August 9, 2012
The Recovery of the Catalina Island fox
By: Roxi Aslan
A great success in efforts to maintain biological diversity has occurred on Santa Catalina Island. After having come close to extinction with a population of just one hundred in 1999, the Catalina Island fox has made a recovery. With the help of a program that cost $2-million, the Institute for Wildlife Studies and the Santa Catalina Island Conservancy were able to respond to the 1998 outbreak of distemper disease that was devastating the population by vaccinating the foxes, breeding them in captivity, and injecting microchips to monitor their behavior. As the population is stabilizing, the U.S. Fish and Wildlife service will continue to review the status of the Catalina Island fox for five more years before removing it from the endangered species list.
While the recovery of the fox is cause for celebration, the near extinction of the species cannot be taken lightly and will serve as an important case study of the fragility of island ecosystems. Scientists believe that the foxes were exposed to the disease that killed so many of them by either a raccoon or pet dog that had come on a boat from the mainland. Because the foxes are geographically isolated, they lacked the immunity necessary to fight off such a disease and were therefore especially vulnerable. Although the introduction of the disease was most likely accidental, it is a great example of the unintended consequences that come with the settlement and activities of humans on native lands. By introducing mammals such as goats, sheep, pigs, feral cats, and the American bison; the native Catalina Island foxes now face degradation of their habitat as well as diminished food supply. In addition, automobile accidents have caused many fox fatalities.
Another more indirect way that human activities have altered this island’s ecosystem is through the pollution of DDT in the 1950s. The bald eagle went into decline after being exposed to DDT and this gave the golden eagle an opportunity to inhabit the island free from competition. The golden eagle, which we had the chance of visiting today during our tour of the island, has now become a large predator of the Catalina Island fox. While there were efforts to eliminate some of the introduced species on the island such as the feral pig, it turned out that the pig was one of the golden eagle’s main source of food and without them the eagles began to prey on the foxes. Now another proposal is the removal of golden eagles.
It is not difficult to see that once the disturbance of an ecosystem has gone into effect, it is not easy to solve such a problem. A lot of effort, time and money has went into the recovery of the island fox population and it remains an ongoing battle. The foxes will have to continue to be monitored for many more years to come, but hopefully this case will cause awareness of the consequences of certain human activities and the need to take a preventative approach to solving such problems.
About the author: Roxi Aslan forgot to submit her author bio….
Wildflowers or weeds: the answer is all in your shoes
By Connie Ge
“Wildflowers and weeds are the same thing; it’s a matter of perception in our mind” said Kate Cruikshank, a former associate professor of education at Indiana University, in regards to the increased use of pesticides on “weeds” from ancient times to the development of chemical warfare since World War II.
“We have to start back 200 million years ago, when there was no barrier to movement of animals and plants. (Weeds) first became a problem when we evolved from a hunter/gatherer lifestyle towards industrial forms of agriculture,” she said. “We stopped coexisting with weeds. Fifteenth and 16th century European exploration mixed plants and animals, spreading them ahead of immigration.”
One thought that has crossed my mind since starting ENST courses is the subjectivity of how knowledge is accumulated and passed on from generation to generation. The Catalina Island Conservancy, founded in 1972 attempts to monitor and curb the growth of invasive species introduced when Europeans and their descendants invaded the formerly native Pimungan-occupied island. These invasive species include fennel, which obstructs hawks and eagles from seeing smaller birds, as well as rats, mule deer, bison, bullfrog, and the feral cat. To me the story of human invasion, or migration on Catalina is enough to question present human-plant and human-animal relations.
“Pimu” is the last known name which Tongva, Pimungans, or Pimuvit people called the island upon European arrival in the 1500’s[1]. Various groups of Native American people before the Pimuvit are thought to have inhibited the island over the course of hundreds of years, at least 7,000 years ago. Still in search of Asia 50 years after Columbus’ arrival in the Bahamas, the Viceroy of New Spain (Mexico) sponsored an expedition up the coast of California.
“Santa Catalina” was the second name the island was dubbed by a Spanish explorer. The Pimuvit are said to have been dismayed when Spanish sailors shot ravens, which held a place in native folklore. They were hit hard by microbes brought by the Spanish and those that survived and abandoned the island in the early 1800’s were known in southern California as Gabrielinos. Today there are people descended from Gabrielinos.
Some animals that lived alongside the Pumuvit may have included the small endemic fox, quail, bald eagles, and raven, which were said to be a part of native folklore[2]. There are 76 invasive plants identified by the Conservancy that, “left unmanaged, these invaders would overtake native habitats, potentially dooming some to extinction.” While non-native plants compete for resources with native plants, what makes humans today think they have control over an ecosystem?
