We Need to Treat Human Noise as a Global Pollutant, New Study Says - via Herp Digest

ScienceAlert, 11/20/19

It is well known that human hubbub can have a negative impact on some animals, but a new study Wednesday says the noise we make should be treated as a "major global pollutant".

"We found that noise affects many species of amphibians, arthropods, birds, fish, mammals, mollusks and reptilians," scientists at Queen's University Belfast said in the Royal Society's Biology Letters.

Human noise pervades the environment, from vehicles and industry in dense urban centres, to planes flying overhead, to ocean going vessels whose propellors are thought to interfere with whale sonar communications and may be implicated in mass beaching as the disorientated animals lose their sense of direction.

Reviewing a series of individual studies in what is known as a meta-analysis, Hansjoerg Kunc and Rouven Schmidt said the issue should be seen as the "majority of species responding to noise rather than a few species being particularly sensitive to noise.”

"The interesting finding is that the species included range from little insects to large marine mammals such as whales," he Kunc told AFP.

"We did not expect to find a response to noise across all animal species.

The paper said that an animal's response to the clatter of human activity is not necessarily straightforward, and cannot be easily termed as positive or negative.

Human made noise, for example, has been shown to interfere with the sonar detection systems that bats use to find their insect prey, making it more difficult for the flying mammals to catch insects.

But that may be good news for the bugs: "Potential prey may benefit directly from anthropogenic noise," the paper said.

Kunc cautioned, however, that the big picture is still one of serious disruption across the natural environment.

"In the bat example, the predator might suffer because they cannot locate their prey... but in species where potential prey rely on sound to detect predators, the prey might suffer because they might not be able to hear them early enough to escape.”

Human sound pollution and the animal response to it must be seen in the context of an ecosystem, especially when considering conservation efforts, the authors note.

"Noise must be considered as a serious form of environmental change and pollution as it affects both aquatic and terrestrial species," they said.

"Our analyses provide the quantitative evidence necessary for legislative bodies to regulate this environmental stressor more effectively."

Human-made noise can affect how animals use information from scents

Date: October 24, 2016

Source: University of Bristol

Research by scientists at the University of Bristol has, for the first time, found that human-made noise can have a detrimental impact on an animal's use of scent -- putting them at greater risk of being attacked by predators.

Using field-based experimental trials on dwarf mongooses in South Africa, the researchers combined sound recordings and fecal samples to demonstrate that road-noise playback negatively affected the mongooses' ability to detect predator feces. Even after detection, the additional noise led to less information gathering and less vigilance, making the mongooses more vulnerable to danger.

Professor Andy Radford from the School of Biological Sciences said: "We've known for a long time that noise from urbanisation, traffic and airports can detrimentally affect humans by causing stress, sleep deprivation, cardiac problems and slower learning. What's becoming increasingly clear is that a lot of other species -- mammals, birds, fish, insects and amphibians -- are also impacted in all sorts of ways by anthropogenic, or human-made, noise."

One obvious way in which human-made noise can cause animals problems is through the masking of valuable acoustic information. Lead author Amy Morris-Drake says: "What our study shows for the first time is that there could also be disruption to the use of olfactory information; human-made noise could affect decision-making based on information gathered using a different sense."

The Bristol team's experiment used groups of wild dwarf mongooses that were so familiar with the researchers' close presence that they could walk within a few feet of them. Co-author Dr Julie Kern adds: "This habituation allows us to conduct ecologically relevant experiments in the mongooses' natural habitat while collecting incredibly detailed and accurate information."

Closely monitoring the mongooses, the team found that their adaptive responses to predatory cues, such as increased inspection of the cue, vigilance scanning for danger and more time spent near the safety of the burrow, were all disrupted by road-traffic noise.

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