Proposed the Enemy Constraint Hypothesis, which predicts weakened top-down effects on mesopredators towards the edge of top predators’ ranges.
Type of Study:
Pre-existing contrasts ("natural experiment")
The effects of top predators on mesopredators increase from the margin towards the core of their ranges
Studies assessing the strength of topdown mesopredator control will need to consider whether the mesopredator is located on the periphery or core of the top predator’s range
Australia, Europe and North America
Response variable :
North America:136 hunting units; Europe 255 hunting units; Australia 145 100 x 100km areas.
From Arid to forest,
Newsome T. M., Greenville A. C., Cirovic D., Dickman C. R., Johnson C. N., Krofel M., Letnic M., Ripple W. J., Ritchie E. G., Stoyanov S. & Wirsing A. J. (2017) Top predators constrain mesopredator distributions. Nat Commun 8, 15469.