Raccoons and skunks are common examples of mesopredators. Pictured is a common raccoon and a striped skunk eating cat food in an urban area.

A Mesopredator is a predator that occupies a mid-ranking trophic level in a food web.[1] There is no standard definition of a mesopredator, but mesopredators are usually medium-sized carnivorous or omnivorous animals, such as raccoons, foxes, or coyotes.[2][3] They are often defined by contrast from apex predators or prey in a particular food web.[3][2][4] Mesopredators typically prey on smaller animals.[2]

Mesopredators vary across different ecosystems. Sometimes, the same species is a mesopredator in one ecosystem and an apex predator in another ecosystem, depending on the composition of that ecosystem.[3] When new species are introduced into an ecosystem, the role of the mesopredator often changes; this can also happen if species are removed.[4]

Mesopredator release effect

Main article: Mesopredator release hypothesis

When populations of an apex predator decrease, populations of mesopredators in the area often increase due to decreased competition and conflict with the apex predator.[2] This is known as the mesopredator release effect, which refers to the release of mesopredators from the trophic cascade.[5] These mesopredator outbreaks can lead to declining prey populations, destabilize ecological communities, reduce biodiversity, and can even drive local extinctions.[2][4]

Typically, mesopredators are in competition with apex predators for food and other resources.[2] Apex predators reduce mesopredator populations and change mesopredator behaviors and habitat choices by preying on and intimidating mesopredators.[6] When apex predator populations decline, mesopredators can access hunting and den areas once controlled by the apex predators, essentially assuming the role of an apex predator.[2] However, mesopredators often occupy different ecological niches than the former apex predator and will have different effects on the structure and stability of the ecosystem.[3][4]

Mesopredator outbreaks are becoming more common in fragmented habitats, which are areas where a species' preferred environment is broken up by obstacles.[4] Fragmented habitats can be caused by geological or human activity, and particularly affect larger animals that roam and hunt across large territories, such as apex predators.[7] Fragmented habitats can drive these species to leave and find more suitable habitats.[4]

Additionally, in many fragmented habitats, apex predators have more encounters with humans, leaving them susceptible to harmful or deadly conflicts, sometimes resulting in eradication of the apex predator population entirely.[4] Human development also promotes mesopredator outbreaks through increasing access to resources such as pet food, trash, and crops.[4]

The mesopredator release effect is not entirely understood. Most research has been conducted on mammal species, with limited studies on non-mammal animal species.[3] Additionally, it is not well understood how these dynamics may play out in ecosystems with many mesopredator and apex predator species.[3]

See also


  1. ^ Groom, Martha; Meffe, Gary (August 5, 2005). Principles of Conservation Biology. Sinauer Associates, Inc. ISBN 978-0878935970.
  2. ^ a b c d e f g "mesopredator release | ecology | Britannica". www.britannica.com. Retrieved 2022-07-08.
  3. ^ a b c d e f Hodge, Anne-Marie. "Laikipia Plateau: What is a Mesopredator?". Scientific American Blog Network. Retrieved 2023-10-04.
  4. ^ a b c d e f g h Prugh, Laura R.; Stoner, Chantal J.; Epps, Clinton W.; Bean, William T.; Ripple, William J.; Laliberte, Andrea S.; Brashares, Justin S. (2009-10-01). "The Rise of the Mesopredator". BioScience. 59 (9): 779–791. doi:10.1525/bio.2009.59.9.9. ISSN 0006-3568. S2CID 40484905.
  5. ^ "mesopredator release | ecology | Britannica". www.britannica.com. Retrieved 2022-09-22.
  6. ^ Ritchie, Euan G.; Johnson, Christopher N. (2009-09-01). "Predator interactions, mesopredator release and biodiversity conservation". Ecology Letters. 12 (9): 982–998. doi:10.1111/j.1461-0248.2009.01347.x. hdl:10536/DRO/DU:30039763. ISSN 1461-0248. PMID 19614756.
  7. ^ Quintana, Itxaso; Cifuentes, Edgar F.; Dunnink, Jeffrey A.; Ariza, María; Martínez-Medina, Daniela; Fantacini, Felipe M.; Shrestha, Bibek R.; Richard, Freddie-Jeanne (2022-02-21). "Severe conservation risks of roads on apex predators". Scientific Reports. 12 (1): 2902. doi:10.1038/s41598-022-05294-9. hdl:10852/101068. ISSN 2045-2322.