IMPACT ON ANIMALS

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IImpact of outdoor lighting on insects
Light pollution doesn't only impede  astronomical observations  but also threatens  some animals. Streetlighting  is quickly spreading into the countryside and to natural resorts of animals.. This has a strong impact on the life cycle of insects, who are an animal group with the largest number of types  and thus contribute the largest share to the biotic diversity on our planet. Two institutions in Slovenia, Bird Watching and Bird Study Association of Slovenia and Slovenian Museum of Natural History have appealed to the public this year to reduce light pollution.
So as all living creatures insects are also influenced by inner and outer factors:
              - inner (food and mating)
              - outer (temperature, moisture, gravity and light, which is the most important outer factor)

The majority of insects have a good eye-sight. There are several ways of protecting insects from light pollution:
              - full closed light
              - use non-UV lights and automatic switch-off lights
             - ban the emission of light over lamp's horizontal line after 10pm  to reduce luminosity

How do insects react to light?
Some types of insects flee away from light and we say that they are phototactic negative. Others always turn towards it  because they are attracted to it, so they are phototactic positive. 

What do insects see?
Insect eye sensitivity goes far into the ultraviolet light spectrum invisible to man - to 300nm (nanometre) or still farther. 

How do insects orientate themseles?
Insects orientate themselves by picturing a light source and directing it on the same ommatidia in a compound eye. So when they move they can keep the same angle towards the sun or other celestial body all the time.  This is the so-called compass orientation. Their sense for time is also important. /biological clock). The rotation of earth causes virtual moving of celestial bodies. Insects must monitor the angle of flying constantly if they want to fly in line.
 
Impact of artificial  light sources on insects

During migration insects fly at the same angle towards the sun and other stars. They retain this angle when disturbed by an artificial light source. They are particularly attracted to UV light. They approach the light source spiralling and finally crash into it. They are so often attracted to light because they are phototactic positive. To prevent this  we should use full cut-off lights.

Night butterflies
Night butterflies balance feeding, reproduction and flying with the quantity of light. They start their  night cycle with feeding. They contribute an important share to the pollination  of plants. They are the second most  important pollinators after bees. Their reproduction is also important.

Night butterflies with longer life expectancy go on long migrations. They spend winter in the Mediterranean and fly back to central Europe in spring.    Butterflies' time  and orientation  depend on the Moon and other celestial bodies, which enables them to be at the right place at the right  time.                                                                            A number of surveys in Germany showed that the  whole populations of different species had disappeared. We can avoid this with the use of appropriate lights and casings.  The most attractive and thus lethal for insects are high-pressure mercury light bulbs.  Unfortunately the majority of roads, parking areas and others public areas are illuminated with  these lights. Fluorescent tubes radiate light too, but kill three times fewer insects than mercury lights.
The most suitable are low-pressure sodium lights, which are rarely used.  The form is also important. Globe lamps are the worst possibility  because butterflies mix them with the Moon. The best choice is box lamp casing, with flat protection cover,  without side openings.
 
Impact of light pollution on birds
Light pollution also influences birds. There are 9600 types of birds in the world, 1111 of which are threatened. In the last 200 years 74 types of birds have become extinct. Further 130 are  on the red list, 15 of them have already become extinct. During March-May and September-November periods migratory birds are on the move and thus are influenced by light pollution the most.

Examples:
A LITTLE OWL (Athene noctua ) - 50% of its food are insects. If the number of insects doesn't stop falling there will be less  food for them. These birds often (perhaps also because of hunger?) move to urban areas and meadows and become  frequent victims of traffic.

A SCOOPS-OWL ( Otus scops ) – it also eats insects

A ROLLER (Coracias garulus) – not more than 3 decades ago it was quite common in Štajerska and Prekmurje valleys, groves and vineyards. Now there are only 4 couples left in remote areas of Slovenske gorice and Celje hills. The solution is the re-introduction  of traditional forms of agriculture. It's just the question of time when it will become extinct because there in not enough food.

A RED-NECKED GREBE (Podiceps grisegena) AND A BLACK-THROATED DIVER (Gavia arctica) - These types of birds land on water.  They mistakenly take incorrectly illuminated surfaces of roads and airport runways for water surfaces and thus try to land,  breaking their wings, legs and die.

Bird Watching And Bird Study Association of Slovenia conference already suggested actions against light  pollution in 2000. They proposed switching off advertising light after 11pm, full cutoff lights and the prohibition of high-pressure mercury lights. This doesn' t mean that all the lights should be switched off. This just means a better control of their emission into our environment. Natural environment in urban areas and around astronomical observatories should be equally protected.

We keep planet.
 

Garden butterflie.

Night butterflie.

Night butterflie.

Little owl.

Sparrow owl.