Light pollution and its impact on Migratory Birds
Description
Light pollution and its impact on Migratory Birds
World Migratory Bird Day has been celebrated on 8th October, 2022 with the theme of Impact of Light Pollution on Migratory Birds
About World Migratory Bird Day
World Migratory Bird Day is organized by a collaborative partnership among two UN treaties - the Convention on the Conservation of Migratory Species of Wild Animals (CMS) and the African-Eurasian Migratory Waterbird Agreement (AEWA), and the non-profit organization, Environment for the Americas (EFTA).
The overall mission of World Migratory Bird Day (WMBD) is to raise awareness of migratory birds and issues related to their conservation. The campaign highlights the importance of international cooperation and encourages national and local action to protect migratory birds.
Who are migratory birds?
Avian migration is a natural process, whereby different birds fly over distances of hundreds and thousands of kilometres in order to find the best ecological conditions and habitats for feeding, breeding and raising their young. When the conditions at breeding sites become unfavourable due to low temperatures, migratory birds fly to regions where conditions are better.
There are many different migration patterns.
• The majority of birds migrate from northern breeding areas in the summer, to southern wintering grounds.
• Some birds breed in southern parts of Africa and migrate to northern wintering grounds, or horizontally, to enjoy the milder coastal climates in winter.
• Some birds migrate in terms of altitude, moving higher up a mountain in summer, and residing on lowlands during the winter months.
Examples: Siberian cranes and Greater flamingo are migratory birds that are usually seen in India in the winter season.
Why migratory birds need to be protected?
Human activities are the source for most dangers migrating birds are exposed to. The loss of habitats due to pollution or exploitation caused by encroachment for settlement, agriculture, grazing etc. is the main threat migrating birds face, as they are dependent on finding suitable breeding and wintering grounds as well as stopover sites along their flyways where they can rest and feed. The loss of any of these sites used by the birds during their annual cycle could have a dramatic impact on the birds’ chances of survival.
Also, high-voltage power lines and wind turbines have a dramatic impact on birds, which are in danger of being killed by electrocution or collision.
Poaching remains widely practised in countries where people are highly dependent on biodiversity for their livelihoods.
Hence World Migratory Bird Day is celebrated and is an effective tool for the international community to help raise awareness on the threats faced by migratory birds, their ecological importance, and the need for international cooperation to conservation them.
The theme of this year was Light Pollution and its impact on the Migratory birds.
What is Light pollution?
Light pollution is the presence of unwanted, inappropriate, or excessive artificial lighting. It disrupts the natural patterns of wildlife, contributes to the increase in carbon dioxide (CO2) in the atmosphere, disrupts human sleep, and obscures the stars in the night sky.
Impact on Birds
• Light pollution can alter birds' behaviours, including migration, foraging and vocal communication.
• It also affects their activity levels and their energy expenditures.
• Light pollution attracts and disorients nocturnally migrating birds, which may end up circling in illuminated areas. This unnatural light-induced behaviour can mean they end up depleting their energy reserves and puts them at risk of exhaustion, predation and lethal collision. Each year, light pollution contributes to the death of millions of birds from collisions with buildings and other built infrastructure. Long distance migrants, such as the blackpoll warbler (Setophaga striata), the Asian stubtail (Urosphena squameiceps) and the oriental plover (Charadrius veredus), may start and end their migrations in areas with relatively low levels of light pollution, but during migration they may fly over areas of intense urban development where they experience high levels of artificial light.
• Migrating birds can be attracted to lights, particularly when there is low cloud, fog or rain and they are flying at lower altitudes
• Many nocturnally migrating birds such as ducks, geese, plovers, sandpipers and songbirds of all kinds are affected by light pollution. Seabirds such as petrels and shearwaters commonly get drawn into hazardous situations on land and on ships by artificial light sources.
Solutions to the light pollution
• Changing the bulbs in the street lamps: Street lighting is often lit by sodium vapor bulbs. Lowering the pressure in these bulbs results in a light that is less bright, yet still perfectly fine for illuminating the streets. These less bright bulbs are also less disruptive to species of animals living nearby.
• Downward facing street lights: These lamps turn light down onto the pavement (and so do their job) but are hooded to prevent it from being scattered into the sky. When the light from the bulb only falls downwards, rather than streaming up into the sky, its effect on light pollution will be negligible.
• Reducing air pollution: Light pollution is significantly worsened by the presence of dust and polluting gases in the air, as these can be lit up by the city below and cause a fiery glow in the air. Reducing the amount of fumes sprays and so on that we release into the air will thus help in our fight against light pollution.
• Switching lights off at night: Turn off unnecessary lights both at home and in commercial premises sounds simple, but turning our lights off at bedtime, whether at home or in a business, is the easiest solution to the problem of light pollution. Our sleeping patterns will then be much more regular and if we want to read in bed, we can use a dim reading light which does not contribute to light pollution.
• Dark hours: Initiatives such as ‘earth hour’, which encourage people to turn off all of their electrical appliances for an hour every week, can significantly reduce the amount of light pollution in the atmosphere. These initiatives have the added benefit of saving electricity and energy – which also help to battle climate change.
