Restoration of Native Grasslands & Bird Populations

Sheep Grazing on the San Marcos Foothills

 

Overview

The San Marcos Foothills Preserve is a 200-acre open space of rolling grasslands, oak woodlands, and shaded creeks. These types of habitats are important to our local wildlife, but they have largely been taken over by invasive weeds and urban expansion throughout California. The Foothills contain one of the largest grasslands in our area, but much of the preserve is dominated by non-native grassland species which greatly reduce the quality of habitat that these grasslands can provide - thereby reducing the numbers of species that can live on the Preserve.

Location

The Foothills lie at the base of the Santa Ynez Mountain range above Santa Barbara, just to the east of Highway 154 which winds its way up through the San Marcos Pass towards Lake Cachuma.

 

History

Tule elk were once common in the Santa Barbara area, but today are most commonly found in the Central Valley.

Tule elk were once common in the Santa Barbara area, but today are most commonly found in the Central Valley.

In the distant past, ground sloths, mastodons, wild horses, mammoths, and other pre-historic megafauna inhabited this region. Grasslands evolved alongside these creatures and adapted to not only be able to withstand trampling, grazing, and soil disruption, but to thrive and outcompete other plants for space and nutrients.

In more recent history, elk and deer were common grazers in the Santa Barbara area before being displaced when ranchers brought livestock into the Santa Barbara foothills. While grazing patterns of these managed livestock was not a perfect replacement for native grazers, cattle, sheep, and other livestock effectively filled a similar role to their pre-historic counterparts.

Livestock were taken off the Preserve in 2008, which was quickly followed by the Jesusita Fire of 2009 (map). The fire left much of the Preserve's grasslands open, allowing for quick-growing invasive annual grasses to establish themselves, without interference from grazers, and exclude native plants. Many of our native perennial grasses take the time to grow deep root systems that enable them to regrow after their above-ground parts are grazed. Conversely, invasive annual grasses are adapted to grow quickly after the first rain of the season, produce and drop their seeds, and then die off. After any sort of large disturbance (e.g., wildfires or mudslides), a thick mat of invasive grasses can grow quickly and inhibit the growth of any of our slower-growing native grasses. Today, much of the 50 acres of grassland on the Preserve is dominated by invasive non-native grasses, which form a thick homogenous thatch that excludes native growth, inhibits ecosystem nutrient cycling, and provides poor habitat for grassland-dependent birds and other wildlife.


Current Status

Grasslands

Much of the 50 acres of grassland has been taken over by invasive plants like ripgut brome (Bromus diandrus), black mustard (Brassica nigra), fennel (Foeniculum vulgare), and more.

Native perennial bunchgrassses like purple needlegrass (Stipa pulchra) still inhabit some parts of the Preserve.

Unlike our native bunchgrasses, non-Native annual grasses grow tall and thick - though sometimes native wildflowers like fiddleneck can grow among the non-natives.

Non-native annual grasslands dry out at the end of the rainy season, leading to dead grasslands devoid of nutrition while also creating a significant fire hazard.

There are also a number of native shrub communities on the fringes of the grassland that provide yet more habitat for birds and other wildlife.

Native wildflowers are an important part of the Preserve

 

Birds

As the quality of the grasslands has diminished, many grassland-reliant bird species have declined in presence to become uncommon visitors or not present on the Preserve at all.

Bird Guilds on the Preserve

Guild Common Name Presence During the
Breeding Season
Presence During the
Non-Breeding Season
Seed Eating Guild Grasshopper Sparrow Formerly present - not present since 2007 Not Present
Black-headed Grosbeak Present Present
Lark Sparrow Present Present
Lazuli Bunting Present Present
Rufous-Crowned Sparrow Present Present
Vesper Sparrow Not Present Present
Savannah Sparrow Not Present Present
Western Meadowlark Not Present Present
Birds of Prey Red-tailed Hawk Present Present
Red-shouldered Hawk Present Present
Cooper's Hawk Present Present
American Kestrel Present Present
White-tailed Kite Present Present
Loggerhead Shrike Not Present Present
Sharp-shinned Hawk Not Present Present
Northern Harrier Not Present Present
Western Screech Owl Present Present
Burrowing Owl Not Present Present
Barn Owl Not Present Present
Great Horned Owl Not Present Present
Short-eared Owl Not Present Present

Important Grassland Birds on the Preserve

Click each bird to learn more

Grasshopper Sparrow

California Bird Species of Special Concern (breeding) Cumulative Decline in North America since 1966: 75%

Species Presence:
12 May 2001: 25 singing males, 3 pairs, 4 visuals and 2 fly-over individuals
2000 or 2001: 40 pairs of individuals now: 0

These high numbers occurred while the property was grazed by cattle. Once the cattle were removed, grasshopper sparrows disappeared from the property.
Livestock grazing can be designed to create patchy areas, decreasing vegetation height and thinning vegetation which supports grasshopper sparrow (Dechant et al 1988).
Cattle grazing on the San Marcos Foothills supported 47 individuals and multiple breeding pairs. After the cattle were removed, grasshopper sparrows disappeared from the property (Holmgren, pers. comm. 2017).
Grasshopper sparrow are positively associated with native bunchgrasses in a patch grassland structure (Goerissen 2005) that includes occasional shrubs to perch and sing (Dobkin and Granholm 1988).

