Experimentally flight-impaired females show higher levels of extra-pair paternity in the pied flycatcher
            Ficedula hypoleuca

Mireia Plaza; Alejandro Cantarero; Diego Gil; Juan Moreno

doi:10.1098/rsbl.2019.0360

Experimentally flight-impaired females show higher levels of extra-pair paternity in the pied flycatcher Ficedula hypoleuca

Biology Letters ◽

10.1098/rsbl.2019.0360 ◽

2019 ◽

Vol 15 (8) ◽

pp. 20190360 ◽

Cited By ~ 2

Author(s):

Mireia Plaza ◽

Alejandro Cantarero ◽

Diego Gil ◽

Juan Moreno

Keyword(s):

Alternative Hypothesis ◽

Ficedula Hypoleuca ◽

Pied Flycatcher ◽

Wing Loading ◽

Wing Area ◽

Indirect Benefits ◽

Extra Pair Paternity ◽

Study Population ◽

Selection For ◽

Experimental Group

There is no consensus yet on the reasons why females engage in extra-pair copulations (EPCs). In some species, females have been shown to accrue some indirect benefits, but these effects are not consistent across species and studies. The sexual conflict hypothesis posits that extra-pair paternity (EPP) is the result of strong selection for male pursuit of EPC without real benefits for females. In order to test this hypothesis, we experimentally reduced wing area (reversibly tying together some primary feathers), in a group of pied flycatcher females ( Ficedula hypoleuca ). The manipulation increases wing loading (body mass/wing area), which is negatively associated with flying ability, and thus with the capacity to escape from unwanted copulations. We compared the levels of EPP in this experimental group with those of a group of un-manipulated females. Experimental females almost doubled the proportion of extra-pair young (EPY) with respect to control females. In addition, more males sired EPY in experimental than in control broods containing EPY. These results suggest that in our study population, EPP could be partially a product of female capacity to avoid EPCs. We also discuss the alternative hypothesis that results might be due to an eventual reduction of female attractiveness.

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Experimental increase in female mass during the fertile phase leads to enhanced extra-pair paternity in pied flycatchers Ficedula hypoleuca

10.32942/osf.io/qrnkb ◽

2019 ◽

Author(s):

Mireia Plaza ◽

Alejandro Cantarero ◽

Juan Moreno

Keyword(s):

Negative Relationship ◽

Ficedula Hypoleuca ◽

Egg Laying ◽

Female Dominance ◽

Laying Date ◽

Control Group ◽

Wing Loading ◽

Potential Fecundity ◽

Fertile Phase ◽

Extra Pair Paternity

Female mass in most altricial birds reaches its maximum during breeding at egg-laying, which coincides temporally with the fertile phase when extra-pair paternity (EPP) is determined. Higher mass at laying may have two different effects on EPP intensity. On the one hand, it would lead to increased wing loading (body mass/wing area), which may impair flight efficiency and thereby reduce female’s capacity to resist unwanted extra-pair male approaches (sexual conflict hypothesis). On the other hand, it would enhance female condition, favouring her capacity to evade mate-guarding and to search for extra-pair mates (female choice hypothesis). In both cases, higher female mass at laying may lead to enhanced EPP. To test this prediction, we reduced nest building effort by adding a completely constructed nest in an experimental group of female pied flycatchers (Ficedula hypoleuca). Our treatment caused an increase in mass and thereby wing loading and this was translated into a significantly higher EPP in the manipulated group compared with the control group as expected. There was also a significant negative relationship between EPP and laying date and the extent of the white wing patch, an index of female dominance. More body reserves at laying mean not only a higher potential fecundity but a higher level of EPP as well. This interaction had not previously received due attention but should be considered in future studies of avian breeding strategies.

