Individual foraging behaviour indicates resource limitation: an experiment with mallard ducklings

2000 ◽  
Vol 78 (11) ◽  
pp. 1891-1895 ◽  
Author(s):  
Petri Nummi ◽  
Kjell Sjöberg ◽  
Hannu Pöysä ◽  
Johan Elmberg
Keyword(s):  
Foraging Behaviour ◽  
Time Budget ◽  
Resource Limitation ◽  
Boreal Lakes ◽  
High Concentration ◽  
Resource Limited ◽  
Foraging Performance ◽  
The Rich ◽  
Brood Stage ◽  
Do So

The linkage between individual behaviour and population processes has recently been emphasized. Within this framework we studied the effect of resource limitation on the behaviour of mallard (Anas platyrhynchos) ducklings in boreal lakes. One group of 12 human-imprinted ducklings (4-16 days old) were taken to 11 "rich" lakes, i.e., with a relatively high concentration of total phosphorus in the water, and the other group of 12 ducklings to 11 "poor" lakes to forage for a period of 6 h. During this, a time budget study lasting 5 min was done of each of the 12 ducklings. In the rich lakes, ducklings fed significantly more and moved less than in the poor ones. This difference was particularly striking in above-surface feeding. Variation in foraging performance was associated with change in body mass of the ducklings: the less distance the ducklings moved and the more they fed above water, the more they gained mass. Earlier results had suggested that at least some of the boreal wetlands that lack duck broods year after year (70% of the total in one study) do so because they do not harbour enough food. Hence, it is possible that mallard populations are resource-limited at the brood stage during the breeding season.

scholarly journals The rich get richer and the poor get poorer - the Matthew mechanism as an approach to explain selection effects and the occurrence of multiple medalists in the "production" of international success in alpine ski racing

2018 ◽  
Author(s):  
Michael Barth ◽  
Arne Güllich ◽  
Eike Emrich
Keyword(s):  
Turnover Rate ◽  
Social Mechanisms ◽  
High Concentration ◽  
Socialization Process ◽  
National Team ◽  
Selection Processes ◽  
The Rich ◽  
The Individual ◽  
International Success

The study addresses two questions that are under debate in the literature and exemplifies their examination in alpine ski racing. Firstly, are successful athletes the product of a long-term continuous intervention and/or socialization process or do they rather emerge via repeated selection processes? Secondly, to which extent is a nations’ collective success composed of many athletes’ singular successes or of a few athletes’ multiple successes?The study involved the national squad of the Austrian Ski Federation. Data collection comprised membership in a national squad and World or Olympic medal success and was carried out via document analysis (seasons: 1986-2016).The mean annual athlete turnover rate ranged from 24-57% across squad levels while the turnover rate varied substantially over time within each squad level. Among all national squad athletes, the incidence of being a successful (i.e., medal winning) National Team athlete was 8.9% (95% CI: 6.0%; 12.5%). Twenty-eight athletes won a total of 112 medals, 21 athletes achieved winning two or more medals. The six most successful athletes won 56 medals, comprising 50% of all medals won.The study suggests that successful elite athletes emerge from repeated selection and filtering processes. The observation of multiple medalists and a high concentration of exceptional success among a few athletes is reflected with regard to potential causes that rest on characteristics of the individual athlete, on social mechanisms (e.g., Matthew mechanism) of the elite sports system, or both.

Making Class: Children's Perceptions of Social Class through Illustrations

2018 ◽  
Vol 120 (7) ◽  
pp. 1-44
Author(s):  
Adam Howard ◽  
Katy Swalwell ◽  
Karlyn Adler
Keyword(s):  
Social Class ◽  
Young People ◽  
Sixth Graders ◽  
Third Graders ◽  
Poor People ◽  
Class Differences ◽  
The Rich ◽  
And Gender ◽  
Background Context ◽  
Do So

Background/Context Though there has been attention to how class differences impact children's experiences in schools and how young people perceive racial and gender differences, very little research to date has examined how young people make sense of social class differences. Purpose In this article, the authors examine young children's conceptualizations of differences between the rich and the poor to better understand children's process of classmaking. Research Design To access young children's ideas about social class, the authors examined kindergartners’, third graders’, and sixth graders’ (N = 133) drawings depicting differences between rich and poor people and their corresponding explanations of their drawings. These children attended two schools, one public serving a majority working- class population, and one private serving a majority affluent population. Findings/Results Children understand social class to be inclusive emotions, social distinctions, and social status. Children's drawings and explanations show that perpetuated ideology-justifying status quo of poverty and economic inequality. Children have complex sociocultural insights into how social class operates that manifest themselves through four domains: material, intersectional, emotional, and spatial. Conclusions/Recommendations Educators should provide more opportunities for teaching about social class, and can do so in ways that engages students in processes of classmaking that do not reinforce stereotypes and that interrupts inequality.

