Predator interactions, mesopredator release and biodiversity conservation.

@article{Ritchie2009PredatorIM,
  title={Predator interactions, mesopredator release and biodiversity conservation.},
  author={Euan G. Ritchie and Christopher N. Johnson},
  journal={Ecology letters},
  year={2009},
  volume={12 9},
  pages={
          982-98
        }
}
There is growing recognition of the important roles played by predators in regulating ecosystems and sustaining biodiversity. Much attention has focused on the consequences of predator-regulation of herbivore populations, and associated trophic cascades. However apex predators may also control smaller 'mesopredators' through intraguild interactions. Removal of apex predators can result in changes to intraguild interactions and outbreaks of mesopredators ('mesopredator release'), leading in turn… 

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References

SHOWING 1-10 OF 160 REFERENCES

Predator control, mesopredator release, and impacts on bird nesting success: a field test

TLDR
Nest predation rates on natural nests of a suite of nine species did not differ between rangeland and protected area landscapes, suggesting control of top predators does not appear to reduce bird nesting success in this system, and may reflect complex interactions between mammalian mesopredators and other predators of birds' nests, particularly snakes.

Spatial refuge from intraguild predation: implications for prey suppression and trophic cascades

TLDR
Examining the impact of predation by an assemblage of predators containing Pardosa wolf spiders, Grammonota web-building spiders, and Tytthus mirid bugs on herbivore populations (Prokelisia planthoppers) and on the biomass of Spartina cordgrass in simple and complex vegetation found that complex-structured habitats enhanced planthopper suppression by the predator assembLage.

Mesopredator release and avifaunal extinctions in a fragmented system

TLDR
It appears that the decline and disappearance of the coyote, in conjunction with the effects of habitat fragmentation, affect the distribution and abundance of smaller carnivores and the persistence of their avian prey.

Spatial heterogeneity of mesopredator release within an oceanic island system

TLDR
It is shown that initial eradication of cats on Little Barrier Island led to reduced breeding success of Cook's petrels, which also are vulnerable to predation by a mesopredator, the Pacific rat.

Evidence that dingoes limit abundance of a mesopredator in eastern Australian forests

TLDR
Data re-analyse published data on fox vs. wild dog abundance in eastern Australia reveals a triangular relationship of fox to wild dog density: when wild dogs are abundant, foxes are consistently rare, while whenWild dogs are rare, Foxes may be abundant but does not fully determine fox abundance, and illustrates problems and solutions in the statistical analysis of abundance of one species as a function of the abundance of another species with which it has a strong interaction.

Trophic control of mesopredators in terrestrial ecosystems: top-down or bottom-up?

TLDR
This work analyses the response of a mesopredator (the red fox) to declines in top predators and agricultural expansion over 90 years in Sweden, taking bioclimatic effects into account.

Does a top‐predator provide an endangered rodent with refuge from an invasive mesopredator?

TLDR
This study investigated how the abundance of an endangered rodent Notomys fuscus is affected by Australia's largest predator, the dingo Canis lupus dingo, introduced mesopredators, introduced herbivores, kangaroos and rainfall to suggest top-order predators, such as dingoes, could have an important functional role in broad-scale biodiversity conservation programmes.

Intraguild predation reduces redundancy of predator species in multiple predator assemblage.

TLDR
It is shown that interference between two invasive species of predatory crabs, Carcinus maenas and Hemigrapsus sanguineus, reduced the risk of predation for shared amphipod prey, and had redundant per capita effects in most multiple- and single-species predator combinations.

Top Predators as Conservation Tools: Ecological Rationale, Assumptions, and Efficacy

TLDR
Evidence suggests that top predators may function as structuring agents and biodiversity indicators in some ecosystems but not others, and that they perform poorly as umbrella species; more consensus exists for their efficacy as sentinel and flagship species.

Ecological Meltdown in Predator-Free Forest Fragments

TLDR
The densities of seedlings and saplings of canopy trees are severely reduced on herbivore-affected islands, providing evidence of a trophic cascade unleashed in the absence of top-down regulation.
...