Topic
Heron
About: Heron is a research topic. Over the lifetime, 1073 publications have been published within this topic receiving 12839 citations. The topic is also known as: the heron family.
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27 May 2015
TL;DR: Heron is now the de facto stream data processing engine inside Twitter, and in this paper the design and implementation of this new system, called Heron are presented and the experiences from running Heron in production are shared.
Abstract: Storm has long served as the main platform for real-time analytics at Twitter. However, as the scale of data being processed in real-time at Twitter has increased, along with an increase in the diversity and the number of use cases, many limitations of Storm have become apparent. We need a system that scales better, has better debug-ability, has better performance, and is easier to manage -- all while working in a shared cluster infrastructure. We considered various alternatives to meet these needs, and in the end concluded that we needed to build a new real-time stream data processing system. This paper presents the design and implementation of this new system, called Heron. Heron is now the de facto stream data processing engine inside Twitter, and in this paper we also share our experiences from running Heron in production. In this paper, we also provide empirical evidence demonstrating the efficiency and scalability of Heron.
553 citations
TL;DR: The feeding strategy of the first group appeared to be one of searching for new high-quality food patches rather than staying and exploiting food patches that were declining in quality, suggesting that factors affecting bird density at feeding sites may also have affected population size.
Abstract: Reduced prey availability has emerged as a primary hypothesis to explain population constraints on wading birds in numerous wetlands around the world. However, there is almost no understanding of which component of prey availability (i.e., prey density or vulnerability of prey to capture) is affecting populations and whether the relative effects of each component differ among species. In this study, I manipulated prey density and water depth (i.e., prey availability) in 12 0.2-ha ponds to determine their relative effects on the numeric response of eight species of free-ranging wading birds (White Ibis, Eudocimus albus; Wood Stork, Mycteria americana; Snowy Egret, Egretta thula; Glossy Ibis, Plegadis falcinellus; Great Egret, Ardea alba; Tricolored Heron, Egretta tricolor; Great Blue Heron, Ardea herodias; and Little Blue Heron, Egretta caerulea). The experiment was conducted in a constructed wetland adjacent to, and west of, the northern tip of the remnant Everglades, in Palm Beach County, Florida, USA. Each pond was set to a water depth of 10 cm, 19 cm, or 28 cm, and was stocked with golden shiners (Notemigonus crysoleucas) at a density of either 3 fish/m2 or 10 fish/m2. Total bird use (all treatments pooled) increased from day 1 (day after stocking) to day 6, stabilized for several days at ∼280 birds, and then decreased until day 16, when bird use nearly ceased. Fish were depleted most rapidly in the shallow treatment and least rapidly in the deep treatment. The giving-up-density (GUD) of prey increased with increasing water depth. There was no significant difference among species in the slope of that relationship; however, a visual inspection of the data showed that differences in GUDs were becoming more apparent in the deepest treatment. At that depth, the White Ibis, Wood Stork, and Snowy Egret had higher GUDs than did the Glossy Ibis, Great Egret, Tricolored Heron, Great Blue Heron, and Little Blue Heron. Also, the first three species were affected significantly by both prey density and water depth, whereas the latter five species showed a decidedly weaker response to one or the other component of prey availability. The first three species were more abundant in the shallow treatments and the high prey density treatments, and they abandoned the study site before other species reached their maximum density. The feeding strategy of the first group appeared to be one of searching for new high-quality food patches rather than staying and exploiting food patches that were declining in quality. Species that employed a searching strategy also have shown the most severe population declines, suggesting that factors affecting bird density at feeding sites may also have affected population size.
328 citations
TL;DR: In this article, the expressive genres used by women living in rural communities in north India to resist and criticize pervasive ideologies of gender and kinship that subordinate women are examined and discussed.
