Publications

a gallus gallus model for determining infectivity of zoonotic campylobacter.	to better understand public health implications of waterfowl as reservoirs for zoonotic sources of campylobacter in recreational waters, we developed a gallus gallus (chick) model of infection to assess the pathogenicity of environmental isolates of campylobacter. this method involved exposure of 1-day-old chicks through ingestion of water, the natural route of infection. viable campylobacter from laboratory-infected animals were monitored by using a modified non-invasive sampling of fresh chick ...	2019	31695684
whole-genome sequencing of four campylobacter strains isolated from gull excreta collected from hobie beach (oxnard, ca, usa).	campylobacter spp. are commensal organisms in avian species and are one of the leading causes of bacterial foodborne human diarrheal disease worldwide. we report the draft genome sequences of campylobacter volucris, c. lari, and c. jejuni strains isolated from california gull (larus californicus) excreta collected from a california beach.	2019	31395635
spatial trends in a biomagnifying contaminant: application of amino acid compound-specific stable nitrogen isotope analysis to the interpretation of bird mercury levels.	levels of biomagnifying contaminants are greatest in high-trophic level biota (e.g., predatory birds such as gulls). gull eggs have been used to assess contaminant spatial patterns and sources, but such assessments must consider how organism trophic position may influence spatial inferences. stable nitrogen isotopes (δ15 n) in bulk tissue are routinely used in this context. however, bulk δ15 n values are only useful if spatial differences in baseline δ15 n values are considered. amino acid compo ...	2018	29446488
volatile methylsiloxanes and organophosphate esters in the eggs of european starlings (sturnus vulgaris) and congeneric gull species from locations across canada.	volatile methylsiloxanes (vmss) and organophosphate esters (opes) are two suites of chemicals that are of environmental concern as organic contaminants, but little is known about the exposure of wildlife to these contaminants, particularly in birds, in terrestrial and aquatic ecosystems. the present study investigates the spatial distributions of nine cyclic and linear vmss and 17 opes in the eggs of european starlings (sturnus vulgaris) and three congeneric gull species (i.e., herring gull (lar ...	2017	28771368
factors determining a clutch size reduction in california gulls (larus californicus): a multi-hypothesis approach.	in the thirty-five years since david lack first highlighted the importance of clutch size, a large number of hypotheses have been proposed relating clutch size variation to various environmental and demographic factors. despite a great deal of both empirical and theoretical work on clutch size, there has been very little effort to test many of the competing hypotheses in explaining a clutch size difference between two populations of the same species. i have taken the latter approach in an effort ...	1985	28561963
unintended consequences of management actions in salt pond restoration: cascading effects in trophic interactions.	salt evaporation ponds have played an important role as habitat for migratory waterbirds across the world, however, efforts to restore and manage these habitats to maximize their conservation value has proven to be challenging. for example, salinity reduction has been a goal for restoring and managing former salt evaporation ponds to support waterbirds in the south bay salt pond restoration project in san francisco bay, california, usa. here, we describe a case study of unexpected consequences o ...	2015	26030415
mercury trends in colonial waterbird eggs downstream of the oil sands region of alberta, canada.	mercury levels were measured in colonial waterbird eggs collected from two sites in northern alberta and one site in southern alberta, canada. northern sites in the peace-athabasca delta and lake athabasca were located in receiving waters of the athabasca river which drains the oil sands industrial region north of fort mcmurray, alberta. temporal trends in egg mercury (hg) levels were assessed as were egg stable nitrogen isotope values as an indicator of dietary change. in northern alberta, cali ...	2013	24070029
molecular detection of campylobacter spp. in california gull (larus californicus) excreta.	we examined the prevalence, quantity, and diversity of campylobacter species in the excreta of 159 california gull (larus californicus) samples using culture, pcr- and qpcr-based detection assays. campylobacter spp. prevalence and abundance was relatively high in the gull excreta examined; however, c. jejuni and c. lari were detected in less than 2% of the isolates and dna extracts from the fecal samples that tested positive. moreover, molecular and sequencing data indicated that most l. califor ...	2011	21622785
california gull chicks raised near colony edges have elevated stress levels.	coloniality in nesting birds represents an important life history strategy for maximizing reproductive success. birds nesting near the edge of colonies tend to have lower reproductive success than individuals nesting near colony centers, and offspring of edge-nesting parents may be impaired relative to those of central-nesting parents. we used fecal corticosterone metabolites in california gull chicks (larus californicus) to examine whether colony size or location within the colony influenced a ...	2011	21596043
