Russell Bradley

Russell Bradley
California State University, Channel Islands | CSUCI · Santa Rosa Island Research Station

Master of Science

About

80
Publications
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Publications

Publications (80)
Article
Full-text available
The Marbled Murrelet Brachyramphus marmoratus is a threatened seabird that relies on old-growth forest for nesting. We compare marine space use between breeding and non-breeding birds, and how marine home range locations and overlap vary with respect to nesting location and breeding status. We collected very high frequency (VHF) radio-telemetry dat...
Article
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Background House mice ( Mus musculus ) are widespread and invasive on many islands where they can have both direct and indirect impacts on native ecological communities. Given their opportunistic, omnivorous nature the consumptive and competitive impacts of house mice on islands have the potential to vary over time in concert with resource availabi...
Article
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Seabirds in more variable habitats generally live longer and more readily forgo or reduce breeding investments in poor resource seasons to maximize their overall lifetime fitness. Their breeding success is dependent on factors including diet, prey availability, and proximity to foraging habitat. Furthermore, seabird colonies in upwelling ecosystems...
Preprint
Full-text available
Background House mice ( Mus musculus ) are widespread and invasive on many islands where they can have both direct and indirect ecological impacts on native ecological communities. Given their opportunistic, omnivorous nature the consumptive and competitive impacts of house mice on islands have the potential to vary over time in concert with resour...
Article
Fish papillomaviruses form a newly discovered group broadly recognized as the Secondpapillomavirinae subfamily. This study expands the documented genomes of the fish papillomaviruses from six to 16, including one from the Antarctic emerald notothen, seven from commercial market fishes, one from data mining of sea bream sequence data, and one from a...
Article
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Wildlife managers must be able to assess the long‐term, population‐wide impacts of mortality events on long lived vertebrates, taking into account the stochastic nature of population fluctuations. Here, we present a case study of the potential impacts on Western gulls (Larus occidentalis) of a single, non‐target mortality event, potentially resulti...
Article
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We tested the hypothesis that segregation in wintering areas is associated with population differentiation in a sentinel North Pacific seabird, the rhinoceros auklet (Cerorhinca monocerata). We collected tissue samples for genetic analyses on five breeding colonies in the western Pacific Ocean (Japan) and on 13 colonies in the eastern Pacific Ocean...
Article
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We quantify the expected demographic benefit to a seabird of conservation concern, the ashy storm‐petrel Oceanodroma homochroa, from the proposed eradication of introduced house mice Mus musculus on the South Farallon Islands, California. A key objective of the eradication is to reduce storm petrel predation by burrowing owls Athene cunicularia, wh...
Article
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Avian species host diverse communities of microorganisms which have important roles in the life of birds, including increased metabolism, protection from disease, and immune system development. Along with high human populations and a diversity of human uses of coastal zones, anthropogenic food sources are becoming increasingly available to some spe...
Article
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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 ecol...
Article
Farallonophilus cavernicolus (Rentz, 1972) is a member of the family Rhaphidophoridae (camel crickets) endemic to the Farallon Islands. Rentz (1972) hypothesized that F. cavernicolus had characteristics between those of the genera Pristoceuthophilus Rehn, 1903 and Ceuthophilus Scudder, 1862 but closest to the genus Pristoceuthophilus. Currently Pri...
Article
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Understanding the colonization or recolonization of breeding sites used by colonial animals is fundamental to metapopulation theory and has practical applications in conservation biology. Historically, pinniped species were heavily exploited worldwide, resulting in some breeding colonies becoming extirpated. As populations recover, some abandoned s...
Article
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Ashy storm-petrels (order Procellariiformes) are seabirds that are found along the coast of California to Baja Mexico. A novel gyrovirus was identified from a cloacal swab of an ashy storm-petrel, which is the second gyrovirus to be identified in sea birds, the first being found in the related northern fulmar.
Article
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As global climate changes, there is increasing need to understand how changes in the frequencies of environmental variability affect populations. Age-structured populations have recently been shown to filter specific frequencies of environmental variability, favoring generational frequencies, and very low frequencies, a phenomenon known as cohort r...