These questions pressed me while the class and I sweated hacking away at the roots of fennel, which were well suited for the dry, rocky soil of the desert island. Fennel is abundant not but twenty miles away on the coast of southern California – that it arrived and thrived should be an indicator of the limitations and transience of efforts by one species to alter the entire balance of an ecosystem.
Are (essentially “invasive” species ourselves) humans inserting themselves into a foreign ecosystem and assigning themselves the role of keystone species through science? If a weed is an organism that proliferates rapidly, homo sapiens is a weed in the world – why don’t we focus on controlling our own population? I’m supportive of natural research, but pondering the practicality of long-term conservation and value of accepting change as it naturally comes, due to its inevitability, just like an ocean wave.
Institutionalized science is shaped by cultural conjecture. Wildflowers or weeds? Pimu, Santa Catalina, or Catalina? The answer depends on whom you are talking to. Fennel is frivolous to homo sapiens, but food for mule deer. So the answer is all in your shoes. Or watch – either way, keep looking.
Sources:
1. Catalina Island History.” Catalina Island Chamber of Commerce & Visitor’s Bureau. http://www.catalinachamber.
2. “Professor pleads for weeds: Address urges appreciation of simpler ways of life.” David A. Nosko. September 27, 2004. Indiana Daily Student.
3. Catalina Island Conservancy website
About the author: Connie Ge is a sophomore at the University of Southern California from Boulder, Colorado. She is working to complete a Bachelor of Science in Earth Sciences.
February 14, 2012
California Coastal Sage Habitat: On the Brink of Extinction
Many residents of Southern California are unaware of the growing threat to the California coastal sage habitat. This widespread ecosystem ranges from central to southern California. The habitat is known for its high species and soil biodiversity as it houses a wide range of organisms and diverse soil levels. This region is threatened by human and agriculture expansion and consists of diverse habitats that range from forests to woodlands to grasslands and salt marshes. Because of this variety of habitats, the soils in these regions have to be able to support the growing habitats and ensure their survival.
The eco-region of the coastal sage habitat is home to about 200 species of butterflies, the widest range of native bees in the United States, and a wide variety of other organisms that rely on this region for their home. The California legless lizard and the rosy boa are just some of the reptiles and amphibians that belong to this certain Southern California region. The Channel Islands also take part in this eco-region, but because they are isolated, they house certain rare plant and animal species that are only native to that island.
Because of anthropogenic development, native habitats in this region are threatened. Human air pollution, specifically smog, reduces production and growth in the environment. When humans introduce outside species, such as sheep, cattle, and deer, their grazing and physical presence on the land reduces the productivity and fertility of the land. Agricultural practices do not allow for healthy regrowth of the soil and plants. Only about 15% of the coastal sage habitat is intact because of the growing expansion of agricultural lands and housing. Human invasion of this land has altered the physical makeup of the region enough to affect the organisms that live on and in the soils. Invasive plants, brought in by humans, displace native species, which change the flora and fauna of the specific eco-region.
Since humans have started to develop the land, the larger habitats are divided into smaller regions. These small habitats are more vulnerable to outside threats of animal and human predators. Humans use processes such as grazing, herbicides and burning to convert the land to their specifications. However these methods alter the soil composition, which affects the organisms that live in the soil and the organisms that rely on the soil. These unfamiliar conditions destroy the native seed beds and organisms within the soil, which negatively impacts soil productivity. Unhealthy soil leads to overall ecosystem degradation.
Because of these huge environmental impacts and risks, conservation ecology is crucial to preserve this eco-region from becoming extinct. Not only are the organisms threatened, but the diversity of the soil relies on the preservation of this coastal sage habitat. Many humans are only concerned with development and expansion, but for human society to thrive, the environment surrounding humans needs to thrive as well. With population increasing, we can’t ignore human needs, however there has to be a balance between human and environmental needs. Destroying this coastal sage habitat threatens the ecosystem services that communities depend on, such as water, oxygen from the wide range of trees, food, and other vital resources. There needs to be a bigger focus on soil preservation and protection of organisms in this region because many of them are so rare and specific to this coastal sage region. Without this eco-region, a whole group of organisms would become extinct. We might not even know the benefits of all of these organisms, and to destroy them in order to expand our agricultural land, would be a huge loss to this treasured habitat in Southern California.
Links:
http://www.eoearth.org/article/California_coastal_sage_and_chaparral
http://www.laspilitas.com/nature-of-california/communities/coastal-sage-scrub
http://audubon2.org/watchlist/viewSpecies.jsp?id=57
http://www.ncbi.nlm.nih.gov/pubmed/10801992
http://www.treesearch.fs.fed.us/pubs/27020
http://www.jstor.org/pss/3235887
Chantal Morgan and Alanna Waldman are undergraduates in the USC Dornsife College of Letters, Arts and Sciences.