Mating success of alternative male phenotypes and evidence for frequency-dependent selection in Chinook salmon, Oncorhynchus tshawytscha

2010 ◽  
Vol 67 (12) ◽  
pp. 1933-1941 ◽  
Author(s):  
Barry A. Berejikian ◽  
Donald M. Van Doornik ◽  
Rob C. Endicott ◽  
Timothy L. Hoffnagle ◽  
Eugene P. Tezak ◽  
...  
Keyword(s):  
Mating Success ◽  
Oncorhynchus Tshawytscha ◽  
Pacific Salmon ◽  
Adult Males ◽  
Frequency Dependent ◽  
Frequency Dependent Selection ◽  
Male Density ◽  
The Family ◽  
Breeding Groups ◽  
One Year

As with other species, frequency-dependent selection during reproduction has long been proposed as an important mechanism in maintaining alternative male reproductive phenotypes in Pacific salmon ( Oncorhynchus spp.). Jack salmon mature one year earlier than the youngest females in a population and are much smaller than older “adult” males. We tested the hypothesis that mating success of both phenotypes is consistent with the frequency-dependent selection model. By holding male density constant and varying the frequency of adults and jacks in eight separate breeding groups, we found that adult male access to females, participation in spawning events, and adult-to-fry reproductive success increased with their decreasing frequency in a breeding group. Jacks exhibited the same pattern (increasing success with decreasing frequency), although the relationships were not as strong as for adults. Overall, jack and adult males mated with a similar number of females, but jacks sired only 20% of all offspring. Observational data suggested that adult males benefited from sperm precedence associated with their ability to court females and enter the nest first at the time of spawning. Our work provides the first experimental evidence of frequency-dependent selection during mating in the family Salmonidae.

Corrigendum: Mating success of alternative male phenotypes and evidence for frequency-dependent selection in Chinook salmon, Oncorhynchus tshawytscha

2011 ◽  
Vol 68 (1) ◽  
pp. 183-183 ◽  
Author(s):  
Barry A. Berejikian ◽  
Donald M. Van Doornik ◽  
Rob C. Endicott ◽  
Timothy L. Hoffnagle ◽  
Eugene P. Tezak ◽  
...  
Keyword(s):  
Chinook Salmon ◽  
Mating Success ◽  
Oncorhynchus Tshawytscha ◽  
Frequency Dependent ◽  
Frequency Dependent Selection

scholarly journals Behavioral snake mimicry in breeding tits

2020 ◽  
Author(s):  
Anders Pape Møller ◽  
Einar Flensted-Jensen ◽  
Wei Liang
Keyword(s):  
Nest Predation ◽  
Parus Major ◽  
Frequency Dependent ◽  
Frequency Dependent Selection ◽  
Nest Box ◽  
Venomous Snakes ◽  
Lower Abundance ◽  
The Family ◽  
Tropical China

Abstract Many animals mimic the behavior or the appearance of venomous snakes. When humans or other potential predators place their hand near the nest of tits belonging to the family Paridae (and a few other species), the incubating female performs a hissing display that mimics the inhalation hiss of a viper or another snake. They hiss vigorously while lunging their head forward and shaking their wings and tail, repeating this behavior several times. The structure of the hiss in tits is similar to that of the inhalation hiss of a snake, providing evidence of significant convergence of the mimic toward the model. The behavior of individual females is repeatable among trials. Individuals that flew away from their nest box only performed the hissing display on 6% of later trials, when present at their box, whereas individuals that did not fly away hissed on 28% of occasions, consistent with great tits Parus major either cautiously flying away or staying put on their nest while actively defending it. Individuals that flew away produced fewer chicks than individuals that stayed and hissed. The hissing display was more common when snakes were more abundant: 1) When breeding late during the season; 2) when breeding at sites with more snakes; and 3) when breeding in subtropical and tropical China with a higher abundance of snakes than in Denmark with a lower abundance. The frequency of nest predation was higher in sites with no snakes, and the frequency of predation increased with decreasing frequency of hissing display. These findings are consistent with expectations for frequency-dependent selection acting on snake mimicry.

