The mesoscavenger release hypothesis and implications for ecosystem and human well-being.

@article{OBryan2019TheMR,
  title={The mesoscavenger release hypothesis and implications for ecosystem and human well-being.},
  author={Christopher J. O’Bryan and Matthew H. Holden and James E. M. Watson},
  journal={Ecology letters},
  year={2019}
}
Many apex scavenger species, including nearly all obligate scavengers, are in a state of rapid decline and there is growing evidence these declines can drastically alter ecological food webs. Our understanding of how apex scavengers regulate populations of mesoscavengers, those less-efficient scavengers occupying mid-trophic levels, is improving; yet, there has been no comprehensive evaluation of the evidence around the competitive release of these species by the loss of apex scavengers. Here… 
A biological invasion impacts ecosystem services: cane toads change the rate of scavenging and the suite of scavengers
TLDR
In tropical areas where the arrival of fatally toxic cane toads has massively reduced the abundance of monitors, rates of removal of deployed baits are more than halved, and the assemblages of scavengers are dominated by birds or mammals rather than reptiles.
Dominant carnivore loss benefits native avian and invasive mammalian scavengers
TLDR
The results reveal the efficiency of carrion consumption by mammalian scavengers and supports novel management approaches, such as rewilding in areas where the natural suite of carnivores is missing, and demonstrates the significance of global carnivore conservation.
Monitoring the dead as an ecosystem indicator
TLDR
It is suggested that knowledge of scavenging and decomposition rates, scavenger diversity, abundance, and behavior around carrion, along with assessments of vegetation, soil, microbe, and parasite presence, can be used individually or in combination to understand food web dynamics.
Scavenging Effects of Large CanidsBoth authors contributed equally to this work.
TLDR
This work comprehensively examines the roles played by, and impacts of, facultative scavengers, with a focus on large canids: the African wild dog (Lycaon pictus), dhole (Cuon alpinus),Dingo (Canis dingo), Ethiopian wolf (C. simensis), gray wolf ( c. lupus), maned wolf (Chrysocyon brachyurus), and red wolf (Rufus).
Uncovering the vertebrate scavenger guild composition and functioning in the Cerrado biodiversity hotspot
Scavenging is widespread among vertebrates, being very important for maintaining certain ecosystem functions. Despite this, the scavenger communities remain poorly known in some biomes, especially in
Population modelling insights of extinct environments: the case of the Kem Kem palaeocommunity
TLDR
This paper simulates a small community module of this environment, consisting of Carrion, Fishes, Spinosaurus, and a functional group composed of large terrestrial Theropods, and shows that these exclusive food sources could have assured the possibility of coexistence, and in their absence, one top predator could be locally extinct.
Effects of intraspecific competition and body mass on diet specialization in a mammalian scavenger
Abstract Animals that rely extensively on scavenging rather than hunting must exploit resources that are inherently patchy, dangerous, or subject to competition. Though it may be expected that
Reviewing the Role of Vultures at the Human-Wildlife-Livestock Disease Interface: An African Perspective
Abstract. Vultures are a key component of an effective scavenger guild and have evolved a number of adaptations that allow them to locate and dispose of carcasses quickly and efficiently. The
Roadkill islands: carnivore extinction shifts seasonal use of roadside carrion by generalist avian scavenger.
TLDR
It was found that roadkill carcasses were a strong predictor of raven presence along road networks, and this suggests that in the absence of competing mammalian scavengers, ravens choose to feed on roadside carrion throughout the year, even in seasons when other resources are available.
...
...

References

SHOWING 1-10 OF 57 REFERENCES
The contribution of predators and scavengers to human well-being
TLDR
It is argued that researchers must work in concert with the media, managers and policymakers to highlight benefits of these species and the need to ensure their long-term conservation, as many predators and scavengers are in a state of rapid decline.
The nested structure of a scavenger community
TLDR
Nested patterns in scavenger communities appear to be promoted by the high diversity in carrion resources and consumers, the differential predictability of the ungulate carcass types and stressful environmental conditions, which supports recent findings in scavenging ecology.
Understanding how mammalian scavengers use information from avian scavengers: cue from above
TLDR
Using a spatially explicit model and data from experimental carcasses, evidence is found that mammals benefit from local enhancement provided by vultures and that mammalian-avian following patterns are consistent with the idea that species-specific cueing is occurring.
Ecosystem consequences of bird declines
TLDR
A general framework for characterizing the ecological and societal consequences of biodiversity loss and applying it to the global avifauna is presented and projections indicate that by 2100, 6–14% of all bird species will be extinct, and 7–25% (28–56% on oceanic islands) will be functionally extinct.
Top carnivore decline has cascading effects on scavengers and carrion persistence
TLDR
It is shown that mesopredators consume more carrion in areas where devils have declined, suggesting a relaxed landscape of fear where devils are suppressed and broad relevance to the vast areas of the world that have suffered carnivore declines.
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.
Trophic Downgrading of Planet Earth
TLDR
This empirical work supports long-standing theory about the role of top-down forcing in ecosystems but also highlights the unanticipated impacts of trophic cascades on processes as diverse as the dynamics of disease, wildfire, carbon sequestration, invasive species, and biogeochemical cycles.
Scavenger community response to the removal of a dominant scavenger
TLDR
This experiment experimentally manipulated a scavenging community within an agricultural landscape by reducing the abundance of the dominant scavenger, raccoons Procyon lotor, to demonstrate the vulnerability of a critical ecosystem service, carrion removal, to perturbations of the scavengingcommunity.
Scavenging by vertebrates: behavioral, ecological, and evolutionary perspectives on an important energy transfer pathway in terrestrial ecosystems
TLDR
A deeper understanding of carrion use by facultative scavengers will improve knowledge of community and ecosystem processes, especially the flow of energy through food webs.
...
...