Santa Cruz Island Reserve

12 Apr, 03 AM - 17 Apr, 05 AM

Research Objectives and Questions A recent survey published in the journal Nature reveled that the number of parasite species found in native populations are twice as great as those found in exotic populations, and that introduced species are often less parasitized than natives (Torchin et al 2003). It is important to test the generality of this claim because it suggests that species released from the pathogens that keep them at bay in their native range are more likely to have negative impacts on species in their naturalized ranges. My research objectives are twofold: 1) to test this theory by comparing the composition and diversity of black rat parasites in native California mainland populations to exotic Channel Island populations, and 2) to assess the spread of black rat parasites to native deer mice and harvest mice. Specifically, I will address the following six questions: 1. Do black rats harbor the same parasite composition and diversity in their exotic range on the Channel Islands as they do in their native range on the California mainland? 2. Do deer mice and harvest mice, that are native to both the Channel Islands and the mainland, harbor the same parasite composition and diversity in both regions? If not, what does this suggest about the effects of insularity on parasite distributions? 3. Do deer mice and harvest mice harbor the same parasite composition and diversity between islands? How does parasite diversity vary with island size and host biodiversity, and what can this tell us about the mechanisms that regulate parasite distributions? 4. Based on island comparisons, can we infer which parasites were lost and which remained in native rodent populations after black rat eradication on Anacapa Island? 5. Based on island comparisons, can we infer which parasites were passed from black rats to native rodents? 6. Of the parasites potentially passed from black rats to native rodents, which species have the potential to cause harmful effects? Methodology During the spring and summer of 2004, in collaboration with the National Park Service and Island Conservation, I will collect harvest mice, deer mice, and black rats at six locations: San Miguel Island, Anacapa Island, Santa Barbara Island, and Santa Cruz Island in the California Channel Islands National Park, as well as Sedgwick Reserve and Stunt Ranch Santa Monica Mountains Reserve on the mainland. At each location, I will sample three sites selected to maximize habitat heterogeniety. At each site, rodents will be collected using 49 live traps set in a 7x7 trap grid where traps are separated by 3m. Traps will be set for two nights at each site. No more than 10 individuals of each species will be collected from each site. Rodents will be euthanized following Animal Care and Use Committee Protocol at UCSB, frozen for transport, and returned to the Kuris parasitology lab at USCB for preparation and helminth parasite sampling. Following a protocol developed by the UCSB EID Parasitology Group (PIs: Drs. Armand Kuris and Kevin Lafferty), rodents will be sampled for helminth parasites to determine species composition and diversity. Data will then be summarized and analyzed to address the aforementioned questions. Relevance to the Natural Reserve System The objectives of this research strongly comply with the fundamental mission of the UC Natural Reserve System, ?to contribute to the understanding and management of the Earth and its natural systems?. The results of this research will contribute to our understanding of natural systems by assessing the dynamics of pathogens in their native and naturalized ranges. This, in turn, will provide conservationists and land managers with pertinent information on the potential for exotic species to introduce detrimental pathogens into native populations. Given the broad geographic expanse and natural diversity of the UC Natural Reserve System, there is no doubt that reserves will continue to encounter exotic species. Not all exotic species cause detrimental effects in their naturalized ranges, however, very little is known about the relative effects of the pathogens they bring with them. By incorporating Santa Cruz Island Reserve, Sedgwick Reserve, and Stunt Ranch Santa Monica Mountains Reserve in this research, the UC Natural Reserve System will gain information on the parasitology of native deer mice and harvest mice, as well as the implications of a globally recognized invasive, the black rat.

Visit #1981 @Santa Cruz Island Reserve

Approved

Under Project # 1582 | Research

University of California Santa Barbara - Ecology, Evolution, Marine Biology

graduate_student - University of California, Santa Barbara

Reservation Members(s)

Katherine Smith Apr 12 - 17, 2005 (6 days)

Reserve Resources(s) | Create Invoice

Dorm 1 Apr 12 - 17, 2005
Jeep 1 Apr 12 - 17, 2005