Ano Nuevo Research Articles

Cassin's Auklet (Ptychoramphus aleuticus) Population Size, Reproduction, and Habitat Management on a Recently Colonized Island in California, USA

Responses to climate change by seabirds in the North Pacific may include range restrictions and require colonizing new habitats. To inform conservation actions supporting climate adaptations, we examined the colonization of Ano Nuevo Island, a nearshore island in central California, by Cassin's Auklets (Ptychoramphus aleuticus). We quantified population growth, reproduction, band returns, mortality, and habitat metrics from 1995-2017 and described habitat management that facilitated colony persistence. Cassin's Auklet breeding population grew to 136 birds by 2014, despite population declines during 2005-2007 and 2016-2017 concurrent with reproductive failures and die-offs that affected Cassin's Auklets regionally. Annual productivity of this small colony was similar to larger populations in the region at 0.72 ± 0.23 SD chicks fledged per pair from 1999-2017 (n = 15 years). Band returns indicated population connectivity with the Farallon Islands, California. Annual rates of burrow damage were 14 ± 8%, with up to 30% damaged a year. Habitat management to prevent erosion damage to nesting burrows included sea lion exclusion, erosion control, and ceramic artificial burrows. Describing conditions that facilitated the colonization and growth of this Cassin's Auklet breeding site can inform actions that support other locations and multiple burrowing seabird species.

The genesis of giants: Behavioral, social, and vocal development of northern elephant seals

To identify the conditions that support the development of hierarchical relationships within networks of familiar competitive rivals, we consider the ontogeny of area use, social relationships, and communicative behavior among male northern elephant seals (Mirounga angustirostris). We cross-sectionally sampled the behavior of 207 males during reproductive development on the breeding colony at Ano Nuevo, CA to determine (1) whether space utilization changes as a function of age, (2) how social relationships vary across different age classes, and (3) the structural development of their ritualized acoustic displays. As males mature, space use within the breeding colony decreases, creating a more predictable social environment in which repeated interactions promote greater connectivity between individuals. Additionally, the vocalizations of sub-adult males transition from highly variable and unstructured to stable adult calls that reliably convey individual identity. The emergence of these acoustic signatures during a profound period of physical development—along with concurrent changes in movement patterns—coincides with the establishment of stable relationships between mature competitors. These findings indicate that ontogenetic changes in male behavior can be important determinants of adult position within structured hierarchies and provide insight into the role of behavioral development in species that exhibit intense competition for access to resources.To identify the conditions that support the development of hierarchical relationships within networks of familiar competitive rivals, we consider the ontogeny of area use, social relationships, and communicative behavior among male northern elephant seals (Mirounga angustirostris). We cross-sectionally sampled the behavior of 207 males during reproductive development on the breeding colony at Ano Nuevo, CA to determine (1) whether space utilization changes as a function of age, (2) how social relationships vary across different age classes, and (3) the structural development of their ritualized acoustic displays. As males mature, space use within the breeding colony decreases, creating a more predictable social environment in which repeated interactions promote greater connectivity between individuals. Additionally, the vocalizations of sub-adult males transition from highly variable and unstructured to stable adult calls that reliably convey individual identity. The emergence of these acoustic signatures...

Contextualización histórica de algunos textos literarios publicados en la revista mexicana decimonónica El año nuevo. Presente amistoso, en torno al tópico del paisaje como elemento de identidad nacional

Within the context of early XIX century Mexico, its socio-political situation, and the way its nation started settling its foundations based on certain identity paradigms, this text explores the topic of natural and urban landscape through poems and tales printed in El ano nuevo. Presente amistoso, a magazine of which four issues were published between 1837 and 1840.

Killer whales redistribute white shark foraging pressure on seals

Predatory behavior and top-down effects in marine ecosystems are well-described, however, intraguild interactions among co-occurring marine top predators remain less understood, but can have far reaching ecological implications. Killer whales and white sharks are prominent upper trophic level predators with highly-overlapping niches, yet their ecological interactions and subsequent effects have remained obscure. Using long-term electronic tagging and survey data we reveal rare and cryptic interactions between these predators at a shared foraging site, Southeast Farallon Island (SEFI). In multiple instances, brief visits from killer whales displaced white sharks from SEFI, disrupting shark feeding behavior for extended periods at this aggregation site. As a result, annual predations of pinnipeds by white sharks at SEFI were negatively correlated with close encounters with killer whales. Tagged white sharks relocated to other aggregation sites, creating detectable increases in white shark density at Ano Nuevo Island. This work highlights the importance of risk effects and intraguild relationships among top ocean predators and the value of long-term data sets revealing these consequential, albeit infrequent, ecological interactions.

