Conservation traditionally focused on protecting species where they are. As species redistribution has become increasingly unpredictable, how should strategies evolve?
Such shifts are difficult to predict, since they depend on many factors and biotic interactions. But we already observe such redistributions on very short timescales (less than 10 years for research on lizards). Healthy forests might be the best and only option for insects to avoid heat mortality unless the temperature increase can be significantly reduced. Along elevational gradients, such as investigated in our study, animals could have the opportunity to migrate from hot lowland areas into cooler habitats at higher elevations. For this, it would be essential to provide so-called climate corridors: continuous, undisturbed habitat connecting lowland and highland regions. Maintaining the complexity of tropical forests, multiple layers and dense vegetation further provides more microhabitats for insects to avoid the hottest hours of the day.
One of your studies examines thermal tolerance in nearly 2,300 tropical insect species across Africa and South America. What is the most surprising finding to emerge from such a large dataset?
The close relationship between heat tolerance and protein melting temperatures were very interesting. This indicates that heat tolerance is deeply founded in insect DNA, supported by other results in our study, such as the differences between taxonomic groups. A potentially highly conserved trait like this is very unlikely to evolve over shorter time scales—especially not on the time scale of recent climate change (since this would require changes or mutations in a set of very fundamental protein structures). Our study paves the way for further exploring this novel result, providing new insights into the evolution of heat tolerance. We can further conclude that half of the insect community in the Amazon lowland might vanish under almost 60 per cent of the predicted surface temperatures and under over 40 per cent of the predicted air temperatures. Loosing half of the insect community would have cascading consequences for the ecosystem.
Could you share examples of tropical insects already living close to their upper thermal limits, and the impacts this has on their future?
Dung beetles in tropical lowland areas are often already living close to their upper thermal limits. Unlike insects in temperate regions, tropical species experience relatively stable temperatures year-round and have therefore evolved to tolerate only a narrow thermal range. By focusing on dung beetles as a specific model group, we showed that species diversity is lower at the lowest elevation (250 metres above sea level), while it peaks at mid-elevations (around 500 metres). Temperature was the main driver of these patterns. At low elevations, high temperatures can lead to critical heat stress, which likely excludes several more heat-sensitive species. Dung beetles play a key role as recyclers by breaking down animal dung and returning nutrients to the soil. This process improves soil fertility, supports plant growth, and enhances overall ecosystem productivity. By removing dung, they also reduce breeding sites for parasites and disease-causing organisms, helping to limit the spread of diseases. Because of these functions, dung beetles are essential for maintaining ecosystem health and stability, and their loss could disrupt nutrient cycling and broader ecological processes.
Your research suggests that insects at higher elevations retain greater thermal plasticity than lowland species. Is there any explanation or reason for this?
On a cellular level, there are certain protection mechanisms, so-called heat shock proteins, which can get activated through heat and then allow a slightly higher thermal tolerance. While highland insects in our study can temporarily boost their heat tolerance after a heat shock, lowland insects performed worse after the same treatment—suggesting their heat-stress mechanisms are already running at full capacity. Our results suggest that heat tolerance is constrained by fundamental biological mechanisms, meaning evolution is unlikely to keep pace with current climate change. So, while highland species might still have “room” to buffer higher temperatures, an upper ceiling is already reached in lowland species.
Will tropical insects with short life cycles be able to adapt or shift ranges to the rapidly changing climate?
The described cellular protection mechanism supporting short-term adaptation to heat might already be maxed out in lowland regions. Through behav-iour they might still be able to escape heat. But once the air temperatures are equally effected, and if not sufficient shade is available, the insects might not be able to escape. Also, frequent exposure to stressful temperatures also accumulate and could eventually be lethal, even if the temperature is way below their physiological limit. As our study points out, an evolutionary adaptation in pace with climate change is unlikely—this would eventu-ally lead to range shifts or local extinctions of populations—which can eventually lead to global extinctions.
This article is part of the cover story, “Great Migration”, which examines how climate change is redrawing the map of life on Earth. It was first published in the November 1-15, 2026, print edition of Down To Earth.