Frequency-Dependent Selection at the Payne Inversion in Drosophila melanogaster

Evolution ◽  
1973 ◽  
Vol 27 (4) ◽  
pp. 558 ◽  
Author(s):  
R. Nassar ◽  
H. J. Muhs ◽  
R. D. Cook
Keyword(s):  
Drosophila Melanogaster ◽  
Frequency Dependent ◽  
Frequency Dependent Selection

Loudness Growth under Masking: Relation to True Sensorineural Impairment

1973 ◽  
Vol 16 (4) ◽  
pp. 597-607 ◽  
Author(s):  
Alan M. Richards
Keyword(s):  
Hearing Loss ◽  
Power Function ◽  
Threshold Shift ◽  
Essential Difference ◽  
Frequency Dependent ◽  
Masker Level ◽  
Loudness Recruitment ◽  
The Family ◽  
Balance Functions ◽  
Loudness Growth

Alternate binaural loudness balances between masked and unmasked normal ears were performed to examine the growth of loudness as a function of masker level at each of several frequencies (500, 1000, 2000, and 4000 Hz) and to determine whether the recruitmentlike phenomenon in masked ears is comparable in its growth and form to actual recruitment growth in sensorineural impaired ears. The results for 28 subjects indicated that for all frequencies a power function relating the perceived loudness in the masked ear to the unmasked ear could be drawn, and that the slope of this function rose as a function of increased masking. The family of slopes for each frequency was linearly related to the induced threshold shift. The slope of this latter relation proved to be frequency dependent. Comparison between the slope growth in simulated hearing loss and the family of loudness-balance slopes obtained from patients with true unilateral loss of varying degree indicated that the slopes of loudness-balance functions in the latter group also increased linearly with increased loss. In this latter instance, however, the slope growth was not frequency dependent, thus pointing to an essential difference between simulated and actual loudness recruitment growth.

Attitudes of Psychiatric Ex-Patients toward a Study of Community Adjustment

1968 ◽  
Vol 23 (2) ◽  
pp. 567-572 ◽  
Author(s):  
Mary Helen Michaux ◽  
William W. Michaux ◽  
Eugenie K. Esser ◽  
Barbara A. Oliver
Keyword(s):  
Mental Illness ◽  
Study Participation ◽  
Community Adjustment ◽  
The Family ◽  
One Year ◽  
Research Demands

Questionnaires were presented to 73 psychiatric ex-patients to determine their retrospective attitudes toward participation in a one-year study of post-hospital adjustment. More than 50% of Ss reported that research contacts had been helpful in one or more specific respects. Attitudes toward research demands were predominantly neutral. Patients who completed 6 or more monthly interview-test sessions ( N = 53) differed from those who completed 5 or less ( N = 20) in finding research contacts more helpful, questions easier to answer and enlightening vs confusing, and study participation conducive to cohesion vs disruption in the family. Dropouts appeared to have in common wishes to deny mental illness and to forget hospitalization.

Assessing covariability among populations in the presence of intraseries correlation: Columbia River spring-summer chinook salmon (Oncorhynchus tshawytscha) stocks

2000 ◽  
Vol 57 (3) ◽  
pp. 616-627 ◽  
Author(s):  
Louis W Botsford ◽  
Charles M Paulsen
Keyword(s):  
Chinook Salmon ◽  
Degrees Of Freedom ◽  
Oncorhynchus Tshawytscha ◽  
Columbia River ◽  
Data Types ◽  
Natural Logarithm ◽  
Different Types ◽  
John Day River ◽  
One Year ◽  
John Day

