In many tropical bird species, both males and females maintain elaborate plumage traits. Although there is considerable evidence that many male plumage traits function as status signals that convey ...information about fighting ability, less is known about status signaling in females. We tested whether the carotenoid-based orange breast coloration of the female streak-backed oriole (Icterus pustulatus pustulatus) signals status during territorial interactions. To do this, we simulated territorial intrusions using taxidermic models and compared the roles of the sexes within pairs during territorial defense directed toward different types of simulated intruders. Females were more territorial than their mates during the breeding season, whereas males were more territorial than their mates in the nonbreeding season, contrary to patterns seen in studies of temperate zone birds. The coloration of simulated female intruders also influenced territorial responses: When presented with color-augmented female models, females responded with greater intensity than their mates, whereas the intensity of defense was similar for both sexes when presented with average-colored female models. The greater female response to more colorful intruders suggests that females perceive more ornamented females as greater threats to their territorial tenure or to their pair bond. These results are consistent with the hypothesis that female carotenoid-based coloration signals status in this species.
In species in which both sexes have similar ornamentation, the ornaments often function as sexual or social signals in both sexes. However, males and females may use ornaments in different signalling ...contexts. We previously demonstrated that carotenoid-based bill colour of female American goldfinches, Spinus tristis, functions as a signal of status during intrasexual, but not intersexual, competition. Here we test whether male bill colour functions as a competitive status signal during both intra- and intersexual contests. We tested whether focal males and females avoided feeding adjacent to taxidermic male models as a function of the models' experimentally altered bill colour. We additionally tested whether male bill colour functions as a mate choice signal by presenting females with a choice of two live males with experimentally altered bill colour. In the status signal experiment, neither focal males nor females avoided male models with more colourful bills, as was predicted by the status-signalling hypothesis. These results indicate that male bill coloration does not function as a signal of competitive status and that the signal function of male bill colour does not parallel that of female bill colour. In our mate choice experiment, females showed no preference for male bill colour, suggesting that male bill colour may have some yet untested signalling function or that male bill colour may no longer be under selection. Our findings suggest that selection can lead to different signalling strategies in males and females, even in species that express mutual ornamentation.
•Males and females often express similar ornamentation used as communication signals.•The sexes compete for different resources, so may communicate different messages.•Female goldfinches use bill colour to communicate fighting ability, but males do not.•Results indicate that selection for ornamentation can vary between the sexes.
Abstract
The trade-off between the number of friendships and the closeness of friendships of humans arises due to the limitations of time and cognitive capacities for communication. This trade-off ...distinguishes asynchronous text communication through the internet (lightweight communication) from face-to-face communication and the social grooming of primates (elaborate communication). This study modelled communication as messaging flows driven by edge and node activations to investigate micro-mechanisms that realise the trade-off law and the differences between the two types of communications. We observed the emergence of five patterns of social structures depending on the strengths of the two types of activations, namely, edge and node activations. The two patterns that show known statistics on empirical studies, such as the trade-off and power-law distributions of closeness, emerged around a threshold between elaborate and lightweight communications, where network structures qualitatively changed. A balance between edge and node activations shifts one pattern (elaborate communication) to another pattern (lightweight communication). Consequently, relation networks that communicate through lightweight communication become less clustered. These results suggest how communication systems construct different social structures, e.g., the impact of popularising the internet.
The item count technique, which is an indirect questioning method, aims to yield more valid results in social surveys than the direct questioning method by eliminating the effects of social ...desirability on responses. The technique requires respondents to only answer the number of applicable items on an item list. However, the mean responses of the technique are often smaller than those of the questions that require respondents to select “applies” or “does not apply” for each item. This underreporting tendency of respondents often prevents the technique from yielding valid results. Tsuchiya and Hirai (2010) proposed an elaborate item count technique for reducing underreporting. Based on this technique, respondents are asked to reply both the number of applicable and non-applicable items. In this study, the data used by Tsuchiya and Hirai (2010) is re-analyzed from the viewpoint of response latency. The analysis reveals that underreporting of the item count technique is remarkable in short-time respondents. The analysis also elucidates that the elaborate item count technique demands more response time than the direct “applies/does not apply” questions and the technique successfully suppresses underreporting even in short-time respondents. The redundancy of the elaborate item count technique is considered to be a main cause of suppressing underreporting by forcing respondents to more thoroughly examine their responses.
The effects of song and elaboration were assessed on the acquisition and retention of lexical items by beginner learners of Italian. Lexical acquisition investigated through an incidental learning ...experiment based on the premise that growth in L2 vocabulary can be facilitated by subvocal rehearsal and elaborate processing of lexical items. Participants were divided into a control group and four treatment groups. Treatment groups were exposed to a song either in a sung condition or read as a poem, and groups completed lexical tasks designed with low or high levels of elaboration. It was hypothesized that (a) song groups would score higher than poem groups, and that (b) high elaboration groups would score higher than low elaboration groups. With scoring based on Wesche and Paribakht's Vocabulary Knowledge Scale, at post-test and delayed post-test the song/high elaboration group scored higher than all other groups in both receptive and productive vocabulary learning, suggesting that song and high elaboration are effective in facilitating the acquisition and retention of L2 lexical items and that song and high elaboration activities should be implemented in the L2 curriculum. An 8-page appendix follows this article.
The website of elaborate course plays an important role in the construction of elaborate course, and website construction is still in its infancy in most institutions. There are technical ...difficulties, and there is not high quality too in the construction of elaborate course. In the paper, a design method of content management system for elaborate course is proposed based on XML aiming at the present situation. The system uses crucial technologies of custom content objects and regional components to implement the separation of data and interface, which facilitates system expansion and reuse. Using this system, the users can quickly customize all types of elaborate course websites without web page design and database skills.
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