Disturbance‐specific behavioral responses of giant otters exposed to ecotourism and extractive activities

A Barocas,J Mendoza,J Groenendijk,R R Swaisgood,J A Ochoa,J Farfan,O Mujica,D W Macdonald,J Silva

doi:10.1111/acv.12713

Abstract

AbstractHuman activities increasingly result in disturbance of wild animal populations. Behavioral responses vary according to the type, duration, frequency and intensity of disturbance. Exposure to disturbance, for example, arising from ecotourism, may promote tolerance of humans and drive a decrease in vigilance and avoidance behaviors, whereas disturbance resulting from extractive activities is typically more intense and is likely to be perceived as a threat. To understand how animals cope with land transformation and human presence, it is imperative to study their responses under different disturbance regimes. We performed behavioral sampling of groups of the giant otter, a charismatic top carnivore, exposed to ecotourism, extractive activities (mining and fishing) and control sites without disturbance to compare their responses. Foraging efficiency was impacted by fish abundance and thus was reduced in mined and fished areas. Giant otters in lakes with managed ecotourism did not show avoidance of research vessels and demonstrated reduced rates of defensive behavior compared to control lakes. Groups from lakes with fishing and gold mining showed increased avoidance, suggesting that these types of disturbance may involve more direct conflict. Our findings suggest that noninvasive disturbance such as ecotourism may promote giant otter tolerance to the presence of humans, whereas extractive activities may be perceived as riskier. Current protected area conservation strategies of strict ecotourism regulation and the maintenance of no‐access oxbow lakes may ensure the maintenance of behavioral flexibility in giant otter populations. However, resource depletion and more intense human‐giant otter interactions in disturbed areas may not be sustainable. Further studies are necessary to determine whether distinct disturbance regimes drive longer‐term demographic effects.

Highlights

Human activity drives various types of disturbance to wildlife, with evident, increasing impacts on animal behavior across aquatic and terrestrial ecosystems (Tucker et al, 2018; Samia et al, 2019; Suraci et al, 2019)
We examined whether exposure to human activity has impacts on giant otter foraging, avoidance and vigilance, by sampling behaviors of giant otter groups in oxbow lakes subject to a gradient of disturbance intensities
Our findings indicate that giant otters were more tolerant of human presence – as measured by duration of follows by researchers – when there was no previous exposure to humans or human activity involved ecotourism than when lakes were used for mining and fishing, suggesting that giant otters exposed to such activities may subsequently be more likely to avoid humans

Summary

Introduction

Human activity drives various types of disturbance to wildlife, with evident, increasing impacts on animal behavior across aquatic and terrestrial ecosystems (Tucker et al, 2018; Samia et al, 2019; Suraci et al, 2019). Human activity can vary in type and intensity. Animal behavioral responses to anthropogenic disturbances can vary by individual and include increased avoidance and changes in foraging patterns, reducing investment in fitness-related activities such as foraging, parental care and breeding (Sih, 2013). Such responses can have consequences for the survival and reproductive output of individuals and affect population-level processes (Bejder et al, 2006).

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Conclusion