Carcass Provisioning to Support Scavengers: Evaluating a Controversial Nature Conservation Practice

Abstract

A number of scavenger species have suffered population declines across Europe. In attempts to reverse their decline, some land and wildlife managers have adopted the practice of leaving or placing out carcasses of wild or domestic herbivores to provide a source of carrion. However, this can be a controversial practice, with as yet unclear outcomes for many target species and the ecosystems they are part of. Here we bring out the key aspects of this increasingly common conservation practice illustrated using three contrasting cases studies. We show that the provision of carcasses is often motivated by a desire to benefit charismatic species or to facilitate nutrient cycling throughout an ecosystem. Evidence for the effectiveness of this practice in achieving these objectives, however, is mostly lacking, with ecologists studying “easier” species groups such as beetles and therefore not providing relevant insights. Moreover, conflicts between environmental policies that carcass provisioning is aimed at and other social and economic objectives do occur but these projects are often designed without taking into account this broader context. We conclude that expecting carcasses to simply be “good for biodiversity” may be too naïve a view. A greater knowledge of the impact of carcass provisioning and placement on ecosystems and society at large is required before it can become a more effective conservation tool at a wider scale.

EU Sanitary Regulation on Livestock Disposal: Implications for the Diet of Wolves

“…The practice of placing carcasses in centralized vulture feeding stations is controversial and has demonstrated several ecological problems, as to promote non-natural behaviour in avian scavengers, and potential to alter communities (Fielding et al 2013). Proper carcass disposal is one of the management strategies often recommended for decreasing wolf attacks on livestock (Hosseini-Zavarei et al 2013;Tourani et al 2014).…”

Rewilding with large herbivores: Positive direct and delayed effects of carrion on plant and arthropod communities

“…Carcasses of domestic animals are only allowed to remain in the landscape when the aim is to provide food for endangered scavengers such as vultures [5]. The carcasses of culled or hunted wild herbivores are legally allowed to remain in situ [4], but such a practice is controversial in many parts of Europe, and has met fierce public opposition [6,7].…”

Optimization of supplementary feeding programs for European vultures depends on environmental and management factors

“…Carrion ecology and its role in the feeding of wild scavengers is a field of study that has gained special relevance in recent years (Barton et al 2013, Oro et al 2013, Fielding et al 2014, particularly from the perspective of conservation management in European and African countries (Cortés-Avizanda et al 2010, Margalida et al 2011a, Duriez et al 2012, Kane et al 2015. In addition, several authors have highlighted the importance of carrion in balancing trophic relationships and cascades, both at small and large scales, influencing carnivore communities, the conservation status of large predators and even the population dynamics of prey species (Wilmers et al 2003, Selva and Fortuna 2007, Wilson and Wolkovich 2011.…”

“…Therefore, a general consensus exists among ecologists and conservationists that supplementary feeding should be used as a temporary management option, determined by very specific performance requirements (Gonzalez et al 2006, Robb et al 2008, Ewen et al 2015. In this sense, the relationship between scavengers and food availability should be primarily shaped by natural scenarios regulating the population dynamics of the involved species, which should evolve and interact without human intervention (Oro et al 2013, Fielding et al 2014). However, although in several countries some of the above mentioned threats are declining , Prakash et al 2012, there continue to be economic and livestock management schemes with supplementary feeding as an influential and long-term component balancing food availability and ecological requirements for scavenger species.…”