Channel Islands National Park

Channel Islands National Park

Flora & Fauna

ANIMALS

A variety of organisms can be found on and around the Channel Islands, from top predators like bald eagles and sharks, to intertidal residents such as seastars and barnaces, to the tiniest parasites living on other animals and plants. For this page we have organized the information into Birds, Marine Animals, and Terrestrial Animals, although many animals utilize resources from both the ocean and the land.

Because of their isolation and remote nature, the Channel Islands support fewer native animal species than similar habitats on the mainland. Species that reached the islands were aerial, such as birds and bats, or rafted across the water on debris and other material. Over time some vertebrate species evolved into distinct subspecies on the islands. For example, the deer mouse and island fox are recognized as distinct subspecies on each of the islands they occur. A total of 23 endemic terrestrial animals have been identified in the park, including 11 land birds that are Channel Island subspecies or races.

Marine Animals

An extremely rich and diverse community of marine mammals is found on and around the Channel Islands. Many species of pinnipeds (seals and sea lions) and cetaceans (whales and dolphins) either breed on the islands or feed in the productive waters of the Santa Barbara Channel.

Visitors to the islands often spot huge pods of common dolphins and smaller groups of Risso's dolphins, and occasionally see the more rare pacific white-sided and bottlenose dolphins. Dolphins feed on anchovies and other small fish, and follow schools of these prey as they move around the channel. Often groups of dolphins will come to a boat and ride the bow wave for long distances. Why do they do this? It may simply be fun, or it may allow them to conserve energy; no one really knows.

During the winter pacific gray whales migrate between summer feeding grounds in Alaska and breeding areas in Baja, Mexico, passing through the Santa Barbara Channel. Gray whales are often seen by passengers on whale-watching trips between December and March. Other whale species such as humpbacks, blue, orca and fin whales are less common, but can occasionally be seen during the summer when they come to the channel to feed.

California sea lions are often seen by boaters as they haul-out on sea buoys and offshore rocks, and are frequently encountered by divers and snorkelers in the kelp forest. Less often seen by most people are the enormous colonies of sea lions and seals that come to island beaches to breed. At Point Bennett, on the west end of San Miguel Island, hundreds of thousands of northern elephant seals, California sea lions, northern fur seals and harbor seals all breed at varying times throughout the year. The sight is remarkable, and seen by only a few hundred visitors a year who make the trip out to San Miguel Island and then the six mile hike out to the Point, the westernmost point of all the California Islands.

In many ways pinnipeds are as much terrestrial animals are they marine. For much of their lives they haulout on islands and offshore rocks, either for breeding, to give birth or simply to rest. Their presence in large numbers can have significant impacts on terrestrial systems. For example pinniped carcasses, particularly those of non-surviving pups, provide food for seabirds and bald eagles on the islands. And when animals come farther up the shore away from the beaches and the rocks, they can severly impact the vegetation in those areas. Some pinniped species, especially California sea lions and elephant seals, appear to be increasing in abundance while others like harbor seals may be fewer in number around the islands than they were in the past. Significant changes in sea water temperature like those caused by El Nino events appear to have significant effects on pinniped populations around the Channel Islands.

Giant (Black) Sea Bass

Common Name:

Giant (Black) Sea Bass

Scientific Name:

Stereolepis gigas

Habitat:

Kelp forests and deep, rocky reefs.

Conservation Status:

There is no formal conservation status, but fishing is prohibited in California.

Additional Information:

This gentle giant is the largest and most magnificent species of fish in the kelp forest. They are capable of growing to lengths of over 7 feet and weighing 750 pounds! Adults are dark brown to black with large dark spots and a light belly. It is believed that they have the ability to alter their spot pattern at will. As carnivores, they eat many things including Pacific mackerel, shrimp, small sharks, crabs, lobster, anchovies, and squid.

Prior to the 1950's, this species of bony fish was very common to the near shore waters of Southern California. Due to over-fishing, their population was reduced to critically low levels. In 1982, both commercial and sport fishing of Giant Black Sea Bass was banned in California waters. Since then, the populations have been steadily recovering and encounters by divers are becoming more common.

California Spiny Lobster

Common Name:

California Spiny Lobster

Scientific Name:

Panulirus interruptus

 

Habitat:

Kelp forests and surfgrass beds.

Additional Information:

This species of spiny lobster is often encountered in rocky dens or in beds of surfgrass at relatively shallow depths. As highly prized targets for fishermen and divers, most California spiny lobsters do not live longer than 5-7 years before being caught. They have been known to achieve lengths of over 3 feet long and weighing 16 pounds. 

As predators, lobsters play a central role in maintaining the diversity of intertidal and subtidal communities. Predation on kelp-eating species such as sea urchins helps to maintain a balance in the kelp forest ecosystem, providing a more stable habitat for other species that rely on the kelp for food and shelter. The kelp forests of the Channel Islands offer an excellent rocky habitat for their pelagic larvae arriving with the converging currents from the south.

Sunflower Star

Common Name:

Sunflower Star

Scientific Name:

Pycnopodia helianthoides

 

Habitat:

Near-shore sand and rocky bottom.

Additional Information:

The magnificent sunflower star inhabits low intertidal and subtidal areas ranging from Alaska to San Diego, California. Juvenile stars begin life with 5 arms, but once mature, adults have close to 24! They have very soft, spongy skin that comes in a kaleidoscope of colors - purple, green, brown, orange, pink and yellow. They are the largest sea star in the kelp forest reaching lengths of over a meter from tip to tip. The sunflower star is a voracious predator often traveling up to 40 inches per minute to chase down its prey. This unique species of sea star has a skeleton composed of disconnected pieces. This allows for them to open their mouths wide enough to engulf large prey. They eat sea urchins, snails, clams, sea cucumbers, crabs and even other sea stars.

Garibaldi

Common Name:

Garibaldi

Scientific Name:

Hypsypops rubicundus

 

Conservation Status:

The Garibaldi is the California State fish and is protected from fishing.

Habitat:

These fish mainly live in the kelp forest ecosystem.

Additional Information:

This species of damselfish inhabits the warmer waters of the Pacific Ocean from Monterey Bay, California to Baja California along rocky coastal reefs and among kelp forests. They are especially common to the more southern Channel Islands. Easily distinguishable by their vibrant orange color, adult fish may reach up to 17 inches. Juvenile garibaldi fish are yellow-orange with iridescent blue spots and do not mature until five or six years old and eight inches long. They feed on various invertebrates.

