Effects of ambient noise on zebra finch vigilance and foraging efficiency

Abstract

Ambient noise can affect the availability of acoustic information to animals, altering both foraging and vigilance behaviour. Using captive zebra finches Taeniopygia guttata, we examined the effect of ambient broadband noise on foraging decisions. Birds were given a choice between foraging in a quiet area where conspecific calls could be heard or a noisy area where these calls would be masked. Birds foraging in noisy areas spent a significantly more time vigilant than those in quiet areas, resulting in less efficient foraging. Despite this there was no significant difference in the amount of time spent in the two noise regimes. However there did appear a preference for initially choosing quiet patches during individuals’ second trial. These results emphasise how masking noise can influence the foraging and anti-predation behaviour of animals, which is particularly relevant as anthropogenic noise becomes increasingly prevalent in the natural world.

Zebra finches show spatial avoidance of near but not far distance traffic noise

“…This makes neophobia or startle reactions unlikely explanations for our results but suggests that the louder near-distance noise (rather than any audible and unfamiliar sound) was being actively avoided. This avoidance response could prevent the negative impact of noisy conditions on acoustic communication, social decision making and foraging which have been reported from other experimental studies exposing zebra finches to noise playbacks (Swaddle et al, 2006;Swaddle & Page, 2007;Villain et al, 2016;Evans et al, 2018).…”

“…However, the set-up used by Evans et al (2018) was different in several aspects from our two-aviary study: a much smaller testing apparatus, individual rather than group testing of birds, manipulation of food availability, and simultaneous playbacks of noise and conspecifics. Any of these differences in design could be the reason why most birds in the set-up by Evans et al (2018) only entered one compartment and stayed there. These differences stress the importance of potential context-dependency of active noise avoidance.…”

“…In the experiment, the tested birds avoided noisy conditions to move into a quieter space. This behaviour would confer an advantage outside the laboratory as complementary research in zebra finches has already shown that noise negatively impacts zebra finches: it increases vigilance reducing food uptake during foraging (Evans et al, 2018), affects intra-pair communication (Villain et al, 2016), offspring initial growth rates (Potvin & MacDougall-Shackleton, 2015), reduces telomere length (Dorado-Correa et al, 2018) and affects song learning (Funabiki & Funabiki, 2009;Potvin et al, 2016).…”

“…To date, only one other study also offered zebra finches a choice between quiet and noisy spaces: however, this was concurrent with access to food and playback of conspecific vocalisations (Evans et al 2018). Birds showed increased vigilance in noise but little spatial sampling (most birds stayed in the first chamber they entered) and no preferences for quiet versus noisy cage compartments.…”

“…These studies, however, passively exposed birds to noise without offering quiet(er) alternative spaces. To the best of our knowledge, only one bird study offered birds to move between different noise levels (Evans et al, 2018), while testing the masking effect of noise on foraging behaviour. In this study, high level noise affected individuals' vigilance during foraging, but not their spatial choices: Birds were not observed to move from louder to more quiet foraging chambers after having entered either one of them.…”