Carrion Availability in Space and Time

Introduction Availability of carrion to scavengers is a central issue in carrion ecology and management, and is crucial for understanding the evolution of scavenging behaviour. Compared to live animals, their carcasses are relatively unpredictable in space and time in natural conditions, with a few exceptions (see below, especially Sect. “Carrion Exchange at the Terrestrial-Aquatic Interface”). Carrion is also an ephemeral food resource due to the action of a plethora of consumers, from microorganisms to large vertebrates, as well as to desiccation (i.e., loss of water content; DeVault et al. 2003; Beasley et al. 2012; Barton et al. 2013; Moleón et al. 2014). With a focus on vertebrate carcasses, here we give an overview of (a) the causes that produce carrion, (b) the rate of carrion production, (c) the factors affecting carrion quality, and (d) the distribution of carrion in space and time, both in terrestrial and aquatic environments (including their interface). In this chapter, we will focus on naturally produced carrion, whereas non-natural causes of animal mortality are described in chapter “Human-Mediated Carrion: Effects on Ecological Processes”. However, throughout this chapter we also refer to extensive livestock carrion, because in the absence of strong restrictions such as those imposed in the European Community after the bovine spongiform encephalopathy crisis (Donázar et al. 2009; Margalida et al. 2010), the spatiotemporal availability of carrion of extensive livestock and wild ungulates is similar

vertebrate scavenging communities

A scavenger is an animal that feeds on the carcass or remains of any dead animal which it did not participate in its killing. Scavenging is pervasive across the animal kingdom and almost all predator species use carrion to a certain extent in both terrestrial and aquatic ecosystems. There is a group of animals, the obligate scavengers, which rely (almost) entirely on carrion. Among vertebrates, only birds have evolved into obligate scavengers, namely vultures, which suggests that the costs of adaptation to obligate scavenging are high. Obligate and facultative scavengers exhibit a wide array of adaptations to locate and exploit carrion across systems, including inexpensive locomotion to find the unpredictable carrion on savannas, caching carrion in cold tundra or chemotaxis in aquatic systems. Traditionally viewed as an opportunistic process, particularly for facultative scavengers, carrion consumption by vertebrates often follows complex and structured patterns and is crucial in maintaining the stability and structure of food webs.Peer reviewe