The City of Seattle recently brought in a goat farmer from Spokane (Healing Hooves, via Treehugger) to help clear away blackberry brambles on a steep hillside around a utility substation that had become a fire hazard, and the brown-eyed herd proved quite obliging.
Turns out, with the right training, goats, sheep and even cattle can survive and thrive on a mixture of weeds, brush, and grasses, thus helping to control weeds and reduce fire danger.
Now then, what about Cat's Claw (Caesalpinia decapetala)? One of the islands' most troubling invasive species, this woody vine with sharp thorns and yellow flowers forms impenetrable thickets over widespread areas of Kaua'i, O'ahu, and Hawai'i.
Cat's Claw is not among Kauai's top-10 priority invasives, yet it gets a mention since I'm a hiker. (Ever try to extricate yourself from Cat's Claw? Kolohe nui!)
This native of tropical Asia was introduced as a fence plant for ranches before 1910, but the recurved thorns proved lethal, killing a cow on Kaua'i.
But heck, goats are also an introduced species (brought to the islands by Europeans as a food source in the early 1800s), and goats are known to eat other woodies, like catbrier...
They might as well be guided to eat vegetation we don't want.