Adult male garibaldi carefully constructs circular nest sites about one foot in diameter in shallow reef habitats. They weed out all organisms except for red algae. The more well-prepared and maintained the nests are, the more likely a female will choose that nest to deposit her eggs for fertilization by the hosting male. Once the eggs are fertilized, the male continues to guard the nest often warning divers of their close proximity with a loud thumping noise.

Point Bennett on the west end of San Miguel Island is known as the only place in the world where six species of pinnipeds breed. San Miguel Island is the northern extent of the range of Guadalupe fur seals and the southern limit of the Northern or Steller sea lion's range. Both of these animals are listed as threatened and are extremely rare at the Channel Islands now because of declining populations. The other pinnipeds are northern fur seals, California sea lions, northern elephant seals, and harbor seals. Information about each species can be found at the National Marine Mammal Laboratory. the Channel Islands are important to the survival of pinnipeds because most need protected undisturbed beaches to raise their young. Point Bennett is particularly important because it is centrally located, so close to rich feeding grounds for most of these species. Their biggest threats tend to be encounters with fishing gear, pollution, disease, and El Nino.

See below for summeries of the most common pinnipeds found around the Channel Islands.

Elephant Seals

Common Name:

Northern Elephant Seal

Scientific Name:

Mirounga angustirostris

Habitat:

Elephant seals primarily live on and around sand beaches.

Additional Information:

Northern elephant seals, Mirounga angustirostris, are large true seals common in the winter and spring months at the islands. True seals do not have external ear flaps and cannot walk using their hind flippers like sea lions, thus they move by pulling with their front flippers and undulate like slugs.  Hunted nearly to extinction elephant seals have made a phenomenal comeback, numbering around 100,000. Males may weigh up to 6,000 pounds. Females are generally less than 2,000 lbs. After breeding in December and January at the Channel Islands they swim to the Bering Sea to feed on squid and deep water fish. They return to the islands in the spring to molt, then return to Alaska to feed some more. Elephant seals dive continuously during their migrations and have been recorded diving to 4500 ft and up to two hours, though typically shallower and shorter. Pups are weaned after only about one month though they typically triple their birth weight during that time. They are then abandoned and left to learn to swim and find food on their own.

Sea Lion

Common name:

California Sea Lion

Scientific name:

Zalophus californianus

Habitat:

Sea lion habitat ranges from sandy beaches to rocky shore cliffs.

Additional Information:

California sea lions, Zalophus californianus, are probably the most familiar marine mammal at the islands. These smart, playful animals are often seen playing in the surf or lounging on beaches around San Miguel, Anacapa, and Santa Barbara Islands in particular. Males may reach 8 feet in length and 1000 lbs, females about 220 lbs. They are easily recognized by their pointed nose, external ear flap, "Charlie Chaplin" walk, and loud sometimes incessant barking. Sea lions are very social animals. They can be quite curious in the water coming to investigate divers and boats. On the breeding they are very skittish and will retreat into the water if disturbed. Males set up beach territories and defend their harems from other males. Pups are generally born in June and July and females nurse their pups for nearly year. Sea lions feed on fish and squid near the surface generally but can dive to 500 ft. The 2001 population of California sea lions was estimated at about 200,000 and 80,000 might live at San Miguel Island. The population has been growing steadily since 1975 except for set backs in El Niño years.

Harbor Seal

Common Name:

Harbor Seal

Scientific Name:

Phoca vitulina

Habitat:

Harbor seals live around sandy beaches.

Additional Information:

Harbor seals, Phoca vitulina, stick closer to shore than their larger cousins but they are more widespread and are found in both the Pacific and Atlantic oceans. Harbor seals are very shy on land but can be very curious in the water, often coming up to divers to investigate their fins or other gear. Their faces are somewhat rounded and their fur is usually dark gray with darker rings. Adults only reach about 500lbs. Pups are able to swim about an hour after birth, an adaptation to life on small isolated beaches that may become inundated by high tides. Mothers often leave their pups alone on a beach while feeding but will return, so it is important to leave pups alone.

Birds

Seabirds

Channel Islands National Parkis recognized as an important breeding and resting area for a variety of seabirds. The rich marine food sources and isolated islands support numerous colonies of seabirds. Indeed, the park's colonies and the surrounding waters that are used for foraging are vital for the survival of several seabird species. Although the mainland may provide roosting areas, in many cases seabirds depend on the islands for breeding and nesting success. Collectively, the islands constitute a major seabird breeding area in the eastern north Pacific, the largest such area in the United States south of the Farallon Islands. For example, half of the world's population of ashy storm-petrels and western gulls, 80% of the U.S. breeding population of Xantus's murrelets(33.5% of the world's population and the only breeding ground north of Mexico), and the only major breeding population of California brown pelicans in the western U.S. occur in the park.

Landbirds

Landbird populations and species compositions on the islands can change from year to year, depending on mainland species that reach the islands, changes in habitats, competitors or predators that arrive or leave the islands, or areas that are disturbed by people. Most of the bird species probably have experienced a loss of preferred food and shelter due to the alteration of the islands' scrub habitats.

Nine raptor species live in the park and are primarily seen on Santa Cruz and Santa Rosa. Hawks and owls also occur intermittently on Anacapa, San Miguel, and Santa Barbara, which have limited habitat to support these birds.

Several bird species disappeared from the park during the 20th century. An endemic subspecies of song sparrow (Melospiza melodia graminea) on Santa Barbara was driven to extinction due to habitat destruction by introduced rabbits, direct predation by feral cats, and a fire in 1959 that destroyed much of its habitat. Both Bald Eagles (Haliaeetus leucocephalus) and peregrine falcons (Falco peregrinus anatum) also formerly bred on the islands, but largely disappeared due to harassment, shooting, egg stealing, and reproductive failure caused by organochlorine pesticides, such as DDT. However, both of these species are making a comeback due to reintroduction efforts. Peregrines were reintroduced on the islands in the 1980s, and there are now about 10 active peregrine falcon nests in the park. A study to determine the feasibility of reintroducing bald eagles began on Santa Cruz Island in summer 2002. Twelve eagles will be released annually on the island during a five-year period.

Golden Eagle

Common Name:

Golden Eagle

Scientific Name:

Aquila chrysaetos

Habitat:

The golden eagle seeks open terrain throughout mountains, foothills, and plains.

Natural History:

This powerful bird of pretty is widespread in the wilder country of North America, Europe, and Asia. Approximately the size of the bald eagle, the golden is less of a scavenger and more of a predator, regularly taking prey up to the size of foxes and cranes. Also spiritually important to many Native American tribes.

