The night sky is one where you can look up and see all the stars, rather than have ‘light pollution’ from the wrong kind of street lamps, neon signs, sports stadiums, billboards, car parks and lights left off in glass buildings (one of the main reasons for bird strike – to help, see how to stop birds flying into windows).
Today nearly all urban areas suffer from light pollution, with around 80% of the world’s population living under ‘skyglow’ (99% of people in Europe and the US do not get to enjoy a night sky). Other areas are lit to deter crime, when in fact ‘designing out crime‘ (carefully designing areas to avoid ‘hidden spaces’) is far more effective, than just blasting everywhere with artificial light.
Light pollution also causes us to miss the marvels of the earth. Around 50% of the world’s population has never seen the Milky Way (a hazy band of light made up of at least 1000 billion stars, dust and gas), simply due to it being blocked by artificial light. Light pollution has four main components:
- Glare (too bright to be comfortable to the eyes)
- Skyglow (a brightened night sky over urban areas)
- Light trespass (light falling when not needed)
- Clutter (too many lights, confusing)
Ever seen a night sky? Unless you live out in the country or are in an area that is renowned for retaining night skies due to good local policy, chances are you haven’t. A night sky is simply a blanket of sky unaffected by light pollution, where the only ‘lights’ you can see are the stars. Did you know there are almost 10,000 visible stars in our sky? How many have you ever seen?! You can even see 9 galaxies with the naked eye – the brightest being the Andromeda Galaxy, pretty easy to spot on a dark night when there’s no moon.
Stars don’t ‘twinkle’ (this is just an illusion due to vision turbulence), but you can see them nonetheless. Along with many of our planets (the brightest are Mars, Jupiter, Venus and Saturn). No telescope required! But stars are more likely (most are bigger than the sun). They are also much brighter, so are easier to spot.
Wildlife-Friendly Street Lamps
Iris Clelford for Whistlefish
One of the biggest sources of light pollution are conventional street lamps. Obviously we need street lamps, but many emit a blue light that attracts (sometimes endangered) insects that are killed in their millions. Light pollution also messes up the circadian rhythms of birds and other wildlife (in some cities, birds have been known to start singing their dawn choruses in the middle of the night, as the light confuses them as to what time it is). This in turn can affect mating and migration, which in turn can cause some species to become endangered.
Newer orange lamps are sodium vapour and generally thought to be of better quality. A few places (like London) still use old-fashioned gas lamps, and it’s a skilled job of someone to adjust the timers, so they keep in pace with days as they get shorter or lighter, depending on the season. Years ago, gas lamps were very dangerous, and often exploded and even caused people to die. Modern street lamps should be positioned so as not to give glare, and run on clean energy, point downwards and only come on, when needed. You have to have more than one to be effective, and lamps need to be coated with a special finish near the sea, to avoid corrosion. In most cases, solar clocks and photocells self-adjust, to automatically switch in summertime.
Did you know that in Germany alone, over 1 billion insects die each summer night, simply due to street lighting? Wildlife-friendly lights are better with an amber glow, which also helps nocturnal moths (they pollinate our food, just like bees). In Worcestershire, the council installed glowing red lights that are much better for resident bats (many avoid areas with white light, which can cause less safe migration routes). Other creatures affected by street lamps are glow worms (that obviously have to glow to find a mate).
Why Some Street Lamps Harm Birds
Birds are negatively affected by street lamps, as the artificial light confuses them as to what time (or season it is). There have been reports of some birds waking up at around midnight, to sing their dawn chorus. Just as with other wildlife, the light pollution can also their biological systems.
In Canada, the Lights Out Campaign is saving billions of birds from flying into buildings, by encouraging people to turn off bright artificial lights and street lamps (you can download free sample letters to officials at the site, to help change policy). In just one week in 2017, 400 birds were caught in the floodlights of a 32-story Texas skyscraper, and killed via window collusions (see how to stop birds flying into windows). Their advice to anyone working or living in urban areas is:
- Turn off all exterior decorating lights
- Extinguish pot and flood-lights
- Use strobe lighting, if needed
- Reduce atrium lighting, if possible
- Turn off interior lights (use desk lamps), especially on higher stories
- If staying late, pull window coverings shut
- Down-shield exterior lamps to eliminate horizontal glare or upward light
- Install automatic motion sensors and controls
Cornell Lab of Ornithology found that turning off bright lights, helps birds to move on within minutes. In the Dutch city of Ameland, motion sensors detect human activity, to dim lights if no-one is around. And in New Zealand, one village switched off all its street lights, to avoid confused baby birds crash landing on the road. This was done after learning that birds were ‘seeing a blue light’ and diving in, thinking that like the sea or a fish. As for how the locals manage, it’s simple – they carry torches!
Wildlife-Friendly Lighting Ideas
- In Lille (Paris), a park light with a nocturnal corridor has been created, with motion sensors turning off lights, when not in use. Early morning and evening commuters can see – but after 10pm, the lights revert to amber, so the ‘animals sleep soundly at night’. If a cyclist or car arrives, the sensors switch on LEDs, but only temporarily.
- In Devon, the council worked with an ecologist to stop ‘light spilling’ on a local river that has a healthy bat population. The LEDs are mounted into handrails, so light is controlled and won’t disturb local wildlife. Lights again only operate dusk to midnight, and from 6.30am to daylight.
- Access Fixtures Wildlife LIghting Fixtures emit light in a wildlife-friendly way, and area ideal for walkways, roads, parking lots of coastal areas. Friendly to frogs and sea turtles, the lights can be seen by us but are almost invisible to other creatures, to avoid baby turtles following the ‘white light of the moon’ to find their way to the car park, instead of the ocean. Their motto for wildlife-friendly lights:: ‘Keep it long, keep it low, and keep it shielded’.
- The Dutch town of Zuidhoek-Nieuwkoop created a ‘bat-friendly light recipe’ using a red hue that is used on a wavelength that does not affect a bat’s internal compass. The light is remotely controlled by the council who can dim or turn it off, when not in use.
- Zaniboni Lighting has a good post on how to protect sea turtles, which follow the brightest light (sun, moon or office building with street lights outside). They recommend recessed amber lights near nesting sites, with no head-on view so the light can’t mimic the sea. First Light Technologies offers wildlife-friendly lighting solutions, approved for safe installation near turtle-nesting beaches. The low mounting height ensures minimal effect on sea turtles, where lighting is needed.
Wildlife-Friendly Street Lamps
Pure Night Lighting Solution offers lighting to respect biodiversity and limit light pollution. You can find a wide choice to send light where it’s needed, and work with specialists to choose the best lighting solution for you.
Blue and bright white bulbs are three times more harmful to wildlife, than soft yellow or amber light. Their FlexiWhite lamp switches automatically from amber to white light on sensor detection, and then presumably back again to protect wildlife, when not in use.
A Wind-Powered Street Lamp
Papilio is a wind-powered street lamp with an integrated rotor as a climate-neutral way to produce energy. Wind power (which can harm wildlife if done with big whirring blades sited wrongly) is naturally generated by narrow streets and subjway shafts, and this uses air streams from natural wind and horizontal air streams, caused by airflow traffic. The lamp can be connected to existing power grids, and due to only emitting downward light, it does not harm insects (the warm colour is also designed to be less attractive to them). It also only activates when needed, so does not shine when there is nobody around.