Duckling

14,000,000 Leading Edge Experts on the ideXlab platform

Scan Science and Technology

Contact Leading Edge Experts & Companies

Scan Science and Technology

Contact Leading Edge Experts & Companies

The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform

Junwei Wang - One of the best experts on this subject based on the ideXlab platform.

  • Comparative liver transcriptome analysis in Ducklings infected with duck hepatitis A virus 3 (DHAV-3) at 12 and 48 hours post-infection through RNA-seq
    Veterinary Research, 2018
    Co-Authors: Xuelian Zhang, Chong Cao, Yue Liu, Wenjing Zhang, Chunxue Hao, Haotian Chen, Qi Zhang, Wenlong Zhang, Mingchun Gao, Junwei Wang
    Abstract:

    AbstractDuck hepatitis A virus 3 (DHAV-3), the only member of the novel genus Avihepatovirus, in the family Picornaviridae, can cause significant economic losses for duck farms in China. Reports on the pathogenicity and the antiviral molecular mechanisms of the lethal DHAV-3 strain in Ducklings are inadequate and remain poorly understood. We conducted global gene expression profiling and screened differentially expressed genes (DEG) of Duckling liver tissues infected with lethal DHAV-3. There were 1643 DEG and 8979 DEG when compared with mock Ducklings at 12 hours post-infection (hpi) and at 48 hpi, respectively. Gene pathway analysis of DEG highlighted mainly biological processes involved in metabolic pathways, host immune responses, and viral invasion. The results may provide valuable information for us to explore the pathogenicity of the virulent DHAV-3 strain and to improve our understanding of host–virus interactions.

Robert G. Clark - One of the best experts on this subject based on the ideXlab platform.

  • landscape level correlates of mallard Duckling survival implications for conservation programs
    Journal of Wildlife Management, 2012
    Co-Authors: Pauline M Bloom, Robert G. Clark, David W Howerter, Llwellyn M Armstrong
    Abstract:

    Despite recent work, uncertainty remains concerning how abiotic and biotic factors affect Duckling survival. Additionally, upland habitat characteristics may affect Duckling survival rates but this potential relationship has largely been ignored. We evaluated several unresolved hypotheses about causes of mallard (Anas platyrhynchos) Duckling survival variation, with an emphasis on assessing effects of managed and remnant natural upland habitats. During 1993–2000, 617 radio-marked females provided information about brood habitat use and Duckling survival on 27 sites in prairie Canada. We contrasted a priori and exploratory models that incorporated effects of upland, wetland, weather, female, and brood-related variables on Duckling survival rates. Survival was highest for Ducklings when a greater proportion of their surrounding landscape (i.e., within a 500-m radius buffer around the brood) was comprised of wetlands characterized by a central expanse of open water and a peripheral ring of flooded emergent vegetation. Cold and wet weather in the first week of life resulted in lower Duckling survival. In a post hoc analysis, Duckling survival (of older Ducklings) was negatively related to increasing proportions of managed hayland. © 2011 The Wildlife Society.

  • seasonal variation in pre fledging survival of lesser scaup aythya affinis hatch date effects depend on maternal body mass
    Journal of Avian Biology, 2012
    Co-Authors: Kirsty Gurney, Robert G. Clark, Stuart M Slattery
    Abstract:

    Among temperate-breeding birds, offspring survival and reproductive success are often inversely related to timing of breeding. The mechanisms that produce seasonal declines in offspring survival are not fully understood but may be related to temporal changes in parental quality, environmental quality, or both. We analyzed data for lesser scaup Aythya affinis to evaluate hypothesized effects of parental quality and date on pre-fledging survival. Maternal quality, as indexed by body mass, did not have an independent effect on offspring survival in this species. Maternal body mass did not decline seasonally and did not have an independent effect on Duckling survival. Although we did not detect an independent effect of hatch date on Duckling survival, Duckling survival declined seasonally for broods raised by lightweight females, indicating an interactive effect of maternal mass and date. We hypothesize that this interaction may be driven by seasonally declining food resources coupled with the influence of female condition on the ability to monopolize food resources or remain attentive to the brood. We also tested morphological predictions of the date hypothesis by examining physical characteristics of Ducklings. When corrected for age and size, late-hatched Ducklings tended to have marginally larger digestive systems and smaller leg muscles than did early-hatched birds. Abundances of intestinal parasites acquired through diet decreased marginally in late-hatched Ducklings. Results for digestive system and parasite infection patterns suggested that later-hatched broods may shift diets, consistent with a contribution of environmental factors to seasonal variation in offspring survival. Taken together, our results suggest that both female attributes and environmental conditions may influence seasonal patterns of offspring survival in this species.