Additional Information:

Golden eagles are currently being removed from the park because golden eagle predation is the primary source of mortality for island foxes and is likely responsible for the massive island fox decline from 1994—2000. Until recently, golden eagles never bred on the Channel Islands. They are able to exist in the park because of the occurrence of feral pigs on Santa Cruz Island, and because bald eagles no longer are present to deter them. They were discovered in the winter of 2002—03 to also be nesting on Santa Rosa. The Santa Cruz Predatory Bird Research Group, with the support of the Park Service and The Nature Conservancy, has been relocating golden eagles to distant sites on the California mainland. To date, 32 golden eagles have been removed from Santa Cruz and Santa Rosa Islands, and as of February 2005 it is thought that at least 10 golden eagles remain on the islands. However, until bald eagles become reestablished and/or feral pigs are removed, other golden eagles may come from the mainland to the islands.

Snowy Plover

Common Name:

Western Snowy Plover

Scientific Name:

Charadrius alexandrinus

Conservation Status:

The snowy plover is declining on the Pacific coast and considered threatened due to human disturbance of nesting.

Habitat:

Snowy plovers look for flat, sandy beaches and dunes with little vegetation.

Additional Information:

Western snowy plovers (Charadrius alexandrinus nivosus) breed from Washington State to Baja, California, and winter in coastal areas from southern Washington to Central America. Most western snowy plovers return to the same site in subsequent breeding seasons. They breed primarily above the mean high tide line. Their preferred coastal nesting habitats are sand spits, dune-backed beaches, unvegetated beach strands, open areas around estuaries, and beaches at river mouths. Their nests typically are shallow scrapes or depressions on the ground on flat, open areas with sandy or saline substrates, where vegetation and driftwood is sparse or absent. The nesting season extends from early March through September, with peak nesting occurring from mid-April through mid-August. Chicks reach fledging age about one month after hatching. Adults forage on invertebrates primarily along the water's edge. On the Channel Islands they forage in the wet sand and amidst surf-cast kelp in the intertidal zone and in dry, sandy areas above the high tide. In winter, snowy plovers are found on many of the beaches used for nesting as well as on beaches where they do not nest, and on estuarine sand and mud flats.

 

The Pacific coast population of the western snowy plover was listed as threatened by the U.S. Fish and Wildlife Service on March 5, 1993. The population has declined due to many factors. Recreational and other human disturbance, loss of habitat to urban development, introduction of beachgrass (Ammophila spp.) and other nonnative species, and expanding predator populations have all contributed to a decline in active nesting areas and in the size of the breeding and wintering populations. It is estimated that about 2,000 snowy plovers may breed along the U.S. Pacific coast and that there are 157 current or historical snowy plover breeding or wintering locations along the U.S. Pacific coast.

 

Channel Islands National Park is one of the few locations in southern California that still supports breeding and wintering populations of western snowy plovers. In the 1990s Santa Rosa and San Miguel Islands had both breeding and wintering populations, but numbers have declined precipitously. A few birds also lived on The Nature Conservancy portion of Santa Cruz. On Santa Rosa the birds inhabited about 16 miles of coastline, while on San Miguel they were present on about 10 miles of shoreline. The Skunk Point area on Santa Rosa is an important nesting area and foraging area for juvenile and migrating plovers. Forty to fifty percent of the nests in this area have been found on rocky outcrops in the backdunes, about 490 to 980 feet (150 to 300 meters) from the shoreline.

 

Nesting snowy plovers are sensitive to disturbance. Activities that are detrimental to nesting birds include walking, jogging, unleashed dogs, and beachraking, among other uses. Recreationists can inadvertently step on eggs and chicks, destroying them. In addition, adults will stay away from a nest while people are present. Birds generally flush from nests when people come within 328 feet (100 meters). Separation of plover adults from their eggs or chicks may result in increasing mortality due to overheating in the sun, cold, blowing sand, or predators such as gulls or ravens. Trash left on a beach also may attract predators. People may cause broods of snowy plovers to run away from favored feeding areas.

 

To avoid disturbance of the birds, several of the beaches where snowy plovers currently nest are closed to recreational use. Specifically, all of the shoreline of San Miguel is closed to pubic landing or entry with the exception of Culyer Harbor. On Santa Rosa the coastline from and including Skunk Point to just north of East Point is closed to visitors, including landing or hiking, from March 1 to September 15. However, some people occasionally land or hike on these beaches during the nesting season. From South Point to Sandy Point and from Sandy Point to Carrington Point, camping also is permitted on the beaches only from September 1 through December 31. Camping and landing are prohibited year-round at the beaches around Sandy Point.

 

In the park, population numbers have declined on both Santa Rosa and San Miguel, concurrently with an overall decline in the breeding population in southern California. On Santa Rosa it is estimated that less than 30 breeding pairs were on the island in 2002 (most recent survey), down from 60 pairs in 1993. An estimated 200 birds still winter on the island's beaches. On San Miguel, snowy plovers are sometimes sighted on beaches during the breeding season, but they are no longer known to breed on the island. An unknown number of birds also winter here.  

 

Different factors may be responsible for these declines on the islands. On San Miguel human disturbance of plovers has not been documented, nor have data been collected on the impacts of people on the Cuyler Harbor beach — the only beach visitors are permitted to use and once an important nesting area. It is believed that the decline in the breeding population on San Miguel may be due to a large increase in the number of northern elephant seals and California sea lions that have occupied snowy plover nesting habitat. This increase occurred simultaneously with the western snowy plover decline.

 

Several factors may be responsible for the decline of western snowy plovers on Santa Rosa. In the past, ranch activities affected the plovers, including cattle and horses trampling nests and flushing birds from nests. Ungulate carcasses may have attracted predators such as ravens. Raven numbers are thought to be unnaturally high on Santa Rosa, which may be resulting in an increase in predation by ravens on plover eggs. Accumulations of trash also may have attracted predators. In the past, visitors, including hikers, surfers, and kayakers, affected the plovers at Skunk Point. But with the beach closures these impacts are happening less frequently on the beaches. High winds and predators are still a frequent cause of nest loss. In the past winds accounted for 28% to 34% of all nest losses, while predators (e.g., ravens, Santa Rosa Island spotted skunks) accounted for another 26% to 44% of losses. Both Santa Rosa and San Miguel have 20—30 knot winds on a regular basis through the plover nesting season, which can cause eggs to be sandblasted or blown out of the nest when the adult steps off the nest. It is also possible that ravens, which eat plover eggs and chicks, live on the island and may be more numerous than thought due to the presence of ungulate carcasses. In addition, increasing numbers of elephant seals hauling out on the south beaches of Santa Rosa could be reducing nesting habitat.

