There is no question that human activities create noise pollution, and that we humans find some of these noises rather stressful: There is nothing like a quiet afternoon in Snell’s Beach being interrupted by the blazing noise of motor boats in the water. But how this noise affect other animals is the issue brought up in a recent review by JR Barber, KR Crooks and KM Fristrup in Trends in Ecology and Evolution.
The presence of noise reduces our perception of sounds (including those that are biologically relevant) a phenomenon that is known as auditory masking. Masking reduces our ability not only to detect, for example, communication signals, but also other sounds that may be important, such as an approaching predator. It is known that animals can change some aspects of their
communication signals to overcome the effects of masking. For example, some birds in urban areas sing at a higher pitch than their counterparts in rural environments. Lyrebirds even incorporate some of these human generated sounds into their song (and this is beautifully shown in a Attenborough’s video that can be found here).
But we cannot only blame humans for loud environmental noise. Peter Narins, for example, describes the sounds in his field site in China as “so loud that you cannot hear yourself thinking”. And it was in this loud environment that he discovered that some local frogs shifted their communication signals to the ultrasound, probably to avoid the effects of auditory masking from the natural environment.
So the question is: is anthropogenic noise detrimental to animal species?
The answer appears not to be so simple. On the one hand, while masking may have a negative effect on vocal communication, if a predator is using those same communication signals to locate its prey, masking may lower the chances of being detected (and eaten!). The authors also argue that one of the problems of determining the impact of loud noises in the ecology of species is that anthropogenic sounds do not come in isolation: they come with us, humans, as well as everything we bring with us, including habitat fragmentation.
After reviewing the literature, the authors state that:
Taken individually, many of the papers cited here offer suggestive but inconclusive evidence that masking is substantially altering many ecosystems. Taken collectively, the preponderance of evidence argues for immediate action to manage noise in protected natural areas.
Something to think about as we look forward to the warm days of summer while oiling our beloved motorboats and motorcycles.
Barber JR, Crooks KR and Fristrup KM (2009) The costs of chronic noise exposure for terrestrial organisms. Trends in Ecology and Evolution doi:10.1016/j.tree.2009.08.002
Random samples of my reading list brought to you through the magic of the internet, bloggers and Open Access.
The Society for Neuroscience just held its annual meeting in Chicago, and this year they encouraged the use of social media to disseminate the results presented. Many registered as official neurobloggers and the list can be found here. I, for one, am grateful to all of those who have allowed me to take a peek into the meeting, which I was unable to attend.
A new article in PLoS Biology looks at what it is that determines whether a bee will differentiate into a male or a female. The article by Gempe, Hasselmann, Schiøtt, Hause, Otte and Beye shows how sex in bees is determined by the regulation of two genes (csd and fem). Based on their data, the authors suggest that males are the default developmental programme, and that the female phenotype is expressed when bees are heterozygous to csd, which in turn results in the expression of the female form of fem that leads to a developmental path towards femaleness. There is a very nice comment on the original article by Mary Hoff.
There is a great post by Eric M Johnson on his blog the Primate Diaries on “Science and the Worship of Truth”. Here is a guy that is constantly making me think and reframe my position around issues. And he does it again on this post. It is worth a read, as is the post he links to by Henry Gee on the same topic.
And my favourite tweet this week is this one from @CameronNeylon. It links to a video of a session on making science public (featuring Felix Reed-Tsochas, Maxine Clarke, Ben Goldacre and Cameron Neylon). I tried to follow this session through twitter, and I was elated to see the video put online.
There is the data, and then there is the interpretation of the data. They are not the same thing, although this line gets blurred too often.
Many years ago Andy Moiseff, a colleague of mine, showed me a ‘Letters to The Editor’, published in 1887 in Science. (G Hay. Instinct in the cochroach. Science Vol IX 1887 p. 622 ). I used to present this article as my first lecture to emphasise the importance of extracting the data from an article, and the perils of relying too heavily on the author’s description or interpretation.
Starting tomorrow, Monday 19th to the 23rd of October the world celebrates its first international Open Access Week. To celebrate, I have removed the brackets from my title. As stated in their website:
Open Access is the principle that all research should be freely accessible online, immediately after publication, and it’s gaining ever more momentum around the world as research funders and policy makers throw their weight behind it.