Article
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Individuals increase lifetime reproductive output through a trade-off between investment in future survival and immediate reproductive success. This pattern may be obscured in certain higher quality individuals that possess greater reproductive potential. The Cassin's auklet (Ptychoramphus aleuticus) is a long-lived species where some individuals e...
Article
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Reproductive timing in many taxa plays a key role in determining breeding productivity ¹, and is often sensitive to climatic conditions ² . Current climate change may alter the timing of breeding at different rates across trophic levels, potentially resulting in temporal mismatch between the resource requirements of predators and their prey ³ . Thi...
Article
Effective ecosystem-based fishery management involves assessment of foraging interactions among consumers, including upper level predators such as marine birds and humans. Of particular value is information on predator energetic and consumption demands and how they vary in response to the often volatile dynamics of forage populations, as well as th...
Article
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Identifying frequently complex and dynamic spatial distributions of marine predators via the modeling of at-sea observations can be inherently challenging, especially when attempting to predict habitats of specific populations. Remotely-sensed tracking devices provide a viable alternative way to gather this information. We collected fine-scale spat...
Article
The Brandt's Cormorant of the California Current is a "boom-or-bust" species like its congeners in other eastern boundary, upwelling driven ecosystems, and like many of the prey upon which they depend. These birds produce many recruits when fish availability is high, leading to rapidly increasing populations, but few recruits, and may even exhibit...
Article
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This report examines the ecosystem state of the California Current System (CCS) from spring 2016–spring 2017. Basin-scale indices suggest conditions that would support average to below average coast-wide production across the CCS during this time period. Regional surveys in 2016 sampled anomalously warm surface and subsurface waters across the CCS....
Article
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Background: Plasticity in foraging behavior among individuals, or across populations may reduce competition. As a generalist carnivore, western gulls (Larus occidentalis) consume a wide range of marine and terrestrial foods. However, the foraging patterns and habitat selection (ocean or land) of western gulls is not well understood, despite their u...
Article
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On the Farallon Islands, 48 km west of the coast of central California, Burrowing Owls (Athene cunicularia) are a native migrant and a predator of the nonnative house mouse (Mus musculus) and the native Ashy Storm-Petrel (Oceanodroma homochroa). Previous research showed that Burrowing Owl predation on Ashy Storm-Petrels is likely unnaturally exacer...
Article
Effective ecosystem-based management requires a comprehensive understanding of the functional links in the system. In many marine systems, forage species constitute a critical link between primary production and upper trophic level marine predators. As top predators, seabirds can be indicators of the forage species they consume and the ocean proces...
Article
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Fitness can be profoundly influenced by the age at first reproduction (AFR), but to date the AFR-fitness relationship only has been investigated intraspecifically. Here we investigated the relationship between AFR and average lifetime reproductive success (LRS) across 34 bird species. We assessed differences in the deviation of the Optimal AFR (i.e...
Article
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Differences in reproductive output for marine vertebrates are driven by a combination of environmental, physiological, and behavioral cues. Individuals use these cues when balancing the tradeoff between current reproductive investment and future survival, particularly when resources vary on spatial and temporal scales. A common strategy for maximiz...
Article
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Warm conditions in the North Pacific in 2014-15 were a result of the continuation of the North Pacific marine heat wave, a large area of exceptionally high SST anomalies that originated in the Gulf of Alaska in late 2013. The North Pacific heat wave interacted with an El Niño developing in the equatorial Pacific in 2015. Weekly periods of exception...
Article
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With a rapidly changing climate, there is an increasing need to predict how species will respond to changes in the physical environment. One approach is to use historic data to estimate the past influence of environmental variation on important demographic parameters and then use these relationships to project the abundance of a population or speci...
Article
Aim Our aim was to investigate the influence of biogeographical barriers along the Pacific coast of North America on population genetic structure and gene flow using Cassin's auklet ( Ptychoramphus aleuticus ) as a test case. Location We collected samples from 287 Cassin's auklets breeding along the Pacific coast of North America from the Aleutian...