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Sexual selection and morphological design: the tale of two territorial butterflies

Australian Journal of Zoology ◽

10.1071/zo10060 ◽

2010 ◽

Vol 58 (5) ◽

pp. 289 ◽

Cited By ~ 3

Author(s):

Darrell J. Kemp

Keyword(s):

Sexual Selection ◽

Aspect Ratio ◽

Mate Location ◽

Wing Loading ◽

Wing Area ◽

Sexual Competition ◽

Flying Insects ◽

High Acceleration ◽

Flight Morphology ◽

Selection For

Sexual competition promotes sexual selection and may influence the evolution of morphology, physiology and life history. In many flying insects, selection for efficient mate location is thought to have influenced male flight morphology in characteristic ways, with exponents of sit-and-wait tactics selected to possess high acceleration designs (i.e. high flight musculature and relatively small, elongate wings). However, many of these species also engage in elaborate and extended aerial disputes over territory ownership, and the need for contest ability may also select for a particular design. I attempted to tease apart the effects of these two influences by contrasting the flight morphology of two closely related Hypolimnas butterflies: H. bolina and H. alimena. While the males of both species rely predominantly on sit-and-wait tactics, only male H. bolina compete for territories via extended aerial manoeuvres. Males of this species possessed lower body mass per unit wing area (i.e. lower wing loading) and more elongate wings (i.e. higher aspect ratio), but did not differ from male H. alimena in relative flight musculature (thoracic mass). Males of both species varied from conspecific females in having higher relative flight musculature, lower wing loading and lower aspect ratio, which only partly supports expectations based solely upon sexual selection. These data suggest that selection for aerial contest ability may act weakly upon wing parameters, favouring a compromise between power/maneuverability and energetically efficient flight.

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THE EFFECT OF USING COLLABORATIVE STRATEGIC READING (CSR) ON STUDENTS’ ACHIEVEMENT IN READING COMPREHENSION ON HORTATORY EXPOSITION TEXT

GENRE Journal of Applied Linguistics of FBS Unimed ◽

10.24114/genre.v4i1.4108 ◽

2015 ◽

Vol 4 (1) ◽

Author(s):

Rut Emi Febriyani Simamora ◽

Lince Sihombing ◽

Johannes Jefria Gultom

Keyword(s):

Reading Comprehension ◽

Alternative Hypothesis ◽

Sampling Technique ◽

T Test ◽

Control Group ◽

Strategic Reading ◽

Collaborative Strategic Reading ◽

Post Test ◽

Csr Strategy ◽

Experimental Group

This study is aimed at finding out the effect of Collaborative Strategic Reading (CSR) on students’ achievement in reading comprehension on hortatory exposition text. Experimental design was applied in this research. The population was the 2014/2015 second year students (grade XI) of SMA Swasta YAPIM Medan. There were two paralel classes that consisted of 34 students. The total number of the population were 68 students. The total number of the sample were 68 students. The researcher selected the sample by using total sampling technique. The sample was divided into two groups, experimental group and control group. The experimental group was taught by using Collaborative Strategic Reading (CSR) strategy while the control group was taught without using Collaborative Strategic Reading (CSR) strategy. The data were taken by administering the pre-test and post-test to both control and experimental groups. These data were analyzed by using t-test. The result of computing the t-test obviously showed that t-observed (5.61) is higher than t-table (1.99) with the degree of freedom (df= 66) at the level significance 0.05. It means that the alternative hypothesis stating that there is a significant effect of Collaborative Strategic Reading (CSR) on students’ achievement in reading comprehension on hortatory exposition text is accepted. Keywords : Collaborative Strategic Reading, Reading Comprehension

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The Effect of Applying POSSE (Predict- Organize-Search-Summarize-Evaluate) on the Students’ Reading Comprehension

GENRE Journal of Applied Linguistics of FBS Unimed ◽

10.24114/genre.v2i1.725 ◽

2013 ◽

Vol 2 (1) ◽

Cited By ~ 1

Author(s):

Eka Rejeki Maha ◽

Berlin Sibarani

Keyword(s):

