Papers O-Z

Papers A-G | Papers H-N | Papers O-Z | Posters

Title:	Social attraction techniques stimulate group display and nesting behavior in a reintroduced population of Caribbean flamingos (Phoenicopterus ruber ruber) on Guana Island, BVI
Author:	Caitlin O'Connell-Rodwell, Stanford University Nora Rojek, California Department of Fish and Game Timothy Rodwell, Stanford University Peter Shannon, San Francisco Zoo
Format:	paper
Presentation:	Concurrent Sessions I, Avian Demography and Behavior, 10:00 - 11:00 am, 2060 VLSB
Abstract:	We used artificial social stimulation (decoys, vocalization playbacks, and artificial nests) to encourage breeding in a population of six Caribbean flamingos (Phoenicopterus ruber ruber) that had not successfully bred since their introduction to Guana Island, BVI, in 1992. During a control period prior to the introduction of stimuli, flamingos exhibited no social displays or nest building activities. All flamingos were observed approaching the decoy area as a flock a few hours after the decoys were introduced, and social displays were exhibited at a low rate by a few birds within the first 24 hours. In a 12-hour watch conducted two-weeks post decoy introduction, there were significantly more group display behaviors, as well as nest-building, as compared with the control period and immediately after the introduction. Two individuals performed the majority of group displays (although at least one social display posture was observed for each bird) and three birds exhibited nest-building behaviors. Overall, individuals spent most of their time feeding and resting/sleeping during all observation period. We demonstrate for the first time that decoys and vocalization playbacks induce group displays in flamingos. We suggest that social attraction techniques may be a useful tool to stimulate breeding in captive and wild small populations of flamingos.

Title:	Landscape-scale influences on aquatic ecosystems: Land use and spawning habitat in the Russian River basin
Author:	Jeff Opperman, University of California at Berkeley Adina Merenlender, University of California at Berkeley Colin Brooks, University of California at Berkeley Maggi Kelley, University of California at Berkeley
Format:	paper
Presentation:	Concurrent Sessions IV, Aquatic Conservation and Biology, 3:10 - 4:10 pm, 2060 VLSB
Abstract:	Aquatic habitat is influenced by land use at various spatial and temporal scales. Understanding these scales of influence is critical for predicting cumulative watershed effects and matching restoration and management efforts with the appropriate scales. We examine the relative influences of land use and land cover (LULC) at various scales on levels of fine sediment within spawning gravels (embeddedness) in 54 stream reaches in the Russian River basin. These streams provide habitat for endangered populations of anadromous fish (coho salmon and steelhead trout). We used multiple regression to explore the relationship between LULC and embeddedness at several scales of analysis including the entire watershed, the local riparian corridor, and the riparian corridor of the stream network upstream of the focal reach. Watershed-scale variables for LULC consistently explained the most variation in embeddedness levels. Agriculture, urban, and herbaceous LULC categories had significantly positive relationships with embeddedness, indicating these LULC categories were associated with higher levels of fine sediment. Forest and shrub LULC categories had significantly negative relationships with embeddedness. The explanatory power of models generally increased when the analysis was restricted to larger watersheds. A model using watersheds greater than 2500 ha had the greatest explanatory power. Within these largest watersheds, models for LULC within the whole watershed and for the riparian corridor of the entire upstream stream network explained equivalent levels of variation in embeddedness. These results suggest that restoration efforts at the reach scale will have little influence on levels of sediment within spawning gravels.

Title:	Conservation easements and the endangered species act: An unholy union?
Author:	Jessica Owley, University of California at Berkeley
Format:	paper
Presentation:	Concurrent Sessions IV, Policy Perspectives, 3:10 - 4:10 pm, 2050 VLSB
Abstract:	Species are going extinct at an alarming rate. Although the exact numbers are uncertain, anthropogenic causes have accelerated the rate to levels that parallel the loss in diversity that accompanies mass extinctions. The number one cause of species extinction is habitat destruction. Private lands are an important element of any biodiversity or species protection regime. Approximately fifty percent of the species listed under the Endangered Species Act are found only on private lands and many more have substantial parts of their remaining range on private property. A strong belief in private property rights accompanied by a distrust of bureaucracy and governmental regulations by much of the country has inspired government agencies, activists and scholars to explore new mechanisms for environmental protection. In recent years property rights advocates have claimed that regulations have gone too far. Communities, developers, and government agencies are adopting market-based approaches to habitat conservation. The search for ways to protect endangered species habitat and preserve private property rights has led to a variety of new institutions and tools including conservation easements. Although many scholars have written on conservation easements as a tool for biodiversity protection there has been little mention of conservation specifically targeted to meet the habitat goals outline in the Endangered Species Act. This paper specifically explores that option with a special eye towards incorporating conservation easements into Endangered Species Act Habitat Conservation Plans.

