Insights

That you don’t think about.

We actively maintain green spaces, in part, so that people can enjoy them. However, in our increasingly urbanised world, the hum of machinery can often detract from this experience, by overshadowing the relaxing sounds of nature, which is a shame, as exposure to natural sounds is shown to promote physiological expressions of relaxation¹. During ground maintenance works, the noise from equipment can be annoying, but we know that this noise is temporary, so we generally just put up with it.

But what if we didn’t know that the noise is temporary? What if we didn’t understand what the noise was?

This article invites you to put yourself in the mindset of unsuspecting wildlife and to consider how they might perceive noise from ground maintenance machinery.

Anthropogenic (human generated) noise pollution refers to an excess of unwanted sounds that can disturb the natural behaviour and/or health of wildlife. Research indicates that terrestrial animals can begin to react adversely to noise at levels as low as 40-50 dBA². Above 70 dBA, effects such as reduced feeding in birds³, signs of stress in lizards⁴, and increased likelihood of stillborn pups in mice⁵ are observed. Yet, common grounds maintenance machinery operates at much higher levels. For example, leaf blowers are found to generate noise levels between 78 and 81 dBA around 15m (50 feet in referenced text⁶) away. When people are operating machinery within a few metres of wildlife, the levels of noise are considerably higher. Plus, the animals are presented with (from their perspective) a very large intimidating animal (i.e., us) to accompany the high noise levels. To contextualise just how loud this equipment is, people carrying out ground maintenance works are often advised to wear hearing protection to protect against hearing loss and comply with UK regulatory requirements⁷. Moreover, various US cities (e.g. San Clemente, California)⁸, place restrictions on the levels of noise that leaf blowers are allowed to emit.

Thinking this through raises critical questions about the justification of using such loud machinery. How much are we unknowingly impeding biodiversity by disrupting wildlife behaviour? If this noise is altering communication and increasing stress levels, as research implies, then should we not be seeking quieter methods?

In the contemporary landscape of grounds maintenance, it is vital to find a balance between human needs and those of nature. As we collectively push for cleaner, greener spaces, we must also consider the soundscape we create, the shadow we cast. It is becoming clearer that better knowledge of anthropogenic pollution (noise, vibration, light, odour, etc) is essential for us to effectively boost biodiversity, which has been continually depleting for some time⁹, to the detriment of the UK¹⁰ and to the planet as a whole¹¹.

By integrating awareness of noise impacts into our maintenance practices, incorporating up to date knowledge into local policy, and by considering alternative, quieter methods, we can help preserve the natural soundscapes essential for wildlife health and biodiversity.

Footnotes

1. Jo H, Song C, Ikei H, Enomoto S, Kobayashi H, Miyazaki Y. Physiological and Psychological Effects of Forest and Urban Sounds Using High-Resolution Sound Sources. Int J Environ Res Public Health. 2019 Jul 24;16(15):2649. doi: 10.3390/ijerph16152649. PMID: 31344973; PMCID: PMC6695879.
2. Shannon G, McKenna MF, Angeloni LM, Crooks KR, Fristrup KM, Brown E, Warner KA, Nelson MD, White C, Briggs J, McFarland S, Wittemyer G. A synthesis of two decades of research documenting the effects of noise on wildlife. Biol Rev Camb Philos Soc. 2016 Nov;91(4):982-1005. doi: 10.1111/brv.12207. Epub 2015 Jun 26. PMID: 26118691.
3. Cutts, N., Phelps, A. and Burdon, D. Construction and Waterfowl; Defining Sensitivity, Reponse, Impacts and Guidance. University of Hull : Institute of Estuarine and Coastal Studies, 2009. ZBB710-F-2009
4. Mancera Alarcon, Karen F. M. Effects of anthropogenic noise on the behaviour, physiological traits and welfare of two animal models: wild mice (Mus musculus) and Eastern blue tongued lizard (Tiliqua scincoides). s.l. : The University of Queensland, 2015
5. Rasmussen, Skye, et al. Construction Noise Decreases Reproductive Efficiency in Mice. J Am Assoc Lab Anim Sci. 2009, Vol. 48, 4.
6. Walker E, Banks JL. Characteristics of Lawn and Garden Equipment Sound: A Community Pilot Study. J Environ Toxicol Stud. 2017 Dec;1(1):10.16966/2576-6430.106. doi: 10.16966/2576-6430.106. Epub 2017 Nov 3. PMID: 31448365; PMCID: PMC6707732.
7. Control of Noise at Work Regulations 2005, SI 2005/1643, available at: Legislation.gov.uk
8. Public Interest Research Group (PIRG) Education Fund. “Interactive Map of Lawn Mower and Leaf Blower Policies,” available at: https://pirg.org/edfund/resources/interactive-map-of-lawn-mower-and-leaf-blower-policies/.
9. Burns, F et all. State of Nature 2023. s.l. : the State of Nature Partnership, 2023.
10. Brondizio, E S, et al. Global assessment report on biodiversity and ecosystem services of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. Bonn, Germany : IPBES secretariat, 2019
11. Protecting biodiversity and ecosystems helps mitigate climate change: The contribution of the Aichi Biodiversity Targets to land-based climate mitigation. Leadley, P, et al. 2015, The Secretariat of the Convention on Biological Diversity at UNFCCC COP-21.