Street lights are preventing moths pollinating and that's bad

David Attenborough, perhaps worrying about street lighting and moths. Image: Getty.

For centuries, we have observed that artificial sources of light hold a strange fascination for moths. And despite decades of research, we still don’t know the cause of this attraction. Some theories put it down to the way moths navigate; others think it’s a mechanism to help them to escape from perceived danger. But the truth is, little evidence exists to support either of these ideas.

Whatever the cause is, research has shown that this deadly attraction may have even more sinister consequences than we first thought. In an open access paper in Global Change Biology, my colleagues and I describe the first evidence which shows that the effects of artificial light on moths may have serious implications for the wider ecosystem.


There has been plenty written about the danger posed by declining bee and butterfly populations, on the basis that some plants rely on these insects to carry pollen and fertilise flowers, in order to reproduce. But many people aren’t aware that moths also perform this task: our study of field sites across Oxfordshire found that one in four moths were carrying pollen, from at least 28 different plant species.

And like their cousins the butterflies, moths are in trouble: according to Butterfly Conservation’s Richard Fox: “the total abundance of moths in Britain has decreased by over a quarter since the 1960s”. Research indicates that artificial light, such as street lamps, has contributed to this decline by affecting moths' development, reproduction and ability to escape predators.

Now, our data suggests that street lights are also directly thwarting night-time pollination, by attracting moths upwards, away from the fields and hedgerows. We found that the abundance of moths at ground level was halved in lit areas, while flight activity at the height of the street light was nearly doubled. The diversity of species was also reduced at ground level, with 25 per cent fewer moth species in lit areas, compared to places without street lighting.

This change is likely to disrupt nighttime pollination by moths, and indeed we found some evidence that moths may carry less pollen, from fewer plant species, in lighted streets. This could mean that the impacts of street lights go beyond posing a health risk to moths. Plants that rely on moths for pollination would also suffer if their reproduction is impeded – and this might, in turn, affect organisms that eat those plants or drink their nectar.

In a best-case scenario, some of these so-called cascading effects might be mitigated where flowers can rely on other insects such as bees for pollination. But there are further factors driving declines in pollinator populations, such as climate change, pesticides and habitat loss. Now, our research suggests that artificial light can be added to the list.

Unnatural selection

So how can we protect these beautiful, under-appreciated insects and the important role they play in our environment?

The Spindle Ermine moth knows what’s good for it. Image: gailhampshire/flickr/creative commons.

Another recent paper published by researchers in Switzerland suggests that moths may be evolving to be less strongly attracted to lights. Under controlled experimental conditions in a flight cage, they found that Spindle Ermine moths from urban populations were less likely to be captured in light-baited moth traps than their rural counterparts.

These findings suggest that moths which can resist the temptation of lights put themselves at a significant advantage over their peers. Over time this has led city-dwelling moth populations to become less attracted to lights, through natural selection. But this is all relative: urban moths are still far from immune to the deadly allure of urban street lights.


We can’t simply switch street lighting off: although the evidence for its actual benefits is questionable, it certainly contributes to many people’s feeling of safety and security when outside after dark and proposals to turn lights off are often unpopular.

But if we don’t wish to wait for the slow crawl of evolution, it may be that recent advances in street lighting technology can help to mitigate the impacts of artificial light. For example, developments born out of a desire for energy efficiency could also minimise the impact of street lighting on moths. Measures such as switching on street lights for part of the night, dimming them or introducing motion-activated lighting would reduce moths' exposure to street lights. Similarly, the flexibility of LED lights might allow for the creation of street lights that are less attractive to moths, which respond most strongly to short-wavelength blue light.

Nevertheless, artificial light at night continues to increase as we seek to drive darkness from the streets. Our research is another warning that this may have far-reaching consequences for the organisms around us.The Conversation

Callum Macgregor is a PhD candidate at Newcastle University.

This article was originally published on The Conversation. Read the original article.

 
 
 
 

Owning public space is expensive. So why do developers want to do it?

Granary Yard, London. Image: Getty.

A great deal has been written about privately owned public space, or POPS. A Guardian investigation earlier this year revealed the proliferation of “pseudo-public spaces”. Tales of people being watched, removed from or told off in POPS have spread online. Activists have taken to monitoring POPS, and politicians on both sides of the pond are calling for reforms in how they are run.

Local authorities’ motives for selling off public spaces are normally simple: getting companies to buy and maintain public space saves precious public pounds. Less straightforward and often overlooked in this debate is why – given the maintenance costs, public safety concerns and increasingly unflattering media attention – developers would actually want to own public space in the first place.

To answer that question it’s important to note that POPS can’t be viewed as isolated places, like parks or other public spaces might be. For the companies that own them, public spaces are bound up in the business that takes place inside their private buildings; POPS are tools that allow them, in one way or another, to boost profits.

Trade-offs

In some cities, such as Hong Kong and New York, ownership of public space is a trade-off for the right to bend the rules in planning and zoning. In 1961 New York introduced a policy that came to be known as ‘incentive zoning’. Developers who took on the provision of some public space could build wider, taller buildings, ignoring restrictions that had previously required staggered vertical growth to let sunlight and air into streets.

Since then, the city has allowed developers to build 20m square feet of private space in exchange for 80 acres of POPS, or 525 individual spaces, according to watchdog Advocates for Privately Owned Public Space (APOPS).