Conference Paper
Background/Question/Methods Non-native house mice (Mus musculus) were introduced on the Farallon Islands in the 19th century and are now at extremely high densities. As a consequence, migratory burrowing owls (Athene cunicularia) now over-winter on the Farallon Islands during the fall and winter, feeding on the mice. However when the mice populat...
Article
The population, productivity and diet of two Brandt’s cormorant (Phalacrocorax penicillatus) colonies located in the central California Current were compared. The offshore colony on Southeast Farallon Island has experienced a declining population over time and anomalously low productivity in recent years. The nearshore colony near Point Arguello ha...
Article
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Egg turning is unique to birds and critical for embryonic development in most avian species. Technology that can measure changes in egg orientation and temperature at fine temporal scales (1 Hz) was neither readily available nor small enough to fit into artificial eggs until recently. Here we show the utility of novel miniature data loggers equippe...
Article
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The impacts of the El Niño Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO) on the ecology of the northeast Pacific are well known. However, recently there has been a shift in the dominance of El Niño events from the eastern Pacific (canonical) El Niño, to the central Pacific (Modoki) El Niño, concurrent with a strengthening of...
Article
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The Farallon Islands in the Gulf of the Farallones National Marine Sanctuary (GFNMS) is a 7-island chain located 48 km west of San Francisco, California. Since 1993, GFNMS biologists and associates have monitored algal and invertebrate species abundances on the intertidal shores of the 2 South Farallon Islands. The monitoring occurred 1–3 times yea...
Article
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In 2013, the California current was dominated by strong coastal upwelling and high productivity. Indices of total cumulative upwelling for particular coastal locations reached some of the highest values on record. Chlorophyll a levels were high throughout spring and summer. Catches of upwelling-related fish species were also high. After a moderate...
Article
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This report reviews the state of the California Current System (CCS) between winter 2012 and spring 2013, and includes observations from Washington State to Baja California. During 2012, large-scale climate modes indicated the CCS remained in a cool, productive phase present since 2007. The upwelling season was delayed north of 42 degrees N, but re...
Article
Full-text available
This report reviews the state of the California Current System (CCS) between winter 2012 and spring 2013, and includes observations from Washington State to Baja California. During 2012, large-scale climate modes indicated the CCS remained in a cool, productive phase present since 2007. The upwelling season was delayed north of 42°N, but regions to...
Article
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The state of the California Current System (CCS) since spring 2011 has evolved in response to dissipation of La Niña through spring and summer, resurgence of cooler La Niña conditions in fall and winter, and finally a transition towards ENSO-neutral conditions in spring 2012. The resurgence of La Niña was uneven, however, as indicated by variable r...
Conference Paper
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Background/Question/Methods In the central California Current, annual productivity is primarily determined by the wind-driven upwelling of nutrients. In this bottom-up system, we expect parallel trends in productivity across trophic levels. For this study, we utilized 41 years of data from the Farallon Islands in California, to examine recent con...
Article
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Growth, age at maturity, and survival are life-history parameters that provide important information for understanding population dynamics. We modeled growth and age at maturity for an island population of Arboreal Salamanders, Aneides lugubris, using snout–vent length (SVL) growth intervals from a 4-yr capture–mark–recapture study fit to the von B...
Article
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AbSTRACT the state of the california current system (ccs) since spring 2010 has evolved in response to the devel-opment of cooler la Niña following the dissipation of the relatively weak and short-lived El Niño event of 2009–2010. the 2009–2010 El Niño appears to have dissipated quite rapidly in early spring 2010, yet the transition to anomalously...
Article
Juvenile rockfish (Sebastes spp.) are important prey to seabirds in the California Current System, particularly during the breeding season. Both seabird breeding success and the abundance of pelagic juvenile rockfish show high interannual variability. This covariation is largely a response to variable ocean conditions; however, fishing on adult roc...