perfluoroalkyl carboxylates and sulfonates and precursors in relation to dietary source tracers in the eggs of four species of gulls (larids) from breeding sites spanning atlantic to pacific canada.	in the present study, we identified and examined the spatial trends, sources and dietary relationships of bioaccumulative perfluorinated sulfonate (pfsa; c(6), c(8), and c(10) chain lengths) and carboxylate (pfca; c(6) to c(15) chain lengths) contaminants, as well as precursor compounds including several perfluorinated sulfonamides, and fluorotelomer acids and alcohols, in individual eggs (collected in 2008) from four gull species [glaucous-winged (larus glaucescens), california (larus californi ...	2011	21529948
metals and polycyclic aromatic hydrocarbons in colonial waterbird eggs from lake athabasca and the peace-athabasca delta, canada.	in 2009, aquatic bird eggs from a variety of species were collected from three sites in northern alberta, canada. two sites were located in receiving waters of the athabasca river, which drains the oil sands industrial region north of fort mcmurray, alberta. the third site, located on the peace river, was remote from the influence of the athabasca river. levels of mercury, arsenic, and polycyclic aromatic hydrocarbons (pahs) were measured in the eggs along with nitrogen stable isotopes (δ¹⁵n) as ...	2011	21312251
selenium and mercury concentrations in california gulls breeding on the great salt lake, utah, usa.	we examined selenium (se) and mercury (hg) concentrations in adult california gulls (larus californicus) nesting on the great salt lake, utah, usa, during 2006 and 2007. during 2006, the mean se concentration (+/- standard error) was 18.1 +/- 1.5 microg/g in blood on a dry-weight basis and 8.1 +/- 0.4 microg/g in liver. during 2007, se concentrations were 15.7 +/- 1.5 microg/g in blood and 8.3 +/- 0.4 microg/g in liver; hg concentrations were 2.4 +/- 0.3 microg/g in blood and 4.1 +/- 0.5 microg/ ...	2009	18767915
increased reproductive effort with age in the california gull (larus californicus).	comparisons of reproductive behaviors of three age classes of california gulls demonstrate that reproductive effort increases with age in this seabird. these findings contradict the assumption that increased reproductive success with age results from increased experience and social status and demonstrate that selection for increased reproductive effort can occur in long-lived species.	1981	17752279
cestodes of california gulls.		1950	15402949
anatomy and histochemistry of spread-wing posture in birds. 2. gliding flight in the california gull, larus californicus: a paradox of fast fibers and posture.	gliding flight is a postural activity which requires the wings to be held in a horizontal position to support the weight of the body. postural behaviors typically utilize isometric contractions in which no change in length takes place. due to longer actin-myosin interactions, slow contracting muscle fibers represent an economical means for this type of contraction. in specialized soaring birds, such as vultures and pelicans, a deep layer of the pectoralis muscle, composed entirely of slow fibers ...	1997	9259122
probable epizootic chlamydiosis in wild california (larus californicus) and ring-billed (larus delawarensis) gulls in north dakota.	during the summer of 1986, more than 400 california gulls (larus californicus) and ring-billed gulls (larvus delawarensis), primarily fledglings, died on an island in lake sakakawea near new town, north dakota (usa). mortality was attributed largely to chlamydiosis. necropsy findings in nine carcasses included splenomegaly (n = 9), hepatomegaly (n = 4), and pericarditis (n = 1). livers from three california gulls and two ring-billed gulls, and spleens from the same five birds plus a third ring-b ...	1995	8592370
some internal parasites of the california gull larus californicus lawrence, in wyoming.		1973	4699872
mono lake virus infecting argas ticks (acari: argasidae) associated with california gulls breeding on islands in mono lake, california.		1988	2848128
argas (argas) monolakensis, new species (acari: ixodoidea: argasidae), a parasite of california gulls on islands in mono lake, california: description, biology, and life cycle.	argas (argas) monolakensis, n. sp., is described from adults, nymphs, and larvae collected from under and around nests of california gulls, larus californicus lawrence, on islands in mono lake, mono county, calif., and from specimens reared in the laboratory. this species is closely related to a. cooleyi kohls & hoogstraal, a parasite of cliff swallows, hirundo pyrrhonota vieillot, but is easily distinguished by hypostome dentition and roof of haller's organ in all stages and chaetotaxy of the l ...	1992	1552533
isolation of salmonella spp. from dead gulls (larus californicus and larus delawarensis) from an idaho irrigation reservoir.	an epizootic of unknown etiology resulting in the death of about 500 sea gulls (larus californicus and larus delawarensis) in 24 hr occurred on an irrigation reservoir in southwestern idaho in april 1975. salmonella spp. were isolated from necropsy specimens from 2 of 6 gulls examined. no salmonella spp. were isolated from fecal specimens or dead gulls collected at a nesting site.	1977	334150