Title:	Saving an ocean connector: Ecological and community-based solutions for conserving the endangered North Pacific loggerhead turtle
Author:	Hoyt Peckham, University of California at Santa Cruz Wallace J. Nichols, WiLDCOAST Peter H. Dutton, NOAA - National Marine Fisheries Service Javier Villavicencio, Grupo Tortuguero de las Californias
Format:	paper
Presentation:	Concurrent Sessions IV, Aquatic Conservation and Biology, 3:10 - 4:10 pm, 2060 VLSB
Abstract:	The loggerhead turtle (Caretta caretta) connects the entire Pacific basin through its developmental and reproductive migrations. Previous studies have demonstrated that the C. caretta which occur off of California, USA, and the Baja California peninsula, Mexico (BCP) are of Japanese origin and in the midst of their transoceanic developmental migration. Despite strong national and international laws and agreements protecting sea turtles and long-term protection efforts on nesting beaches, there are currently fewer than 1,000 loggerhead turtles nesting each year in Japan, the only nesting site for this species in the North Pacific, representing a decline of more than 50% since 1992. Baja California’s shark and halibut fisheries cause much of the C. caretta mortality in the North Pacific, taking more than 1,950 juvenile loggerhead turtles per year. We are working with local fishers to assess, characterize, and localize fisheries bycatch of C. caretta off the BCP. Thro ugh beach surveys and fisher interviews we have identified several bycatch hotspots where fishing and turtle distribution collide the hardest. Through satellite telemetry we are studying C. caretta habitat use and foraging ecology as they relate to P. planipes distribution, the primary prey of C. caretta in BCP waters. We are raising awareness of the bycatch problem among Mexican fishers through the community-based conservation network Grupo Tortuguero de las Californias and we are partnering with fishers and their communities to apply our research findings to develop bycatch reduction solutions. Unlike with many endangered species, the reasons for C. caretta decline in the North Pacific are relatively straightforward and reasonably reversible. Through a combination of ecological research and community-based conservation we are reducing the bycatch which threatens the North Pacific population of the loggerhead turtle.

Title:	Marbled Murrelet demography in central California
Author:	Zach Peery, University of California at Berkeley Steve Beissinger, University of California at Berkeley
Format:	paper
Presentation:	Concurrent Sessions I, Avian Demography and Behavior, 10:00 - 11:00 am, 2060 VLSB
Abstract:	The Marbled Murrelet (Brachyramphus marmoratus) is one of the most threatened seabirds along the California coast due to a variety of potential factors such as the harvesting of its old-growth nesting habitat, oil spills, and increased nest predation. We initiated a demographic study in 1997 to estimate the murrelet’s population trend in central California and to understand the environmental and demographic factors responsible for any observed declines. We estimated the population trend using three approaches, one based on at-sea counts, one using a Leslie Matrix model, and one based on the recently developed suite of Pradel models. Models were parameterized with breeding, recruitment, and survival estimates from 289 banded and 46 radio-marked murrelets. We observed significant annual variation in the proportion of breeders, presumably due to annual variation in the marine environment. However, all nests failed even in a “good” year, resulting in a fecundity estimate of 0.0. Furthermore, survival rates were much lower than expected for a murrelet-sized alcid. Not surprisingly, the Leslie Matrix approach parameterized with these estimates suggested a dramatic annual rate of decline. However, the trend based on both at-sea counts and the Pradel approach indicated that the population was stable. Because the latter two approaches incorporate recruitment from outside populations, while the Leslie Matrix does not, we suggest that the central California murrelet population may be sustained by immigration processes and constitutes a classic sink population.