Reading Comprehension ◽

Experimental Design ◽

Null Hypothesis ◽

Alternative Hypothesis ◽

Choice Test ◽

Control Group ◽

Multiple Choice Test ◽

Level Of Significance ◽

And Control ◽

Experimental Group

This study was aimed at finding out The Effect of Applying POSSE (Predict-Organize-Search-Summarize-Evaluate) Strategy on the Students’ Reading Comprehension. This study used the experimental design. The population of this study was the students of SMA Negeri 2 Medan. There were sixty students taken as the sample of the research. This study was conducted with two randomized groups namely experimental and control group. The experimental group was taught by applying POSSE strategy while control group was taught without applying POSSE strategy. The instrument of collecting the data was multiple choice test which consists of 40 items. To obtain the reliability of the test, the researcher used Kuder-Richardson (KR-21). The calculation shows the reliability was 0.81(high). The data were analyzed by using t-test. The calculation shows that t-observed (4.76) is higher than t-table (2.00) at the level of significance (α) 0.05 with the degree of freedom (df) 58. Therefore, the null hypothesis (Ho) is rejected and alternative hypothesis (Ha) is accepted. It means that there was a significant effect of applying POSSE strategy on the students’ reading comprehension. Keywords: POSSE Strategy, Reading Comprehension.

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The Effect of Applying Learning Together Method on the Students’ Reading Comprehension

GENRE Journal of Applied Linguistics of FBS Unimed ◽

10.24114/genre.v1i2.744 ◽

2012 ◽

Vol 1 (2) ◽

Author(s):

Haryato Siregar ◽

Elia Masa Ginting

Keyword(s):

Reading Comprehension ◽

Alternative Hypothesis ◽

Choice Test ◽

Control Group ◽

Teaching Reading ◽

Multiple Choice Test ◽

Level Of Significance ◽

And Control ◽

Experimental Group ◽

Learning Together

This study was aimed at finding out the effect of applying Learning Together Method on the students’ reading comprehension. This study used the experimental design. The population of this study was the students of SMP Negeri 1 Muara. There were sixty students of eighth class as the sample of the research. This study was conducted with two randomized groups namely experimental and control group. The experimental group was taught by applying Learning Together Method while control group was taught without applying Learning Together Method. The instrument of collecting the data was multiple choice test which consists of 20 items. To obtain the reliability of the test, the researcher used Kuder-Richardson (KR-21) formula. The calculation shows the reliability was 0.82(high). The data were analyzed by using t-test. The calculation shows that t-observed (4.9) is higher than t-table (2.00) at the level of significance (α) 0.05 with the degree of freedom (df) 58. Therefore, the null hypothesis (Ho) is rejected and alternative hypothesis (Ha) is accepted. It means that teaching reading comprehension by applying Learning Together Method significantly affect reading comprehension. Keywords: Learning Together Method, Reading Comprehension

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THE EFFECT OF PEER REVIEW STRATEGY ON THE STUDENTS’ ACHIEVEMENT IN WRITING DESCRIPTIVE PARAGRAPH

10.24114/reg.v4i2.2105 ◽

2015 ◽

Vol 4 (2) ◽

Author(s):

Sri Agus Murniasih And I Wayan Dirgeyasa

Keyword(s):

Peer Review ◽

Experimental Research ◽

Research Method ◽

Alternative Hypothesis ◽

Control Group ◽

Post Test ◽

Class Viii ◽

And Control ◽

Essay Test ◽

Experimental Group

This study was conducted to know the effect of applying Peer Review Strategy on the students’ achievement in writing descriptive paragraph. It was conducted by using experimental research method. This research design was conducted pre-test, post test in experimental and control group. The population of this research was the eight (VIII) grade students of SMP IT IQRA’ Medan. The sample of this research was taken by lottery technique. They were in class VIII-1 by experimental group and the class VIII-2 by control group. The experimental group was taught by using Peer Review Strategy while the control group was given no treatment. The instrument used to collect the data was writing essay test. The data were analyzed by using t-test formula. The result showed that the value of t-observed was higher than the value of t-table. (3,55 > 2,05 (a = 0.05)) with the degree of freedom (df) = 28. It means that there was a significant effect of applying Peer Review Strategy on the students’ achievement in writing descriptive paragraph. So, the alternative hypothesis (Ha) was accepted.

