A herd of living lawnmowers are now devouring high grasses at the Cache Creek Nature Preserve.

Perennial Gazing of Capay Valley brought in 575 sheep this past week to perform “grazing maintenance” on the waist-high grasses in the oak savannah and grassland habitat of the preserve located west of Woodland.

The sheep help keep native perennial grasses healthy by controlling annual invasive plants, such as common vetch and black mustard. Nature Preserve staff will also be able to see how the grasses react to the grazing.

People can see the sheep at work but they should keep their distance.

The animals are being protected by an electric fence and Schoen, an Anatolian Shepherd dog, as well as Perennial Grazing owners Christian and Shannon Cain, who live on-site during the work.

Perennial Grazing is a 100-acre farm in the Capay Valley, which in addition to providing sheep for grazing and slaughter, also raises ducks, turkeys and table grapes.

Christian explained that the business has been in operation since 2016 and this is the second year it has brought the sheep to the Nature Preserve, although the couple has visited the preserve of many years.

The first three years of the business, Christian said, were spent proving the concept “and the ecology of what could be done with sheep in orchards and vineyards.”

“We were (providing) sheep and goats for neighbors so it wasn’t a crazy leap to take the business on the road,” he added.

The sheep will be allowed to graze on 10 acres of the 130-acre preserve, munching through just over an acre a day through this coming Monday, May 29.

Asked the distinction between sheep and goats (which are also commonly used for controlling brush), Christian said, sheep are “grazers” and goats are “browsers.” Both animals hold their heads at a 45-degree angle but sheep will look down toward the ground and goats will look up.

This means sheep are better for controlling grass pastures while goats are better for controlling “woody stuff” such as small twigs and leaves hanging off trees.

Christian also said there are primarily three seasons during which the animals are at work. The first, from mid January through the end of March and beginning of April is for vineyards, or a perennial crop system. The second, is primarily between April and May to the first part of June, which is for “ecological grazing.” The third season extends from June through the end of August, which is fire safety work, where more goats come into play to control woodier brush.

Both sheep and goats work better with the environment then using herbicides to control unwanted grasses or other foliage.

By simply eating, the animals will allow grasslands to hold more water because they plants won’t be spreading as fast.

Additionally, the dung left by the sheep will provide a more flourishing insect population, which will draw more birds and other animals.