Artificial light in cities exerts negative effects on humans, animals, and their environment. In an ongoing research project, behavioral biologists at Vetmeduni Vienna are investigating how blue tits in the Viennese Forests react to “light pollution”. The study might help to understand effects of “light-at-night” on reproductive behavior of birds. In consequence, it could help developing concepts, minimizing negative effects on the lives of animals and the ecological system, by reducing light sources in specific regions. The research project started this year and is supported by the city of Vienna.
The so-called circadian rhythm or “body clock” influences the behaviour of living beings. Light is an important “Zeitgeber”, especially for birds. Based on light, birds know when it is time to mate, breed, forage or migrate. If the natural day and night rhythms are affected by artificial light, the natural behavioral patterns of the animals may also change.
The “light-at-night”-effect disturbs migrating birds
Katharina Mahr and Herbert Hoi from the Konrad Lorenz Institute of Ethology at the Vetmeduni Vienna are interested in the effects of “light-at-night” in wild birds. “There are studies investigating the effect of artificial light on the orientation and activity of birds. Light, for instance, limits the sense of orientation, but also activity patterns in birds to a great extent,” study coordinator Mahr explains.
The Viennese research team is one of the first to experimentally test the effects of artificial light in the natural environment of animals, by actively manipulating ambient light conditions. The team is particularly interested in the reproductive behavior of blue tits in the Viennese Forests. “Blue tits seem to be good model species for this study because we know a lot about their mating and reproductive behaviour. Besides, they frequently breed in cities and therefore are exposed to artificial light,” Mahr states.
Research using LED lights in the forest
Over a period of about three weeks, LED lights illuminated various areas of the Viennese Forests for two additional hours in the morning, before sunrise, and in the evening after sunset. In this period scientists examined, activity patterns such as singing and mating behavior, growth and development of the nestlings, as well as stress hormones. The number of extra-pair copulations females perform, could be affected and offspring may more frequently originate from various fathers.
“There is evidence that the circadian rhythm influences mate choice, but does it also affect the development of nestlings?,” Mahr states. “A well-known phenomenon that can be found in chicken farming is the manipulation of the day and night rhythm in order to make the animals lay more eggs.”
Does light pollution affect the honesty of sexual signals?
“We assume that light at night affects the birds’ strategies of choosing partners. Males, for instance, like to be in the “limelight” whereas females might prefer to “remain in the dark”. Thus, light may exert different effects on the love lives of the different sexes. Besides, male blue tits are “morning singers”. Particularly fit males start to sing pre-dawn songs. We also know that female blue tits tend to be unfaithful to their partners, but do so covertly. Therefore, we want to find out whether artificial light generates a certain conflict between the sexes,” says Mahr.
The fact that such a conflict impairs the reproduction of tits was shown by Mahr in a previous study. Here is the link to the study. Besides, artificial light may cause shorter resting periods and thus impose additional stress on the fledglings.
Light possibly has impact on the entire ecological system of the woods
“More light may also affect other living beings in the Viennese Forests. Insects may for instance be affected. They are an important source of food for many inhabitants of the woods and their presence is therefore essential,” says Mahr.
“Urban lights are obviously important for human safety and comfort. Nevertheless, urban planning should take into account the question of where light sources are really necessary. Illuminated billboards, for instance, can be dispensed with. Non-illuminated zones could be planned consciously. Our study is intended to encourage decision-makers to devote greater attention and thought to the subject,” Mahr pleads.
Every year power plants generate 140 million tons of coal ash, enough to fill a train stretching from the North Pole to the South Pole.
It contains chemicals like arsenic, mercury and lead. It can cause cancer and developmental problems. It poisons fish and wildlife in rivers and lakes.
In some places the ash is dumped into uncovered pits. In others it sits behind leaky dams. It poisons the air. It destroys the water. And the corporate polluters responsible, they claim that cleaning up this toxic mess would hurt their profits
But in 2008, when that dam broke, something changed.
Nearly half a million people asked the EPA for stronger protections. Thousands of citizens attended public meetings. Local and national environmental and public health groups got involved. We brought the coal industry face to face with the people they were hurting. Those people are America, and America spoke with one voice.
“Clean Up Coal Ash!”
But that was then and this is now. Four years later there are still no federal protections. Right now some senators want to pass a bill that will prevent the EPA from ever regulating coal ash. They want to ignore the disaster in Tennessee and avoid deadlines to clean up this toxic waste all across America. But we can’t let polluter profits triumph over public health. We have to do something to clean up this mess.
So call your senators. Send this email. And share this video with your friends right now. Together we can clean up this toxic mess. But we have to take action now.
Take Action Now – http://earthjustice.org/coalashaction
As a species, we’re just beginning to recognize that the environment is vital to our health. The need to reduce acid rain emissions, stop dumping hazardous wastes, and slow down deforestation needs be addressed from the perspective of people’s health. Evidence is increasing from multiple scientific fields that exposure to the natural environment can improve human health.
The health of our environment affects human health in different forms. The air we breathe, the water we drink and the food we eat are quickly becoming polluted to the point of being unsafe to consume without endangering our well-being. Will there be a point of reversal?
For Geoffrey Donovan, a research forester at the Forest Service’s Pacific Northwest Research Station, and his colleagues, the loss of 100 million trees in the eastern and midwestern United States was an unprecedented opportunity to study the impact of a major change in the natural environment on human health.
In an analysis of 18 years of data from 1,296 counties in 15 states, researchers found that Americans living in areas infested by the emerald ash borer, a beetle that kills ash trees, suffered from an additional 15,000 deaths from cardiovascular disease and 6,000 more deaths from lower respiratory disease when compared to uninfected areas. When emerald ash borer comes into a community, city streets lined with ash trees become treeless.
The researchers analyzed demographic, human mortality, and forest health data at the county level between 1990 and 2007. The data came from counties in states with at least one confirmed case of the emerald ash borer in 2010. The findings — which hold true after accounting for the influence of demographic differences, like income, race, and education — are published in the current issue of the American Journal of Preventive Medicine.
” There’s a natural tendency to see our findings and conclude that, surely, the higher mortality rates are because of some confounding variable, like income or education, and not the loss of trees,” said Donovan. “But we saw the same pattern repeated over and over in counties with very different demographic makeups.”
Although the study shows the association between loss of trees and human mortality from cardiovascular and lower respiratory disease, it did not prove a causal link. The reason for the association is yet to be determined.
We can longer neglect the mounting evidence of wasteful and destructive human activities which are undermining the capacity of our planet to provide a secure and hospitable home for all its peoples, both rich and poor.
Human activities have created a technological civilization that is now global in scale and pervasive in its influence on the lives and the prospects of all members of the world community. It has produced a world with stark dichotomies between the benefits enjoyed by the few, and the deprivation and suffering experienced by the majority. The gross imbalances created by the concentration of economic growth in developed nations and the high rates of population growth in developing countries are at the centre of the current dilemma.
It’s time we realized that our entire world is a reflection of our health and our interactions with each other. If we refuse to nurture our environment and care for our own planet, what does that say about how we think of ourselves?
Karen Foster is a holistic nutritionist, avid blogger, with five kids and an active lifestyle that keeps her in pursuit of the healthiest path towards a life of balance. Read more at: Prevent Disease