Island Scrub-Jay

Common Name:

Island Scrub-Jay

Scientific Name:

Aphelocoma insularis

Conservation Status:

Channel Islands National Park has afforded some protection for the island scrub-jay. Sheep and pigs have severely degraded habitat on the islands, but efforts to control their impact have been underway.

Habitat:

This species breeds in coast live oak woodland or chaparral dominated by scrub oak on Santa Cruz Island.

Natural History:

This species has been split from the Western Scrub-Jay because of its brighter plumage and different genetic makeup. It is restricted to the island of Santa Cruz off the California coast, where its entire population would be threatened by any major disturbance.

Xantus's Murrelet

Common Name:

Xantus's Murrelet

Scientific Name:

Synthliboramphus hypoleucus

Conservation Status:

After feral cats were removed from Santa Barbara Island in 1978, numbers of this species increased from zero in 1939 to approximately 1,500 in 1992. Programs are underway at many of the current or former nesting islands to remove feral cats and other introduced predators and to educate island residents about the importance of predator-free islands for the survival of these and other colonial nesting seabirds.

Habitat:

Nests on steep sea-slopes, canyons and cliffs with a sparse cover of herbaceous and shrubby plants on Anacapa and Santa Barbara Islands.

Natural History:

As a member of the auk family that usually favors norhtern waters, the Xantus's Murrelet is found mostly off Baja and southern California in pairs or faimily groups, but not flocks. It nests on offshore islands and is rarely seen from the mainland.

Brown Pelican

Common Name:

Brown Pelican

Scientific Name:

Pelecanus occidentalis       

Conservation Status:

Numbers declined drastically in the mid-20th century due to eggshell thinning from DDT. By 1970, North American populations were almost eliminated except for Florida, but after the ban of the pesticide, the Pelicans made a strong recovery and are now common on the west coast

.

Habitat:

Pelicans live in coastal waters nesting on the ground or cliffs of islands.

Additional Information:

The California subspecies of the brown pelican (Pelecanus occidentalis californicus) was classified as federally endangered in 1970 and as endangered by the state of California in 1971. Channel Islands National Park provides essential habitat for this species. The only breeding colonies of brown pelicans in the western United States are on West Anacapa and Santa Barbara islands. The Channel Islands also provide roosting habitat for the birds, with major roosting areas occurring on Scorpion Rock off of Santa Cruz Island and near the lighthouse on East Anacapa.

Pelicans breed in nesting colonies on islands without mammalian predators and permanent human habitation. They typically build a nest on the ground and on low shrubs. On West Anacapa and Santa Barbara pelicans generally nest on inaccessible slopes, canyons, and high bluff tops and edges. Brown pelican are asynchronous nesters. The nesting season can extend from January through October. Normal clutch size is three eggs. The peak of egg laying is usually March or April; however, eggs are often laid through June. Pelican breeding success is largely determined by the availability of their primary prey items, northern anchovies (Engraulis mordax) and Pacific sardines (Sagax sarinops), which during the breeding season comprises nearly their whole diet.

 

In the 1970s the park's colonies almost disappeared due to eggshell thinning and consequent reproductive failure. Pelicans are extremely sensitive to bioaccumulation of the organochlorine contaminants in the marine environment, particularly DDT and its metabolites, and polychlorinated biphenyls (PCBs). DDT has been shown to alter the birds' calcium metabolism, resulting in egg-shell thinning.

 

The park's breeding populations have steadily increased since 1980, although they are now believed to be fairly stable. An estimated 6,000 pairs were found on West Anacapa in 2002, although this was an unusually high number. Between 1979 and 2001 the colony produced a mean of about 3,600 nests per year. On Santa Barbara there are an estimated 1,200 pairs. Pelicans were not known to nest on Santa Barbara in recent times until 1980; the first significant nesting occurred in 1985. From 1985 to 2001 the colony produced a mean ofabout 770 nests per year. Starting in 2000 the pelicans started moving their nesting area around on the island. Santa Barbara is unusual in that it is the only island known along the Pacific Coast where both nesting pelicans and humans cohabit.

 

California brown pelicans still face several threats. Breeding populations and productivity vary dramatically yearly, depending on climatic and oceanographic conditions, which affect food availability and abundance. Other threats include disturbance of roosting and nesting birds, oil spills and other pollution, entanglement with hooks and fishing lines, and disease outbreaks resulting from overcrowding at winter roosts.

 

Nesting and roosting birds are very sensi­tive to human disturbance. Pelicans are affected by ancillary fishing activities, including the presence of vessels, noise, and lights, near roosting and breeding areas. Increased light levels are known to alter the behavior of diurnal species such as pelicans, leading to nest abandonment and increased egg and chick mortality. In 1999 large increases in nighttime squid fishing activity on park waters probably affected nesting pelicans — higher than average rates of nest abandonment and chick mortality were recorded and could not be explained by other environmental factors.

 

Activities such as sea kayaking and recreational boating also can disrupt nesting and significantly lower breeding success, as well as affect distribution patterns of roosting pelicans in both breeding and nonbreeding seasons. It has been suggested that people not be allowed within 328 feet (100 meters) of nesting or roosting pelicans to prevent disturbance due to the presence of people.

 

In the past human activities affected pelicans in the Channel Islands. Boaters and kayakers often approached within meters of the park's main islands and rocks that supported roosting and nesting pelicans. Maintenance of the U.S. Coast Guard lighthouse and foghorn also may have affected roosting pelicans. Scientists conducting seabird research occasionally flush small numbers of roosting birds. And research by the National Marine Fisheries Service at Point Bennett on San Miguel sometimes may disturb roosting birds. Some disturbance from recreational visitors in boats may still occur, although visitor access restrictions are believed to be largely limiting this potential impact.

 

Park visitor access is restricted on West Anacapa. A no-entry closure from January 1 through October 31 also keeps boats well offshore to protect fledglings in the vicinity of the nesting colony and provides a buffer zone to nesting pelicans. On Santa Barbara the pelican nesting area is closed to visitors and trails are closed when birds nest or show initial nesting behavior.

Ashy Storm-Petrel

Common Name:

Ashy Storm-petrel

Scientific Name:

Oceanodroma homochroa

 

Conservation Status:

Most of the Californian population nests on protected and specially managed islands.

Habitat:

Breeds in protected rock crevices and burrows in colonies on offshore islands. The breeding season is protracted with egg-laying recorded from January to August from within the same colony.

