Vulture Exclusion Halves Large Carcass Decomposition Rates and Doubles Fly Abundance

Area of Science:

• Ecology
• Wildlife Conservation
• Public Health

Background:

• Scavengers, particularly vultures, are vital for ecosystem health and disease mitigation.
• Vulture populations have declined globally, with less data on Neotropical species.
• The impact of vulture decline on invertebrate scavengers and carrion decomposition is largely unknown.

Purpose of the Study:

• To investigate the impact of neotropical cathartid vulture exclusion on carrion decomposition rates.
• To assess changes in insect scavenger abundance (flies and dung beetles) following vulture exclusion.
• To evaluate the role of habitat type and season in vulture exclusion experiments.

Main Methods:

• Experimental exclusion of vultures from domestic pig carcasses (Sus scrofa) in Costa Rica.
• Comparison of decomposition rates and insect abundance between excluded and control carcasses.
• Study conducted across grassland and forest habitats and different seasons.

Main Results:

• Carcass decomposition rates were halved in the absence of vultures.
• Vulture abundance positively correlated with carcass decomposition rate.
• Fly abundance doubled with vulture exclusion, while dung beetle abundance remained unaffected.

Conclusions:

• Neotropical vultures significantly accelerate carrion decomposition, a service invertebrates cannot fully replace.
• Vulture declines may lead to slower decomposition and increased fly populations, posing ecological and public health risks.
• Further research is needed on the broader implications for ecosystem services and zoonotic disease transmission.