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THE EFFECT OF APPLYING THINK-TALK-WRITE STRATEGY ON STUDENTS’ ACHIEVEMENT IN WRITING DESCRIPTIVE TEXT

10.24114/reg.v4i1.2092 ◽

2015 ◽

Vol 4 (1) ◽

Author(s):

Indah Pratiwi And Lince Sihombing

Keyword(s):

High School ◽

Experimental Research ◽

Alternative Hypothesis ◽

Senior High School ◽

T Test ◽

Degree Of Freedom ◽

Control Group ◽

English Teacher ◽

Written Test ◽

Experimental Group

This study is an attempt to discover the effect of applying Think-Talk-Write strategy on students’ achievement in writing descriptive text. The objective of this study were to find out whether applying Think-Talk-Write strategy affect the students’ achievement in writing descriptive text. This study was an experimental research. In conducting the research, the writer used 60 students of Al-Fattah Senior High School Medan as the sample. The 60 students were taken from two classes and they were divided into two groups namely the experimental group who was taught by using Think-Talk-Write strategy and the control group who was taught without Think-Talk-Write strategy. The data of the test were collected by administering written test. The data were analyzed by using t-test formula. The result of the analysis shows that the value of t-observed is higher than the value of t-table (2,3> 2,00 (α = 0.05)) with the degree of freedom (df) = N-2 = 58. It means that there is significant effect of applying Think-Talk-Write strategy on students’ achievement in writing descriptive text. So the alternative hypothesis (Ha) is accepted. The conclusion is that applying Think-Talk-Write strategy can encourage and increase the students’ achievement in writing descriptive text. Therefore, it is suggested that English teacher should try to apply this strategy.

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THE EFFECT OF USING NOTING INTERACTING SUMMARIZING AND PRIORITIZING STRATEGY ON STUDENTS’ ACHIEVEMENT IN READING COMPREHENSION

10.24114/reg.v2i4.694 ◽

2013 ◽

Vol 2 (4) ◽

Author(s):

Maruh Sianturi And Berlin Sibarani

Keyword(s):

Reading Comprehension ◽

Experimental Design ◽

Null Hypothesis ◽

Alternative Hypothesis ◽

Control Group ◽

First Year ◽

Teaching Reading ◽

First Year Students ◽

Level Of Significance ◽

Experimental Group

This study was aimed at finding out the effect of using Noting, Interacting, Summarizing, and Prioritizing Strategy on Students’ Achievement in Reading Comprehension. This study was designed with the experimental design. The population of this study was the first year students at academic 2013/2012 of SMA swasta YP St. Paulus Martubung, Medan. There were fourty students taken as the sample of the research. The sample was divided into two groups: the first group (20 students) as the experimental group and the second group (20 students) as the control group. The experimental group was taught by Using Noting, Interacting, Summarizing, and Prioritizing Strategy, while the control group was taught by using conventional method. The instrument for collecting the data was multiple choices which consisted of 40 items. To obtain the reliability of the test, the researcher used Kuder -Richardson (KR-21) formula. The calculation showed that the reliability of the test was 0.75. The data were calculated by using t-test formula. The result of the analysis shows that t-observed (4.98) was higher than t-table (2.025) at the level of significance (α) 0.05 and the degree of freedom (df) 38. Therefore, the null hypothesis (H0) was rejected and alternative hypothesis (Ha) was accepted. It meant that teaching reading comprehension by using Noting, Interacting, Summarizing, and Prioritizing Strategy significantly affects reading comprehension.

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