  • consequences of egg size for offspring survival a cross fostering experiment in ruddy ducks oxyura jamaicensis
    The Auk, 2003
    Co-Authors: Jeffrey T Pelayo, Robert G. Clark
    Abstract:

    Abstract In birds, large egg size often enhances subsequent offspring survival, but most previous studies have been unable to separate effects of egg size from other maternal influences. Therefore, we first evaluated variance components of egg size both within and among individual female Ruddy Ducks (Oxyura jamaicensis), and then tested for egg-size-dependent survival of Ducklings in the wild by switching complete broods among females. Forty broods consisting of 244 individually color-marked, day-old Ducklings of known egg size were given to foster mothers, and survival was monitored to one month. Analysis of mark–resighting data showed that offspring survival was best modeled to include effects of egg size and hatching date; survival probability increased with egg size, but declined with advancing hatching date. Duckling body mass, body size, and body condition measured at hatching were positively correlated with egg size. Unlike most other duck species, and for reasons that are speculative, egg sizes va...

  • Patterns of reproductive effort and success in birds: path analyses of long-term data from European ducks
    Journal of Animal Ecology, 2002
    Co-Authors: Peter Blums, Robert G. Clark, Aivars Mednis
    Abstract:

    Summary 1 We tested ecological hypotheses about timing of breeding and reproductive effort in birds, by analysing > 15-year data sets for individually marked females in three species of Latvian ducks (northern shoveler, tufted duck, common pochard). 2 Duckling survival and recruitment declined with advancing hatch date in pochard and tufted duck, after controlling for effects of female age and other factors with path analysis, a novel finding which indicates that fitness advantages associated with early hatching extended beyond the prefledging period. Logistic regression analysis suggested further that individual Duckling prefledging survival was moderate in the earliest phase of the breeding season, greatest in mid-season and lowest later on. 3 However, selection acting against early hatched Ducklings was surpassed by strong directional selection favouring recruitment of the earliest hatching females. The absolute and relative numbers of female recruits produced by a breeding female declined sharply with advancing hatch date in all species. 4 Unlike previous studies, an hypothesized intraspecific trade-off between Duckling mass and brood size was detected, being very robust in two of three species. 5 Unexpectedly, female age effects on recruitment were manifested only indirectly by several pathways, the most important being the earlier hatching dates of older females. Size-adjusted body mass (i.e. condition index) was positively related to reproductive success, and was 2–8-fold more influential than female size (indexed by wing length). 6 Overall, fecundity-independent variables (e.g. hatching date, weather, indices of Duckling production and habitat quality) generally had 2–10 times greater influence on recruitment rates than did fecundity-dependent variables such as female size or condition, Duckling mass and brood size, suggesting a critical role for external environmental factors vs. individual female-specific traits in the recruitment process.

  • effects of variation in egg size and hatching date on survival of lesser scaup aythya affinis Ducklings
    Ibis, 1996
    Co-Authors: Russell D. Dawson, Robert G. Clark
    Abstract:

    The consequences of avian egg-size variation on offspring quality and survival remain unclear. We evaluated the effects of egg-size and hatch-date variation on survival of Lesser Scaup Aythya affinis Ducklings in the wild. Duckling mass at hatching increased significantly with increasing egg size. Ducklings from larger eggs survived better than those from smaller eggs. We suspect that Ducklings from larger eggs survived better because of advantages associated with larger or more efficient utilization of nutrient reserves, or both. We were unable to detect any within-clutch differences in egg size of survivors and non-survivors, nor any consistent direction in the difference in egg size between survivors and nonsurvivors within clutches. This suggests that within-clutch variation may be insufficient to have survival consequences for offspring. In addition, Ducklings that hatched later in the breeding season had a higher probability of survival. We suggest a food-dependent hypothesis as an explanation for the seasonally increasing survival and for later nest initiation of Lesser Scaup compared with other North American ducks.

Xuelian Zhang - One of the best experts on this subject based on the ideXlab platform.

G. C. Perry - One of the best experts on this subject based on the ideXlab platform.

Mingchun Gao - One of the best experts on this subject based on the ideXlab platform.

Duckling - 15 days free trial to Access Experts & Abstracts