28Human activities have caused a near-ubiquitous and evolutionarily-unprecedented increase in 29 environmental sound levels and artificial night lighting. These stimuli reorganize communities 30 by interfering with species-specific perception of time cues, habitat features, and auditory and 31 visual signals. Rapid evolutionary changes could occur in response to light and noise, given their 32 magnitude, geographical extent, and degree to which they represent unprecedented 33 environmental conditions. We present a framework for investigating anthropogenic light and 34 noise as agents of selection, and as drivers of other evolutionary processes, to influence a range 35 of behavioural and physiological traits, such as phenological characters and sensory and 36 signalling systems. In this context, opportunities abound for understanding contemporary and 37 rapid evolution in response to human-caused environmental change. The overcast night sky radiance in urban areas has been found to be as much as four orders of 55 magnitude larger than in natural settings (Figure 1) [5]. Similarly, increased noise levels affect a 56 sizable proportion of the human population. In Europe for instance, 65% of the population is 57 exposed to ambient sound levels exceeding 55 dB(A) [6], roughly equivalent to constant rainfall. 58Of the land in the contiguous U.S., 88% is estimated to experience elevated sound levels from 59 anthropogenic noise (Figure 1) [7]. These effects are not limited to terrestrial environments; 60 ocean noise levels are estimated to have increased by 12 decibels (an ~16-fold increase in sound 61 intensity) in the past few decades from commercial shipping alone [8], while an estimated 22% 62 of the global coastline is exposed to artificial light [3] and many offshore coral reefs are 63 chronically exposed to artificial lighting from cities, fishing boats, and hydrocarbon extraction 64 [9]. 65The changes in light at night and noise levels are occurring on a global scale similar to 66 well-recognized ecological and evolutionary forces such as land cover and climate change. In 67 4 parallel with research involving climate change [10], much of our understanding of organismal 68 response to noise and light is restricted to short-term behavioural reactions. Organismal 69 responses might be associated with tolerance to these stimuli in terms of habitat use [11,12] Status of research on anthropogenic light and sound in ecology 98Night lighting and noise are highly correlated in many landscapes (e.g., [21]). It is critical to 99 understand whether the selective pressures these stimuli exert are additive, synergistic (Figure 2), 100 or if they mitigate one another. Few studies have examined the influence of each simultaneously 101 (e.g., [21]). In one study, flashing lights combined with boat motor noise suppressed antipredator 102 behaviour in hermit crabs (Coenobita clypeatus) more so than noise alone [22]. Future research 103 should quantify both light and sound simultaneously in the same population. Existing r...

Actions taken to control the coronavirus disease 2019 (COVID-19) pandemic have conspicuously reduced motor vehicle traffic, potentially alleviating auditory pressures on animals that rely on sound for survival and reproduction. Here we evaluate whether a common songbird responsively exploited newly emptied acoustic space by comparing soundscapes and songs across the San Francisco Bay Area prior to and during the recent statewide shutdown. We show that noise levels in urban areas were dramatically lower during the shutdown, characteristic of traffic in the mid-1950s. We also show that birds responded by producing higher performance songs at lower amplitudes, effectively maximizing communication distance and salience. These findings illustrate that behavioral traits can change rapidly in response to newly favorable conditions, indicating an inherent resilience to long-standing anthropogenic pressures like noise pollution.

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Physiological factors are rarely proposed to account for variation in the morphology of feeding structures. Recently, bird bills have been demonstrated to be important convective and radiant heat sinks. Larger bills have greater surface area than smaller bills and could serve as more effective thermoregulatory organs under hot conditions. The heat radiating function of bills should be more important in open habitats with little shade and stronger convective winds. Furthermore, as a means of dumping heat without increasing water loss through evaporation, bills might play a particularly important thermoregulatory role in heat loss in windy habitat where fresh water is limited. North American salt marshes provide a latitudinal gradient of relatively homogeneous habitat that is windy, open, and fresh‐water limited. To examine the potential role of thermoregulation in determining bill size variation among ten species or subspecies of tidal marsh sparrows, we plotted bill size against maximum summer and minimum winter temperatures. Bill surface areas increases with summer temperature, which explained 82–89% of the variance (depending upon sex) when we controlled for genus membership. Latitude alone predicted bill surface area much more poorly than summer temperature, and winter temperatures explained < 10% of the variance in winter bill size. Tidal marsh sparrow bill morphology may, to a large degree, reflect the role of the bill in expelling excess body heat in these unbuffered, fresh‐water‐limited environments. This new example of Allen's rule reaffirms the importance of physiological constraints on the evolution of vertebrate morphologies, even in bird bills, which have conventionally been considered as products of adaptation to foraging niche.

Protected areas are intended to safeguard biodiversity in perpetuity, yet evidence suggests that widespread legal changes undermine protected area durability and efficacy. We documented these legal changes—protected area downgrading, downsizing, and degazettement (PADDD) events—in the United States and Amazonian countries and compiled available data globally. Governments of the United States and Amazonian countries enacted 269 and 440 PADDD events, respectively. Between 1892 and 2018, 73 countries enacted 3749 PADDD events, removing 519,857 square kilometers from protection and tempering regulations in an additional 1,659,972 square kilometers; 78% of events were enacted since 2000. Most PADDD events (62%) are associated with industrial-scale resource extraction and development, suggesting that PADDD may compromise biodiversity conservation objectives. Strategic policy responses are needed to address PADDD and sustain effective protected areas.