Peregrine falcons return to a greener London

LONDON--A peregrine falcon with a wingspan of almost a meter wheels above the Houses of Parliament and alights on the Victoria Tower, gripping a pigeon in its talons.

It is 5 a.m. in early July, and high above Westminster, the falcon begins tearing into its freshly killed breakfast. White feathers ripped from its prey flutter and dance in the breeze around the tower.

This magnificent bird was once endangered in Britain.

Peregrine falcons used to inhabit cliffs and rocky outcrops around the southeast of England, but they were targeted for extermination during World War II in an effort to prevent attacks on carrier pigeons used by the military.

After the war, the use of the agricultural chemical DDT and other factors caused a collapse of the population of these birds of prey.

About 10 years ago, however, peregrine falcons began to appear in the center of London. The city's high buildings offer them prime vantage points from which to look for prey.

At the Houses of Parliament, to which the birds returned in March 2009, a square plywood tray measuring 50 by 50 centimeters was affixed about halfway up the 100-meter-tall Victoria Tower to help the birds nest.

David Morrison, 50, who has been involved in falcon conservation efforts in London for nearly 10 years, says 18 falcon chicks were born this year and that numbers are increasing annually.

Currently, 24 peregrine falcon pairs have been identified in the central part of London.

Every year, from spring through summer, young birds born in the city are testing their wings and learning to catch prey in the capital's urban canyons.

The return of the falcons is a result of a number of initiatives aimed at tempting the natural world back into one of the world's great cities.

On top of the bare concrete rooftops of many buildings, gardens of wild flowers and shrubberies, known as "brown roofs," are cropping up across city center.

An effort to push corridors of greenery into the heart of the urban jungle has included encouraging vegetation beside railway tracks.

The wetlands to the south of the Thames have been brought back to life as the London Wetland Center, a stopover for migratory birds and home to moths, butterflies and other insects at the bottom of the urban food chain. The small birds and animals that feed on those insects are in turn the prey of the peregrine falcon, perched atop the city's ecosystem.

Nick White, 40, manager of the London Biodiversity Partnership (LBP), a group comprising 62 organizations including NGOs, transportation authorities and the fire department, says it is important to consider how the entire ecosystem can be preserved, not just one species or one specific location.

The "brown roof" movement is a key part of that effort. On a portion of the 11th floor rooftop of the London Underground Headquarters Building, wild grasses about 20 to 30 centimeters in height grow thick. Honeybees buzz about the grass.

When I stepped into the garden, the sensation is like walking on dry, sharp gravel. Instead of soil, the grass grows in a mixture of sand and finely crushed fragments of concrete and brick, from 10 to 15 centimeters deep, spread across the rooftop. Plants requiring more shadow are planted under the solar panels on the roof.

The roof was designed by Dusty Gedge, 46, and completed in November 2009. Gedge has helped realize nearly 400 brown roof projects, primarily in Britain.

In the late 1990s, he began to wonder whether the natural environment that existed at a site prior to its development could be lifted "up into the air." A key part of his vision is to make an environment designed for living creatures, not to just green a property to make it look good.

Gedge's goal is for the city's rooftop gardens to knit themselves into a vast network, rather than serving simply as an isolated oasis in a sea of concrete. There are reports that the black redstart, whose numbers had rapidly decreased in London, have started to appear on the brown roofs of the city's high buildings.

The organizers of the 2012 London Olympics have declared that they will be sensitive to preserving biodiversity. Many of the Olympic facilities' rooftops will be employing similar eco-friendly programs.

Richard Jackson, 41, environment manager for the Olympic Delivery Authority, says the organizers plan to integrate the games site with the surrounding habitat.

The London Wetland Center, which lies on the outskirts of a quiet residential neighborhood, is a former reservoir. The 42-hectare facility is situated about 30 minutes from central London by bus and subway.

In the latter half of the 1980s, an NGO spent about 18 million pounds (2.4 billion yen) to restore the wetlands. A water company provided it with the disused reservoir site free of charge, while a housing company provided funding.

All the concrete which had formed the basin of the reservoir was removed, and clipped grass was mixed into the soil. As a result, the plot was returned to a near natural state.

All the vegetation now growing at the center is native to Britain.

Grounds and facilities manager John Arbon says that 180 species of birds can be seen at the center every year and that other creatures include 19 species of dragonfly and six kinds of bat.

The facility is also trying to breed water voles, whose numbers had decreased because of deteriorating water quality and attacks by non-native minks.

Big cities pave their streets with grass, not gold

A movement to foster biodiversity in some of the world's leading cities is challenging notions that urban and natural environments cannot coexist.

In 2007, the first Mayors Conference on Local Action for Biodiversity was held in Brazil, with 21 cities representing seven countries taking part.

The next year, at its meeting in Germany, the conference adopted the Bonn Call for Action, pointing out the threat to urban biodiversity from such factors as pollution, urban sprawl, the sealing of land surfaces and climate change.

It asserted a "fatal link between poverty, limited access to natural resources and the loss of biodiversity." But it spent most of its four pages mapping out a positive vision of how local communities and governments could revitalize their own natural environments and integrate development and biodiversity.

A number of cities are now pursuing innovative projects aimed at bringing nature back into the city.

In Amsterdam, "animal trails" have been created by covering the sides of roadways and rail lines with grass, allowing foxes, weasels and other animals to access city parks.

In Barcelona, financial incentives have been offered to building owners to allow swallows to nest in their old structures.

In Seoul, the Cheonggyecheon River, which had been covered by a roadway, was restored to a more natural state in 2005, resulting in dramatic payoffs for the citizenry. Air temperature dropped by almost three degrees compared with neighboring areas. The number of species living along the river is reported to have increased to 573 in 2007 from 93 in 2003, before the start of the project.

The London Biodiversity Partnership is carrying out 26 action programs, setting targets for 2015. They cover peregrine falcon, house sparrow and other species, as well as parks, green spaces and other habitats.

In April, it started a research project into the effect greening rooftops in central London might have on flooding and other problems bedeviling the city. LBP manager Nick White said some districts of South London experienced above floor level flooding after moderate rain because the concreting of rivers and road surfaces had badly affected drainage.

A number of biodiversity projects are under way in Tokyo.

For instance, an NGO has built an environment friendly to little terns on a building close to Haneda Airport, using gravel and decoys to attract the migratory birds. The terns have established the rooftop as a regular habitat.

Kajima Corp., a general contractor, made gaps in a concrete seawall in a waterfront area near the Tokyo Monorail to encourage a natural environment friendly to crabs.

Mori Building Co., which owns Roppongi Hills and other urban developments, is creating green spaces around its skyscrapers where native species and natural vegetation can be encouraged.

How to preserve urban biodiversity will be a subject of discussions at the 10th meeting of the Conference of the Parties to the Convention on Biological Diversity, to be held in Nagoya in October.