A before–after control–impact assessment to understand the potential impacts of highway construction noise and activity on an endangered songbird

Abstract

Anthropogenic noise associated with highway construction and operation can have individual‐ and population‐level consequences for wildlife (e.g., reduced densities, decreased reproductive success, behavioral changes). We used a before–after control–impact study design to examine the potential impacts of highway construction and traffic noise on endangered golden‐cheeked warblers (Setophaga chrysoparia; hereafter warbler) in urban Texas. We mapped and monitored warbler territories before (2009–2011), during (2012–2013), and after (2014) highway construction at three study sites: a treatment site exposed to highway construction and traffic noise, a control site exposed only to traffic noise, and a second control site exposed to neither highway construction or traffic noise. We measured noise levels at varying distances from the highway at sites exposed to construction and traffic noise. We examined how highway construction and traffic noise influenced warbler territory density, territory placement, productivity, and song characteristics. In addition, we conducted a playback experiment within study sites to evaluate acute behavioral responses to highway construction noises. Noise decreased with increasing distance from the highways. However, noise did not differ between the construction and traffic noise sites or across time. Warbler territory density increased over time at all study sites, and we found no differences in warbler territory placement, productivity, behavior, or song characteristics that we can attribute to highway construction or traffic noise. As such, we found no evidence to suggest that highway construction or traffic noise had a negative effect on warblers during our study. Because human population growth will require recurring improvements to transportation infrastructure, understanding wildlife responses to anthropogenic noise associated with the construction and operation of roads is essential for effective management and recovery of prioritized species.

Effects of road construction noise on golden‐cheeked warblers: An update

“…Human population growth and aging infrastructure will require recurring improvements to roadways for the foreseeable future, and road construction and operation are likely to be a consistent source of anthropogenic noise and potential disturbance along human‐wildland interfaces. Our research corroborates other studies, which suggest that low frequency noise does not degrade warbler habitat (Benson , Long et al ). However, warblers are affected by patch size (Arnold et al , Baccus et al , Butcher et al , Robinson ), edge effects (Peak ), tree species composition (Marshall et al , Long ), and canopy cover (Dearborn and Sanchez , Magness et al ).…”

“…Louder highway construction or traffic noise could have a negative effect on warblers. However, results of our playback experiment and concurrent research conducted in urban areas and on military land where daily maximum noise levels exceed 70–100 dB(A) suggest this is unlikely (Long et al ; M. L. Morrison, Texas A&M University, unpublished data).…”

“…This suggests that any differences in song characteristics were attributable to individual variation rather than a response to differences in noise levels. Concurrent studies on warblers where mean and maximum noise levels were greater support these findings (Long et al ; M. L. Morrison, unpublished data). However, birds may be more likely to adjust their songs in response to the frequency of noise rather than its loudness (Dooling and Popper ).…”

Traffic Noise Pollution Does Not Influence Habitat Selection in the Endangered Little Bustard

“…In the case of birds, many studies have shown that occurrence and abundance are often reduced near roads due to traffic disturbance or direct road mortality (bautista et al, 2004;Fahrig & Rytwinski, 2009;Summers et al, 2011;Torres et al, 2011). In particular, traffic noise exerts important negative effects on birds (Reijnen et al, 1995;Fahrig & Rytwinski, 2009;Goodwin & Shriver, 2011; see however Long et al, 2017) due to their general dependence on acoustic communication when breeding (Rheindt, 2003;Summers et al, 2011).…”

Defining practical and robust study designs for interventions targeted at terrestrial mammalian predators

“…It can be applied to both random and non-random samples, and is especially popular in interventions where random sampling is impossible, e.g. for spatially fixed land plots, waterbodies or protected areas (Geldmann et al 2013;Larson et al 2016;Long et al 2017). Before-after comparisons of non-random treatment and control samples may reduce limitations of the selection bias, but only if these samples are similar in location, landscapes and management histories (Adams et al 2019).…”