Title:	The influence of harvester ants on plant community composition in a serpentine grassland
Author:	Halton Peters, Stanford University
Format:	paper
Presentation:	Concurrent Sessions III, Invertebrates, 1:30 - 2:50 pm, 2063 VLSB
Abstract:	California serpentine grasslands have long been considered biologically significant because they are refuges for native California flora, including numerous rare and endemic species. The integrity of these communities is now threatened by the widespread displacement of the native black harvester ant, Messor andrei, by the invasive Argentine ant, Linepithema humile. Seed-harvesting ants such as M. andrei can influence plant community composition through both the selective harvesting of seeds and the construction of nest mounds that provide unusual edaphic conditions for plant establishment and growth. Because Argentine ants do not eat seeds and do not build nest mounds, they are unlikely ecological surrogates for the native harvester ants. This suggests that the extent to which serpentine outcrops will continue to serve as reservoirs of native California vegetation is dependent upon the influence of M. andrei on plant community composition. The purpose of this study was to assess the influence of the harvester ant foraging and nest construction on plant species demography in a serpentine grassland at the Jasper Ridge Biological Preserve in San Mateo County, Northern California. The results indicate that M. andrei influences the distribution and abundance of plant species through selective seed harvesting and the construction of nest mounds. There were pronounced gradients of plant species abundance around ant nests, suggesting that seed harvesting by M. andrei is influencing the spatial distribution of serpentine grassland species. Furthermore, harvester ant nest mounds were found to support vegetative communities that are compositionally distinct from the surrounding serpentine grassland. The density and distribution of ant nests indicates these processes are likely to influence much of the serpentine grassland at this site. Based upon the results of this study, changes in plant community composition are to be expected if harvester ants are supplanted by Argentine ants in this grassland.

Title:	The role of education in local conservation: A habitat restoration program in the central valley of California.
Author:	Michael Plotkin, University of California at Davis Dan Leroy, Farms Leadership, Inc
Format:	paper
Presentation:	Concurrent Sessions II, Human Wildlife Interface, 11:20 - 12:20 pm, 2050 VLSB
Abstract:	Conservation of biological diversity ultimately depends on public support, and many conservation efforts include extensive educational components. However, conservation education often ignores large segments of biodiversity and ecological process and instead focuses on the proximate goal of saving “umbrella species”—particularly charismatic and evocative members of the local biota whose protection would incidentally protect other species. These efforts frequently do not convey a detailed knowledge of local ecology, and therefore do not prepare people to make decisions about complex conservation concerns. Perhaps more importantly, efforts to educate children about the local ecology and enlist their activist and volunteer efforts is also frequently lacking. A wealth of research shows that children both need and desire contact with and knowledge of their local biota, and that given sufficient involvement, they are more likely to become supporters of protection for wild nature. In addition, children can be effective advocates for conservation. We surveyed public school students in the Central Valley of California to assess ecological knowledge of the local biota both current and historical. We then compare these data with data from students who have engaged in an innovative program called the Student and Landowner Education and Watershed Stewardship (SLEWS) Program (a collaboration between Audubon and Farms Leadership, Inc.) and document the positive influence of the program on local ecological knowledge and support of conservation among students. SLEWS introduces high school students to native plants, ecosystems and wildlife and sustainable development, and has them engage in ongoing ecological restoration efforts on local farms.

Title:	Conservation planning for an African flagship species: A strategy for Livingstone’s flying fox and the Comorian rainforest
Author:	Brent Sewall, University of California at Davis Elise F. Granek, Oregon State University
Format:	paper
Presentation:	Concurrent Sessions III, African Conservation, 1:30 - 2:50 pm, 2050 VLSB
Abstract:	Livingstone’s flying fox, Pteropus livingstonii, is a giant fruit bat endemic to two small islands of the Union of the Comoros, located near Madagascar in the western Indian Ocean. Due to its charismatic appearance, unique natural history, and ecological role in seed dispersal and pollination, Livingstone’s flying fox has become a flagship species for conservation of its montane rainforest habitat. This rainforest ecosystem contains a high concentration of endemic species, and provides essential ecological services to the Comorian people, including erosion control, stream maintenance, and the production of wood, fuel, food, and medicines. Livingstone’s flying fox, however, is threatened due to increasing human encroachment on roost sites and deforestation of foraging habitat. Recent censuses indicate that only about 1,200 individuals remain in the wild, and the World Conservation Union (IUCN) has listed Livingstone’s flying fox as Critically Endangered, indicating that conservation action is urgently needed. In response, the Comorian government has initiated the development of a national Conservation Action Plan for the species and its rainforest habitat. I am coordinating the development of this plan, through collaboration with the government, local Comorians, and international scientists and conservation organizations. The intent of the Conservation Action Plan is to provide a net benefit for local people, the endangered bat species, and the Comorian rainforest ecosystem. To achieve this mission, we have focused on several key programs: habitat protection, forest management, environmental education, population monitoring, ecotourism development, ecological research, and captive breeding. The plan will emphasize local involvement and capacity-building, supplemented by support from the national government and international conservation organizations. We anticipate implementation of the plan over a five-year period beginning in late 2003.

