ST HELENA AND ASCENSION ISLAND:
ORIGINS, EVOLUTION AND NATURAL HISTORY

by Philip and Myrtle Ashmole

CONTENTS


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  DEDICATION
ACKNOWLEDGEMENTS
GLOSSARY AND CONVENTIONS
PREFACE
PART I VOLCANOES IN THE SEA
1.
The islands come to life
  From the depths of the ocean
Early arrivals Ocean currents
Colonisation by flowering plants
Colonisation by animals
Getting established
PART II ST HELENA
2.
The island and its people
 

Discovery and early visitors
The colony and its history
The "Saints" today

3.
The physical environment
 

Landforms and geology:
The volcano and the island
The rocks of St Helena
Dykes and sills
Erosion and weathering
soils
Sea leval changes and the size of St Helena
Sand and 'limestone'
Caves
Earthquakes

Climate
Winds
Temperature
Cloud and rain
Hydrology
Surrounding Sea

4.
The native plants and their discovery
  Discovery of the St Helena flora
Origin and Evolution of the native plants
Group 1. Relict endemic genera
Group 2. Old endemic species
Group 3. Young endemic species
Group 4. Indigenous but not endemic species
A reconstruction of the pristine vegetation
Fossils from the distant past - a detective story
5.
The animals: discovery, evolution and extinction
 

Discovery and evolution of invertebrates
The St Helena Green Turtle population
Marine mammals
Native birds in historical times
Introduced birds
Ancient bird communities

6.
The major habitats on land today
 

Stacks and islands
Shore
Cliffs
Semi-desert
Prosperous Bay Plain - a unique habitat
Scrub zone
Lantana dominated scrub
Tungy dominated scrub
Scrub with Wild Coffee, Poison Peach and Black Olive
Animals of the scrub zone
Rupert's Valley
Jamestown and the Heart Shape Waterfall

Creeper Waste
Arable land, pasture and New Zealand Flax
Woodland
The Central Ridge
Fresh water
Caves and underground spaces

7.
St. Helena - an ecological history
  The devastation of the native vegetation
The vanishing Great Wood - a case Study
The rise of alien plants
8.
Caring for the wildlife of the island
 

Conservation of the endemic plants
Conservation of dolphins, turtles and birds
Conservation of insects and other invertebrates
Broader issues

  PART III. ASCENSION ISLAND
9.
The island and people
  Location and administration
Discovery and occupation
Human activity in the 20th century
10.
The physical environment Geological map
 

Landforms and Geology
The volcano and the island
The rocks of Ascension
Other geological features
Changes in sea level
Caves

Climate
Surrounding sea

11.
The anmals and plants: a historical view
  Animals on the pristine island
Native vegetation and the impact of goats
The arrival of rats and mice
Seabird decline and the feral cats
The other introduced animals
Plant introductions and transformation of the vegetation
12.
Turtle migration, bird biology and animals of the clinker
  Turtle migration and molecular biology
Seabird biology
The search for subfossil bird bones
Animals of clinker and caves: colonisation, ecology and evolution on a young volcanic island
13.
The major habitats on land
 

The coast and coastal pools
Boatswainbird Island
Stacks and coastal cliffs
The lava desert
The middle levels
Green Mountain

14.
Conservation and ecological restoration
 

Protection of volcanic landscapes
Conservation of endemic plants
Conservation of invertebrates
Conservation of turtles
Restoration of seabird populations and the eradication of feral cats and rats

PART IV. ANIMALS AND PLANTS OF ST HELENA AND
ASCENSION ISLAND
15.
Animals
 

Mammals
Reptiles
Amphibians and freshwater fish
Birds
Invertebrates other than insects
Insects

16.
Plants
 

Conifers and Flowering plants
Ferns
Bryophytes

 

BIBLIOGRAPHY

INDEX

 


ENDPAPERS
Map of St Helena
Map of Ascension Island

FRONTISPIECE
Birth of an oceanic island

MAPS, LINE ILLUSTRATIONS AND DIAGRAMS
Atlantic Ocean
Hot spots and plate boundaries in the Atlantic Ocean
Surface circulation in the South Atlantic
St Helena volcano
St Helena: phases in volcanism
St Helena: exposed rock types
Worldwide sea level changes in the last 250,000 years
St Helena and its wave-cut platform
Productivity in the South Atlantic
Modern and fossil pollen grains
Giant Earwig Lablidura herculeana
Giant Beetle Aplothorax burchelli
John Charles Melliss
Peter Mundy’s ‘strange creature’
Fossil bones of extinct St Helena Rail Atlantisia podarces
Fossil bones of extinct St Helena Hoopoe Upupa antaios
Bridled Dolphin Stenella attenuata
Iais aquilei caring for its young
Extract from ‘St Helena Records’ 1709
Map of the Great Wood 1716
Burchell’s drawing of the Great Wood 1809
Ascension Island geology
Peter Mundy’s Rail
Waterloo Plain (the airfield) photographed in the 1920s
Turtle migration from Ascension Island
Timing of breeding of Ascension seabirds 1957-59
Section through the ‘fumaroles’
Skull and leg bone of extinct Ascension Rail
The giant pseudoscorpion and a smaller relative
Anchialine shrimps in a coral pool


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