Burrowing Owl

33% decline in North America since 1966.
In 1886 and 1912 in Santa Barbara it was a Common Breeding Species.
Now, nearly completely extirpated.
Now, # of wintering birds in the region: 1-3.

Inhabits extensive, dry/sparse grasslands. Often associated with a high density of ground squirrels. Nests in a burrow in areas with high density of burrows. Eats grasshoppers, crickets, moths, beetles, voles, mice, etc.
Livestock grazing reduces thatch, which means more bare ground, which lead to more squirrel burrows (CDFW, Rancho Jamul 2018). More squirrel burrows may support increased presence of burrowing owls.
Livestock grazing can be designed to decrease the height of the grasses which means increased visibility across the landscape. Low and open vegetation structure is critical for burrowing owl (San Diego Zoo Institute for Conservation Research (2017).

Western Meadowlark

48% cumulative decline in North America since 1966.
In the Santa Barbara area during non-breeding season:
1981: 900
1994 and beyond: 400
Uncommon breeder in the Santa Barbara-Goleta area by 1990. Probably extirpated by 2005.

Nests on the ground, often in a small depression. Eats seeds, ants, beetles, grasshoppers, crickets, worms.
Livestock grazing reduces litter and creates bare patches which results in a vegetation structure preferred by western meadowlarks (Gennet et al 2017).
Western meadowlarks were observed most often on plots with higher levels of native plant cover and flat terrain, and a slight increase in meadowlark presence with more bare ground that is a result of livestock grazing (Gennet et al 2017).
Harrison et al (2010) found that low intensity grazing over a long period of time resulted in no net change in overall abundance of western meadowlark. They did find that the meadowlark population increased in response to increased bare ground.

Raptors on the Preserve

 

Habitat Restoration Goals

Primary Goal

Restore populations of grassland-dependent birds on the Preserve by restoring 50 acres of grassland to native perennial grassland.

Secondary Goals

  • Ecosystem: Create and sustain habitat for common and special-status species.
  • Water: Increase the amount of water that is stored under ground and slowly released and decrease runoff.
  • Climate: Increase ability of animals to survive effects of climate change. Increase carbon sequestration.
  • Culture: Provide opportunities for gathering of native plants.
  • Recreation: Provide public access.
  • Participation: Provide educational opportunities and public participation in monitoring.

Vegetation Goals

  • Native grassland should have a minimum of 10 percent native grass cover and a maximum of 50 percent cover of native grass, a presence of several native forb species, and some bare ground ranging from 10 to 50 percent of the total amount in the grassland.
  • Native grassland should have structural diversity including some tall grass and some short grass and forbs in order to provide shelter for grassland-dependent birds.
  • Create and maintain a mosaic of grassland in which some areas have bare ground between native grasses, and other areas have some thatch between grasses with which ground nesting birds can build and hide nests.
  • Recognize that it is impossible to completely remove non-native grasses from the grasslands. Nevertheless, time the livestock grazing so that the seed stocks of non-native grasses are depleted.
 

Restoration Methods

Channel Islands Restoration has been restoring habitat at the San Marcos Foothills Preserve since 2010. However, our methods have mostly focused on restoring riparian habitat and a few key areas of grassland.

Restoring 50 acres of grassland has been seen as a monumental task that we have neither the time nor the funding to work towards. However, if we are able to successfully manage grazers on the Preserve, we may be able to get them to do the work for us - naturally. Therefore, we are using sheep to graze the 50 acres at high intensity and short durations.

Why Grazing and Why Sheep?

In an effort to recreate the historic effects of grazing, we are bringing grazing back to these grasslands. Grazing is helpful for a number of reasons. Grazing is an excellent way of suppressing annual grasses while only temporarily impacting perennial grasses. Our plan is to graze the grasslands as the non-native annual grasses start to sprout, but before they develop and drop their seeds. This way, after being grazed, the non-native annuals won't have enough energy in resreve to continue to grow and produce new seeds. Meanwhile, our native perennial grasses, like purple needlegrass, have a strong system of roots that helps keep them alive year round and also helps them rebound from grazing. In fact, grazing may even promote plant growth!

As for why sheep - sheep are relatively lightweight and do not eat the roots of the plants. In comparison, cows are heavy and compact the ground and can contribute to soil erosion. Goats eat everything - roots and all (cows also may eat the roots of grass, but to a lesser extent).

Grazing Methods

Using 400 - 450 sheep we will graze an average of two acres per day. It will take 25 - 30 days to graze the entire 50 acres of grassland. This will happen twice per year, in late December/early January and in March.

The sheep will be enclosed in a two-acre electric fence and protected by sheep dogs.


Contact

For questions or comments email us at contact@cirweb.org.

Thanks for reading!

 
 

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