Title:	Effectiveness of protection strategies for large mammals in Tanzania based on long-term aerial survey data
Author:	Chantal Stoner, University of California at Davis
Format:	paper
Presentation:	Concurrent Sessions III, African Conservation, 1:30 - 2:50 pm, 2050 VLSB
Abstract:	Currently, much controversy surrounds the issue of how African ecosystems might best be preserved. Some conservationists have suggested that the key to maintaining wildlife species and habitats lies in the classic protectionism strategy of concentrating conservation efforts into heavily protected areas that exclude human activities. Others argue that rigid protectionist strategies tend to ignore the needs and rights of rural people, and that partially protected areas are successful in preserving wilderness. Using population estimates taken from aerial surveys conducted since the 1970s, I examine the effectiveness of different protection strategies in conserving ungulates in Tanzania. Specifically, I compare temporal population trends across heavily protected areas (National Parks and Game Reserves), partially protected areas (Game Controlled areas), and areas receiving virtually no conservation funding (Open Areas, and elsewhere). Linear regressions identifying significant temporal changes in population density show that a higher percentage of ungulate species declined in Game Controlled Areas than in any other protected area category. An examination of individual species’ trends across protected areas revealed that some species fare better in heavily protected areas while others fare better in partially protected areas. Some species declined in every type of protected area and may therefore need even heavier protection than National Parks can presently provide.

Title:	Wildlife need habitat off limits to humans!
Author:	Mike Vandeman, World Without Cars
Format:	paper
Presentation:	Concurrent Sessions IV, Policy Perspectives, 3:10 - 4:10 pm, 2050 VLSB
Abstract:	In 4 million years of human evolution, there has never been an area off limits to humans -- an area which we deliberately choose not to enter so that the species that live there can flourish unmolested by humans. Yet, our observations and intuition about wildlife suggest that most want and need such seclusion in order to survive. Recent research confirms this: even recreation traditionally considered harmless is actually detrimental to wildlife. Restoring true wilderness will require rethinking and redesigning all land uses and wildlife management regimes, as well as changing how we relate to wildlife.

Title:	Modeling individual variation in the western gull, Larus occidentalis
Author:	Jennifer Wang, University of California at Berkeley William J. Sydeman, PRBO Conservation Science Russell Bradley, PRBO Conservation Science Nadav Nur, PRBO Conservation Science
Format:	paper
Presentation:	Concurrent Sessions I, Avian Demography and Behavior, 10:00 - 11:00 am, 2060 VLSB
Abstract:	Current stochastic population viability analysis may overlook individual variation in survival and fecundity. As variation in survival probability increases, demographic stochasticity is expected to decrease. Variation in fecundity may have varying effects on demographic stochasticity, depending on the mean-variance relationship of the fecundity data. I tested ways in which variation in survival and fecundity may be incorporated into a population model of the western gull, Larus occidentalis. The model was based on lifetime reproductive success data obtained by researchers at PRBO Conservation Science for a cohort of western gulls on Southeast Farallon Island, California. To explore variation in survival, I compared models using normal and binomial distributions for survival rates and a normal distribution for fecundity rates. To explore variation in fecundity, I compared models using a binomial distribution for survival and using normal, beta, uniform, and actual distributions for fecundity. The fecundity models using normal and beta distributions consistently underestimated lambda values and predicted population sizes, while the fecundity model using a uniform distribution consistently overestimated lambda values and predicted population sizes.

Title:	Land management and elephant movements in Samburu, Kenya
Author:	George Wittemyer, University of California at Berkeley Iain Douglas-Hamilton, Save the Elephants Henrik Rasmussen, Save the Elephants
Format:	paper
Presentation:	Concurrent Sessions IV, Policy Perspectives, 3:10 - 4:10 pm, 2050 VLSB
Abstract:	The Samburu District holds the largest free ranging population of elephants remaining primarily outside protected areas in Kenya. Land use in the region varies from group ranches, privately owned ranches, recently demarcated community conservation areas, three small national reserves, and uninhabited government holdings. We deployed Global Positioning System (G.P.S.) radio collars on elephants using the national reserves in order to determine the spatial requirements of the population. We present information on elephant movements and use in the mosaic of land use types in the study area. This information will assist the understanding of elephant spatial requirements, which is essential for their conservation and the management of the ecosystems they inhabit.

Papers A-G | Papers H-N | Papers O-Z | Posters

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