Natural History:

An entirely gray seabird roughly the size of a Purple Martin, the Ashy Storm-petrel can only be found on the islands off California and in the adjacent waters of the continental slope. Unlike most other species of storm-petrel, ashy storm-petrels do not travel far from their colonies after breeding, and the breeding season is spread out over most of the year. Due to its restricted range and very small population size, the status of this species requires continued monitoring.

Loggerhead Shrike

Common Name:

Loggerhead Shrike

Scientific Name:

Lanius ludovicianus anthonyi

Conservation Status:

Breeding population is unknown. Due to lack of research on demographics of this subspecies, population trends are uncertain.

Habitat:

Loggerhead shrikes utilize ecotones, grasslands, and other open habitats with scattered shrubs and trees, suitable perches, bare ground, and low or sparse herbaceous cover as primary habitat and breeding territories.

Natural History:

The loggerhead shrike is an endemic subspecies of the California Northern Channel Islands. They are predatory songbirds with strong, hooked bills they use to kill and dismember prey, which include insects or small vertebrates, birds, and small reptiles.

Common Name:

Bald Eagle

Scientific Name:

Haliaeetus leucocephalus

Conservation Status:

Population declined seriously during the first two-thirds of the 20th century. Even after eagles were fully protected their numbers continued to decline because of DDT and other pesticides. The numbers have increased steadily since the banning of DDT in the 1970s.

Habitat:

The bald eagle explores coasts, rivers, large lakes, and mountainous open country.

Additional Information:

Bald eagles were once permanent residents of Channel Islands National Park. Historical records indicate that bald eagles bred on all islands within the park, with at least two dozen nesting pairs over the 8 Channel Islands. Persecution by humans and the effects of organochlorine chemicals such as DDT eliminated breeding bald eagles on the Channel Islands by the mid-1950's.

Breeding bald eagles provided some ecosystem functions that are currently missing in the northern Channel Islands. For example, bald eagles were once the top marine aerial predator and probably fed upon a variety of seabirds and fish. Bald eagles are generally highly territorial, and in the past this behavior may have prevented golden eagles from colonizing the islands. The existence of breeding golden eagles on the islands at present may therefore be partially due to the absence of bald eagles.

In 2002, with funding from the Montrose Trustees Restoration Program, the park (in conjunction with partner, Institute for Wildlife Studies) began to introduce juvenile bald eagles to the northern Channel Islands. This was done using a technique called "hacking". Birds of approximately 8 weeks of age were kept in one of two hack towers on Santa Cruz Island until they were ready to fly (at approximately 3 months of age). Sixty-one young bald eagles were introduced to the northern Channel Island between 2002 and 2006.

2006 marked the first successful bald eagle nest on the Channel Islands in over 50 years. In fact, there were two successful nests; both on Santa Cruz Island. One of the nests has a "web cam" and can be watched live during the nesting season.

Bald eagles were an important part of the island ecosystems. It is still unknown whether pollutant levels at the northern Channel Islands are sufficiently low to allow the eagles to consistently produce strong eggs and naturally hatch their young.

Terrestrial Animals

The number of different animal species found on the Channel Islands, defined as species diversity, is small compared to what would likely be found on a mainland area of similar size. The level of species diversity on islands reflects the challenges to a species of first arriving and then of adapting to unique island conditions. Consequently the ecology of islands is often simpler, but the relationships between species more important and the persisting plants and animals often more unique, than what might be found in mainland habitats. For example the islands within Channel Islands National Park support only four native mammals, the island fox, the island deer mouse, the harvest mouse and the spotted skunk. The fox and the deer mouse have evolved into separate sub-species on each island, resulting in eight unique mammal species found only on the Channel Islands.

The number of reptile and amphibian species (herptiles) is likewise low, and includes four lizards, one salamander, one frog, and two non-venomous snakes. None of these species is found on all of the islands, and no island supports all the species. For example the island night lizard, a threatened species found nowhere else in the world, occurs on only three islands, one within the park and two owned by the U.S. Navy outside park boundaries.

Because it is easier for birds to reach islands than it is for animals that can't fly, bird species diversity on islands is often relatively high. Although the high number is due to migrants, infrequent visitors, and rare species that have arrived on the islands only after being blown off course during spring and summer migrations. Like the island fox, two bird species, the Santa Cruz Island scrub jay and the San Miguel Island song sparrow, have evolved into unique (endemic) island species. The largest landbird native to the islands is the bald eagle -- a species that has recently been reintroduced to the islands.

Bats, though infrequently seen by most visitors, are common on Santa Cruz and Santa Rosa islands. Bats fulfill an important role, or niche, by consuming large numbers of insects and pollinating some plants. Eleven species of bats have been found on Santa Cruz, and the island is home to an important maternity colony of rare Townsend's long-eared bats.

Current research focusing on terrestrial animals includes several studies on the island fox, one on the role of deer mice in affecting vegetation community recovery, and one on the response of lizards to the removal of rats on Anacapa. Ongoing monitoring efforts are measuring changes in amphibian and reptile population biology in response to pig removal on Santa Cruz Island, the number of bats occupying important maternity colonies on Santa Cruz, and mouse population dynamics as they relate to changes in fox numbers on San Miguel Island.

Each island has a unique complement of animals, dependant in many ways on the size of the island. Over time some of these species have evolved into new species, and are present today, while others, like the pygmy mammoth, the Santa Barbara Island song sparrow, and the giant deer mouse, evolved into unique island species before becoming extinct. While it may not appear so to relatively short-lived humans, the islands are still changing and evolving, and what lives here in the future may be very different than what we see today.

Island Fox

The island fox (Urocyon littoralis) is the largest of the Channel Islands' native mammals. A descendent of the mainland gray fox, the island fox evolved into a unique species over 10,000 years ago. The island fox has similar markings to its ancestor, but is one-third smaller.

Environmental and ecological factors such as drought or food scarcity may have contributed to the natural selection for a smaller size. At 12 to 13 inches in height and 4 to 5 pounds, the island fox is about the size of a housecat. Island foxes have gray coloring on the back, rust coloring on the sides, and white underneath. The face has a distinctive black, white, and rufous-colored patterns.

Scientific Classification & Taxonomy:

The scientific name of the Island fox is Urocyon littoralis. It shares the genus with its mainland ancestor the gray fox, Urocyon cineroargenteus. Littoralis translates from Latin as "situated or growing on or near a shore especially of the sea." Island foxes are distributed as six different subspecies, one on each of the six Channel Islands on which they occur. Foxes from separate islands are still capable of interbreeding, but are physically and genetically distinct enough to be recognized as separate subspecies. For example, the average number of caudal (tail) vertebrae differs significantly from island to island. Subspecies are named for their island of origin.