The glossy black-cockatoo (Calyptorhynchus lathami halmaturinus) spends little time and energy foraging on Kangaroo Island, South Australia

2005 ◽  
Vol 53 (3) ◽  
pp. 177 ◽  
Author(s):  
Tamra F. Chapman ◽  
David C. Paton
Keyword(s):  
Food Supply ◽  
Small Proportion ◽  
Foraging Behaviour ◽  
Time Budget ◽  
South Australia ◽  
Breeding Birds ◽  
Additional Energy ◽  
Allocasuarina Verticillata ◽  
Risk Of Predation ◽  
Time And Energy

The endangered Kangaroo Island glossy black-cockatoo (Calyptorhynchus lathami halmaturinus) relies entirely on the seeds of the drooping sheoak (Allocasuarina verticillata) for food. The time budget of the glossy black-cockatoos and their foraging behaviour was recorded to provide an indication of whether their food supply was likely to be limiting. The foraging behaviour of non-breeding and breeding cockatoos was also compared to record the strategy they used to collect the additional energy needed to raise young. Glossy black-cockatoos spent a relatively small proportion of their time foraging, suggesting that the food supply was abundant in the habitats used for feeding. Non-breeding birds spent only 26% of their time feeding and breeding birds spent only 36% of their time feeding. The cockatoos spent 0.4% of their time flying, foraged in a mean of only five trees per day and harvested cones in no more than five bouts per tree. This shows that the cockatoos made few movements between drooping sheoaks and within the canopy of the sheoaks when foraging. When breeding, the cockatoos spent significantly more time per day foraging, cropped cones in significantly more bouts per tree and harvested significantly more cones per tree than non-breeding birds. This shows that breeding birds increased their energy intake without greatly increasing movement between trees. The small number of movements made by glossy black-cockatoos when foraging on Kangaroo Island reflects the abundance of food trees and may be a strategy to reduce the risk of predation.

High Quality cDNA synthesis and Amplification of Chalcone Synthase Gene (CHS) from Justicia gendarussa Burm. F.

2013 ◽  
Vol 64 (2) ◽  
Author(s):  
Arman Amani Babadi ◽  
Faezah Mohd Salleh
Keyword(s):  
Chalcone Synthase ◽  
High Concentration ◽  
Cdna Synthesis ◽  
Chalcone Synthase Gene ◽  
Malonyl Coa ◽  
Flavonoid Biosynthetic Pathway ◽  
Ctab Method ◽  
Preliminary Study ◽  
The Rich ◽  
Flavonoid Biosynthesis Pathway

Chalcone synthase (CHS) (EC 2.3.1.74) catalyzes the first committed step of flavonoid biosynthesis pathway. It combines 4-coumaroyl-CoA with three C2 units from malonyl-CoA to produce naringenin chalcone which transforms to various numbers of flavonoids. In this work, we attempt to isolate the CHS gene from Gendarusa, which could serve as a preliminary study to elucidate the CHS gene regulation in the flavonoid biosynthetic pathway of Malaysian medicinal plants generally, and in Justicia gendarussa Burm. F. species specifically. The total RNA was isolated from the mature leaves of Justicia gendarussa Burm. F. using the modified CTAB method. Extracted RNA, treated with RQ1 RNase-free DNasekit and cDNA synthesis in order to prepare the rich template of DNA for PCR by using M-MLV Reverse Transcriptase kit. High concentration of cDNA and A260/280 ratio reversely transcribed cDNAs guarantee the quality and quantity of synthesized cDNA. The CHS gene was amplified using the Phusion DNA Polymeraseand showed the same size of the previously amplified CHS gene from Melastoma, 1100bp.

Shaping scientific instrument collections

2018 ◽  
Vol 31 (3) ◽  
pp. 445-452 ◽  
Author(s):  
Samuel J M M Alberti
Keyword(s):  
Scientific Instrument ◽  
Scientific Instruments ◽  
Original Function ◽  
Historiography Of Science ◽  
History Of ◽  
The Rich ◽  
Do So

Abstract Many histories of scientific instruments concentrate on their manufacture and original function, but such artefacts as survive often do so in collections – many will have spent far longer in a museum than anywhere else. Alongside the rich literature on the history of scientific instruments, accordingly, there is a body of work on the histories of scientific instrument collections. This survey outlines genres and themes in the historiography of scientific instruments, focusing in particular on display and other collection-based functions. Fluid and contingent, collections are instrumental in the history, heritage, and historiography of science.

