Mast seeding promotes evolution of scatter-hoarding

Many plant species worldwide are dispersed by scatter-hoarding granivores: animals that hide seeds in numerous, small caches for future consumption. Yet, the evolution of scatter-hoarding is difficult to explain because undefended caches are at high risk of pilferage. Previous models have attempted to solve this problem by giving cache owners large advantages in cache recovery, by kin selection, or by introducing reciprocal pilferage of ‘shared’ seed resources. However, the role of environmental variability has been so far overlooked in this context. One important form of such variability is masting, which is displayed by many plant species dispersed by scatterhoarders. We use a mathematical model to investigate the influence of masting on the evolution of scatter-hoarding. The model accounts for periodically varying annual seed fall, caching and pilfering behaviour, and the demography of scatterhoarders. The parameter values are based mostly on research on European beech ( Fagus sylvatica ) and yellow-necked mice ( Apodemus flavicollis ). Starvation of scatterhoarders between mast years decreases the population density that enters masting events, which leads to reduced seed pilferage. Satiation of scatterhoarders during mast events lowers the reproductive cost of caching (i.e. the cost of caching for the future rather than using seeds for current reproduction). These reductions promote the evolution of scatter-hoarding behaviour especially when interannual variation in seed fall and the period between masting events are large. This article is part of the theme issue ‘The ecology and evolution of synchronized seed production in plants’.

Download Full-text

Mast seeding promotes evolution of scatter-hoarding

10.1101/698761 ◽

2019 ◽

Author(s):

Rafał Zwolak ◽

Dale Clements ◽

Andrew Sih ◽

Sebastian J. Schreiber

Keyword(s):

Plant Species ◽

Environmental Variability ◽

Mast Seeding ◽

Scatter Hoarding ◽

Hoarding Behavior ◽

Future Consumption ◽

Seed Fall ◽

The Cost ◽

Important Form

ABSTRACTMany plant species worldwide are dispersed by scatterhoarding granivores: animals that hide seeds in numerous, small caches for future consumption. Yet, the evolution of scatterhoarding is difficult to explain because undefended caches are at high risk of pilferage. Previous models have attempted to solve this problem by giving cache owners unrealistically large advantages in cache recovery, by kin selection (but individuals that cache and those that pilfer are usually unrelated), or by introducing reciprocal pilferage of “shared” seed resources. However, the role of environmental variability has been so far overlooked in this context. One important form of such variability is masting, which is displayed by many plant species dispersed by scatterhoarders. We use a mathematical model to investigate the influence of masting on the evolution of scatter-hoarding. The model accounts for periodically varying annual seed fall, caching and pilfering behavior, and the demography of scatterhoarders. Masting, through its effects on population density, reduces cache pilferage and lowers the reproductive cost of caching (i.e. the cost of caching for the future rather than using seeds for current reproduction). These reductions promote the evolution of scatter-hoarding behavior especially when interannual variation in seed fall and the period between masting events are high.

Download Full-text

THE ROLE OF INSURANCE IN ENTERPRISE RISK MANAGEMENT

Zeszyty Naukowe Wyższej Szkoły Humanitas Zarządzanie ◽

10.5604/01.3001.0010.8286 ◽

2017 ◽

Vol 18 (4) ◽

pp. 133-147

Author(s):

Ewa Wierzbicka

Keyword(s):

Risk Management ◽

Environmental Variability ◽

Traditional Approach ◽

Risk Transfer ◽

Economic Practice ◽

Enterprise Risk ◽

Theoretical Thinking ◽

The Cost ◽

Business Security

In the last several years, both in the economic practice of the OECD countries and in the development of theoretical thinking, there has been a significant breakthrough in the approach to corporate insurance. Insurance in business management is no longer considered only as a category of finance and accounting for an enterprises , which results from the traditional understanding of this issue. Today’s approach is insufficient to define the role of business risk management. In the traditional approach to insurance, its importance is focused on the recording and analysis of the cost of risk transfer. As a consequence, in practise, many companies and institutions implement the short-term approach to managing the cost of insurance and analyzing the degree of risk coverage, primarily property, relative insurance, relative to the cost of insurance cover.The purpose of this article is to explain how insurance contributes to increasing business security and business turnover, especially in the context of cyberbullying. It is therefore hypothesized that in the turbulent environmental variability and under pressure of changes resulting from technological synergies, the importance of insurance in risk management, especially regulatory risk and technological risk, is growing.