Island Fox Subspecies:

Urocyon littoralis littoralis San Miguel Island Fox U. littoralis santarosae Santa Rosa Island Fox U. littoralis santacruzae Santa Cruz Island Fox U. littoralis dickeyi San Nicolas Island Fox U. littoralis catalinae Santa Catalina Island Fox U. littoralis clementae San Clemente Island Fox

Taxonomy is the orderly classification of living things in terms of their relationships with one another. Here is how the island fox relates to other animals.

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Carnivora

Family: Canidae

Genus: Urocyon

Species: Urocyon littoralis

Island Fox Fossil Record:

The fossil record shows evidence of foxes on Santa Rosa Island dating back 10,400 to 16,000 years ago. How did the gray fox get across the water barrier of Santa Barbara Channel? The most plausible and accepted theory is one of "rafting." During the last Ice Age, as the ocean levels lowered and the distance between the mainland and the islands shrunk, the northern islands became one large island called "Santarosae." The gray fox could have rafted on debris propelled by storms and/or currents. As the climate warmed and the ocean levels began to rise, Santarosae became the islands of Anacapa, Santa Cruz, Santa Rosa, and San Miguel. Due to the lack of a fresh water source, the foxes did not persist on Anacapa, but the other three islands had suitable habitat for foxes.

Island foxes were probably brought to the southern Channel Islands of Santa Catalina, San Nicolas, and San Clemente by the Chumash native people who traded with the Gabrielino people of the southern islands. The Chumash considered the fox to be a sacred animal--a pet of the sun, and possibly a dream helper. The island Chumash performed a fox dance and probably used the pelts of foxes to make articles like arrow quivers, capes, and headdresses.

Island Fox Habits and Behavior:

Island foxes communicate with one another through sight, sound, and smell. Visually, island foxes show signs of dominance or submission through facial expressions and body posture. They communicate auditorily by barking and sometimes growling. Their keen sense of smell plays an important role in the marking of territories. Island foxes are known to scent-mark their territories with a few drops of urine and tend to concentrate scats in particular areas, often conspicuously positioned on well-traveled paths. Island fox tracks are similar to those of the gray fox only smaller.

Compared with the gray fox, island foxes are relatively diurnal (active during daylight hours) with peaks in activity occurring at dusk and dawn. Island fox diets consist primarily of fruits from plants like the sea fig, insects like the Jeruasalem cricket, and one of the few small mammals found on the islands, the deer mouse. Occasionally, foxes forage along the shoreline for crabs and other marine invertebrates.

Island Fox Reproduction:

Island foxes are generally monogamous (mate for life), and breed only once a year. Pairs are seen together frequently beginning in January, and mating takes place in late February to early March. The gestation period is thought to be similar to the gray fox, which is around 52 days, and pups are born from late April through early May. Litter size ranges from one to as many as five pups, but two or three is considered average. Born in the protection of a den, pups are blind and helpless with short dark brown hair at birth. They emerge from the den at about one month of age, much furrier but still considerably darker than adults. They begin to resemble their parents by late summer.

It is believed that island fox pups undergo a period of extended parental care. In a recent study of island foxes, scientists found adults and pups in the same trap on 22 occasions. In 24 traps containing only pups, they found killed mice and other prey items outside the traps, apparently left by the parents for their young. As with most wild canids, males play an important role in the rearing of young.

Island Spotted Skunk

Common Name:

Island Spotted Skunk

Scientific Name:

Spilogale gracilis amphiala

Habitat:

Hills and steep canyons covered by grasses, chaparral, coastal sage, and scrub oak throughout Santa Rosa and Santa Cruz Islands.

Natural History:

The recent decline of the endemic island fox (Urocyon littoralis) on the northern Channel Islands prompted investigation on the status of the island spotted skunk on Santa Rosa Island. Little is known about the island spotted skunk on Santa Cruz Island, and no data have been collected on the status of the Santa Rosa Island population.

Townsend's Big-eared Bat

Common Name:

Townsend's Big-eared Bats

Scientific Name:

Corynorhinus townsendii

Conservation Status:

Townsend's big-eared bats are listed as an Endangered species in Washington, a Sensitive species in Oregon, a Species of Special Concern in Texas, Montana and California, and are on the Blue List in British Columbia.

Habitat:

They prefer open roosting areas in large rooms and do not tuck themselves into cracks and crevices like many bat species do.

Additional Information:

Natural History:

Townsend's big-eared bats are medium-sized, light brown bats with very large ears. They specialize in eating moths and other insects. They occur throughout the Western U.S. and use a variety of habitats, almost always near caves or cave-like roosting areas. They prefer open roosting areas in large rooms and do not tuck themselves into cracks and crevices like many bat species do. Their preference for open spaces in caves makes them easy to detect and vulnerable to vandalism.

Summer maternity colonies range in size from a few dozen to hundreds of individuals. These colonies form between March and June (depending on climate), with pups born between May and July. Maternity colonies choose sites that have warm, stable temperatures for pup rearing. Males remain solitary during the maternity season. Winter hibernation colonies are comprised of males and females and range in size from a few individuals to several hundred bats. Townsend's big-eared bats are very sedentary, with movement by females during the nursing season rarely exceeding 15 km., and movement at other times usually being less than 50 km. If undisturbed, colonies will occupy the same site indefinitely.

 

Status:

Townsends big-eared bats occur throughout the Western U.S from Texas to British Columbia, from sea-level to over 10,000 feet. Distribution is strongly correlated with the availability of caves and cave-like roosting habitat, with population centers occurring in areas dominated by exposed, cavity forming rock and/or historic mining districts. They are generally in decline in most areas, and are listed as an Endangered species in Washington, a Sensitive species in Oregon, a Species of Special Concern in Texas, Montana and California, are on the Blue List in British Columbia ('rare or uncommon, and may be susceptible to large-scale disturbances'). They are considered Sensitive by the U.S. Forest Service.

A study sponsored by the California Department of Fish and Game in the late 1980's documented a population decline of between 40 and 60% in the past 30 years. Only about half of the maternity colonies known to exist in California prior to 1980 were relocated by 1991, resulting in an estimated 54% decline of adult females. Only three maternity colonies increased in size during the period, and all three are located in National Park areas (Point Reyes National Park, Lava Beds National Monument, and Pinnacles National Monument). Of the 23 roosts that are no longer available to bats, 9 (mostly buildings) have been demolished, 4 (all buildings) have burned, 4 (all buildings) have been renovated in such a way that bats were excluded, and 6 (including buildings, caves, mines, and a water diversion tunnel) have had the entrance closed.

