Essay by Eric Worrall
That stink at the Belém Climate Conference was climate change, not overloaded toilets.
Dung beetles have a tough life. Climate change is making it worse
Doyle Rice
USA TODAY
Updated April 5, 2026, 7:27 p.m. ETNot exactly the poster child for cute animals, dung beetles now join the list of species affected by human-caused climate change.
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Indeed, the long tentacles of climate change now extend all the way into the dreary lives of dung beetles in the Amazon rainforest, a new study suggests.
“With ongoing climate change, rising temperatures may push dung beetles beyond their physiological limits,” said study lead author Kim Lea Holzmann of the University of Wurzburg in Germany, in an e-mail to USA TODAY.
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“We studied the populations [of dung beetles] at altitudes of 250 to 3,500 metres above sea level,” said Holzmann, in a statement. “Unexpectedly, the number of dung beetle species fell rapidly between 250 and 500 metres above sea level.”
The reason for this: At an altitude of 500 metres, the temperatures are in a range that is ideal for the beetles, while the higher temperatures in the lowlands lead to heat stress.
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Read more: https://www.usatoday.com/story/news/nation/2026/04/05/climate-change-dung-beetles/89434093007/
The abstract of the study;
RESEARCH ARTICLES| 25 MAR 2026
Temperature boosts and constrains dung beetle diversity along an Andean–Amazonian elevation gradient
Kim L. Holzmann Corresponding Author ; Pedro Alonso-Alonso; Yenny Correa-Carmona; Andrea Pinos-Leon; Felipe Yon; Mabel Alvarado; Adrian Forsyth; Friederike Gebert; Alejandro Lopera-Toro; Andreas Kolter; Gunnar Brehm; Alexander Keller; Ingolf Steffan-Dewenter; Marcell K. Peters
Abstract
In the light of a warming climate, understanding factors shaping tropical biodiversity becomes increasingly urgent. Temperature can enhance diversity by increasing diversification and ecological rates but may also restrict diversity when exceeding organisms’ thermal limits. Changes in diversity can subsequently influence community specialization patterns. We tested the influence of temperature, moisture and food availability on the diversity of dung beetles (Scarabaeinae), food specialization and the mechanism of thermal limits along an Andean–Amazonian gradient from 250 to 3500 metres above sea level (m.a.s.l.). Beetles were sampled with dung, carrion and fruit-baited pitfall traps to test specialization; mammal activity was recorded as a proxy for food availability. Diversity showed no significant relationship with mammal biomass but increased with higher temperatures to 500 m.a.s.l., with a sharp drop at lower elevations. Lowland diversity was restricted by upper thermal limits, with small or negative thermal safety margins. Resource specialization increased towards the lowlands, potentially a product of greater diversity. Our findings highlight temperature as a primary driver of diversity, with upper thermal limits acting as a key constraint in lowland areas. Our data suggest that additional warming of the Amazonian lowlands may have detrimental consequences for dung beetles and their ecosystem functions, even in intact rainforests.
The study “tested” thermal range of dung beetles by stuffing them in plastic bottles and leaving them in the sun, to see if they survived. “… The experiment was done by exposing insects in individual plastic tubes (2 or 5 ml depending on body size) to increasing temperatures using a programmable thermoblock (Eppendorf Thermostat C, Hamburg, Germany) …“
Study authors dismissed previous studies which suggested higher rainfall in alpine regions might be driving diversity – “… Water availability has also been identified as a potential factor determining diversity gradients in previous studies … While dung beetle reproductive success has been shown to increase under moist conditions …“
In my opinion this study is an absurdity. Dung beetles modify their environment, if they’re too hot they dig a little deeper – not something they can do when stuck in a plastic tube. The researchers have no idea what killed the beetles in the tubes. More reliable moisture in my opinion is by far the most plausible explanation for why abundance is higher a few hundred meters above sea level.
There are other possible explanations for differences in species distribution at different altitudes. Dung beetles can be specialists, when cattle were introduced to Australia the local dung beetles couldn’t handle cattle dung, so different abundance of species at different altitudes might be driven by the abundance of species which produce the dung, and have nothing to do with any direct impact of environmental conditions on Dung Beetle survival.
