Spatial Risk Effects From Lions Compound Impacts of Prey Depletion on African Wild Dogs.

Area of Science:

• Ecology
• Conservation Biology
• Wildlife Management

Background:

• Prey depletion poses a significant threat to carnivore populations worldwide, particularly subordinate competitors like African wild dogs.
• Dominant competitors, such as lions, can limit subordinate species' densities, especially in ecosystems with reduced prey availability.
• Understanding these interspecific dynamics is crucial for effective conservation strategies in large carnivore guilds.

Purpose of the Study:

• To investigate whether African wild dogs continue to avoid lions and associated high-prey-density habitats in an ecosystem with anthropogenically reduced prey and lion densities.
• To determine if the competitive effects of lions on wild dogs persist despite lower lion densities.

Main Methods:

• Spatial data analysis of wild dog and lion movements and densities within the prey-depleted Greater Kafue Ecosystem.
• Testing the hypothesis that wild dogs avoid lions and consequently avoid habitats preferred by their key prey species.

Main Results:

• Wild dogs strongly avoided lions, even at densities three times lower than in comparable ecosystems.
• Wild dogs also avoided habitats rich in their primary prey species, which were also utilized by lions.
• Prey-base homogenization, where lions increasingly rely on the same prey as wild dogs, exacerbates competitive effects.

Conclusions:

• Reduced lion density does not necessarily alleviate competitive pressure on African wild dogs.
• The continued avoidance of lions and preferred prey habitats by wild dogs explains their population declines in tandem with dominant competitors in prey-depleted areas.
• Conservation efforts must focus on protecting prey populations in critical wild dog strongholds to prevent further declines and address carnivore guild dynamics.