Sustainability in Action

Rancho Colibrí

The Sea Ranch

"The Science of Sheep Grazing" draws members to January 2015 Forum

By Laurie Mueller

An overflow crowd attended this January's Forum at the Del Mar Hall entitled "The Science of Sheep Grazing" to learn more about The Sea Ranch sheep. The presentation was given by Sea Ranch Shepherd Leland Falk, a local fifth-generation rancher who has been managing the herd since 2004.

The Sheep Grazing Program was started by the Association in 2002 as a means of reducing the large fuel load of dry grass and thatch buildup on commons without the use of mechanical equipment. The specifics of the grazing project have continued to evolve from some early "trial and error" adjustments to the current herd of healthy sheep.

The herd of about 320 ewes and their lambs now graze the Sea Ranch meadows and hillsides in a cycle which moves them through each area about once a year. By eating the dead grass and thatch, the sheep reduce the buildup of the biological fuel load, stimulate the growth of new, fire-resistant green grasses and improve opportunities for the resurgence of native perennials.

The sheep are contained by portable electric fencing which is moved from field to field every 12-36 hours depending on the size of the fenced area and the amount of vegetation. Fences are usually placed at the edge of mow lines or game trails. Leland works closely with TSRA staff and nearby landowners as the sheep are moved throughout the ranch.

Effects of "mob grazing"

In his talk, Leland noted that herding the sheep together and moving them frequently, rather than allowing them to spread out on a large range, has an effect similar to grazing patterns of native herd animals such as elk and antelope who bunched together to graze and moved frequently in response to predators. This "mob grazing" pattern has a beneficial effect on grasses since the hooves of the clustered animals break down the dead grasses more effectively and the more concentrated dung and urine provide nutrients for the growth of new grass. Leland allows only about 70% of the grass to be eaten in each area in order to leave enough nutrients to replenish the soil and to avoid overgrazed dirt patches.

He said that ten test plots around The Sea Ranch show a 50 percent reduction in thatch fuel load, improved soil quality and an increase in native perennial grasses which are more fire-resistant, provide more nutrients to the soil and are a longer-lived nutritious source of green grass for the sheep.

Fields are grazed at different times each year for a variety of reasons. For example, fields where azaleas or lupine are growing are avoided during certain times of the year when the plants are toxic to sheep. Changing the cycle so that fields are grazed at different points in the growing season from year to year is beneficial for the health of the grasses. Based on his observations, Leland believes that The Sea Ranch commons are under-grazed and would benefit from being grazed twice a year.

The normal cycle of grazing has recently been shortened from a year to eight months because the lengthy drought has had an impact on grass growth, and the sheep need to be moved more frequently.


One of the major changes made over time has been the improvement of the herd's health and adaptability to the local climate through breeding for "successful performance" and culling the weak links.

Leland is in the process of converting most of his flock to sheep with hair rather than wool. Hair sheep do well in cold rainy climates because their coats don't hold water and they are hardier and less susceptible to foot rot and other problems than many other breeds. Katahdins are a hair sheep breed also known for breeding twins. By breeding Katahdin bucks and other hair sheep with his existing herd of ewes, in 3-4 generations all of Leland's sheep, other than a few he is setting aside as wool producers, will be hair sheep.

Since Leland's herd is a mixture of several types of sheep and he culls sheep and lambs that do not perform well in this climate, he is essentially developing his own specialized breed for The Sea Ranch climate and vegetation.

The sheep are checked annually for general health and parasites. At one time, The Sea Ranch herd included goats, which effectively trimmed the shrubs and trees, but goats have been phased out because they did not prosper in the rainy climate, and now only a few favorites remain.


Leland says notes that lambs are usually born in March or April (this past summer some bucks were left in with the ewes, so nearly 300 lambs were born a bit early in January or February). Once they are weaned, at between 3-5 months, lambs are moved to a separate pasture where they can fatten up on green grass without competition from the adult ewes. Some with good breeding potential are returned to the main herd at around one year old. Those not needed to replenish the herd are shipped to auction.

Leland is considering locally marketing about 40 grass-fed lambs for meat this summer. He notes that meat from hair sheep is known for its milder, sweeter taste. He says that selling some lambs locally would be a bonus rather than a central part of his business plan.

Leland's presentation demonstrated that the "science"of sheep grazing to reduce fuel load is a complex interplay, integrating knowledge and continuing assessment of the terrain and climate, sheep genetics and behavior, vegetation health and life-cycles, and soil condition and enrichment. An hour of questions and answers followed the engrossing talk. A DVD of the presentation and following Q and A is available from Sea Ranch members Walt and Nancy Custer at

For Sea Ranch sheep aficionados, there is also a website,, which shows the current location of the sheep, and a Facebook page, which has photos and information about the sheep.