Invasive deer and goats are stripping grazing land on Hawaii's ranches, bad news for ranchers who depend on that grass to feed their cattle.

• A first-of-its-kind University of Hawaii study found invasive deer and goats are eating away at ranchland across the islands.
• Two-thirds of the ranch sites surveyed showed a loss of forage, the grass and plants cattle need to graze.
• The survey covered ranches on Hawaii Island and other islands, showing the damage is widespread rather than isolated.
• Less forage means ranchers face higher costs to feed livestock and more pressure on an already tight local beef supply.

Outlook: Expect growing calls for stronger control of wild deer and goat populations to protect Hawaii's ranching and local food production.