Behavioral Plasticity Allows Short‐Term Adjustment to a Novel Environment

Abstract

Many species are currently experiencing anthropogenically driven environmental changes. Among these changes, increasing noise levels are specifically a problem for species relying on acoustic communication. Recent evidence suggests that some species adjust their acoustic signals to man-made noise. However, it is unknown whether these changes occur through short-term and reversible adjustments by behavioral plasticity or through long-term adaptations by evolutionary change. Using behavioral observations and playback experiments, we show that male reed buntings (Emberiza schoeniclus) adjusted their songs immediately, singing at a higher minimum frequency and at a lower rate when noise levels were high. Our data showed that these changes in singing behavior were short-term adjustments of signal characteristics resulting from behavioral plasticity, rather than a long-term adaptation. However, more males remained unpaired at a noisy location than at a quiet location throughout the breeding season. Thus, phenotypic plasticity enables individuals to respond to environmental changes, but whether these short-term adjustments are beneficial remains to be seen.

Environmental variability and acoustic signals: a multi-level approach in songbirds

“…In contrast, because environmental seasonality explained intraindividual song variation, selection may favour song variability to cope with different acoustic environments that an individual encounters throughout its life or even shorter timescales such as a single breeding season or day. Recent findings suggest that birds and frogs may adjust their signals immediately in response to increase in background noise or structural habitat changes, respectively [6,7]. Coupled with our results, these studies suggest that individual song variation, rather than a restricted set of traits, may be adaptive and represent a key aspect to understanding signal evolution in response to various sources of selection.…”

“…Additionally, most studies have used acoustic traits (e.g. frequency, song length) averaged per population or species, but recent studies show that signal variation at the level of the individual can also be important for acoustic communication in a variety of environments [4][5][6][7].…”

Anthropogenic noise weakens territorial response to intruder's songs

“…Decreased ability to locate the signaler might also explain decreases in pairing success reported in noisy environments (Habib et al 2006, Gross et al 2010. Disruption of acoustic signals, especially critical ones such as those produced by a competitor, can have direct and indirect negative effects for an organism relying on these cues.…”

Developmental plasticity in vision and behavior may help guppies overcome increased turbidity

“…As previously mentioned, such plasticity often allows for the quickest adaptive phenotypic change in a human-disturbed environment (Van Buskirk 2012), and studies showcasing such plasticity abound. Some birds and anurans, for example, exhibit short-term changes in aspects of acoustic communication in order to overcome anthropogenic background noise (e.g., Gross et al 2010;Cunnington and Fahrig 2010), great tits plastically adjust the timing of reproduction with climate change (Charmantier et al 2008), orangecrowned warblers adjust nesting behavior and parental provisioning in the presence of a novel predator (Peluc et al 2008), etc. While some plastic changes in response to novel environments are adaptive, other plastic changes are clearly maladaptive (e.g., Ghalambor et al 2015).…”