Esses burros exóticos, cujas populações crescentes ameaçam a biota nativa, se tornaram o item mais frequente da dieta das onças pardas nessa região. reportam um experimento natural mostrando evidências contundentes de que onças pardas superaram a ingenuidade ecológica – i.e., os desajustes entre predadores e presas que não compartilham uma história evolutiva comum – e agora estão predando os indivíduos mais jovens de burros ferais com sucesso. No Parque Nacional do Vale da Morte (Estados Unidos), Lundgren et al. Nesse contexto, é relevante entendermos o quanto os predadores nativos atuais podem impor controle de cima para baixo sobre mega-herbívoros não-nativos, e como cascatas tróficas oriundas de novas interações predador-presa influenciam a biodiversidade e as funções ecossistêmicas. A refaunação não-intencional com grandes herbívoros não-nativos, tais como equídeos, oferece oportunidades extraordinárias para os ecólogos entenderem as consequências do uso de espécies substitutas para restaurar as funções ecológicas da extinta megafauna nativa. A refaunação trófica é uma abordagem promissora para a restauração das interações da megafauna, de seus papéis funcionais e das cascatas tróficas delas decorrentes. Apesar de estarem ausentes da maioria das regiões do mundo contemporâneo, as espécies da megafauna dominaram a dinâmica das comunidades ecológicas até o Pleistoceno tardio. (2022) A novel trophic cascade between cougars and feral donkeys shapes desert wetlands. Addressing them can help us to elucidate the costs and benefits of using non-native megaherbivores in the functional restoration of permanently invaded ecosystems. Whether the emerging cascade is transient or persistent, the relative roles of consumptive and non-consumptive effects as underlying mechanisms, and their consequences for food web structure, functioning and stability, are questions of general interest. present a promising model system for studying the effects of fearful grazers on community structure in the context of novel ecological interactions being established in the Anthropocene. Donkeys concentrate their activity mostly in topologically plain terrains lacking proper sites for the ambush behaviour of cougars and with more intense human presence, likely acting as a shield against the predators. Areas with cougars have less trampled ground, fewer donkey trails, and much more canopy cover and vegetation around water. The cougar–donkey interaction triggered a behaviourally mediated trophic cascade emerging from a ‘landscape of fear’, that is, from the perception of spatial heterogeneity in predation risk by donkeys. On the other hand, donkeys remain more active and forage throughout the day and night in areas without cougars. In areas with cougars, donkeys changed their spatiotemporal foraging patterns, becoming diurnal and less active. These non-native donkeys, whose growing wild populations threaten the native biota, became cougars' most frequent dietary item in that region. depict a natural experiment showing compelling evidence of native cougars overcoming ecological naïveté-that is, the mismatches between predator and prey species that do not share a common evolutionary history-and are now successfully preying on younger individuals of feral donkeys. In Death Valley National Park (United States), Lundgren et al. In this context, it is relevant to understand the extent to which extant native predators can impose top-down control on non-native megaherbivores and how trophic cascades arising from novel predator–prey interactions influences biodiversity and ecosystem functions. Unintentional rewilding with large non-native herbivores, such as equids, offers outstanding opportunities for ecologists to understand the outcomes of using replacement species to restore the ecological functions of extinct native megafauna. Trophic rewilding is a promising approach to restoring megafauna interactions, their functional roles and the consequent trophic cascades. Despite being absent from most regions of the contemporary world, megafauna species dominated the dynamics of ecological communities until the late Pleistocene.
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