Curriculum Construction: A Critical Analysis of Rich Tasks in the Recontextualisation Field

2007 ◽  
Vol 51 (2) ◽  
pp. 112-128 ◽  
Author(s):  
Doune Macdonald ◽  
Lisa Hunter ◽  
Richard Tinning
Keyword(s):  
Primary Field ◽  
Health And Physical Education ◽  
Construction Of Knowledge ◽  
Assessment Tasks ◽  
The Social ◽  
Social Construction Of Knowledge ◽  
The Rich ◽  
Curriculum Construction ◽  
Do So ◽  
Rich Tasks

Within Education Queensland's recent ‘new basics' curriculum initiative, Education Queensland developed 20 transdisciplinary learning and assessment tasks for Years 1 to 9, called ‘rich tasks’. This paper critiques two of the rich tasks that were most closely aligned to knowledge and skills within the health and physical education learning area. To do so we draw on Bernstein's (1996) theory of the social construction of knowledge. Through this framework we analyse how two rich tasks recontextualise the discourses from the primary field in the production of the highly-valued healthy citizen. We argue that these particular rich tasks do not fully realise the tenets of the new basics agenda and, more broadly, of contemporary physical activity and health discourses. We conclude that, for curriculum artefacts to be meaningful, curriculum makers must be informed by closer attention to the primary field of knowledge.

Theories of Majority Rule

1932 ◽  
Vol 26 (3) ◽  
pp. 452-469 ◽  
Author(s):  
John Gilbert Heinberg
Keyword(s):  
Canon Law ◽  
Majority Rule ◽  
Greek City ◽  
External Resources ◽  
The People ◽  
Long Run ◽  
The Rich ◽  
City States ◽  
The Right ◽  
Do So

The term “majority rule” is as impossible to escape as it is apparently difficult to define with precision. Aristotle generally employed it to designate the conduct of government by the poor citizens, who were more numerous than the rich, in the Greek city states. In canon law, it meant the verdict of the maior and sanior pars of a small group. Frederic Harrison wrote about the “rule” of the “effective majority”—that section of any community or social aggregate, which, for the matter in hand, practically outweighs the remainder. He explains that it may do so “by virtue of its preponderance in numbers, or in influence, or in force of conviction, or in external resources, or in many other ways.” Sir George Cornewall Lewis thought that where the ultimate decision is vested in a body there is no alternative other than to count numbers, and to abide by the opinion of a majority. But in alleging that “no historian, in discussing the justice or propriety of any decision of a legislative body, or of a court of justice, thinks of defending the decision of the majority by saying that it was the decision of the majority,” he did not anticipate the view of the English historian Hearnshaw. According to the latter, “The faith of a democrat requires him to believe that in the long run the majority of the people finds its way to the truth, and that in the long run it tries to do the right.”

scholarly journals Historical and cultural heritage of the Tyumen Territory and the possibility of its use

2021 ◽  
Vol 4 (1) ◽  
pp. 29-43
Author(s):  
O. Anoshko
Keyword(s):  
Cultural Heritage ◽  
Urban Areas ◽  
Transport Network ◽  
Archaeological Sites ◽  
Tourist Industry ◽  
High Concentration ◽  
Natural Landscape ◽  
Archaeological Heritage ◽  
Natural Landscapes ◽  
The Rich

The  article  presents  brightness  and  identity  of  ancient  and  medieval monuments  of  the  Tyumen  region  and  demonstrates  the  possibilities  of  their  use  in  the  development  of  the  tourist  industry  of  this  region,  which  was  distinguished  by  extensive  lowland  territories  and  a  convenient  transport  network.  The  high  concentration  of  archaeological  sites  on  certain  sites  surrounded  by  unique  natural  landscapes  allows  us  to  talk about  the  creation  of  natural  landscape  archaeological  complexes  as  synthesis  of  nature, archeology  and  architecture.  Particular  attention  is  paid  to  the  rich  archaeological  heritage  of  Tobolsk,  the  first  Russian  capital  of  Siberia,  the  need  to  organize  museum  and  tourist complexes in historically significant urban areas, free from any constructions.

scholarly journals Diurnal feeding strategies of the Ferruginous Duck (Aythya nyroca) in Lake Tonga (Northeastern Algeria)

