| 11. |
- Bergman, Martin, 1981-
(författare)
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The evolution of territoriality in butterflies
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Competition over mating opportunities is a conspicuous characteristic of animal behaviour. In many butterfly species the males establish territories in places advantageous for encountering females. This thesis addresses questions about how territoriality has evolved and is maintained in butterflies. The studies have been conducted using the speckled wood butterfly, Pararge aegeria, as a model species. Males of P. aegeria are found in sunspots on the forest floor (paper I-V), on the lookout for females visiting the sunspots. However, males are only found in sunspots above a certain size (paper III). This behavior is maintained by a mating success advantage, where using large sunspots instead of small sunspots as perching areas generates a higher reproductive output (paper I). The mating success asymmetry is not explained by female choice or by a female preference for large sunspots per se (paper I, V), but rather the large sunspot facilitates visual performance of perching males and improves flight pursuit and interception of females (paper III). Winners of territorial contests gain sole ownership of large sunspot territories, while losers search for a new suitable sunspot territory (paper I, II & IV) or use smaller, suboptimal sunspots as perching sites (paper II). Territorial contests between P. aegeria males are not settled due to an obvious morphological/physiological asymmetry (paper I). Rather, variation in resource value and motivational asymmetries are important for settling contests (paper IV). A majority of male-female interactions (paper V) and matings (paper I) are initiated by a perching male detecting and intercepting a flying female. Furthermore, females can affect their chances of being detected by a perching male by behaving more conspicuously (paper V). This thesis highlights the role of female behaviour, variation in resource value and motivation asymmetries to understand the evolution of territoriality in butterflies.
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| 12. |
- Brändström, Sture, et al.
(författare)
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Developing distance music education in arctic Scandinavia : electric guitar teaching and master classes
- 2012
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Ingår i: Music Education Research. - : Informa UK Limited. - 1461-3808 .- 1469-9893. ; 14:4, s. 448-456
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this article was to present the project Vi r Music, with a focus on electric guitar teaching (Case 1) and master classes (Case 2). What were the benefits and shortcomings in the two cases and how did online teaching differ from face-to-face teaching? A guitar teacher with a specialisation in jazz music introduced distance teaching to three of his students. Under supervision the students taught upper-secondary students living 290 km from the university. The guitar lessons were held with the use of Skype. In the project, 11 distance master classes were also studied. The devices used were a video-conference system, external microphones and speakers, and 50–52′′ TV screens. The methods for data collection in both cases were above all qualitative interviews with teachers and students and to some degree observation of the teaching sessions. The overall impression from the study was that teachers and students seemed to consider the online teaching in the project a positive experience. The informants looked upon the distance-learning situation as a fruitful complement to face-to-face teaching. Because of the time delay, the most difficult part of the online teaching was playing together or marking the rhythm. The results suggested that video-conference teaching is more intensive than face-to-face teaching and requires both thorough planning and readiness to improvise during the lesson.
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| 13. |
- Brändström, Sture, et al.
(författare)
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Distance Music Education in Northern Europe
- 2010
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The name of the project we are going to present is Vi r Music (www.vi-r-music.blogspot.com/). The aim of the project is to create a network that will start researching the possibilities for virtual music education at different levels. The Swedish part of the project consists of masterclasses, electric guitar tuition and vocal tuition. Some preliminary results: In distance education there are several technical equipments added to the traditional music education context. We have found that 30 minutes lessons are optimal concerning distance tuition. Try to use rooms with calm visual backgrounds and without too much echo.
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| 14. |
- Brändström, Sture, et al.
(författare)
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The relevance of distributed master classes
- 2011
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Ingår i: Musik och kunskapsbildning. - Göteborg : Konstnärliga fakulteten Göteborgs universitet. - 9789197847629 ; , s. 39-47
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 15. |
- Dinca, Vlad, et al.
(författare)
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Reproductive isolation and patterns of genetic differentiation in a cryptic butterfly species complex
- 2013
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Ingår i: Journal of Evolutionary Biology. - : Wiley. - 1010-061X .- 1420-9101. ; 26:10, s. 2095-2106
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Tidskriftsartikel (refereegranskat)abstract
- Molecular studies of natural populations are often designed to detect and categorize hidden layers of cryptic diversity, and an emerging pattern suggests that cryptic species are more common and more widely distributed than previously thought. However, these studies are often decoupled from ecological and behavioural studies of species divergence. Thus, the mechanisms by which the cryptic diversity is distributed and maintained across large spatial scales are often unknown. In 1988, it was discovered that the common Eurasian Wood White butterfly consisted of two species (Leptidea sinapis and Leptidea reali), and the pair became an emerging model for the study of speciation and chromosomal evolution. In 2011, the existence of a third cryptic species (Leptidea juvernica) was proposed. This unexpected discovery raises questions about the mechanisms preventing gene flow and about the potential existence of additional species hidden in the complex. Here, we compare patterns of genetic divergence across western Eurasia in an extensive data set of mitochondrial and nuclear DNA sequences with behavioural data on inter- and intraspecific reproductive isolation in courtship experiments. We show that three species exist in accordance with both the phylogenetic and biological species concepts and that additional hidden diversity is unlikely to occur in Europe. The Leptidea species are now the best studied cryptic complex of butterflies in Europe and a promising model system for understanding the formation of cryptic species and the roles of local processes, colonization patterns and heterospecific interactions for ecological and evolutionary divergence.
