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10 Years Till Rhinos Go Extinct in Africa?

Posted by Richard Conniff on February 1, 2012

White rhino, past tense. (Photo by Richard Conniff)

At the end of my recent report on the new rhino poaching epidemic, I wrote that one park, which was once the motherlode for rhino repopulation, is no longer  replacing even its own rhino population.  Now South African blogger Nikela has run the numbers and suggests that, at the current rate of loss, rhinos could be extinct in Africa in 10 years.

It sounds incredible.  But almost all of Africa’s surviving rhino population is concentrated in one country, South Africa, which lost 448 rhinos last year.  Rhinos have already gone extinct in many other African and Asian nations, including Vietnam just last year.

A big caveat:  The blogger merely describes her husband, the source of the analysis, as “a numbers guy,” no further credentials, nothing even remotely like peer review.  So this require further work by someone with a background in large mammal demographics.

And this update, just published this afternoon in South Africa’s Business Day, asserts that South Africa’s rhino population still has a positive growth rate.  It also reports the encouraging news that a judge has just sentenced three poachers to the maximum sentence of 25 years in prison.

Meanwhile, take a look at Nikela’s numbers for yourself.  And keep in mind that extinction of rhinos in Africa almost happened once before, during the age of the Great White Hunters at the turn of the nineteenth century:

If we assume that half the rhino poached last year were female that would leave a female population of female rhino at the end of 2011 at roughly 7,620. We can deduct from this that beginning this year (2012) female rhinos will no longer replace themselves.

Or we can look at it like this: The 222 mothers killed in 2011 resulted in the loss of at least 1,100 calves. Using the same mortality, reproduction and poaching calculations that means, that in just four years we lose close to 10,000 young rhino!

In 2008 83 rhino were killed by poachers, a 638% increase from 13 in 2007. In 2009 122 were lost (147%), 333 in 2010 (273%) and an alarming 445 in 2011 (135%).

If we hypothesize that the rhino poaching rate continues unchecked at a 25% increase (assuming the anti-poaching efforts make a difference) the rhino will be extinct by 2022 or in 10 years. Even if all the female calves born in 2012 survived they would barely be old enough to have a calf before that dreadful day!

Now of course there are far too many variables to make any kind of accurate predictions. Plus we hope that the anti-poaching organizations prove successful. Thus please view these assumptions merely as a means to paint a picture of current trends and the trail to the rhinos extinction, if we can’t curb the poaching and stop the illegal trafficking.

References:

Number of rhino left

http://www.worldwildlife.org/what/globalmarkets/wildlifetrade/faqs-rhinoceros.html

High mortality rates have limited the successful breeding of black rhinos

http://www.honoluluzoo.org/black_rhinoceros.htm

More male calves are born than female calves, but male mortality rate is higher, leading to adult sex ratios biased towards females. Fighting is the most common cause of adult male deaths. Most females die of old age

http://www.savetherhino.org/eTargetSRINM/site/745/default.aspx

 

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