My friend Lawrence pointed out an interesting article on the economist.com site: Putting animals to good use.
Posted on January 23, 2004 12:08 PM. Filed under: environment.Attempts to control coyotes have concentrated on culling them. But coyotes have earned the respect they get from those who know them best: despite all efforts to slaughter them, they survive across a huge swathe of North America, munching on sheep with abandon. The country they share with the sheep is often open prairie, and hard to police. (...)
More effective solutions are clearly needed, and a new application of the ancient role of domestic animals as guardians provides one. It turns out that alpacas, llamas and donkeys have plenty of coyote-scaring power. Being herbivores, they eat the same fodder as sheep, and have no desire to dine out on their charges. Llamas and alpacas are naturally inquisitive, and intolerant of intrusion into their space. And the wily coyote is actually a small creature, easily intimidated, which usually hunts alone. Any old llama or alpaca is more than a match for it.
This is no isolated example of the imaginative use of animals in an age that usually seeks a technological solution to even the simplest of problems. In Florida, for example, attempts have been made to press the local manatees into service to devour the water hyacinths that choke the waterways. These amiable sea-elephants, which eat about 10-15% of their weight each day, can be used instead of herbicides, which can do great damage in an environment already fragile and much-abused. It is not a perfect solution: water hyacinths grow faster than the manatees can eat them, they sprout compensatory leaves for every leaf consumed and, alas, they are not the manatees' favourite food. Even so, with proper management, the manatees can do a lot of good.
In other places, too, local creatures have been recruited to do some of the work more usually done by men or machines. In Mozambique a Belgian charity called Apopo has deployed African giant pouched rats to help clear some of the 500,000 landmines that litter the landscape after the country's long years of civil strife. Elsewhere dogs have sometimes been used to clear the detritus of war. But rats are lighter, so less likely to detonate a buried mine, and smaller, so easier to transport. They also work harder and learn faster than dogs. [continue]