Rabbits were introduced to Australia in 1859 by English settler Thomas Austin. According to Austin "The introduction of a few rabbits could do little harm and might provide a touch of home, in addition to a spot of hunting." The rabbit population quickly exploded and caused major damage to crops and pastureland. Staring in 1901 a 1,139 mile fence was built across western Australia to keep the rabbits from migrating from the east.

An earlier fence proposal was ridiculed in this cartoon.
The first fence is the one furthest to the east. It was the largest unbroken fence in the world. Unfortunately rabbits were found west of the original line so a second and then third fence were constructed. By 1907 2,023 miles (3,256 kilometers) of fence were built. This map, via Wikipedia, has each section color coded.
In the 1930's the fence was used as an escape route for three young indigenous girls back home from a settlement camp near Perth where they had been taken by force. Their route is shown in black above and and the story is recounted in the book Follow the Rabbit-Proof Fence.

Today, much of the shortest fence route still stands (as seen on the map below from 2001) as the State Barrier Fence of Western Australia.  It is used to control emus, wild dogs and feral goats and also serves as a fire break and disease barrier for various animals.

The US Central Intelligence Agency (CIA) recently declassified a bunch of their maps. You can see them on their flickr page. The most strikingly unusual one is this map of elephant populations in Africa.
The map is dense with information, yet fairly easy to interpret. Each country is given a 2013 population estimate with an elephant sized accordingly. Elephant range is shaded in gray and places where dead elephants have been found are color coded by the 2011 CITES index-a ratio of natural deaths to deaths by poaching. Areas with heavy poaching have red dots. However, the map might benefit from proportional dots  - below the dot for the 31 deaths is the same size as the dots representing 1.
They also have a well done map showing ivory smuggling figures and destinations based on seizures.