Stat of the Week Competition Winner: July 12 – 18 2014

Thank you for your nominations in last week’s Stat of the Week competition.

We’ve chosen Nick Iversen’s nomination of the NZ Herald article about elephants facing extinction:

The article claims that 100 elephants are killed every day and that elephants will be extinct by 2025.

Over 11 years 100 per day means 400,000 elephants will be killed. I can think of many reasons why this doesn’t mean that elephants will become extinct.

1) the killing rate will drop as elephants become more scarce

2) there will always be protected populations that aren’t subject to the killing

3) elephants are giving birth to new elephants

According to the Wikipedia page on elephants an estimate is that there were 440,000 elephants in 2012. So now we know how the author of the article did the calculations – divided 400,000 by 100 elephants a day.

So let’s keep using Wikipedia numbers and see what we find. “…populations in eastern and southern Africa were increasing by an average annual rate of 4.0%.” Well there you go. Even with culls of 100 a day the population is still growing. So no extinction.

Let’s assume that the 4% is BEFORE the culling. That’s adding 17,600 animals each year and the cull is removing 100 a day so that extends the population out for 21 years. This won’t happen due to points 1 and 2 above.

Note that the 4% figure doesn’t apply to all populations. But my point is still valid. If some populations are increasing in size there will be no extinction.

Thanks Nick for the great explanation!