Birds are the living beings like other creatures and humans are suffering from noise pollution causing different kinds of physical as well as mental diseases. Noise is a perennial and unavoidable source of stress for birds since they had always been exposed to loud natural sounds of streams, waterfalls, and wind from the days of their ancestors. However, noise pollution due to human beings is very new and hazardous. Substantial research has been conducted establishing the significant effects that this noise carries with regard to harm caused to birds in physical, behavioral and reproductive cycle interference.
The Difference Between Noise and Sound
The word “noise” finds its origin from Latin with the meaning of nausea and is defined as any sound that is either unwanted or disruptive to the prevailing sound. “Sound” is defined as a collection of vibrations that cause an auditory sensation whenever they traverse through space. The perception of sound and noise is subjective, and is different in humans and other species. Although natural sounds can sometimes interfere with our ability to hear or understand other sounds most of the time, noise pollution generally refers to unwanted sounds that are caused by human activities.
Noise Pollution – Anthropogenic Noise Impacting Birds
The level of induced noise, sometimes referred to as anthropogenic, through human activities depends on the level of our daily activities. Human population density is directly proportional to the induced noise density. Indeed, human activities are highest in urban areas where people appreciate a host of modern technologies, vehicles, and conceptions, all bound together by a hum of human activity. Of course, even natural areas have recently been experiencing an increase in noise pollution. Unfortunately, there is no corner of our Earth where noise pollution is not present because even the most distant locations are affected by the sounds of airplanes and land vehicles.
The interference of noise on the acoustic communication of wildlife and a consequence of declining the quality of habitat for birds happens due to the sources of noise that are anthropogenic. The overall condition is colloquially known as noise pollution, which affects birds in a lot of ways, largely: physical injury, stress responses, alteration in feeding and reproduction, disorientation concerning other important sounds, and even alterations in population. Consequently, the impact of noise pollution is variable with the kind of noise and ranges from frequency, volume, consistency, and duration.
Physical Damage
Prolonged exposure to loud sounds can be detrimental to animals, particularly to their sensory hair cells. Mammals commonly experience permanent hearing loss, while birds may regenerate these hairs to some extent, resulting in temporary damage and varying recovery times depending on the species. However, chronic exposure to loud noises can lead to long-term physical effects on birds, such as cardiovascular diseases, feather loss, and weight loss.
Changes in Foraging Responses
Research has shown that noise pollution can impact the behavior of birds. Specifically, studies indicate that excessive noise can negatively affect foraging behaviors. Some birds may prolong their state of awareness instead of focusing on finding food. As a result, noise pollution can directly interfere with feeding behavior. While some birds tend to avoid noisy areas and seek out quieter environments, others are surprisingly tolerant and may even prefer human-inhabited areas, including those with high levels of noise. For instance, the Great-tailed Grackle is often found in urban areas due to the abundance of food available in these environments.
Noise Can Mask Communication
Birds rely on vocalizations and other sounds to communicate with one another. Unfortunately, both natural and human-made noise can impact their ability to hear and respond to these important signals. As a result, birds—who depend on sounds for tasks like protecting their territory, keeping in touch with their mates and offspring, and alerting others to food or danger—may struggle to function in urban or noisy environments. This can lead to a reduction in bird diversity, as only those species that can adapt to the noise and disturbance are able to thrive in these areas.
Changes in Reproductive Success
As previously noted, prolonged stress triggers a range of physical reactions, such as heightened heart rate, hormonal imbalances, and weight loss. It also hinders birds’ immune systems, leading to reduced reproductive success. Noise pollution can impact egg laying, breeding, predator interactions, brood parasitism, abandonment, as well as mating and parental communication. Consequently, some species have experienced a decline in population numbers.
Breeding Habits
Birds that live in wooded environments tend to be more sensitive to noise than those that inhabit open environments. Recent studies have found that noise pollution delays the nesting of birds whose songs have a lower frequency and are therefore more difficult to hear through low-frequency human noise. Therefore, overall nest success is negatively correlated with noise among birds in indoor environments.
Effects on Population Density
Further research has substantiated that amplified noise levels lead to a decline in the population density of avian species. Excessive noise can impede birds’ ability to communicate with one another. Typically, birds reside on isolated patches of greenery that are not linked together. The absence of acoustic connections between these patches can adversely affect the learning process. Consequently, members of the same species inhabiting different regions that struggle to communicate may become fragmented and isolated into small populations.
Changes in Habitat Selection
Noise pollution decreases the quality of habitats because fewer birds choose to stay in noisy areas, rendering these habitats less favorable for the bird community. Habitat degradation results in fewer birds in the area, which could have consequences for the entire ecosystem. This shift in habitat selection not only affects bird populations but also disrupts the intricate balance of ecological interactions involving predators, prey, and plant life.
Why Should We Worry About Noise Pollution Affecting Birds?
The impact of noise pollution extends beyond its effects on birds; it also has significant consequences for humans. Birds play a critical role in ecological functions that are essential to our well-being. They consume insects that we consider pests, including ants, flies, spiders, crickets, wasps, and others. Additionally, birds serve as crucial pollinators and dispersers of various species of flora, some of which are vital crops. Furthermore, this taxon is often used as an indicator of ecosystems and habitats in many studies. For instance, the impacts of noise pollution on stress levels and reproduction in birds could have significant implications concerning human health and the environment as a whole.
Conclusion
Noise pollution is one of the most potent threats to avifauna, with impacts on the physiology, behavior, and reproductive output of birds. Given the fact that urbanization and other human activities are on the increase, this menace needs urgent attention to mitigate its deleterious impacts on the bird population. I would say in relation to this that sound pollution control within urban and natural circles must be a strategic part of both approaches in conservation as well as urban planning. Protecting our bird populations guards the ecological balance which is essential for the health of our planet and for ourselves.
Cited References
1. FRANCIS, Clinton, ORTEGA, Catherine, and Alexander CRUZ. 2011. Noise Pollution Filters Bird Communities Based on Vocal Frequency. PLoS ONE. Available online: Link
2. GILBERT, Emily, SOMPUD, Jephte, and Cynthia B. SOMPUD. 2017. A Review on the Impact of Anthropogenic Noise on Birds. Borneo Science, Vol. 38, No. 1.
3. HALFWERK, Wouter and Hans SLABBEKOORN. 2013. The Impact of Anthropogenic Noise on Avian Communication and Fitness. In Diego Gil and Henrik Brumm (editors) Avian Urban Ecology. Oxford University Press.
4. PERILLO, A., MAZZONI, L.G., FIGUEIREDO-Passos, L., GOULART, VDLR, DUCA, C., and R.J. YOUNG. 2017. Anthropogenic Noise Reduces Bird Species Richness and Diversity in Urban Parks. Liverpool John Moores University, Vol. 159, No. 3, Pages 638 – 646.
5. SENSAKY, Masayuki, BARBER, Jesse, PHILLIPS, Jennifer, CARTER, Neil, COOPER, Caren, et al. 2020. Sensory Pollutants Alter Bird Phenology and Fitness Across a Continent. Nature, Vol. 587, Pages 605 – 609.
