Anthropogenic Impacts as a Driver of Sensory Organ Morphology

All animals require the ability to use visual, auditory, tactile, and olfactory information to survive through activities including locating and identifying conspecifics including potential mates, locating food or shelter, or noticing an approaching predator. Detecting such information invariably requires sensory organs. The morphology of sensory organs evolves under natural selection to optimise the ability to detect salient cues and signals against the background noise in the natural environment. The rapidly proliferating anthropogenic impacts on almost all natural environments include light, noise, and chemical pollution, which can interfere with an animal’s ability to detect visual, acoustic or seismic, and olfactory information, respectively. Many studies examine the resulting changes in the characteristics of signals or the behavioural responses to them in affected natural populations, but very few examine the resulting changes in the sensory organs required to detect the signals; those that do all find evidence of morphological changes. Here, I review the current knowledge on the impact of anthropogenic pollution on sensory organ morphology in wild and captive populations, highlighting knowledge gaps and future directions for addressing them. This is especially important in the context of the growing recognition of the cruciality of sensory ecology in the design of effective threatened species conservation programs and invasive species management strategies.