Changes in California sea lion diet during a period of substantial climate variability

The California Current Ecosystem (CCE) is a productive eastern boundary upwelling system that supports a wide variety of forage stocks. Decadal and interannual variability in the environment influence forage species, which in turn affects predators. The recent diet of California sea lions (Zalophus californianus; CSL) from Central California was determined using identification of hard parts from scat samples (n = 785) collected on Ano Nuevo Island (37.1083°N 122.3378°W) in 2010 and 2012–2016. Comparisons were made with previously reported data from the late 1990’s and with prey availability as measured by fishery-independent surveys. A significant shift in diet was seen between the two decades where diet from the 1990’s was dominated by Pacific sardine (Sardinops sagax) and northern anchovy (Engraulis mordax). By 2010, diet was more diverse, characterized by rockfishes, Pacific hake, and market squid. There were also strong interannual differences in diet during the most recent decade, a time of substantial climate variability in the North Pacific Ocean. In general, prey were consumed in relation to what was available in the environment.

Development of an animal-borne “sonar tag” for quantifying prey availability: test deployments on northern elephant seals

Developments in electronic tagging technologies have provided unprecedented insight into the movements and behavior of marine predators. Concurrent information on the prey of these tracked animals, however, is mostly lacking. We developed and tested a prototype autonomous echosounder (aka the sonar tag) for deployment on large marine animals intended to provide quantification of their prey fields. The resulting fully autonomous, internally recording prototype sonar tag operated at a power of 1 W and a frequency of 200 kHz. A series of test deployments were successfully conducted on four juvenile female elephant seals (Mirounga angustirostris) captured at the Ano Nuevo State Reserve, California, and released short distances away. Translocated seals were instrumented with a sonar tag and a Fastloc GPS tag with an integrated time-depth recorder (TDR). All four animals returned to land after 3–18 days, making dives to depths of up to 778 m. Strong backscattering from the bottom was observed during many dives, indicating an often close association with the seafloor. Numerous observations of strongly scattering targets, potentially indicative of prey, were also made in the water column, often associated with particular dive and movement behaviors. During dives identified as foraging-type and also travel-type, one animal with the acoustic transducer on its head showed successive targets getting increasingly closer to the animal, possibly consistent with prey pursuit. These results demonstrate the value of active acoustic backscattering measurements made from free-ranging animals, complementing the ecological insight afforded by traditional depth- and position-logging tags. Future refinements will include further miniaturization, performance optimization, and extensions in the deployment duration.

Elephant seals susceptible to human disturbance

![Figure][1] Northern elephant seals at Ano Nuevo State Park. Photo credit: Tom McElroy (NMFS permit 14636-04). Marine mammals have been pottering around unhindered in the oceans for millions of years. But, more recently, another mammal – humans – has begun exploiting their aquatic

Early performance of Pinus radiata provenances in the earthquakeravaged dry river valley area of Sichuan, southwest China

A provenance experiment involving five native provenances and an Australian landrace of Pinus radiata (D. Don) was established over three sites in the dry river valley area of Sichuan, southwest China in 2004 in order to select the most suitable provenance for environmental planting on the dry, steep and degraded slopes to reduce soil erosion. Although with much lower soil moisture supply and mean minimum temperatures in winter compared to P. radiata provenance trials established elsewhere in the world, these sites are within the working limits of the species defined by previous climate modelling and matching. Because of the difficult site conditions and severe natural disturbances after the experiment was established, mortality was high across the three sites in comparison to provenance trials in other countries. The average mortality rate among the provenance by replicate planting units over the three sites varied from 16% to 76% four years after planting, and from 40% to 88% five years after planting. The repeated measurements of tree size over time were analysed using multilevel linear mixed models to derive growth curves for the mean, median, the 75th and the 90th percentiles of the size distribution of each provenance at each site. There were significant site effects on tree growth, but no significant interactions between site and provenance was detected. Among the six provenances, Cambria was the best performer in diameter, height and stem volume growth across all sites. The better than average and the best trees of this provenance, as represented by the 75th and 90th percentiles of the nominal stem volume distribution, were significantly larger than the Australian landrace, Ano Nuevo, and the two island provenances, Guadalupe and Cedros. Monterey was overall the second best performer behind Cambria. The Australian landrace, Guadalupe and Ano Nuevo had similar performances in general. Cedros was significantly and consistently inferior to all other native provenances and the Australian land race. Because the genetic base of the present Australian plantations was derived largely from Ano Nuevo and Monterey, the superior early growth performance of Cambria at such difficult sites brings a new promise to the search of P. radiata provenances for the vast dryland areas in New South Wales and other parts of Australia.

