Invasion at the Andree Clark Bird Refuge!!

Invasion at the Andree Clark Bird Refuge!!

by Ria Boner, Santa Barbara Zoo

They come in various colors, but typically shades of green. Some can regenerate from their own fragments! Some are capable of producing toxic chemical compounds! Some can grow 9-30ft tall! But ALL of them are invading and wreaking havoc on the locals – right in our own city! But no, we’re not talking about extraterrestrial aliens – these are invasive plant species at the Andree Clark Bird Refuge.

Certain plants thrive when moved out of their native habitat and away from their usual predators. Without any natural processes to keep these species at bay they grow out of control, overwhelming local vegetation and the wildlife that feed on it. Invasive plant species can dramatically alter an ecosystem, changing things such as hydrology, soil chemistry, and overtaking the species diversity of an area. For example, cape ivy (Delairea odorata) grows in such abundance that it can block the sunlight to other vegetation and seedlings, vastly reducing species diversity and replacing it with a plant that, due to its toxic nature, is unsuitable for most animals to eat. It can grow so densely that its weight can cause some trees to fall! While these invaders might not take over the entire planet like a UFO Sci-Fi movie, they can take over important habitats and ecosystems. 

One of these ecosystems being invaded is the Andree Clark Bird Refuge. Established as a bird refuge back in the 1920s, this natural area provides habitat for 228 bird species, including 43 species that breed at the site and five federally listed endangered species. Certain birds rely on the cottony seeds of the native willow (Salix exigua) to build their nests, others on the sweet nectar of the local hummingbird sage (Salvia spathecea), and many benefit from the nutritious rose hips of the California rose (Rosa californica). But if you were to take a Santa Barbara Zoo train ride along the refuge’s edge back before 2010, you would find it quite a challenge to spot these plants or the wildlife that rely on them. Over 100 Myoporum lateum trees, large stands of giant reed (Arundo donax), the sprawling cape ivy, and other various invasive species had taken their place. The thriving fauna once found in this area was struggling to keep up.

Left: invasive Myoporum trees and cape ivy before removal at the Santa Barbara Zoo.  Right: the same view after removal.

But as in any classic alien invasion story, there is a hero. Together Channel Islands Restoration, The City of Santa Barbara, and the Santa Barbara Zoo have helped restore the refuge area for half an acre along the train tracks. After the removal of the larger trees and giant reed stands, groups of volunteers armed with gloves and hand tools were enlisted to help keep the invaders at bay. Furthermore, the volunteers helped plant 635 native species that were specially propagated from seeds and cuttings of the remaining natives found at the site. By continually managing the site, our team is able to pull any freshly sprouted invasive species and cultivate the native plants to give them a better chance at resistance in the future. 

Left: invasive Myoporum trees.  Right: the same view after removal by Channel Islands Restoration.

The battle was hard fought, with over 340 volunteers and staff joining the cause in the past two years. But it was well worth the effort. Last week during another volunteer event, a California towhee was seen fluttering about, foraging among the plants. A red-winged blackbird was seen perched on a willow branch. While there is still work to be done and invasive species to combat, the restoration effort over the past two years is making a difference for the wildlife found on the refuge.

Volunteers learn about invasive plants from Channel Islands Restoration staff at the Santa Barbara Zoo

CIR Removes Invasive Sahara Mustard on San Nicolas Island

San Nicolas Island, as seen from the air by Channel Islands Restoration volunteers recently

Channel Islands Restoration staff and a group of volunteers spent five days on San Nicolas Island beginning last week removing Sahara mustard (Brassica tournefortii) in sensitive Coreopsis scrub habitat.  This is the second trip for CIR this year to work on this project, and the third year in a row that CIR has worked on this project.  The Mustard is a highly invasive, non-native plant that has caused a great deal of destruction to native habitat in the deserts and other environments in California and elsewhere.  The Navy is working to keep the mustard from spreading on San Nicolas, and CIR has been removing it where it grows around some rare plants.  San Nicolas Island is owned by the U.S. Navy, and Channel Islands Restoration is under contract to do habitat restoration on the island.

San Nicolas Island fox

Endemic foxes live on six of the eight California Channel Islands, and there is a healthy population on San Nicolas Island.  Channel Islands Restoration staff and volunteers always see foxes when we visit the island to work, and this last trip was not exceptions!

Island Night Lizard

This Island Night Lizard was seen by Channel Islands Restoration volunteers on our resent trip to San Nicolas Island.  Island Night Lizards are found only on San Nicolas, Santa Barbara, and San Clemente Islands. They have large populations on San Clemente and San Nicolas Islands, and they are still federally listed as an endangered species.

Northern elephant seal

This northern elephant seal (and many more) were seen by Channel Islands Restoration volunteers on our resent trip to San Nicolas Island.  Elephant seals breed on the island.  Elephant seals breed on the island.

Channel Islands Restoration volunteers removing Sahara mustard on San Nicolas

Channel Islands Restoration volunteers removing Sahara mustard on San Nicolas

The photos above show Channel Islands Restoration volunteers hand-removing Sahara mustard on San Nicolas Island on our recent trip there.  Giant Coreopsis (Leptosyne gigantea) is the large, green plants with the yellow blooms.  It grows in huge stands on San Nicolas Island and is the dominant plant in a community of plants called Coreopsis scrub.  Cryptantha traskiae (a rare plant found only on San Nicolas and San Clemente islands) grows in the same habitat and is threatened by the spread of Sahara mustard.  CIR volunteers have to be carefully tried to work in this sensitive environment and around rare plants.

Giant Coreopsis in bloom on San Nicolas Island.  Late February is the peak booming season for this plant on San Nicolas Island.

Sand dune on San Nicolas Island (with giant Coreopsis in the foreground).

The bloom of Giant Coreopsis.  Giant Coreopsis is in the sunflower family.

Channel Islands Restoration volunteers pose at Coral Harbor on San Nicolas Island.