Global expansion of human activities is associated with the introduction of novel stimuli, such as anthropogenic noise, artificial lights, and chemical agents. Progress in documenting the ecological effects of sensory pollutants is weakened by sparse knowledge of the mechanisms underlying these effects. This severely limits our capacity to devise mitigation measures. Here, we integrate knowledge of animal sensory ecology, physiology, and life history to articulate three perceptual mechanismsmasking, distracting, and misleadingthat clearly explain how and why anthropogenic sensory pollutants impact organisms. We then link these three mechanisms to ecological consequences, and discuss their implications for conservation. We argue that this framework can reveal the presence of 'sensory danger zones', hotspots of conservation concern where sensory pollutants overlap in space and time with an organism's activity, and foster development of strategic interventions to mitigate the impact of sensory pollutants. Future research that applies this framework will provide critical insight to preserve the natural sensory world.

Currently, 11 western states and 2 Canadian provinces use sport hunting as the primary mechanism for managing cougar (Puma concolor) populations. Yet the impacts of sustained harvest on cougar population dynamics and demographic structure are not well understood. We evaluated the effects of hunting on cougar populations by comparing the dynamics and demographic composition of 2 populations exposed to different levels of harvest. We monitored the cougar populations on Monroe Mountain in south‐central Utah, USA, and in the Oquirrh Mountains of north‐central Utah from 1996 to 2004. Over this interval the Monroe population was subjected to annual removals ranging from 17.6–51.5% (mean ± SE = 35.4 6 4.3%) of the population, resulting in a >60% decline in cougar population density. Concurrently, the Oquirrh study area was closed to hunting and the population remained stationary. Mean age in the hunted population was lower than in the protected population (F = 9.0; df = 1, 60.3; P = 0.004), and in a pooled sample of all study animals, females were olderthan males (F = 13.8; df = 1, 60.3; P < 0.001). Females from the hunted population were significantly younger than those from the protected population (3.7 vs. 5.9 yr), whereas male ages did not differ between sites (3.1 vs. 3.4 yr), suggesting that male spatial requirements may put a lower limit on the area necessary to protect a subpopulation. Survival tracked trends in density on both sites. Levels of human‐caused mortality were significantly different between sites (χ2 = 7.5; P = 0.006). Fecundity rates were highly variable in the protected population but appeared to track density trends with a 1‐yearlag on the hunted site. Results indicate that harvest exceeding 40% of the population, sustained for ≥4 years, can have significant impacts on cougar population dynamics and demographic composition. Patterns of recruitment resembled a source–sink population structure due in part to spatially variable management strategies. Based on these observations, the temporal scale of population recovery will most likely be a function of local harvest levels, the productivity of potential source populations, and the degree of landscape connectivity among demes. Under these conditions the metapopulation perspective holds promise for broad‐scale management of this species.

Numerous techniques have been proposed to estimate or index cougar (Puma concolor) populations, but few have been applied simultaneously to populations with reliable estimates of population size. Between 1996 and 2003, we evaluated the relative efficacy and accuracy of multiple estimation and index techniques for populations at 2 locations in Utah, USA: Monroe Mountain and the Oquirrh Mountains. We used radiotagging followed by intensive monitoring and repeated capture efforts to approach a complete enumeration of the populations. We used these benchmarks to evaluate other population estimates (Lincoln—Petersen mark—recapture, helicopter‐survey probability sampling, catch‐per‐unit‐effort) and indices (scent‐station visits, track counts, hunter harvest). Monitoring over 600 scent‐station‐nights using different attractants June—September in 1996 and 1997 yielded a single cougar visit. Summer track‐based indices reflected a 54–69% reduction in population size on the Monroe site and a numerically stable population on the Oquirrhs, but relationships between indices and the benchmark population estimates varied among techniques. Aerial track surveys required sufficient fresh snowfall accumulations for adequate tracking coverage of a given unit, conditions that were met only once on one study site in each of 3 years. Population estimates derived from helicopter‐survey probability sampling exceeded reference population estimates by 120–284%, and bootstrapped estimates of standard error encompassed 25–55% of the population estimates (e.g., 5.6 ± 1.4 cougars/100 km2). Despite poor performance in predicting cougar population sizes, track‐based estimates may provide better indices for monitoring large changes in population trends (i.e., with low precision). However, we recommend using multiple indices after determination of a more rigorous initial population estimate for managing populations of conservation concern and when considering connectivity to determine potential refuge sites for regional management (e.g., management by zones).

Artificial nightlight is increasingly recognized as an important environmental disturbance that influences the habitats and fitness of numerous species. However, its effects on wide‐ranging vertebrates and their interactions remain unclear. Light pollution has the potential to amplify land‐use change, and as such, answering the question of how this sensory stimulant affects behavior and habitat use of species valued for their ecological roles and economic impacts is critical for conservation and land‐use planning. Here, we combined satellite‐derived estimates of light pollution, with GPS‐data from cougars Puma concolor (n = 56), mule deer Odocoileus hemionus (n = 263) and locations of cougar‐killed deer (n = 1562 carcasses), to assess the effects of light exposure on mammal behavior and predator–prey relationships across wildland–urban gradients in the southwestern United States. Our results indicate that deer used the anthropogenic environments to access forage and were more active at night than their wildland conspecifics. Despite higher nightlight levels, cougars killed deer at the wildland–urban interface, but hunted them in the relatively darkest locations. Light had the greatest effect of all covariates on where cougars killed deer at the wildland–urban interface. Both species exhibited functional responses to light pollution at fine scales; individual cougars and deer with less light exposure increasingly avoided illuminated areas when exposed to greater radiance, whereas deer living in the wildland–urban interface selected elevated light levels. We conclude that integrating estimates of light pollution into ecological studies provides crucial insights into how the dynamic human footprint can alter animal behavior and ecosystem function across spatial scales.