Dos cuentos del siglo xix sobre indígenas

In this article two short stories from the 1830s are explored, both of which deal with Mexican Indians at the time of the conquest: “Netzula,” by Jose Maria Lacunza, and “La batalla de Otumba,” by Eulalio Ortega. They appeared in the first volume of El Ano Nuevo (1837), an unofficial publication from the Academy of Letran. Both writers turned their eyes toward the prehispanic past, making it their own within the process of formation of a brand-new Mexican identity. A decision is perceived to put forth an idealized and romantic image regarding the beginning of New Spain. If at that time the ancient Mexicans had fallen before the Spanish, the implication for contemporary readers is that at the dawn of the 19th century, that historic age had ended, with the triumph of Independence.

Genetic parameters and provenance variation of Pinus radiata D. Don. ‘Eldridge collection’ in Australia 2: wood properties

Provenance variation and genetic parameters for wood properties of mature radiata pine (Pinus radiata D. Don) were studied by sampling three provenance/progeny trials in southeast Australia. Among the mainland provenances, Monterey and Ano Nuevo had higher density and modulus of elasticity (at one site) than Cambria. Basic density and predicted modulus of elasticity (MoE) for the island provenances, Guadalupe and Cedros, were ∼20% higher at Billapaloola compared to mainland provenances grown at Green Hills and Salicki, differences that may or may not be linked to site differences. Heritability estimates of density, predicted MoE and microfibril angle were significant and \( {\bar{h}^2} \) > 0.45, suggesting moderate to strong genetic control. The estimated genetic correlations between diameter at breast height and wood properties in the current study were weaker (less negative) than the mean estimated from the current breeding population generation in radiata pine. Of the wood properties, density showed the strongest adverse genetic correlations with growth (mean rA = −0.23 ± 0.09). Selection for MoE may produce greater gain than selection for density because MoE had almost twice the estimated additive genetic coefficient of variation (\( {\overline {\text{CV}}_A} \)) compared to density. Estimated type B genetic correlations (rB) for all wood quality traits were typically high, conforming to the trend that wood properties have low genotype-by-environment interaction (G × E). Significant differences in wood properties among provenances, families and/or individual trees provide an opportunity for breeding programmes to select superior trees for solid wood production that will combine superior growth with desirable wood traits.

The Northern Elephant Seal (Mirounga angustirostris) Rookery at Año Nuevo: A Case Study in Colonization

Our aim was to examine the colonization process in a large mammal, documenting the development of a breeding colony from its inception to reaching equilibrium numbers. We describe the development of a colony of northern elephant seals (Mirounga angustirostris) at Ano Nuevo in central California from initial colonization in 1961 to 2010, a period when the worldwide population was expanding rapidly. We recorded pup production and pup mortality prior to weaning from censuses of animals by sex and age categories. Colony growth was rapid initially, and pup production reached approximately 2,700 births during the period 1995 to 2006. Pups born declined subsequently. The pattern of colony growth and decline is explained by species-specific seal behavior; population variables that influence immigration rates; and local environmental factors such as breeding space, animal density, and tidal and surf conditions at peak season that increase pup mortality. Colony growth was driven primarily by external recruitment of young females from large southern rookeries rather than internal recruitment. Births on the island segment of the colony, where breeding space was limited, peaked in 1980 then declined subsequently by 50% in association with increased density and pup mortality. Births on the adjacent mainland stabilized from 1995 to 2006, despite ample breeding space and low pup mortality; cessation of growth here was associated with reduced external recruitment of females. Primiparous females pioneer the establishment of new colonies, settling new sites to avoid low weaning success in crowded natal rookeries where they are dominated by older females. We conclude that the long-term study of the development of a single colony provides vital information on colony and population processes that have wide applicability to other mammals. The colonization of Ano Nuevo recapitulated the process employed at other colonies during the recent growth and expansion of the population and signals the pattern to be expected in future colonies.