Threats:

The primary threat to C. townsendii is almost certainly disturbance or destruction of roost sites (e.g., recreational caving, mine reclamation, renewed mining in historic districts). Surveys conducted in Oregon and California indicate that historic roost sites have been negatively impacted in recent years with most reported colonies exhibiting moderate to sizable reduction in numbers. Additional surveys in Utah indicate that several historic maternity sites have been abandoned, although it is not known if these colonies have relocated.

This species is very sensitive to disturbance events and has been documented to abandon roost sites after human visitation. In California and at a number of sites in the east, depressed populations have recovered with the protection (i.e., gating) of roosts. In large portions of its western range, dependence upon abandoned mines puts this species at risk if mine reclamation and renewed mining projects do not mitigate for roost loss, or do not conduct adequate biological surveys prior to mine closure. Both roosting and foraging habitat my be impacted by timber harvest practices. Pesticide spraying in forested and agricultural areas may affect the prey base.

Townsend's big-eared bats on Santa Cruz Island :

Townsend's big-eared bats were first observed on Santa Cruz Island in the historic 2-story ranch house at Prisoner's Harbor in 1939. At that time the maternity roost was estimated to contain "well over 300" individuals. During the mid-1960's UCSB researchers found the colony still active at Prisoners, but this building was removed around that time. Despite extensive searching from 1974 to 1988, no other big-eared bats were seen on Santa Cruz.

In 1991 Dr. Pat Brown of UCLA was made aware of a colony of Townsend's roosting in the bakery room of the Scorpion adobe building. This room was closed until 1984, so it is unknown whether or not there was a maternity colony on the island between the period when the Prisoners' building was lost and the Scorpion bakery room was opened. Dr. Brown believes that prior to building construction, natural caves and rock formations served as roost sites.

Dr. Brown's research in the early 1990's included radio-tracking of bats mist-netted at the Scorpion colony in the late summer of 1992. (Bats were netted at the end of the maternity season when young bats were old enough to fly on their own.) Radio-tracking showed that the Scorpion bats foraged up to 5 kilometers away to feed on moths and other insects among the native oak and ironwood forest on the north-facing slopes of Scorpion Canyon, returning to the roost each morning. She found that the bats used shallow rock caves as night roosts but rarely as day roosts, and no reproduction was noted from these cave areas.

Bi-annual emergence counts (May and August) and visual surveys of the bakery colony conducted since 2002 indicate that a large maternity colony continues to use the building between April, when the room is made available, and at least early September. According to the 1994 Department of Fish and Game report, the Scorpion roost is one of only two or three coastal maternity colonies known to exist south of Pt.

Island Night Lizard

Common Name:

Island Night Lizard

Scientific Name:

Xantusia riversiana

Conservation Status:

Listed as threatened in 1977, the night lizard population has rebounded since then.

Habitat:

The island night lizard prefers boxthorn, prickly pear cactus, and cracks and crevices in and around rock outcrops and surface boulders.

Additional Information:

Island night lizards (Xantusia riversiana) are an endemic Channel Islands reptile, known only to occur on Santa Barbara Island in the park and on San Nicolas and San Clemente Islands. They are the most morphologically distinct of the endemic vertebrates on the Channel Islands, indicating they have been isolated from the mainland for a long time. The best habitats for the lizards are boxthorn (Lycium californicum), prickly pear cactus (Opuntia oricola and O. littoralis), and cracks and crevices in and around rock outcrops and surface boulders. These areas provide protection from predators. They are also often found under rocks, driftwood, and fallen branches. Suitable habitat on Santa Barbara is in all of the canyons and on some of the sea cliffs, especially on the south side of Signal Peak. Island night lizards are very sedentary and have very small home ranges, averaging about 183 square feet (17 square meters). They are most active at midday. The lizards breed in April, with young being born in September.

Fellers and Drost found densities of 1,300 lizards per acre in boxthorn and 1,000 lizards per acre in prickly pear. This high density is probably due to a combination of factors, including the lizard's low metabolism, diverse diet, sedentary nature, and small, overlapping home ranges.

 

Although abundant in their favored habitats, island night lizards are still sensitive to disturbance. Individual lizards can be trampled and habitat damaged by people walking off trail.

 

On August 11, 1977, the U.S. Fish and Wildlife Service listed the island night lizard as a threatened species because of its restricted range and apparently low population levels on Santa Barbara and San Nicolas islands. Their populations were thought to have been reduced due to past farming and grazing, fire, and the introduction of nonnative animals and plants. However, Feller and Drost estimated that the total population on Santa Barbara was at least 17,600, and concluded that the population was not threatened with extinction as was previously thought.

PLANTS

Channel Islands National Park supports a diverse terrestrial flora, including many rare, relict, and endemic species, as well as many nonnative species. Numerous plants are rare on the islands but have a wider distribution on the mainland. On the other hand, due to environmental conditions and isolation from the mainland, many of the plants that are native on the California mainland do not grow here. A total of about 790 plant taxa, including species, subspecies, varieties, and forms, have been identified in the park, of which about 578 are native and 205 are nonnative.

Each island supports a unique assemblage of vegetative communities, which differ due to climate, microhabitats, topography, geology, soils, plant colonization history, isolation, and land use history. Many of the islands' native vegetative communities have been greatly altered by people and the introduction of nonnative species and are in various stages of recovery. The major vegetative community types on the islands include coastal dune, coastal bluff, coastal sage scrub, grasslands, chaparral, island oak woodlands, mixed hardwood woodlands, pine stands, and riparian areas. Currently, the most extensive vegetation communities on the islands are grassland and coastal sage scrub with significant areas of chaparral on Santa Cruz Island, and to a lesser degree, on Santa Rosa Island. Various phases of coastal bluff scrub constitute the next largest category. Mixed broadleaf woodland stands, oak woodlands, and pine stands are scattered throughout on sheltered slopes and canyons, or on ridges exposed to frequent moist fogs. Smaller but no less significant vegetation communities include coastal dune, baccharis scrub, caliche scrub, and wetlands.

