am fortunate to live in the era of history before the wild places and wild creatures were extirpated from my part of the Earth. With the passing of the wild, I want to pass on, too.


More essays and stories about life in the North Country are published in my six collections of essays, available through at  Jerry Johnson Author Page

About Jerry Johnson

Curmudgeon. Bird hunter and dog trainer. Retired journalist and college public relations director. Former teacher, coach, mentor. Novelist and short story writer. Husband, father, grandfather.
This entry was posted in Wildlife, Wildlife Habitat and tagged , . Bookmark the permalink.

1 Response to Biomass

  1. Thom Hickey says:

    Wise words.

    Regards Thom

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