Genetic parameters and provenance variation of Pinus radiata D. Don. ‘Eldridge collection’ in Australia 1: growth and form traits

Growth and form traits data were obtained from eight provenance trials of radiata pine (Pinus radiata D. Don) planted across the radiata pine plantation estate in southeast Australia. The genetic pool included 466 open-pollinated families collected from Ano Nuevo, Monterey and Cambria provenances on the Californian mainland coast in the USA and from Guadalupe and Cedros islands off the coast of Baja California in Mexico. Early survival of all provenances was around 90%, except for Cedros ( 0.80. Estimates of between-site genetic and provenance correlations for DBH were often low, indicating high genotype by environment interaction across trials, consistent with previous Australian studies. However, there was minimal G × E among trials on high-altitude high-rainfall sites and among trials on low-altitude, low-rainfall sites.

Directionality of male northern elephant seal (Mirounga angustirostris) threat calls and how it influences receiver behavior.

Many animal sounds are directional in which the sound energy is focused in a direction that depends on the signaler’s orientation. In the 1970s, Ron Schusterman quantitatively showed this in barking California sea lions and dogs. Several investigators have suggested ways that such features might be particularly useful among individuals in acoustic communication networks. However, only a few have tested such hypotheses experimentally and even fewer have investigated how directional signals affect receiver behavior. In this study, we measured directivity patterns of male northern elephant seal threat calls and used an acoustic playback approach to determine how call directionality influenced the responses of male seals in reproductive competition. We collected data on adult and older subadult seals on a breeding rookery (Ano Nuevo State Park) over three field seasons. Threat calls had substantial directionality, particularly at frequencies above 1 kHz and responses to playbacks depended on call directivity patterns. Males moved farther away from the playback source when it simulated a caller oriented toward them compared to when playbacks simulated a caller oriented away from them. These results suggest that threat call directionality provides meaningful information about the auditory scene and spatial orientation of male elephant seals in reproductive competition.

Vocal recognition of individuals versus relative dominance rank among breeding male northern elephant seals (Mirounga angustirostris).

Whether an animal truly recognizes an individual or a simple rule-based category (e.g. neighbor or offspring) has important behavioral and evolutionary implications such as the accuracy of social reciprocity. Many tests of individual recognition have focused on neighboring territorial males (dear enemy or neighbour-stranger recognition). Unfortunately the static territorial context of these tests, mostly with male songbirds, opens them to the criticism of being merely associative habituation. More dynamic mating assemblages, such as leks where vocally advertising animals encounter numerous others, are a potentially rich and largely untested alternative. The female defense polygyny practiced by male northern elephant seals during terrestrial breeding is such a dynamic system. To examine whether elephant seals were recognizing individuals or dominance categories we conducted a total of 53 playback experiments to 18 males at Ano Nuevo State Reserve. Each playback was a series of threat calls assigned to four dominance conditions relative to the subject. Dominance was based on the outcomes of interactions among contesting male dyads. Responses were measured using three assays in situ and from video records of each experiment. Results indicate that males do recognize familiar individuals although responses are primarily based on relative dominance rank.

Performance differences among ex situ native-provenance collections of Pinus radiata D. Don. 1: potential for infusion into breeding populations in Australia and New Zealand

Growth and form traits from a series of three provenance trials of Pinus radiata D. Don planted in New Zealand and Australia were analysed at age 9 years from planting. The trials included selections from three mainland California natural populations—Ano Nuevo, Monterey and Cambria. Monterey and Cambria performed better than Ano Nuevo at two New Zealand sites, but Monterey and Ano Nuevo were almost identical in growth, whereas Cambria grew less vigorously at the Australian site. We detected significant provenance differences for diameter at breast height (DBH) growth and stem straightness across countries (p < 0.001). Estimated heritability for DBH ranged from 0.19 to 0.26 within sites, while heritability estimates for stem straightness and branching frequency ranged from 0.10 to 0.24. Estimated type B genetic correlations for DBH were always higher between the two trials in New Zealand trials than between pairs of trials in New Zealand and the Australian site. The genetic coefficient of variation (CVA) for DBH was around 8–10% compared to ca. 5% for the current breeding population. These results suggested that there is appreciable genetic variation in the native populations, and infusion of these materials would increase the genetic variation in current breeding populations. Ten unrelated parents ranked above control seedlots from the older open-pollinated seed orchard stock for DBH growth and would be potential candidates for infusion. The promising performance of the Cambria material is an important result because the genetic base of the present Australian and New Zealand plantations is principally derived from Ano Nuevo and Monterey.

