November 11, 2021 – Step outside and it’s obvious the world is a noisy place. Researchers have studied the effects of noise on people for decades. We know loud and constant noise can create physical and psychological stress, interfere with communication and cause sleep disturbances. In severe cases, noise can cause cognitive impairment, tinnitus, hearing loss and even affect overall health!
If noise has negative effects on human health, it likely has detrimental effects on animals as well. To date, there aren’t many published studies looking at the effect of noise on animals, but this is changing as more researchers turn their attention to this increasingly important problem.
Human-generated noise also is a major concern for free-ranging, wild animals. Growing metropolitan areas, development and land changes increasingly are contributing to a noisier world. It’s getting harder to find places with only natural sounds, like wind in the trees or a babbling brook, without some human-generated noise in the background. And the data backs this up; more than 83% of land in the continental United States alone is exposed to noticeable vehicular noise. What is this doing to our wildlife?
One Morris Animal Foundation-funded study is trying to answer this question in invertebrates. According to the researchers, less than 4% of noise research has been conducted on invertebrates, and yet invertebrates make up more than 95% of the world’s species. Invertebrates are an important component to most of the world’s food webs, and their populations are dwindling in what scientists call a silent extinction. If invertebrate populations continue to decline, we will see decreased pollination, pest control, soil and water health, and food availability for species that feed on insects, including birds and reptiles. Fewer invertebrates also will negatively affect human food webs.
The team is looking at how urban noise affects the health and reproductive success of crickets. Crickets are easy to study in the lab and can be used as a model to inform how noise may be affecting the wider invertebrate families around the world. In addition, the work will fill in a critical missing piece in the invertebrate health and reproduction body
of knowledge. The team also hopes their data will inform legislative and management
decisions about impacts of noise exposure on urban wildlife.
Another recently funded study is focused on assessing the impacts of underwater noise on the behavior and stress levels of two endangered dolphin species in Malaysia. Dolphins rely on sounds and use whistles, squeaks and echolocation (such as clicks) to navigate, communicate and forage. The research team suspects human activities, such as boat traffic from tourism, sea transportation and fishing, increase underwater noise to levels that may be harmful to dolphins. This makes it harder for dolphins to hear each other and forces them to use more energy to whistle louder than the engine sounds of passing boats.
This human-generated noise could be dangerous, making it difficult for the dolphins to hunt for food or even separating individuals from their pods. Researchers hope their findings will inform conservation strategies to protect the dolphins as well as other marine mammal species in the region.