Effects on carrion consumption in a mammalian scavenger community when dominant species are excluded

Antoni Margalida,Esther Descalzo,Pablo Ferreras,Jorge Tobajas,Rafael Mateo

doi:10.1007/s42991-021-00163-w

Antoni Margalida, Esther Descalzo + Show 3 more

Open Access

https://doi.org/10.1007/s42991-021-00163-w

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Abstract

Carrion is a valuable resource exploited not only by obligate scavengers but also by a wide variety of facultative scavengers. These species provide several important ecosystem services which can suffer if the scavenger community composition is altered, thus reducing the ecosystem provided. We studied the response of the Mediterranean facultative scavenger community to the exclusion of larger scavenger species (red fox Vulpes vulpes, European badger Meles meles, and wild boar Sus scrofa) using an exclusion fence permeable to small scavenger species (mainly Egyptian mongoose Herpestes ichneumon, common genet Genetta genetta, and stone marten Martes foina). The exclusion of dominant facultative scavengers led to a significant reduction in the amount of carrion consumed and an increase in carrion available for smaller species and decomposers, over a longer period of time. Although carrion consumption by the non-excluded species increased inside the exclusion area relative to the control area, it was insufficient to compensate for the carrion not eaten by the dominant scavengers. Of the small scavenger species, only the Egyptian mongoose significantly increased its carrion consumption in the exclusion area, and was the main beneficiary of the exclusion of dominant facultative scavengers. Therefore, altering the facultative scavenger community in Mediterranean woodlands can reduce the efficiency of small carcass removal and benefit other opportunistic species, such as the Egyptian mongoose, by increasing the carrion available to them. This interaction could have substantial implications for disease transmission, nutrient cycling, and ecosystem function.

Highlights

Scavenging plays an important role in the maintenance of ecological processes, affecting species assemblages and ecosystem function (Ogada et al 2012; DeVault et al 2016; Sebastián-González et al 2016)
We predicted that when dominant facultative scavengers were excluded from carcasses, there would be: (1) a decrease in the scavenging efficiency of the scavenger community, increasing the time from carcass placement to their fully consumption and the number of carcasses not fully eaten; (2) an increase in the scavenging activity of smaller, subordinate facultative scavenger species; and (3) that other singular opportunistic species would be favored by the removal of larger dominant scavengers
Our findings show that exclusion of the larger facultative scavengers reduces the overall efficiency of the scavenger community (Olson et al 2012; Cunningham et al 2018), reducing the consumption of carrion by half (Fig. 2)

Summary

Introduction

Scavenging plays an important role in the maintenance of ecological processes, affecting species assemblages and ecosystem function (Ogada et al 2012; DeVault et al 2016; Sebastián-González et al 2016). Scavengers provide important supporting, regulatory, and cultural ecosystem services (Moleón et al 2014; DeVault et al 2016). The lack of apex predators has allowed an increase in facultative scavengers such as red fox Vulpes vulpes, European badger Meles meles, and wild boar Sus scrofa that can dominate carrion use through their significant body-size and adaptations to find and use carrion efficiently The lack of apex predators has allowed an increase in facultative scavengers such as red fox Vulpes vulpes, European badger Meles meles, and wild boar Sus scrofa that can dominate carrion use through their significant body-size and adaptations to find and use carrion efficiently (Butler and du Toit 2002; Stiegler et al. Vol.:(0123456789)

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