Opinio Juris in Comparatione, Vol. 3/2009

Paper n. 1, pp. 1 - 40 Vern R. Walker, Designing Factfinding for Cross-Border Healthcare Paper n. 2, pp. 1 - 15 Herman Nys, Protection of the rights of patients in incidents reporting systems Paper n. 3, pp. 1 - 19 Ken Oliphant, Compensation, Ideology and Patient Safety in New Zealand's No-Fault System Paper n. 4, pp. 1 - 8 Chiara Perfumi, La reforme du contrat en France: projets et perspectives, Foggia, 9 – 10 octobre 2009 News/Annonces /Noticias Comparative Health Care Liability and Regulation: A Technology-Based Approach - International Summer School Pisa, Italy 24th - 4th June 2010 New Frontiers of Pharmaceutical Law - Young Researchers Workshop Lecce, Italy, May 2010 Happy New Year! Bonne annee ! iFeliz Ano Nuevo!

Preparing to predict: The Second Autonomous Ocean Sampling Network (AOSN-II) experiment in the Monterey Bay

Abstract The Autonomous Ocean Sampling Network Phase Two (AOSN-II) experiment was conducted in and offshore from the Monterey Bay on the central California coast during July 23–September 6, 2003. The objective of the experiment was to learn how to apply new tools, technologies, and analysis techniques to adaptively sample the coastal ocean in a manner demonstrably superior to traditional methodologies, and to use the information gathered to improve predictive skill for quantities of interest to end-users. The scientific goal was to study the upwelling/relaxation cycle near an open coastal bay in an eastern boundary current region, particularly as it developed and spread from a coastal headland. The suite of observational tools used included a low-flying aircraft, a fleet of underwater gliders, including several under adaptive autonomous control, and propeller-driven AUVs in addition to moorings, ships, and other more traditional hardware. The data were delivered in real time and assimilated into the Harvard Ocean Prediction System (HOPS), the Navy Coastal Ocean Model (NCOM), and the Jet Propulsion Laboratory implementation of the Regional Ocean Modeling System (JPL/ROMS). Two upwelling events and one relaxation event were sampled during the experiment. The upwelling in both cases began when a pool of cold water less than 13 °C appeared near Cape Ano Nuevo and subsequently spread offshore and southward across the bay as the equatorward wind stress continued. The primary difference between the events was that the first event spread offshore and southward, while the second event spread only southward and not offshore. The difference is attributed to the position and strength of meanders and eddies of the California Current System offshore, which blocked or steered the cold upwelled water. The space and time scales of the mesoscale variability were much shorter than have been previously observed in deep-water eddies offshore. Additional process studies are needed to elucidate the dynamics of the flow.

Forecasting and reanalysis in the Monterey Bay/California Current region for the Autonomous Ocean Sampling Network-II experiment

Abstract During the August–September 2003 Autonomous Ocean Sampling Network-II experiment, the Harvard Ocean Prediction System (HOPS) and Error Subspace Statistical Estimation (ESSE) system were utilized in real-time to forecast physical fields and uncertainties, assimilate various ocean measurements (CTD, AUVs, gliders and SST data), provide suggestions for adaptive sampling, and guide dynamical investigations. The qualitative evaluations of the forecasts showed that many of the surface ocean features were predicted, but that their detailed positions and shapes were less accurate. The root-mean-square errors of the real-time forecasts showed that the forecasts had skill out to two days. Mean one-day forecast temperature RMS error was 0.26 ∘ C less than persistence RMS error. Mean two-day forecast temperature RMS error was 0.13 ∘ C less than persistence RMS error. Mean one- or two-day salinity RMS error was 0.036 PSU less than persistence RMS error. The real-time skill in the surface was found to be greater than the skill at depth. Pattern correlation coefficient comparisons showed, on average, greater skill than the RMS errors. For simulations lasting 10 or more days, uncertainties in the boundaries could lead to errors in the Monterey Bay region. Following the real-time experiment, a reanalysis was performed in which improvements were made in the selection of model parameters and in the open-boundary conditions. The result of the reanalysis was improved long-term stability of the simulations and improved quantitative skill, especially the skill in the main thermocline (RMS simulation error 1 ∘ C less than persistence RMS error out to five days). This allowed for an improved description of the ocean features. During the experiment there were two-week to 10-day long upwelling events. Two types of upwelling events were observed: one with plumes extending westward at point Ano Nuevo (AN) and Point Sur (PS); the other with a thinner band of upwelled water parallel to the coast and across Monterey Bay. During strong upwelling events the flows in the upper 10–20 m had scales similar to atmospheric scales. During relaxation, kinetic energy becomes available and leads to the development of mesoscale features. At 100–300 m depths, broad northward flows were observed, sometimes with a coastal branch following topographic features. An anticyclone was often observed in the subsurface fields in the mouth of Monterey Bay.

