Intrapopulation variation in the behavioral responses of dwarf mongooses to anthropogenic noise

Abstract

Anthropogenic noise is an increasingly widespread pollutant, with a rapidly burgeoning literature demonstrating impacts on humans and other animals. However, most studies have simply considered if there is an effect of noise, examining the overall cohort response. Although substantial evidence exists for intraspecific variation in responses to other anthropogenic disturbances, this possibility has received relatively little experimental attention with respect to noise. Here, we used field-based playbacks with dwarf mongooses (Helogale parvula) to test how traffic noise affects vigilance behavior and to examine potential variation between individuals of different age class, sex, and dominance status. Foragers exhibited a stronger immediate reaction and increased their subsequent vigilance (both that on the ground and as a sentinel) in response to traffic-noise playback compared with ambient-sound playback. Traffic-noise playback also resulted in sentinels conducting longer bouts and being more likely to change post height or location than in ambient-sound playback. Moreover, there was evidence of variation in noise responses with respect to age class and dominance status but not sex. In traffic noise, foraging pups were more likely to flee and were slower to resume foraging than adults; they also tended to increase their vigilance more than adults. Dominants were more likely than subordinates to move post during sentinel bouts conducted in traffic-noise trials. Our findings suggest that the vigilance–foraging trade-off is affected by traffic noise but that individuals differ in how they respond. Future work should, therefore, consider intrapopulation response variation to understand fully the population-wide effects of this global pollutant.

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

“…However, our presence and distance from giant otter groups likely constituted a suitable simulation of the conditions during tourist group lake visits and possibly additional human activities. Further understanding of responses by the giant otter groups in question would benefit from control treatment approaches, including observation from a distance during tourist viewing, as is common in marine mammal studies (Lusseau, 2003; Christiansen, Rasmussen & Lusseau, 2013), approach experiments where it is possible to quantify flight initiation distance (Stankowich & Blumstein, 2005), and playback experiments which specifically assess anthropogenic noise effects (Wale, Simpson & Radford, 2013; Eastcott et al ., 2020).…”

“…Such responses can be inferred by comparing animal foraging behavior with and without the presence of disturbance (Lusseau, 2003). Alternatively, vigilance and tolerance to the presence of human observers can be quantified under different disturbance scenarios (Saltz et al ., 2019; Eastcott et al ., 2020). Because different species can vary in their way of coping with disturbance, examining multiple dimensions of their behavioral responses can provide a more complete assessment of the influences of human activity on individuals and populations (Bateman & Fleming, 2017).…”

Behavioral responses to anthropogenic noise at highways vary across temporal scales

“…Monitoring individual responses could also shed light on whether fear responses are characteristic of certain personalities. For instance, Eastcott et al (2020) found among-individual behavioral differences in vigilance behavior of dwarf mongoose to playbacks of traffic noise.…”

Individual differences show that only some bats can cope with noise-induced masking and distraction

“…Yet it is not often understood what mechanisms drive these changes, and if and how different individuals are affected by these mechanisms differently. Individual differences in response to noise has been documented in humans ( Furnham & Strbac, 2002 ; Standing, Lynn & Moxness, 1990 ), birds ( Naguib et al, 2013 ), fish ( Bruintjes & Radford, 2013 ), mongooses ( Eastcott et al, 2020 ), and bats ( Luo, Siemers & Koselj, 2015 ; Luo et al, 2015 ; Simmons et al, 2018 ), among many others (reviewed in Harding et al, 2019 ), yet individual differences are often overlooked as individuals are more often grouped together for analysis than analyzed individually ( Harding et al, 2019 ).…”