The rivers of South Africa

Did you know that "12% of South Africa’s land area generates 50% of the country’s river flow." This highlights the need to plan the development of landscapes to
protect the country’s most important water, soil and biodiversity resources (WWF, 2012).

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REFERENCE

WWF-World Wide Fund For Nature (WWF). (2012). Financial provisions for rehabilitation and closure in South African mining: Discussion document on challenges and recommended improvements. Cape Town: WWF

Story of the Passanger Pigeon

The following is an extract that I found to be of particular interest. It shows clearly how it is necessary to exercise caution in concerving any species regrdless of its abundance.

"CASE STUDY:
The Passenger Pigeon (Ectopistes migratorius)

The Passenger Pigeon was once the most common bird in North America. It was a migratory species that lived in enormous flocks, which were as large as 1.6 km wide and 500 km long, taking several days to pass. It was estimated that such flocks contained up to a billion birds, which were some of the largest groups formed by any animal, second
only to swarms of the desert locust. On 1 September 1914, Martha, the world’s last Passenger Pigeon, died in a zoo in Cincinnati, Ohio. What was probably one of the most abundant birds in the world is extinct today. What happened?

During the early 19th century, Passenger Pigeon meat was commercialized as a cheap source of meat for slaves and the poor, and the birds were hunted on a massive scale. By the 1850s, it was noted that the pigeons were becoming scarcer, but the large-scale slaughter of birds continued and even escalated. One commercial hunter reported shipping three million pigeons to markets in 1878. Between 1800 and 1870, the pigeon population declined slowly, but a catastrophic population crash between 1870 and 1890 resulted in only a few birds remaining by the turn of the century.

Attempts to restore wild populations through captive breeding failed due to the gregarious nature of the birds, which practised communal roosting and breeding in large communal nests housing up to a thousand birds in a single tree. As too few birds remained, and their social structures had been disrupted, flocks continued to dwindle.

The Passenger Pigeon is a practical example of the principles behind Criterion A*, and stands as a lesson to us today that no species is ‘too common’ to go extinct (SANBI, 2010.)"

* Criterion A is a Red List criteria which identifies species that are at risk of extincition due to high rates of population decline relative to the species' life history (SANBI, 2010).

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REFERENCE:
South African National Biodiversity Institute (SANBI). (2010). Threatened Species: A guide to Red Lists and their use in conservation. Threatened Species Programme.
Pretoria, South Africa. 28 pp.