Thin phytoplankton layer formation at eddies, filaments, and fronts in a coastal upwelling zone

Abstract On two cruises in August and September 2003 (hereafter cruises 2 and 3) during wind relaxations and transitions to upwelling conditions, thin layers of phytoplankton were observed in or a few meters below the stratified transition layer at the mixed layer base and in regions of sheared flow on the flanks of eddies, filaments, and fronts near Monterey Bay, California. On an earlier cruise in August (cruise 1), no thin layers were found after a prolonged wind relaxation. Chlorophyll concentrations and shear were both an order of magnitude less than on cruises 2 and 3. Our vertical profiles were made using a fluorometer mounted on a conductivity–temperature–depth package, which was lowered from the ship as slowly as 0.25 m s - 1 every 10 km on five ∼ 80 -km cross-shore transects. Remotely sensed sea-surface temperature, chlorophyll, and currents are required to understand the temporal and spatial evolution of the circulation and to interpret the quasi-synoptic in situ data. Decorrelation scales are ∼ 20 km from lagged temperature and salinity covariances. Objectively mapped sections of the in situ data indicate the waters containing thin layers were recently upwelled at either the Point Sur or Point Ano Nuevo upwelling centers. Spatially limited distributions of phytoplankton at the coastal upwelling centers ( ∼ 40 km alongshore, 20 km cross-shore, and 30 m thick) were transformed into thin layers by current shear and isolated from wind-driven vertical mixing by the stratification maximum of the transition layer. Vertically sheared horizontal currents on the flanks of the eddies, filaments, and fronts horizontally stretched and vertically thinned phytoplankton distributions. These thin, elongated structures were then observed as thin layers of phytoplankton in vertical fluorescence profiles at four stations on cruise 2 and eight stations on cruise 3. Light winds during relaxations did not mix away these thin layers. On cruise 2, thin layers were found at eddies at the inshore and offshore ends of a 100-km-long filament, while broader subsurface chlorophyll maxima were found along the filament. This result suggests that higher-resolution sampling along and across a filament may find thin layers forming and dissipating along its length. On cruise 3, thin layers were found at three adjacent stations across an upwelling front and may have extended continuously for > 20 km , but neither species composition nor bio-optical data are available to confirm this conjecture. The thin layers were 1–5 m thick in the vertical at full width half maximum and had peak fluorescence values from 7 – 30 mg m - 3 . (Bottle chlorophyll samples showed fluorometer chlorophyll readings may have been 1.3 – 1.5 × too large, but the scatter in this relation was considerable especially at the larger fluorescence values detected in thin layers.) While sheared currents thinned an initially thick subsurface chlorophyll maximum into thin layers, the peak values in these thin layers exceeded concentrations in the upwelled source waters and were unexplained by our data.

EFFECTS OF RAPID FLIGHT-FEATHER MOLT ON POSTBREEDING DISPERSAL IN A PURSUIT-DIVING SEABIRD

Abstract Breeding seabirds have been well studied but seabird ecology during the nonbreeding season is poorly understood because many species disperse far from breeding colonies to molt at sea. We characterized the timing of prebasic molt and postbreeding dispersal, described postbreeding dispersal movements, and estimated changes in body mass during molt for Marbled Murrelets (Brachyramphus marmoratus; Alcidae) in central California, 1999–2004. According to mark–recapture and at-sea surveys, 248–315 of 496–637 individuals (43–50%) used Ano Nuevo Bay, located immediately adjacent to nesting areas, for their prebasic molt in August–October. Long-distance dispersal (≥ 100 km) from Ano Nuevo Bay by radiomarked Marbled Murrelets was low during breeding (9–13%, n = 46), but was greater for individuals radiomarked at the end of the breeding season (69–90%, n = 20). The mean dispersal dates were 18 May and 21 October for the breeding and postbreeding samples, respectively, and postbreeding dispersal occurred an ...