Surplus killing by pumas Puma concolor: rumours and facts

Abstract

Surplus killing (i.e. predation in which predators kill more prey than necessary to satiate their hunger) appears to be widespread in carnivores and has the potential to exacerbate human–carnivore conflict. Nevertheless, little is known about the frequency of surplus killing or about its impact on livestock. We review the information available on surplus killing by pumas Puma concolor and use data from central Argentina to quantify its impact on ranching and to analyse both its causes and its implications for puma–human conflicts. We reviewed 73 publications and found nine mentions of surplus killing events from six countries. The sheep was by far the most commonly affected livestock species. In central Argentina, surplus killing was reported by 25–33% of the ranchers. In this region, the number of livestock killed during each event ranged from seven to 160 (median = 23) for the literature reports and from two to 70 (median = 7) in the records we personally collated. The number of individual animals killed per event was greater for interview‐based second‐hand reports than for first‐hand reports and verified events. Our results indicate that although surplus killing by pumas is uncommonly reported in the literature, it may be locally recurrent. Although surplus killing may be overestimated in interview‐based reports, it can produce significant losses for sheep and goat ranchers, may strongly exacerbate puma–human conflicts, and should be considered in puma–human conflict mitigation strategies. Ranchers typically attributed surplus killing to female pumas teaching kittens to hunt. However, there is little evidence supporting this interpretation. Surplus killing by pumas may be more likely to occur in situations where the predator's ‘normal’ hunting sequence is disrupted by the accessibility of large numbers of easy prey. Confinement, stormy weather and poor antipredator behaviour may favour the occurrence of surplus killing events on livestock.

Unravelling negative interactions between humans, mammalian carnivores and raptors in South America

“…To compensate for this, a few studies complemented questionnaires and interviews with field observations (e.g., Perovic and Herrán 1998;Ballejo et al 2020a;Escobar-Lasso et al 2020). Contrasting perceived with actual economic losses (e.g., Ballejo et al 2020a) is useful, because this information can clarify whether people's persecution of wildlife is due to actual negative impacts produced by the species involved or is primarily associated with other (non-material) drivers leading to low tolerance of wildlife (Lucherini et al 2018;Nanni et al 2020;Lambertucci et al 2021a,b). Further research should focus on this issue in different species and geographical areas of South America.…”

Relative influence of wild prey and livestock abundance on carnivore‐caused livestock predation

“…Multiple factors influence the extent of carnivore‐caused livestock predation, including livestock husbandry practices (Kuiper et al., 2015; Ogada et al., 2003; Woodroffe et al., 2007), wild prey availability (Meriggi et al., 1996; Odden et al., 2008), habitat type and structure (Miller et al., 2015), behavioral characteristics of the predator (Lucherini et al., 2018), and predator abundance (Lesilau et al., 2018; Miller et al., 2015; Weise et al., 2018). Understanding the interplay between predator, wild prey, and livestock density is important for identifying mitigation measures.…”

The unequal burden of human-wildlife conflict

“…We feel however, that our analysis is extremely conservative for several reasons, namely we only show the potential economic ramifications of a single predation event. Carnivore depredation often manifests itself in specific areas due to habitat or ecological variables 80,81 , households often experience predation events multiple times per year 15 , and sometimes carnivores engage in surplus killing [82][83][84] . Our analysis does not calculate actual depredation rates, it only illustrates highly vulnerable (and buffered) economic areas globally that would suffer under a predation event.…”