Boom-Bust Dynamics Drive Community-Wide Dietary Structuring in Desert-Dwelling Raptors

Area of Science:

• Ecology
• Zoology
• Environmental Science

Background:

• Dryland environments exhibit boom-bust dynamics, characterized by fluctuating productivity.
• These dynamics significantly impact ecological functions, influencing populations, communities, and consumer diets, including top predators.

Purpose of the Study:

• To investigate how rainfall-triggered productivity changes affect raptor diets in a central Australian desert.
• To understand the influence of boom-bust dynamics on a diverse raptor community (19 species).

Main Methods:

• Long-term monitoring data of a diverse raptor community in a central Australian desert.
• Analysis of dietary structure in relation to extreme boom-bust conditions driven by rainfall.

Main Results:

• Boom-bust dynamics alter raptor community dietary structure, mediated by prey preferences and movement.
• Raptor dietary niche breadth was larger during bust periods compared to boom periods.
• Small mammals and birds were more common in diets during booms, while reptiles dominated during busts.

Conclusions:

• Predators generally focus on preferred prey during high productivity but switch to alternative prey in unfavorable conditions.
• Dietary switching can enhance raptor persistence in destabilizing boom-bust systems due to climate change.
• Dietary specialists, particularly sedentary ones, are vulnerable to long-term declines in preferred prey under future climates.