Temperature boosts and constrains dung beetle diversity along an Andean-Amazonian elevation gradient

Area of Science:

• Ecology
• Climate Change Biology
• Zoology

Background:

• Understanding tropical biodiversity drivers is critical in a warming climate.
• Temperature influences species diversity through ecological rates and thermal limits.
• Biodiversity changes can impact community specialization.

Purpose of the Study:

• To investigate temperature, moisture, and food availability effects on dung beetle diversity and specialization.
• To examine thermal limits as a mechanism shaping dung beetle communities along an Andean-Amazonian gradient.
• To assess the impact of climate change on tropical insect biodiversity and ecosystem functions.

Main Methods:

• Studied dung beetle (Scarabaeinae) diversity and food specialization across an elevation gradient (250–3500 m.a.s.l.).
• Utilized pitfall traps (dung, carrion, fruit-baited) to assess specialization.
• Measured mammal activity as a proxy for food availability.

Main Results:

• Dung beetle diversity increased with temperature up to 500 m.a.s.l., then sharply declined.
• Lowland diversity was constrained by upper thermal limits, indicated by small or negative thermal safety margins.
• Resource specialization increased in lowland areas, potentially linked to higher diversity.

Conclusions:

• Temperature is a primary driver of dung beetle diversity in the Andean-Amazonian region.
• Upper thermal limits significantly constrain lowland biodiversity.
• Further warming in Amazonian lowlands could negatively impact dung beetles and ecosystem services.