Talk:Ant/Archive 3

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Archive 3

Ant to vertebrate biomass information flaws

From biomass information in the Cattle wikipedia article:

"It has been estimated that out of all animal species on Earth, Bos taurus has the largest biomass at roughly 400 million tonnes, followed closely by Euphausia superba (Antarctic krill) at 379 million tonnes, and Homo sapiens (humans) at 373 million tonnes."

From this article:

"Their ecological dominance is demonstrated by their biomass: Ants are estimated to contribute 15–20 % (on average and nearly 25% in the tropics) of terrestrial animal biomass, exceeding that of the vertebrates.[25] Myrmecologist E. O. Wilson estimated that the total number of individual ants alive in the world at any one time is between one and ten quadrillion (short scale) (i.e., between 10^15 and 10^16). According to this estimate, the total biomass of all the ants in the world is approximately equal to the total biomass of the entire human race.[26] According to this estimate, there are also approximately 1 million ants for every human on Earth.[27] A 2022 study based on a systematic sampling dataset suggested a higher figure of 20 quadrillion ants on earth at any given time."

The statement "...exceeding that of the vertebrates." seems substantially incorrect even if the 20 quadrillion ant estimate is used. I reasonably read (close skim of unrelated elements) reference 25 at https://NCBI.NLM.NIH.Gov/pmc/articles/PMC34089/ but found no suggestion that ants exceed the biomass of vertebrates - the reference doesn't seem to support that aspect of the biomass statements in this Wikipedia article.

Consider that cattle and Homo Sapiens each by themselves seem to very roughly equal ant biomass before accounting for any other vertebrates (discounting fish and sea mammals in vast waters where no ants reside), so quite rough though biomass accounting appears to be, ants seem to rank at less than half of the mass of non-aquatic vertebrates - perhaps substantially less. (And much less than that for all Earth vertebrates, and further less for all Earth biomass.)

In addition in many uses "terrestrial" excludes animals which are aquatic, arboreal, or aerial. The aquatic exclusion could be used, but many ants are aerial or arboreal in some measure, so "terrestrial" fails to provide specifically defined boundaries as required for ant and other animal biomass accounting. (In my view reference 25 is also flawed in that regard.)

So, though imperfectly aligned to reference 25, but evidently much more accurate overall, I suggest revising that first sentence to:

'Their ecological significance is suggested by their biomass: Ants are estimated to contribute 15–20 % (on average and nearly 25% in the tropics) of non-aquatic animal biomass.[25]'

I'll await reactions that my sense of this seems either correct or flawed, or other comments, for a week or two before revising that sentence in the article.

Cheers! --H Bruce Campbell (talk) 13:06, 19 October 2022 (UTC)

Like in the past discussions on the topic, it is unclear if the vertebrate estimates are based on dry weight or if they used live weight (about 70% water for mammals, much lower for insects). Shyamal (talk) 14:01, 19 October 2022 (UTC)

PS: The most recent work is quite clear that this is dry weight - "we conservatively estimate 20 × 1015 (20 quadrillion) ants on Earth, with a total biomass of 12 megatons of dry carbon. This exceeds the combined biomass of wild birds and mammals and equals 20% of human biomass." https://www.pnas.org/doi/10.1073/pnas.2201550119 - yes the line needs editing. Shyamal (talk) 16:26, 19 October 2022 (UTC)

Have updated the statements with the latest October 2022 paper results which is much clearer than old estimates. Let me know if you are interested in that paper. Shyamal (talk) 16:50, 19 October 2022 (UTC)