A Complete guide to the frogs of Southern Africa, by Vincent Carruthers and Louis du Preez
Vincent Carruthers and Louis du Preez' complete field guide describes the frogs found in southern Africa south of the Zambezi, Okavango and Cunene rivers and introduces the reader to their biological and conservation significance.
FROGS IN THE ENVIRONMENT
AMPHIBIANS IN DECLINE
In recent decades frogs on several continents have suffered sudden, high mortality rates, resulting in various species becoming extinct and many others undergoing massive population reductions. Globally, amphibians are now the most threatened class of vertebrate. Amphibian population fluctuations are not unusual under natural conditions, but recent declines have been excessively severe and populations have failed to recover. Because of the ecological importance of frog populations in both terrestrial and aquatic ecosystems, these losses may bring about complex and far-reaching consequences. The global decline in amphibian numbers is one of the most vexing conservation issues of recent times. A current report from the lUCN's Global Amphibian Assessment (www.globalamphibians.org) shows that as many as a third of amphibian species have suffered severe declines worldwide and more than 7% are listed as Critically Endangered, many on the brink of extinction (IUCN Red List of Threatened Species www.iucnredlist. org). Despite increased scientific awareness of the threat, recent increases in extinctions remain largely unexplained. Some instances occur in virtually undisturbed regions, far from the adverse effects of habitat destruction and pollution. A number of hypotheses have been presented to explain these enigmatic extinctions and declines, but there has been no scientific consensus on the matter. Synergy between complex factors may be obscuring the root causes of amphibian declines. Some of the environmental hazards that are known to be contributing to these declines are listed below.
Habitat destruction or modification
Annually large areas of natural wetland and vegetation are destroyed for agriculture, forestry and urban development with largescale and permanent loss of amphibian habitat.
Meteorological events and the shifting of seasonal patterns are creating macro-climatic changes that have serious implications for amphibian reproduction and survival. Moreover, shifts in climatic conditions may provide more favourable conditions for disease.
Depletion of stratospheric ozone
The breakdown of atmospheric filters that protect against ultraviolet light and subsequent increased UV exposure affects the development of frog eggs and developing tadpoles, especially in species that breed at high elevations and where eggs are deposited near surface water.
The recent escalation of amphibian die-offs caused by the fungal pathogen Batrachochytrium dendrobatidis, or amphibian chytrid, suggests that this may be a major contributor to amphibian declines and extinctions worldwide. Sudden outbreaks of the disease may be linked to global climate change as well as to international trade in amphibians. A number of southern African species have been found to be infected with 6. dendrobatidis and sporadic die-offs have been reported, but there is currently no evidence of significant population declines. However, the large number of IUCN Red Listed species in southern Africa, many of which have very restricted distribution ranges, may be at risk in the future from chytrid fungus. (...)
This is an excerpt from the book: A Complete guide to the frogs of Southern Africa, by Vincent Carruthers and Louis du Preez.
Title: Complete guide to the frogs of Southern Africa
Author: Vincent Carruthers; Louis du Preez
Publisher: Randomhouse Struik
Cape Town, South Africa 2009
ISBN 9781770074460 / ISBN 978-1-77007-446-0
Softcover, 17x24 cm, 488 pages, throughout colour photographs, 1 CD
Carruthers, Vincent und du Preez, Louis im Namibiana-Buchangebot
For all nature lovers, amateur froggers, students, as well as professional scientists, the complete guide to the frogs of Southern Africa is an inspiring and significant guide.
The wildlife of Southern Africa: The larger illustrated guide to the animals and plants of the region
This is the larger illustrated version of The wildlife of Southern Africa. The content is equal to the standard version.
These little guides are an invaluable resource for beginners
Fauna und Flora im südlichen Afrika ist das erste Handbuch, das die Pflanzen und Tiere aller Art in einem leicht zu handhabenden Band verbindet.
This is an excellent universal field guide to wildlife of Southern Africa.
The field guide Frogs and Frogging in Southern Africa describes all 129 frog species, keys and maps to aid identification.
Frogs and Frogging in Southern Africa examines how these remarkable creatures behave and how they have adapted to different habitats.