High Trophic Niche Overlap between a Native and Invasive Mink Does Not Drive Trophic Displacement of the Native Mink during an Invasion Process

Abstract

The pressure elicited by invasive species on native species significantly increases with the increase of the overlap of their ecological niches. Still, the specific mechanisms of the trophic displacement of native species during the invasion process are unclear. The effects of the invasive American mink (Neovison vison) on the critically endangered European mink (Mustela lutreola) was assessed by analyses of diet and niche overlap during the invasion process. To do this, the isotopic composition (δ13C and δ15N) of both species of mink and their four main types of prey was analysed. Significant trophic overlap between the native European mink and invasive American mink was found when they coexisted in sympatry. Furthermore, both mink species were characterised by significant individual variation in diet and no obvious change in diet of the native species in response to the arrival of the introduced species was observed. High niche overlap registered between both species in sympatry with no displacement in diet of the native mink in response to the arrival of the invasive mink is expected to have important consequences for the viability and conservation of the native mink populations, as it suggests high competitive pressure.

Does invasion by armored catfish shift trophic ecology of native fishes? Evidence from stable isotope analysis

“…Among the significant factors affecting fish isotopic signatures we found invasion intensity to play an important role, along with a Predicting the impact of invasive species on food webs is challenging because they can affect ecosystems via multiple mechanisms (David et al, 2017). For example, when invasive and native species compete for limited resources, native species may expand their trophic niches (Harris et al, 2022), show no change in niche breadth (García et al, 2020), or compress and partition niches F I G U R E 5 Results of the linear mixed effects models with statistical effects of environmental variables on δ 13 C (‰) and δ 15 N (‰) with 95% CI. (David et al, 2017;Tran et al, 2015).…”

“…Predicting the impact of invasive species on food webs is challenging because they can affect ecosystems via multiple mechanisms (David et al, 2017). For example, when invasive and native species compete for limited resources, native species may expand their trophic niches (Harris et al, 2022), show no change in niche breadth (García et al, 2020), or compress and partition niches (David et al, 2017; Tran et al, 2015). Our findings suggest the latter response to the high abundance of Pterygoplichthys .…”

“…Pterygoplichthys were shown to have trophic niche overlap with native fish in southern Mexico (Sepúlveda-Lozada et al, 2015). However, trophic overlap does not necessarily indicate competition, which depends on the ratio of resource demand/supply, ecosystem productivity, and population densities (García et al, 2020). Low niche overlap is generally interpreted as evidence of resource partitioning between invasive and native species (e.g., Ludovisi et al, 2022).…”

Seasonal Variation in Resource Overlap Between Red Swamp Crayfish (Procambarus clarkii) and Native Species in Poyang Lake Wetland, China

“…Stable isotope analysis (SIA) can be used to estimate material and energy flow as well as trophic positions in food webs (Peterson and Fry, 1987). SIA has been used increasingly to estimate resource utilization and trophic interaction among sympatric consumers (García et al, 2020;Ercoli et al, 2021;Wang Y. et al, 2021b). The distribution of consumers in isotopic space has been used as an indicator of trophic niche width and trophic niche overlap (Peel et al, 2019;Azevedo et al, 2022).…”