| differential impact of west nile virus on california birds. | the strain of west nile virus (wnv) currently epidemic in north america contains a genetic mutation elevating its virulence in birds, especially species in the family corvidae. although dead american crows (corvus brachyrhynchos) have been the hallmark of the epidemic, the overall impact of wnv on north america's avifauna remains poorly understood and has not been addressed thoroughly in california. here, we evaluate variation by species in the effect of wnv on california birds from 2004 to 2007 ... | 2009 | 20589226 |
| pathology associated with west nile virus infections in the yellow-billed magpie (pica nuttalli): a california endemic bird. | yellow-billed magpies (pica nuttalli, corvidae) are found exclusively in central california and have experienced alarming west nile virus (wnv)-associated mortality since 2004. the first reported case of wnv in the species was reported in july 2004. subsequently, 81% (304/374) of dead magpies submitted that year to the california department of health services dead bird surveillance program were wnv positive by polymerase chain reaction (pcr) test. we studied 43 magpie carcasses collected in 2004 ... | 2010 | 20688633 |
| development of 10 microsatellite loci for yellow-billed magpies (pica nuttalli) and corvid ecology and west nile virus studies. | we developed 10 polymorphic microsatellite loci for yellow-billed magpies (pica nuttalli). the primers were tested across a population of 57 central california yellow-billed magpies and displayed an average of 3.9 alleles per locus. forty-one american crows (corvus brachyrhynchos) from california were polymorphic for seven of the loci with an average of 2.9 alleles per locus. one additional microsatellite-containing locus displayed diagnostic allele sizes and may be useful to distinguish between ... | 2008 | 21585754 |
| Mosquito host selection varies seasonally with host availability and mosquito density. | Host selection by vector mosquitoes is a critical component of virus proliferation, particularly for viruses such as West Nile (WNV) that are transmitted enzootically to a variety of avian hosts, and tangentially to dead-end hosts such as humans. Culex tarsalis is a principal vector of WNV in rural areas of western North America. Based on previous work, Cx. tarsalis utilizes a variety of avian and mammalian hosts and tends to feed more frequently on mammals in the late summer than during the res ... | 2011 | 22206038 |
| spatial variation in host feeding patterns of culex tarsalis and the culex pipiens complex (diptera: culicidae) in california. | west nile virus (family flaviviridae, genus flavivirus, wnv) is now endemic in california across a variety of ecological regions that support a wide diversity of potential avian and mammalian host species. because different avian hosts have varying competence for wnv, determining the blood-feeding patterns of culex (diptera: culicidae) vectors is a key component in understanding the maintenance and amplification of the virus as well as tangential transmission to humans and horses. we investigate ... | 0 | 22897051 |
| west nile virus-related trends in avian mortality in california, usa, 2003-12. | west nile virus (wnv) is an arbovirus transmitted enzootically by culex mosquitoes among avian hosts. since 2000, the california dead bird surveillance program (dbsp) has tracked avian mortality reported by the public on a telephone hotline and website and measured the prevalence of wnv infection in dead birds. we summarize herein wnv prevalence in dead birds tested and variation of wnv transmission over time and space with the use of dbsp data from 2003 to 2012. prevalence among dead birds was ... | 2015 | 25919466 |
| host-selection patterns of culex tarsalis (diptera: culicidae) determine the spatial heterogeneity of west nile virus enzootic activity in northern california. | the spatial heterogeneity of west nile virus (wnv) activity in sutter county, ca, as measured by mosquito infection rates, was associated with spatial variation in the prevalence of culex blood feeding on competent passeriform hosts. overall, 42 vertebrate host species (31 avian, 11 mammal) were identified from 601 blood-fed culex tarsalis coquillett and 151 blood-fed culex pipiens l. complex females using sequences of the cytochrome c oxidase i gene and the barcode of life data systems database ... | 2013 | 24843936 |
| genetic sequence data reveals widespread sharing of leucocytozoon lineages in corvids. | leucocytozoon, a widespread hemosporidian blood parasite that infects a broad group of avian families, has been studied in corvids (family: corvidae) for over a century. current taxonomic classification indicates that leucocytozoon sakharoffi infects crows and related corvus spp., while leucocytozoon berestneffi infects magpies (pica spp.) and blue jays (cyanocitta sp.). this intrafamily host specificity was based on the experimental transmissibility of the parasites, as well as slight differenc ... | 2016 | 27189064 |
| phylogeny of magpies (genus pica) inferred from mtdna data. | we investigated the phylogenetic relationships of species and subspecies of the cosmopolitan genus pica using 813 bp of the mitochondrial genome (including portions of 16s rdna, trna-leu, and nd1). the phylogenetic relationships within the genus pica revealed in our molecular analyses can be summarized as follows: (1). the korean magpie (pica pica sericea) appears basal within the genus pica; (2). the european magpie (pica pica pica) shows a close relationship to the kamchatkan magpie (pica pica ... | 2003 | 13678680 |
| incidence and seasonal variations in blood and tissue parasites of yellow-billed magpies. | | 1966 | 4957992 |
| frequency of infection and seasonal variation of leucocytozoon berestneffi in the yellow-billed magpie, pica nuttalli. | | 1964 | 14231170 |
| impact of west nile virus on bird populations: limited lasting effects, evidence for recovery, and gaps in our understanding of impacts on ecosystems. | the introduction of west nile virus to north america in 1999 had profound impacts on human and wildlife health. here, we review studies of wnv impacts on bird populations and find that overall impacts have been less than initially anticipated, with few species showing sustained changes in population size or demographic rates across multiple regions. this raises four questions: 1) what is the evidence for wnv impact on bird populations and how can we strengthen future analyses? we argue that futu ... | 2019 | 31549723 |
| genetic diversity of yellow-billed magpies ( pica nutalli) before and after a west nile virus epidemic. | the appearance of west nile virus (wnv) coincided with declines in california, us bird populations beginning in 2004, and particularly affected corvid populations, including yellow-billed magpies ( pica nutalli), an endemic species to california. our objective was to determine if the timing of the wnv epidemic correlated with changes in the genetic diversity or population structure of magpies. we hypothesized the declines in magpie abundance from wnv would lead to genetic bottlenecks and reduced ... | 2019 | 30628856 |
| how do small birds evolve in response to climate change? data from the long-term record at la brea tar pits. | biology textbooks describe the small changes in the beaks of the galápagos finches as exemplars of how birds evolve in response to environmental changes. however, recent studies of the abundant fossil birds at rancho la brea find no evidence of evolutionary responses to the dramatic climate changes of the glacial-interglacial cycle over the past 35 000 years: none of the large birds exhibit any change in body size or limb proportions, even during the last glacial maximum approximately 18 000-20 ... | 2020 | 31912657 |