Project description:The endangered California Condor (Gymnogyps californianus) is the largest New World Vulture in North America. Despite recovery program success in saving the species from extinction, condors remain compromised by lead poisoning and limited genetic diversity. The latter makes this species especially vulnerable to infectious diseases. Thus, taking advantage of the program of blood lead testing in Arizona, condor blood samples from 2008 to 2018 were screened for haemosporidian parasites using a nested polymerase chain reaction (PCR) protocol that targets the parasite mitochondrial cytochrome b gene. Plasmodium homopolare (Family Plasmodiidae, Order Haemosporida, Phylum Apicomplexa), was detected in condors captured in 2014 and 2017. This is the first report of a haemosporidian species infecting California Condors, and the first evidence of P. homopolare circulating in the Condor population from Arizona. Although no evidence of pathogenicity of P. homopolare in Condors was found, this study showed that the California Condors from Arizona are exposed to haemosporidian parasites that likely are spilling over from other local bird species. Thus, active surveillance should be an essential part of conservation efforts to mitigate the impact of infectious diseases, an increasingly recognized cause of global wildlife extinctions worldwide, particularly in avian populations considered vulnerable or endangered.
Project description:Condors and vultures are distinct from most other terrestrial birds because they use extensive soaring flight for their daily movements. Therefore, assessing resource selection by these avian scavengers requires quantifying the availability of terrestrial-based habitats, as well as meteorological variables that influence atmospheric conditions necessary for soaring. In this study, we undertook the first quantitative assessment of habitat- and meteorological-based resource selection in the endangered California condor (Gymnogyps californianus) within its California range and across the annual cycle. We found that condor use of terrestrial areas did not change markedly within the annual cycle, and that condor use was greatest for habitats where food resources and potential predators could be detected and where terrain was amenable for taking off from the ground in flight (e.g., sparse habitats, coastal areas). Condors originating from different release sites differed in their use of habitat, but this was likely due in part to variation in habitats surrounding release sites. Meteorological conditions were linked to condor use of ecological subregions, with thermal height, thermal velocity, and wind speed having both positive (selection) and negative (avoidance) effects on condor use in different areas. We found little evidence of systematic effects between individual characteristics (i.e., sex, age, breeding status) or components of the species management program (i.e., release site, rearing method) relative to meteorological conditions. Our findings indicate that habitat type and meteorological conditions can interact in complex ways to influence condor resource selection across landscapes, which is noteworthy given the extent of anthropogenic stressors that may impact condor populations (e.g., lead poisoning, wind energy development). Additional studies will be valuable to assess small-scale condor movements in light of these stressors to help minimize their risk to this critically endangered species.
Project description:Vertebrates respond to stressful stimuli with the secretion of glucocorticoid (GC) hormones, such as corticosterone (CORT), and measurements of these hormones in wild species can provide insight into physiological responses to environmental and human-induced stressors. California condors (Gymnogyps californianus) are a critically endangered and intensively managed avian species for which information on GC response to stress is lacking. Here we evaluated a commercially available I125 double antibody radioimmunoassay (RIA) and an enzyme-linked immunosorbent assay (ELISA) kit for measurement of CORT and GC metabolites (GCM) in California condor plasma, urate, and feather samples. The precision and accuracy of the RIA assay outperformed the ELISA for CORT and GCM measurements, and CORT and GCM values were not comparable between the two assays for any sample type. RIA measurements of total CORT in condor plasma collected from 41 condors within 15 minutes of a handling stressor were highly variable (median = 70 ng/mL, range = 1-189 ng/mL) and significantly different between wild and captive condors (p = 0.02, two-tailed t-test, n = 10 wild and 11 captive). Urate GCM levels (median = 620 ng/g dry wt., range = 0.74-7200 ng/g dry wt., n = 216) significantly increased within 2 hr of the acute handling stressor (p = 0.032, n = 11 condors, one-tailed paired t-test), while feather section CORT concentrations (median = 18 pg/mm, range = 6.3-68 ng/g, n = 37) also varied widely within and between feathers. Comparison of multiple regression linear models shows condor age as a significant predictors of plasma CORT levels, while age, sex, and plasma CORT levels predicted GCM levels in urates collected within 30 min of the start of handling. Our findings highlight the need for validation when selecting an immunoassay for use with a new species, and suggest that non-invasively collected urates and feathers hold promise for assessing condor responses to acute or chronic environmental and human-induced stressors.
| S-EPMC6198957 | biostudies-literature
Project description:California condor and Andean condor Raw sequence reads
Project description:This data is a re-analysis of samples used in a prior study (doi:10.1371/journal.pone.0123295) evaluating plasma candidate biomarkers of chronic domoic acid toxicosis (DAT) in California sea lions (Zalophus californianus). The previous study used 2D-gel electrophoresis to analyze plasma from a training (n = 32; 12 DAT and 20 non-DAT) and validation set (n = 20; 7 DAT and 13 non-DAT). Using spot intensity followed by in-gel digestion and LC-MS/MS, decreased ApoE was identified and qualified as a classifier of chronic DAT. The current analysis is from 31 of these samples (14 DAT and 17 non-DAT), since some samples were no longer available or had been through too many freeze/thaw cycles and were no longer suitable for robust analysis. This subset of 31 undepleted plasma samples was analyzed using shotgun proteomics with a tribrid mass spectrometer, and searching was performed with the recently completed California sea lion genome (https://www.ncbi.nlm.nih.gov/genome/annotation_euk/Zalophus_californianus/100/). Using MS1-based label-free methods we were able to identify candidate markers of chronic DAT, such as decreasing ApoE, ApoC-III and ApoB-100. We expect other analytical pipelines could be used to analyze this data, and we deliberately collected the MS1 and MS2 at high resolution to enable spectral library creation for approaches such as data-independent acquisition, which may be used in follow-up studies.
Project description:Since 1998, California sea lion stranding events associated with domoic acid toxicosis (DAT) have consistently increased and there are no practical non-lethal clinical tests for the diagnosis of domoic acid toxicosis that can be utilized in a large-scale rehabilitation facility. Proteomic analysis was conducted to discover candidate protein markers of DAT using cerebrospinal fluid (CSF) from stranded sea lions with acute DAT, chronic DAT, or without DAT. A total of 2005 protein families were identified across 40 CSF samples (FDR<0.01) using the annotated California sea lion genome. Of these proteins, 83 were significantly different in abundance across the three groups (p<0.05). Comparisons between all sea lions with DAT versus those without DAT indicated that 119 proteins were significantly different between both groups (p<0.05); whereas, 47 proteins were significantly different between acute DAT and chronic DAT (p<0.05). Significant proteins were assessed as classifiers using ROC curves. Compared to sea lions with non-DAT, those with either acute or chronic DAT displayed higher levels of 14-3-3 proteins and malate dehydrogenase, and lower levels of 5’-3’ exonuclease PLD3, neurosecretory protein VGF, disintegrin and metalloproteinase domain-containing protein, and calsyntenin-1. When comparing acute DAT versus chronic DAT, 4 proteins were identified as good classifiers. Elevated levels of beta-synuclein was detected in acute DAT, and was identified as a high classifier for both comparisons. Many of these proteins have been implicated in a variety of neurodegenerative diseases. These proteins should be considered potential markers for DAT in California sea lions, as well as markers to discriminate between acute or chronic DAT, and should be considered priority for future validation studies as biomarkers.