Behavioral responses of the European mink in the face of different threats: conspecific competitors, predators, and anthropic disturbances

Abstract

Prey species assess the risk of threat using visual, olfactory, and acoustic cues from their habitat. Thus, they modify their behavior in order to avoid encounters with competitors, predators, and human disturbances that endanger their fitness. European mink (Mustela lutreola) is a critically endangered species that can be preyed upon by larger carnivores and displaced by dominant conspecifics to areas of lower quality, e.g., near to more anthropized localities which may be noisier. In this study, the behavioral responses of 24 European mink were evaluated by conducting an experiment in which the presence of a conspecific competitor was simulated with a visual cue (mirror) and the presence of predators (terrestrial and aerial) with odorous cues. Additionally, they were also exposed to potential sources of anthropic disturbance with acoustic cues (road traffic noise and human voices). Our results showed that European mink were hidden for longer periods of time due to the presence of conspecifics and being exposed to the fecal odors of a terrestrial predator such as dog, but especially when they were exposed to anthropic noises. In the presence of a conspecific, the females and the subadults were the ones who remained hidden for the longest time. As well, they were hidden for longer periods of time due to the presence of conspecifics but in combination with dog feces and anthropic sounds did not induce variations in the response, as both by themselves already triggered an increase in the time they spent hiding. The vigilance model showed the effects of the same factors as the hiding model, but with antagonistic effects in the case of vigilance time which decreased during anthropic noises exposition. Finally, we want to highlight that European mink showed an innate response favorable to all three types of threats, but attention should be focused on human disturbances—as they trigger the most extreme responses—which may affect the rate of survival of this threatened species.

Effect of intensity and duration of anthropic noises on European mink locomotor activity and fecal cortisol metabolite levels

“…In addition, human voices had more effect than road noise under LH conditions, probably because of 2 main reasons: humans are considered super-predators ( Darimont et al 2015 ; Suraci et al 2019 ) and not a simple source of noise and disturbance ( Frid and Dill 2002 ), but also because of spectral differences between road traffic noise and human voices at frequencies of between 6 and 10 kHz. Furthermore, in our study case, waveform of the road traffic noise signal is relatively constant, which makes its intensity to be more predictable while human voices signal fluctuates and shows several peaks at different frequencies ( Ortiz-Jiménez et al 2021 ). Therefore, alterations in signal regularity make unpredictable aversive events more stressful ( de Boer et al 1989 ).…”

“…Males roam larger range areas than females ( Palazón 1998 ; Garin et al 2002 ) and, in addition, males probably are routinely exposed to noise during patrolling and could have habituated to both sounds conditions in terms of duration and intensity, since they have more potential to defend themselves from a predator than females (in those species whose body size is greater in males) as some studies indicate ( Leutenegger and Kelly 1977 ; van Schaik and van Noordwijk 1989 ). The age bias could be due to a more cautious nature of younger individuals who prioritize other behaviors such as concealment when they assess the risk of threat from a noisy stimulus ( Ortiz-Jiménez et al 2021 ).…”

“…Proximity to outdoor recreation areas was simulated by community noise recorded next to a school playground. As it was described by Ortiz-Jiménez et al (2021) , spectral composition of the road traffic noise audio file was characterized by a dominant peak at a frequency of ∼1 kHz. Most of road traffic noise energy is comprised ˂2.5 kHz and amplitude of the waveform is relatively constant.…”

Effect of the presence of predatory cues and hunger on cannibalistic behaviour of ladybird beetle,Menochilus sexmaculatusFabricius (Coleoptera: Coccinellidae)

“…However, faecal cues are likely to have an additive effect with tracks indicating predator presence. Multiple studies have reported that predators' faecal cues provide crucial chemosensory information, which can be utilised to assess risk and detect prospective predators in the vicinity (Agarwala et al, 2003; Manassa & McCormick, 2012; Ortiz‐Jiménez et al, 2021; Sánchez‐González et al, 2017).…”

Human activities at night negatively impact Little Penguin (Eudyptula minor) numbers and behaviours

“…Different human activities can have differing impacts on animals and create various disturbances. Some of the major concerns are mostly centred around the number of people present at a location (de la Torre et al 2000, Dixon et al 2021, their distance from wildlife (Holmes et al 2005, Holmes 2007, Allbrook & Quinn 2020 or the noise levels produced (Buxton et al 2017, Ortiz-Jim enez et al 2021. Human activities around wildlife may also lead to the extensive use of artificial white lights (see Wolf & Croft 2012, Rodr ıguez et al 2018, when searching for nocturnal animals for example, or an increase in individuals walking their Dogs Canis lupus familiaris around wildlife (e.g.…”