Abstract: This book examines the expressive genres used by women living in rural communities in north India to resist and criticize pervasive ideologies of gender and kinship that subordinate women. Translations of songs and of personal narratives reveal the profound cultural dissent embedded in womens speech genres. The ethnographic analyses 1) comment on current attempts to redefine use of the term \"culture\" by the social sciences 2) explore the \"hidden transcripts\" implicit in womens expressions 3) spark a reconsideration of standard anthropological conceptualizations of marriage and patrilineality in South Asia and 4) relate this consideration of womens speech genres to the broader relationship between language and gender. The book opens with a preface that describes the field work the degree and type of social acceptance offered to the women and the challenges posed to American women attempting to describe and analyze the lives of women from an alien culture. The introductory chapter considers gender representation and the problem of language and resistance in India. Chapter 2 looks at sexuality fertility and erotic imagery in the songs of Rajasthani women. The third chapter examines the uses of irony and ambiguity to shift perspectives on patriliny and ties to natal kin. Chapter 4 analyzes songs that challenge the devaluation of women as wives and present different perspectives on conjugal kinship relations. The fifth chapter discusses how the story of a \"jungle queen\" provides insights into how female identity can be perceived of as split (from her natal family for example) and yet remain whole throughout her life. Chapter 6 provides a narrative about a storytellers life to reexamine womens perceptions of purdah and power. The concluding chapter reflects on the potency of narrative and on the politics of womens expressive traditions.
264 citations
TL;DR: Data from great egrets and great blue herons were used to test a fundamental assumption of Lack's brood‐reduction hypothesis, that mortality is brood‐size dependent, and it is advanced that parents desert unprofitably small broods when sufficient time remains for production of a larger brood.
Abstract: Data from great egrets and great blue herons were used to test a fundamental assumption of Lack's brood-reduction hypothesis, that mortality is brood-size dependent. This was confirmed for the largest brood sizes (4 and 3), which, in egrets, also have the highest sib-fighting rates. Broods of one, however, experienced paradoxically high mortality, especially early in the season. The hypothesis is advanced that parents desert unprofitably small broods when sufficient time remains for production of a larger brood. A simple game-theory model shows that this parental desertion may hinge primarily on the overall costs of renesting. Egret brood reduction caused by sibling aggression (siblicide) occurred later than less aggressive forms of brood reduction. The inclusive fitness of senior broodmates is maximized by the successful fledging of all sibs, and the physical superiority of seniors (in food-handling for herons; food-handling and aggression for egrets) usually suffices to guarantee their own welfare in brood competitions. Finally, it is shown that the last chick in asynchronously hatching broods represents two kinds of reproductive value (RV) to the parents-"extra RV" (obtained despite the survival of elder sibs) and "insurance RV" (obtained only when at least one elder sib dies first)-which can be distinguished from field data. This approach can be used in comparisons with other asynchronous species for partitioning the fitness contributions of marginal offspring.
139 citations
TL;DR: The young born early in the breeding season contained proportionately more dominants than those born later in the season and dominant birds tended to survive better in winter, but the intensity of selection for an ability for dominance may fluctuate from year to year in relation to the population density and distribution and abundance of food supply.
Abstract: Winter survival with respect to dominance classes of 932 individually colour‐ringed Silvereyes was examined on Heron Island, Great Barrier Reef, between 1965 and 1969. The dominants (winning two‐thirds or more of aggressive encounters) had significantly better chances of survival between May and August (southern winter) than other birds. The 1967/68 year group was studied in detail; the young born early in the breeding season contained proportionately more dominants than those born later in the season and dominant birds tended to survive better in winter. Adults in the same period showed no dominance dependent survival. The weight of birds in winter differed between first‐year birds and adults in most cases, but winter mortality within each year‐group was not related to the weight of individual birds in May. However, the dominant class had a smaller proportion of birds losing weight through the winter than other classes, and the dominant adults and the intermediate class of first‐year birds tended to be heavier than others in August. The lengths of wing, tail, tarsus and exposed culmen examined for the 1967/68 year group showed no significant trends in either survival or dominance classes. Better survival of dominant birds is considered to be a consequence of their feeding advantages over others, but the intensity of selection for an ability for dominance may fluctuate from year to year in relation to the population density and distribution and abundance of food supply.
130 citations