2019 ◽  
Vol 27 (1) ◽  
pp. 85-98 ◽  
Author(s):  
Khalil Draidi ◽  
Badis Bakhouche ◽  
Naouel Lahlah ◽  
Imed Djemadi ◽  
Mourad Bensouilah
Keyword(s):  
Feeding Behaviour ◽  
Foraging Behaviour ◽  
Time Budget ◽  
Search Time ◽  
Environmental Parameters ◽  
Feeding Strategies ◽  
A Minor ◽  
Northeastern Algeria ◽  
Foraging Time ◽  
Minor Activity

Abstract Although the Ferruginous Duck (Aythya nyroca) has thoroughly been studied, the foraging behaviour of this species is still not completely known. In the present paper we studied the diurnal feeding behaviour of ducks. We monitored the annual cycle of birds through two fieldtrips per month. The instantaneous behaviour of birds was recorded in regular 30-minute intervals from 7 a.m. to 4:30 p.m., amounting a total of 456 observation hours. Food searching activity corresponds to a quarter of the total diurnal time budget of the Ferruginous Duck. Foraging behaviour was classified into five categories dominated by the “diving”, which is almost 45.61% of the total search time. Foraging activities at the water surface considered to be secondary activities, including feeding by “bill”, “neck and head”, and “beak and head” in a rate of 19.86%, 14.53%, and 13.98%, respectively. The “toggle” remains a minor activity and represents only 5.99% of foraging time. The feeding behaviour of this species correlated to several environmental parameters (rainfall, temperature and wind velocity), and linked to the group size of ducks visiting the lake. Regarding the food intensity, our results show the highest values for “bill and head” behaviour. “Diving” has the longest feeding interval (16.16±14.1 minutes), while foraging by “bill” has the shortest (0.69 ± 0.48 minutes).

scholarly journals Steampunk! ed. by K. Link and G. J. Grant

2013 ◽  
Vol 2 (4) ◽  
Author(s):  
Matilda Roche
Keyword(s):  
Young Adults ◽  
Graphic Novels ◽  
Public Awareness ◽  
Literary Genre ◽  
Illustrated Books ◽  
The Rich ◽  
One Year ◽  
The University ◽  
Do So

Link, Kelly, and Gavin J. Grant, eds. Steampunk! An Anthology of Fantastically Rich and Strange Stories. Somerville: Candlewick Press, 2011. Print. It's interesting to consider the steampunk trend in contrast with the steampunk genre. If one defines steampunk strictly as a trend then it would be easy to assume that it has reached and surpassed its pinnacle as a popular trend (and certainly a hipster one) after having reached a plateau of modest public awareness. All the gears, brass and buckles associated with its afficionados have been lightly mocked and the world has moved on. It might be easy to forget that, as a literary genre, steampunk has a genuine durability. Steampunk been around sparking writers’ and artists’ creative imaginations for some time and it seems probable that it will continue to do so as the more clichéd charms of the trend’s most recent manifestations fade. The diversity and quality of the stories included in Steampunk! are an indication of the rich and entertaining possibilities inherent in the genre. The stories range in subject from post-feminist-western-train-heist-with-time-travel (Last Ride of the Glory Girls, by Libba Bray) to Edwardian-romance-with-robots (Everything Amiable and Obliging, by Holly Black) and mechanical-Dickensian-doppelgangers (Clockwork Fagin, by Cory Doctorow). All these stories are mischievous and riveting action-packed fun. Co-editor, Kelly Link (The Summer People) and M.T. Anderson's (The Oracle Engine) contributions - utterly different from the previously mentioned stories and from each other - adeptly employ calculated pacing and succeed in being subtly sinister and thought-provoking. There are even two compelling, and again, completely different, graphic novels thrown into the mix (Seven Days Beset by Demons, by Shawn Cheng and Finishing School, by Kathleen Jennings). Steampunk is a genre infatuated with the novelty of conflating ideas and aesthetics from different periods of history, curiosity about technology and a precocious desire to upend conventional narrative and characterization. Steampunk! An Anthology of Fantastically Rich and Strange Stories benefits from the astute and mindful curation by its editors, avoids seeming over-thought and stilted, and succeeds in illustrating how steampunk as a genre is very amendable to imaginative and (mildly) transgressive literature for young adults. I'm at great pains to avoid the word "mash-up" but that is a bit of what steampunk is; a unconstrained, tart and pulpy mash of genres. Steampunk! is an exuberant and convincing sampling and a reminder not to dismiss the genre along with the fashion aviator’s goggles. Highly Recommended:  4 out of 4 starsReviewer: Matilda RocheMatilda spends her days lavishing attention on the University of Alberta’s metadata but children’s illustrated books, literature for young adults and graphic novels also make her heart sing. Her reviews benefit from the critical influence of a four year old daughter and a one year old son – both geniuses. Matilda’s super power is the ability to read comic books aloud.

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