Up to April this year only 14 hornless animals were killed by poachers.
It seemed that the policy might be working. But no longer. ‘There has been
a massacre of both black and white rhinos,’ says Esmond Bradley Martin of
the World Wide Fund for Nature who is a world expert on rhinos. Poachers
have been particularly active in Hwange National Park, where 68 of the 70
or so dehorned rhinos have been killed and the stumps of their horns removed.

Even a newly dehorned rhino is worth killing, says Bradley Martin. Around
15 per cent of the horn remains after the operation, and it regrows at a
rate of around half a kilo a year. A full size horn from an African black
rhino weighs between 2.5 and 3 kilograms. Many of those killed had been
dehorned more than a year ago. African rhino horn can fetch $6000 a kilo
on the black market.

For the poachers, mostly from over the border in Zambia, the stakes
are high, and they take enormous risks. More than 150 poachers have been
killed in Zimbabwe in the past decade. ‘They are willing to get very small
returns economically,’ says Bradley Martin, ‘because they do not have any
alternative employment.’

The solution to the rhino crisis, he says, is not dehorning, but better
policing, as in Kenya and Namibia. Kenya is home to more than 400 black
rhinos and 75 white rhinos, all with their horns intact. None has been killed
by poachers in the past two years. In Namibia, where there is little poaching,
the population of rhinos is increasing.

In the longer term, the most effective way to protect the rhino is
to knock the bottom out of the market for horn. Its main uses are for traditional
medicines in the Far East, particularly for treating fevers in children,
and for dagger handles in Yemen. Bradley Martin is promoting alternatives
to rhino horn for both, and is cautiously optimistic that his efforts are
paying off. Demand in Yemen has fallen from 4 tonnes a year in the late
1970s to less than a tenth of that. Dagger handles are now more likely to
be made from the horn of water buffalo.

In the Far East, horn from buffalo and antelope is becoming an acceptable
substitute for rhino horn. So, although supplies of horn are dwindling,
the price is not increasing. The price of the most valuable horn, from the
Asian rhino, has not risen, while that of African horn has fallen.

It took Stamp almost 18 years to complete the project. In the event, the
face of Britain was changing faster than he could make the maps. The maps
were out of date even before they were published.

Now modern technology has realised Stamp’s vision, providing a digital Land
Cover Map that is simple to use and easy to update. The Institute of
Terrestrial Ecology (ITE) has processed data from NASA’s Landsat satellites
to provide a colour-coded picture of Britain, broken up into 25 categories
of land use – from pasture to urban sprawl, heathland to tilled fields – at
a resolution of 25 square metres. The institute unveiled the map in London
last week.

Instruments aboard the Landsat satellites measure the wavelengths of light
and infrared reflected from the Earth’s surface. Some surfaces can be
identified simply from the ratio of the different wavelengths. Concrete
produces a very different spectrum from forest, for example. But other
surfaces are harder to distinguish. ‘The software could not distinguish, for
example, between natural forest and lush crops,’ says Robin Fuller, head of
the ITE’s Remote Sensing Unit.

To solve this problem, the researchers compared spectra in winter and
summer. This revealed seasonal changes that would be very marked in fields
of crops but not forests. ‘If we combine the two data sets we can identify
those areas which are permanent and those that cycle between winter and
summer,’ says Fuller.

Fuller and his team also went into the field and mapped the type of
vegetation cover in areas characteristic of each particular type of surface.
They then analysed the satellite data for these patches to define the
characteristic spectra more precisely. The results were used to ‘teach’ the
computer how to differentiate between different types of land use more
accurately.

The map gives researchers access to up-to-date information without having to
scrutinise paper maps or go out into the field. All they need is a personal
computer. Mike Roberts, head of the ITE, says the map will come into its own
when used with other collections of data. Over the past 5 to 10 years, the
Natural Environment Research Council has built up national databases on
geology, water supplies and soils. ‘It is the Land Cover Map that glues
these databases together,’ he says.

At the Institute of Hydrology in Wallingford, Oxfordshire, for example,
staff are combining the Land Cover Map with detailed topographical data to
map the country’s hydrology more accurately. It is relatively simple to draw
the boundaries of a water catchment area by looking at a contour map. By
referring to the Land Cover Map, scientists can estimate the runoff rates
from records of the type of vegetation on the land. In the future, it should
be possible to overlay geological data to make allowances for both the type
of soil and the underlying rock.

Robert Kenward, of the ITE, is also finding the map invaluable in his
research into the habits of the buzzard. He tracks birds with radio
transmitters and is relating their journeys to the types of land cover they
seek out.

The map has already led him to conclude that their failure to spread east
from well-populated areas in Devon to the buzzard-free country of East
Anglia has less to do with the landscape or human activity than their innate
drive to breed where they were born.

The ITE believes the Land Cover Map will become an essential tool for policy
makers. Road planners can use it to calculate the environmental costs of new
roads, for example. And ecologists could use it to decide where to spend
limited resources to improve habitats.

But perhaps one of the most intriguing uses of the map is to chart
historical changes in land use. Researchers at the ITE are now digitising
Stamp’s original maps. This will allow them to quantify the changes in the
face of Britain over the past 50 or so years, and to discover what we have
done to the countryside since Stamp toured it in his car.