In print
Losing Strands in the Web of Life
by John Tuxill, (Worldwatch Paper 141), 1998
published by Worldwatch Institute, 1776 Massachusetts Ave., NW, Washington DC 20036-1904
88pp price, US$5.00, ISBN 1-878071-43-2
The Grain-eating Birds of sub-Saharan Africa
by R Allen, 1997
published by Natural Resources Institute, University of Greenwich, Central Avenue, Chatham
Maritime, Kent ME4 4TB, UK
Email n.davidson@gre.ac.uk
191pp, price £25.00, ISBN 0 85954 464-8
It's not often that the saying "you can't
tell a book by its cover" is used in the literal sense. While obviously true to all branches
of publishing, it is particularly appropriate to books about agricultural development and
environmental conservation. Often, although by no means always, a colourful illustration of
brightly clothed
peasants working in a
field adorns a book whose covers clothe a text which is indigestible and dull. Occasionally, though
more rarely, dull covers hide a text that is both colourful and illuminating. Such is the case,
however, with Losing Strands in the Web of Life by John Tuxill.
The first half of this Worldwatch Paper relates the sorry tale of threatened species within the relatively small taxonomic group to which humans belong - the vertebrates. Using information revealed by the IUCN Red List, the author provides the layman, or the student, with straightforward facts, acknowledging that habitat loss through agriculture and other human activities is largely responsible for the accelerating rate of species extinctions.
The second part of the book examines what is being done to minimize this loss and how these efforts could be improved. This is not it seems an easy task. For example, when the US tried to impose a ban on shrimp imports from Asian countries that do not require fishermen to equip their shrimping gear with turtle excluder devices, the WTO ruled against the ban (in April this year), because it deems trade measures implemented to protect threatened species to be illegal under GATT. The argument continues and the US fishermen have appealed against the WTO ruling. It seems that someone is on the side of the turtles, or maybe on the side of the shrimp farmers.
The plight of sea turtles is well known and all seven
species are thought to be endangered. It is thought that between one-fifth and one-quarter of
reptile and amphibian species are
endangered or vulnerable, a proportion similar to that for mammals. Birds, being more
mobile, are often able to escape to a new habitat if threatened, as farmers in sub-Saharan Africa
are well aware. The Grain-eating Birds of sub-Saharan Africa by R. Allan puts the
interests of humans to the fore. This is entirely reasonable to anyone who understands the damage
that quelea birds, for example, can inflict upon a crop. Flocks may number many millions, the birds
seem oblivious to birdscarers and attempts to breed cereals that are resistant to attack have so
far failed. Quelea are so conspicuous and so devastating that, by comparison, other grain-eating
birds and their impact upon grain production are little understood. This book is intended to help
redress this balance for only by knowing the enemy can steps be taken to avoid crop damage in a
cost-effective, environmentally responsible way. The biology and classification of grain-eating
birds, the cereal crops they damage, and methods of conducting bird pest surveys, form the first
part of the book. Crop protection, both lethal to birds and non-lethal, completes this handbook
which is attractively illustrated by Sacha Lauer.
A new laboratory-based molecular diagnostic technique
is presented, which gives rapid, sensitive and accurate identification of the pathogens concerned,
directly from infected banana leaves. Developed at NRI, the method is based on amplification of
fungal DNA by the Polymerase Chain Reaction (PCR). The technique is described in detail and step by
step protocols for DNA extraction and PCR are given, together with details of reagents and their
availability.
