| heavy metals and metalloids in egg contents and eggshells of passerine birds from arizona. | concentrations of inorganic elements were determined in eggs of passerine birds including the endangered southwestern willow flycatcher (empidonax traillii extimus) from four regions in arizona. the main aim of the study was to determine the distribution of metals in egg contents and eggshells, with emphasis on the deposition of sr in eggshells. seventy eggs of 11 passerine species were collected at four nesting locations during 2000. aluminum, ba, cr, cu, mn, se, sr, and zn, were detected prima ... | 2003 | 12826417 |
| the effect of vegetation density on male mate guarding and extra-territorial forays in the yellow-breasted chat (icteria virens). | extra-pair paternity is widely documented in birds, but the behaviors that lead to extra-pair copulations (epcs) have been less well studied, particularly in territorial songbirds. we studied the behaviors associated with extra-territorial forays (etfs) and male mate guarding in a socially monogamous, but genetically promiscuous, neotropical migrant passerine, the yellow-breasted chat (icteria virens). focal observations and radiotelemetry revealed that both males and females engaged in etfs. 65 ... | 2004 | 15085279 |
| wind conditions on migration influence the annual survival of a neotropical migrant, the western yellow-breasted chat (icteria virens auricollis). | long-distance migratory birds in north america have undergone precipitous declines over the past half-century. although the trend is clear, for many migrating species underpinning the exact causes poses a challenge to conservation due to the numerous stressors that they encounter. climate conditions during all phases of their annual cycle can have important consequences for their survival. here, using 15 years of capture-recapture dataset, we determined the effects of various climate factors dur ... | 2017 | 28797249 |
| explicit not implicit preferences predict conservation intentions for endangered species and biomes. | conservation of biodiversity is determined in part by human preferences. preferences relevant to conservation have been examined largely via explicit measures (e.g., a self-reported degree of liking), with implicit measures (e.g., preconscious, automatic evaluations) receiving relatively less attention. this is the case despite psychological evidence from other contexts that implicit preferences are more informative of behavior. thus, the type of measure that predicts conservation intentions for ... | 2017 | 28135298 |
| co-infections of haemosporidian and trypanosome parasites in a north american songbird. | hosts frequently harbour multiple parasite infections, yet patterns of parasite co-occurrence are poorly documented in nature. in this study, we asked whether two common avian blood parasites, one haemosporidian and one trypanosome, affect each other's occurrence in individuals of a single host species. we used molecular genotyping to survey protozoan parasites in the peripheral blood of yellow-breasted chats (aves: passeriformes [parulidae]: icteria virens) from the ozarks of southern missouri. ... | 2016 | 27644582 |
| the ecology of host immune responses to chronic avian haemosporidian infection. | host responses to parasitism in the wild are often studied in the context of single host-parasite systems, which provide little insight into the ecological dynamics of host-parasite interactions within a community. here we characterized immune system responses to mostly low-intensity, chronic infection by haemosporidian parasites in a sample of 424 individuals of 22 avian host species from the same local assemblage in the missouri ozarks. two types of white blood cells (heterophils and lymphocyt ... | 2014 | 25179282 |