Several of those spaces lie in Trump Tower. Before the King of the Deal began construction on his new headquarters in 1979, he secured a pretty good deal with the city: Trump Tower would provide two atriums, two gardens, some restrooms and some benches for public use; in exchange 20 floors could be added to the top of the skyscraper. That’s quite a lot of condos.

Shockingly, the current president has not always kept up his end of the bargain and has been fined multiple times for dissuading members of the public from using POPS by doing things like placing flower pots on top of benches – violating a 1975 rule which said that companies had to provide amenities that actually make public spaces useable. The incident might suggest the failure of the ‘honour system’ under which POPS operate day-to-day. Once developers have secured their extra square footage, they might be tempted to undermine, subtly, the ‘public’ nature of their public spaces.

But what about where there aren’t necessarily planning benefits to providing public space? Why would companies go to the trouble of managing spaces that the council would otherwise take care of?


Attracting the ‘right sort’

Granary Square, part of the £5bn redevelopment of London’s Kings Cross, has been open since 2012. It is one of Europe’s largest privately-owned public spaces and has become a focal point for concerns over corporate control of public space. Yet developers of the neighbouring Coal Drop Yards site, due to open in October 2018, are also making their “dynamic new public space” a key point in marketing.

Cushman Wakefield, the real estate company in charge of Coal Drops Yard, says that the vision of the developers, Argent, has been to “retain the historical architecture to create a dramatic environment that will attract visitors to the 100,000 square feet of boutiques”. The key word here is “attract”. By designing and managing POPS, developers can attract the consumers who are essential to the success of their sites and who might be put off by a grubby council-managed square – or by a sterile shopping mall door.

A 2011 London Assembly Report found that the expansion of Canary Wharf in the 1990s was a turning point for developers who now “assume that they themselves will take ownership of an open space, with absolute control, in order to protect the value of the development as a whole”. In many ways this is a win-win situation; who doesn’t appreciate a nice water feature or shrub or whatever else big developer money can buy?

The caveat is, as academic Tridib Banerjee pointed out back in 2001: “The public is welcome as long as they are patrons of shops and restaurants, office workers, or clients of businesses located on the premises. But access to and use of the space is only a privilege and not a right” – hence the stories of security guards removing protesters or homeless people who threaten the aspirational appeal of places like Granary Square.

In the US, developers have taken this kind of space-curation even further, using public spaces as part of their formula for attracting the right kind of worker, as well as consumer, for nearby businesses. In Cincinnati, developer 3CDC transformed the notoriously crime-ridden Over-The-Rhine (OTR) neighbourhood into a young professional paradise. Pouring $47m into an initial make-over in 2010, 3CDC beautified parks and public space as well as private buildings.

To do so, the firm received $50 million  in funding from corporations like Procter and Gamble, whose Cincinnati headquarters sits to the South-West of OTR. This kind of hyper-gentrification has profoundly change the demographics of the neighbourhood – to the anger of many long-term residents – attracting, essentially, the kind of people who work at Procter and Gamble.

Elsewhere, in cities like Alpharetta, Georgia, 3CDC have taken their public space management even further, running events and entertainment designed to attract productive young people to otherwise dull neighbourhoods.

Data pools

The proposed partnership between the city of Toronto and Sidewalk Labs (owned by Google’s parent company Alphabet) has highlighted another motive for companies to own public space: the most modern of all resources, data.

Data collection is at the heart of the ‘smart city’ utopia: the idea that by turning public spaces and the people into them into a vast data pool, tech companies can find ways to improve transport, the environment and urban quality of life. If approved next year, Sidewalk would take over the mostly derelict east waterfront area, developing public and private space filled with sensors.

 Of course, this isn’t altruism. The Globe and Mail describe Sidewalk’s desired role as “the private garbage collectors of data”. It’s an apt phrase that reflects the merging of public service and private opportunity in Toronto’s future public space.

The data that Sidewalk could collect in Toronto would be used by Google in its commercial projects. Indeed, they’ve already done so in New York’s LinkNYC and London’s LinkUK. Kiosks installed around the cities provide the public with wifi and charging points, whilst monitoring traffic and pedestrians and generating data to feed into Google Maps.

The subway station at Hudson Yards, New York City. Image: Getty.

This is all pretty anodyne stuff. Data on how we move around public spaces is probably a small price to pay for more efficient transport information, and of course Sidewalk don’t own the areas around their Link Kiosks. But elsewhere companies’ plans to collect data in their POPS have sparked controversy. In New York’s Hudson Yards development – which Sidewalk also has a stake in – ambiguity over how visitors and residents can opt out of sharing their data when in its public square, have raised concerns over privacy.

In Toronto, Sidewalk have already offered to share their data with the city. However, Martin Kenney, researcher at the University of California at Davis and co-author of 2016’s ‘The Rise of the Platform Economy’, has warned that the potential value of a tech company collecting a community’s data should not be underestimated. “What’s really important is the deals Toronto cuts with Sidewalk may set terms and conditions for the rest of the world," he said after the announcement in October.

The project could crystallise all three motives behind the ownership of POPS. Alongside data collection, Sidewalk will likely have some leeway over planning regulations and will certainly tailor its public spaces to its ideal workers and consumers – Google have already announced that it would move its Canadian headquarters, from their current location in Downton Toronto, into the first pilot phase of the development.

Even if the Sidewalks Lab project never happens, the motives behind companies’ ownership of POPS tell us that cities’ public realms are of increasing interest to private hands.

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