Article
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To assess long-term temporal trends in White Shark (Carcharadon carcharias) predation, and examine the relationship between C. carcharias and pinnipeds, we examined a 17-year (1988–2004) data set of daily shark attack surveys from Southeast Farallon Island (SEFI), California. We modeled within-season and among-year variation in the number of observ...
Article
1. In order to reproduce successfully in a temporally varying environment, iteroparous animals must exhibit considerable behavioural flexibility across their lifetimes. By adjusting timing of breeding each year, parents can ensure optimal overlap between the energy intensive period of offspring production and the seasonal peak in favourable environ...
Article
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Demographic parameter estimates are essential for understanding population ecology and developing management plans for species of concern. We inferred measures of breeding success using radiotelemetry in the marbled murrelet (Brachyramphus marmoratus), a secretive, forest-nesting seabird, from 1998 to 2001 in Desolation Sound, British Columbia, Can...
Article
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We report a significant male bias in dawn and dusk nest visitations of breeding, radio-marked Marbled Murrelets (Brachyramphus marmoratus) during the chick rearing period in Desolation Sound, British Columbia, Canada, from 1998-2000. Overall visitation rates of males during chick rearing were 1.3 times greater than those of females. Dusk visitation...
Article
We will examine the effects of local ocean conditions and basin-scale patterns of climate variability on phenology and productivity of five species of marine birds to assess how long-term changes in ocean conditions are affecting marine bird populations and to provide insight into how populations may respond to predicted changes in the marine envir...
Article
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The state of the California Current system (CCS) between Oregon and Baja California is summarized in this report, covering spring of 2007 to winter/spring 2008. The 2006-07 period began with moderate El Niño conditions which decayed rapidly in early 2007. By summer 2007, a moderate-to-strong La Niña had developed. The North Pacific sea surface temp...
Article
We conducted an integrated study from physics to upper trophic-level predators in the Gulf of the Farallones, California. We hypothesized that decreased zooplankton abundance for upper trophic-level predators in the Gulf of the Farallones during 2004 and 2005 was a response to reduced upwelling-favorable winds and primary production. Based on their...
Article
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Estimating age-specific vital rates and determining which of them have the greatest influence on population trajectory is very useful for conservation and management of at-risk species. We created multistate capture–recapture models to provide estimates of age-specific variation in survival, recruitment, breeding propensity, and breeding success of...
Article
Long-term studies conducted on breeding populations on the Farallon Islands (1971 to 2007) and in the Point Reyes National Seashore (1980 to 2007), provide the means to characterize breeding phenology of seabird and landbird species and determine how that has changed over multiple temporal scales (variation among years, among decades, shifts in oce...
Article
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This report summarizes the recent state of the California Current System (CCS), primarily during the period April 2005 through early 2006, and includes ob-servations of ocean conditions made from Washington State south to Baja California. During 2005, the CCS experienced very unusual "ocean weather." For exam-ple, off Washington, Oregon and norther...
Article
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1] In spring-summer 2005, anomalous atmospheric-oceanographic coupling caused unprecedented reproductive failures and redistribution of a planktivorous marine bird in both central California (37°N) and southern British Columbia (50°N). At SE Farallon Island, CA, the birds abandoned the breeding colony en masse between 10– 20 May, a unique behaviora...
Article
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We studied habitat selection and breeding success in marked populations of a protected seabird (family Alcidae), the marbled murrelet (Brachyramphus marmoratus), in a relatively intact and a heavily logged old-growth forest landscape in south-western Canada. Murrelets used old-growth fragments either proportionately to their size frequency distribu...
Article
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We used four methods to compare the breeding chronologies of Marbled Murrelet at two sites at similar latitudes in British Columbia: Desolation Sound on the mainland, inshore of the Strait of Georgia, and Clayoquot Sound on the west coast of Vancouver Island. At both sites, we estimated breeding chronologies from the timing of (1) nest initiation d...
Article
Population size is a fundamental variable of interest in most conservation programs, as are the demographic processes underlying variation in numbers. The Marbled Murrelet ( Brachyramphus marmoratus ) is a seabird nesting in coastal old-growth forest in North America and is at the heart of a controversy concerning forest management. Despite the urg...