Scientific Name

Common Name

Plant Family

Federal Status

Arabis hoffmannii

Hoffmann's rockcress

Brassicaceae

(Mustard Family)

Endangered

Arctostaphylos confertiflora

Santa Rosa Island manzanita

Ericaceae

(Heather Family)

Endangered

Berberis pinnata ssp. insularis

Island barberry

Berberidaceae

(Barberry Family)

Endangered

Castilleja mollis

Soft-leaved paintbrush

Scrophulariaceae (Figwort Family)

Endangered

Dudleya nesiotica

Santa Cruz Island live-forever

Crassulaceae

(Stonecrop Family)

Threatened

Dudleya traskiae

Trask's live-forever

Crassulaceae

(Stonecrop Family)

Endangered

Galium buxifolium

Sea-cliff bedstraw

Rubiaceae

(Madder Family)

Endangered

Gilia tenuiflora ssp. hoffmannii

Hoffmann's slender-flowered gilia

Polemoniaceae

(Phlox Family)

Endangered

Helianthemum greenei

Island rushrose

Cistaceae

(Rockrose Family)

Threatened

Malacothamnus fasciculatus var. nesioticus

Santa Cruz Island bush mallow

Malvaceae

(Mallow Family)

Endangered

Malacothrix indecora

Santa Cruz Island chicory

Asteraceae

(Sunflower Family)

Endangered

Malacothrix squalida

Island malacothrix

Asteraceae

(Sunflower Family)

Endangered

Phacelia insularis var. insularis

Northern island phacelia

Hydrophyllaceae (Waterleaf Family)

Endangered

Thysanocarpus conchuliferus

Santa Cruz Island lace pod

Brassicaceae

(Mustard Family)

Endangered

Terrestrial Invasive Plants

Plants and animals living on islands are especially vulnerable to extinction due to the physical boundaries, limited populations, and lack of genetic variability. One threat to these island species are invasive weeds. The term "invasive weed" is generally used to describe non-native plants that are unwanted and grow or spread aggressively. Invasive weeds can take over important wildlife habitat, devastating shelter and forage while reducing the diversity and quality of native habitat. Weeds often do not hold and protect the soil the way native plants do, so erosion increases and causes sedimentation of streams, harming fish populations and water quality. The primary visitor landing points on the park islands are often where we first find non-native plants. Nearly half of the endangered plants and animals in the United States have been negatively affected by invasive species. Invasive species cause an estimated $138 billion in economic damage each year in the United States.

Channel Islands National Park is vulnerable to colonization and recolonization by non-native plants because of human transport to the islands and natural processes such as wind and sea currents. As a result, more than 25 percent of the plants known from the park are introduced. As the number and variety of non-native plants increase on the nearby mainland and as the park visitation and operations increase, the chance of accidental introductions of plants also increases.  Recently arrived non-native plants are easy to eliminate if detected and acted upon promptly. The cost and feasibility of control increases exponentially each year a non-native species is left to spread uncontrolled.

Management

Channel Islands National Park staff work in cooperation with private contractors, interns, and a large variety of volunteer groups to control or eliminate invasive plant species from the park. Many non-native plants have been removed from the park islands, and park personnel have planted native species in their place. On Santa Cruz Island, culturally significant groves of olive and eucalyptus trees have been preserved for historical reasons. Currently on Santa Rosa Island, a large section of island oak woodland is being restored though regeneration of eroded soil and restoration of understory native plant species. On Santa Cruz Island a project to eradicate newly introduced invasive species has begun.

Weeds

The environmental and management impacts of non-native plants can range from negligible to very serious based on a number of factors. The list below reflects a combination of criteria including; 1) invasive plants that currently have a major impact on the ecology, and 2) invasive plants that have the greatest potential to have a future impact if not controlled.

Sweet fennel

Scientific Name: 

Foeniculum vulgare

Origin:

Mediterranean region

Fennel was introduced to park islands in the late 1800's and was first spread by animals along roadsides. It invades areas where the soil has been disturbed, and prevents native species from becoming reestablished in these areas. It outcompetes native plants for water, light, nutrients and possibly through chemical toxicity. Fennel currently grows on San Miguel, Santa Rosa and Santa Cruz Islands.

Blue gum and red gum

Scientific Name: 

Eucalyptus globulus and Eucalyptus camaldulensis respectively

Origin: 

Australia

Eucalyptus was introduced to the park islands as early as the 1880s for lumber production, wind breaks, fuel, and for ornamental reasons. Some of these species have become invasive on Santa Cruz Island, and continue to expand their ranges and numbers rapidly. Eucalyptus trees compete strongly with native plants for limited water and soil nutrient resources. They prevent native seedlings from becoming established by shading the soil surface, accumulating deep litter layers, and though chemical toxicity. They are extremely flammable and greatly increase the probability, magnitude and intensity of fires. Red gum currently grows on Santa Rosa and Santa Cruz Islands. Blue gum currently grows on Santa Rosa, Santa Cruz and Anacapa Islands. Blue gum once briefly grew on Santa Barbara Island as well.

Yellow Star-thistle

Scientific Name: 

Centaurea solstitialis

Origin: 

Europe

Yellow star thistle was first discovered on Santa Cruz Island in 1930. It can form dense, impenetrable stands that threaten natural ecosystems by displacing populations of native plants and animals. The large spines of yellow star-thistle can cause discomfort to visitors, and it is of great concern to land managers because it lowers property values and is toxic to horses. Because it seeds very prolifically and easily sticks to people and equipment, it is difficult to control and spreads quickly. It currently grows Santa Cruz Islands but was briefly found on Santa Rosa Islands as well.

Olive

Scientific Name: 

Olea europaea

Origin: 

Europe

Olive trees were was first planted on eastern Santa Cruz Island around 1900 and since then it has spread dramatically. It alters native plant communities and displaces native species by competing for light availability. On Santa Cruz Island, olive is spread by feral pigs and by birds. Birds also may have been the cause of an olive seedling recently found and removed on Santa Rosa Island. Although it once grew briefly on Santa Barbara Island, Santa Cruz Island remains the main host for this problem weed. 

Harding grass

Scientific Name: 

Phalaris aquatica

Origin: Europe

Harding grass was first introduced to Santa Cruz Island in 1982, where it has spread rapidly. It easily displaces and outcompetes native species and large, dry stands present a fire hazard. It currently grows on Santa Cruz and Anacapa Islands.

Stone Pine

Scientific Name:

 Pinus pinea

Origin: 

Mediterranean Europe

Italian stone pine was introduced to Santa Cruz Island prior to the early 1930s. Before control efforts were started, birds had spread it into pristine stands of island chaparral and other plant communities. Stone pines produce a large amount of seed and can quickly spread and dominate native plant communities. It currently grows only on Santa Cruz Island.