Download Full-text

Hostile Takeovers and Anti-takeover Defenses in the Russian Corporate Market

Voprosy Ekonomiki ◽

10.32609/0042-8736-2007-4-70-84 ◽

2007 ◽

pp. 70-84 ◽

Cited By ~ 3

Author(s):

E. Demidova

Keyword(s):

Cost Benefit Analysis ◽

Cost Benefit ◽

Benefit Analysis ◽

Costs And Benefits ◽

Hostile Takeovers ◽

Russian Market ◽

Takeover Defenses ◽

The Cost ◽

European Markets

This article analyzes definitions and the role of hostile takeovers at the Russian and European markets for corporate control. It develops the methodology of assessing the efficiency of anti-takeover defenses adapted to the conditions of the Russian market. The paper uses the cost-benefit analysis, where the costs and benefits of the pre-bid and post-bid defenses are compared.

Download Full-text

Changing Role of Agriculture in Income and Employment, and Trends of Agricultural Worker Productivity in Indian States

Indian Journal of Economics and Development ◽

10.35716/ijed/ns20-008 ◽

2020 ◽

pp. 183-189

Keyword(s):

Green Revolution ◽

Positive Trend ◽

Worker Productivity ◽

Indian States ◽

Agricultural Worker ◽

The Sixties ◽

High Level ◽

The Cost ◽

Changing Role

The productivity of land has been often discussed and deliberated by the academia and policymakers to understand agriculture, however, very few studies have focused on the agriculture worker productivity to analyze this sector. This study concentrates on the productivity of agricultural workers from across the states taking two-time points into consideration. The agriculture worker productivity needs to be dealt with seriously and on a time series basis so that the marginal productivity of worker can be ascertained but also the dependency of worker on agriculture gets revealed. There is still disguised unemployment in all the states and high level of labour migration, yet most of the states showed the dependency has gone down. Although a state like Madhya Pradesh is doing very well in terms of income earned but that is at the cost of increased worker power in agriculture as a result of which, the productivity of worker has gone down. States like Mizoram, Meghalaya, Nagaland and Tripura, though small in size showed remarkable growth in productivity and all these states showed a positive trend in terms of worker shifting away from agriculture. The traditional states which gained the most from Green Revolution of the sixties are performing decently well, but they need to have the next major policy push so that they move to the next orbit of growth.

Download Full-text

Music publications in Galicia in the 19th — beginning of the 20th centuries: production, advertising, pricing

Proceedings of Vasyl Stefanyk National Scientific Library of Ukraine in Lviv ◽

10.37222/2524-0315-2019-11(27)-20 ◽

2019 ◽

pp. 481-499

Author(s):

Olga Osadtsia

Keyword(s):

Book Publishing ◽

Initial Form ◽

Music Production ◽

Bibliographic Information ◽

Financial Factor ◽

Determining Factors ◽

Book Selling ◽

The Cost ◽

Import Trade

The main forms and methods of distribution of music publications in Galicia in the XIX — early XX centuries are scrutinized. The demand for the relevant music production is one of the determining factors in the formation of the musical publishing repertoire, its structure and special features in the process of the existence of music publications in society. It is noted that export-import trade in books has become especially widespread in Galicia; there are facts about the links between publishers and booksellers in Lviv and Warsaw. The basic types of presentation of book advertising of music products, its regional peculiarities, and ways of its placement are considered. Special emphasis is placed on the role of specialized press in the advertising of music products, typical examples of press advertising. The registration bibliographic information as the initial form of music bibliography and the forms of its compilation are distinguished. The emphasis is placed on the importance of thorough critical articles as a separate typological group of bibliographic publications under the conditions of formation of the Ukrainian bibliography, in which the main importance is given to the disclosure of the content and evaluation of the reviewed work. The combination of article genres and reviews on examples of separate publications by Stanislav Lyudkevych and Ivan Franko is traced. Special book-selling and book-publishing catalogs are characterized. While executing the marketing and advertising function, these directories were addressed primarily to foreign consumers and distributors (the so-called commissioners).One way to distribute music is to subscribe through libraries. A significant financial factor in the distribution of any printed matter was the price that depended primarily on the cost of each process associated with its publication. Keywords: music publications, bookstore, book-trading enterprise, advertising of publications, pricing.

Download Full-text