We assessed covariability among a number of spawning populations of spring-summer run chinook salmon (Oncorhynchus tshawytscha) in the Columbia River basin by computing correlations among several different types of spawner and recruit data. We accounted for intraseries correlation explicitly in judging the significance of correlations. To reduce the errors involved in computing effective degrees of freedom, we computed a generic effective degrees of freedom for each data type. In spite of the fact that several of these stocks have declined, covariability among locations using several different combinations of spawner and recruitment data indicated no basinwide covariability. There was, however, significant covariability among index populations within the three main subbasins: the Snake River, the mid-Columbia River, and the John Day River. This covariability was much stronger and more consistent in data types reflecting survival (e.g., the natural logarithm of recruits per spawner) than in data reflecting abundance (e.g., spawning escapement). We also tested a measure of survival that did not require knowing the age structure of spawners, the ratio of spawners in one year to spawners 4 years earlier. It displayed a similar spatial pattern.

Experience in the examination of children on the pediatric ward

1986 ◽  
Vol 67 (2) ◽  
pp. 131-132
Author(s):  
T. M. Shigabutdinova
Keyword(s):  
Health Status ◽  
Clinical Examination ◽  
Pediatric Ward ◽  
The Family ◽  
One Year

There are 840 children registered at the pediatric area, including 66 children under one year of age and 140 "unorganized" children. In the course of the clinical examination, the health status of children was studied according to the data of preventive examinations, as well as materials of the district therapist on the health status of the family.

The scantness of the effect of corporate governance mechanisms on executive directors’ remuneration in small listed companies: evidence from Malaysia

2018 ◽  
Vol 14 (4) ◽  
pp. 934-949
Author(s):  
Husna Siraji Nyambia ◽  
Hamdino Hamdan
Keyword(s):  
Corporate Governance ◽  
Small Firms ◽  
Independent Directors ◽  
Executive Directors ◽  
Content Type ◽  
Power And Control ◽  
Executive Remuneration ◽  
The Family ◽  
One Year ◽  
And Control

Purpose This study extensively aims to investigate the effects of different aspects of corporate governance (CG) mechanism, including board size, executive directors’ shareholdings, Chief Executive Officer (CEO) duality, a family member as the CEO and/or chairperson of the board, independent directors in remuneration committee and number of board meeting, on executive directors’ remuneration in small firms listed on Bursa Malaysia (BM). Design/methodology/approach The sample of this study consists of 173 bottom-listed companies from Bursa Malaysia in Year 2010. The Year 2010 was chosen because the disclosure of remuneration committee activities and directors’ pay structure is required under the revised Malaysia Code of Corporate Governance, 2007. Furthermore, the period selected is after the global economic crisis (2008), which may have an effect on the remuneration structure in small firms. The ordinary least squares regression was used to estimate the relationship between remuneration as dependent variable and other independent variables. Findings A finding from this study reveals that there is a significant positive relationship between executive ownership and executive remuneration, and between board size and executive remuneration. The results provide evidence that the family members manipulate power and control remuneration in small firms. This indicates that the independent directors are not truly independent to monitor and control the firm activities, including minimizing the excessive remuneration. Research limitations/implications This study examines how the corporate governance (CG) affects remuneration among 173 small firms in Malaysia based on market capitalization, for one year, 2010. Hence, the results may not be generalizable to other periods or types of the companies. This shows the possibility of the absence of some additional variables in the research model and hence a limitation to the findings of the study. Although the study is being parsimonious in the choice of relevant variables, prior literature serves the guide in the selection of the used variables. This therefore gives room for future research using the potential omitted variables. Furthermore, the study focuses on total remuneration, such as fees, salaries, bonuses and benefits in kind, which makes aggregate directors’ remuneration. However, this study did not consider the remuneration related to stock options. Finally, this study only uses secondary data; hence, it could be interesting to use other instruments to collect data like a questionnaire to add more weight to the research. This study only uses one-year data; therefore, impact of changes between years cannot be analysed. Originality/value Results of the study provide evidence that the family members manipulate power and control remuneration in small firms. They reduce the effectiveness of non-executive directors because most of them are appointed by a family member and not socially responsible to their stakeholders.

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