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| 16. |
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| 17. |
- Esperk, Toomas, et al.
(författare)
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Distinguishing between anticipatory and responsive plasticity in a seasonally polyphenic butterfly
- 2013
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Ingår i: Evolutionary Ecology. - : Springer Science and Business Media LLC. - 0269-7653 .- 1573-8477. ; 27:2, s. 315-332
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Tidskriftsartikel (refereegranskat)abstract
- Seasonal generations of short-lived organisms often differ in their morphological, behavioural and life history traits, including body size. These differences may be either due to immediate effects of seasonally variable environment on organisms (responsive plasticity) or rely on presumably adaptive responses of organisms to cues signalizing forthcoming seasonal changes (anticipatory plasticity). When directly developing individuals of insects are larger than their overwintering conspecifics, the between-generation differences are typically ascribed to responsive plasticity in larval growth. We tested this hypothesis using the papilionid butterly Iphiclides podalirius as a model species. In laboratory experiments, we demonstrated that seasonal differences in food quality could not explain the observed size difference. Similarly, the size differences are not likely to be explained by the immediate effects of ambient temperature and photoperiod on larval growth. The qualitative pattern of natural size differences between the directly developing and diapausing butterflies could be reproduced in the laboratory as a response to photoperiod, indicating anticipatory character of the response. Directly developing and diapausing individuals followed an identical growth trajectory until the end of the last larval instar, with size differences appearing just a few days before pupation. Taken together, various lines of evidence suggest that between-generation size differences in I. podalirius are not caused by immediate effects of environmental factors on larval growth. Instead, these differences rather represent anticipatory plasticity and are thus likely to have an adaptive explanation. It remains currently unclear, whether the seasonal differences in adult size per se are adaptive, or if they constitute co-product of processes related to the diapause. Our study shows that it may be feasible to distinguish between different types of plasticity on the basis of empirical data even if fitness cannot be directly measured, and contributes to the emerging view about the predominantly adaptive nature of seasonal polyphenisms in insects.
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| 18. |
- Friberg, Magne, et al.
(författare)
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Asymmetric life-history decision-making in butterfly larvae
- 2011
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Ingår i: Oecologia. - : Springer Science and Business Media LLC. - 0029-8549 .- 1432-1939. ; 165:2, s. 301-310
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Tidskriftsartikel (refereegranskat)abstract
- In temperate environments, insects appearing in several generations in the growth season typically have to decide during the larval period whether to develop into adulthood, or to postpone adult emergence until next season by entering a species-specific diapause stage. This decision is typically guided by environmental cues experienced during development. An early decision makes it possible to adjust growth rate, which would allow the growing larva to respond to time stress involved in direct development, whereas a last-minute decision would instead allow the larva to use up-to-date information about which developmental pathway is the most favourable under the current circumstances. We study the timing of the larval pathway decision-making between entering pupal winter diapause and direct development in three distantly related butterflies (Pieris napi, Araschnia levana and Pararge aegeria). We pinpoint the timing of the larval diapause decision by transferring larvae from first to last instars from long daylength (inducing direct development) to short daylength conditions (inducing diapause), and vice versa. Results show that the pathway decision is typically made in the late instars in all three species, and that the ability to switch developmental pathway late in juvenile life is conditional; larvae more freely switched from diapause to direct development than in the opposite direction. We contend that this asymmetry is influenced by the additional physiological preparations needed to survive the long and cold winter period, and that the reluctance to make a late decision to enter diapause has the potential to be a general trait among temperate insects.
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| 19. |
- Friberg, Magne, et al.
(författare)
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Heterospecific courtship, minority effects and niche separation between cryptic butterfly species
- 2013
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Ingår i: Journal of Evolutionary Biology. - : Wiley. - 1010-061X .- 1420-9101. ; 26:5, s. 971-979
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Tidskriftsartikel (refereegranskat)abstract
- Species interacting in varied ecological conditions often evolve in different directions in different local populations. The butterflies of the cryptic Leptidea complex are sympatrically distributed in different combinations across their Eurasian range. Interestingly, the same species is a habitat generalist in some regions and a habitat specialist in others, where a sibling species has the habitat generalist role. Previous studies suggest that this geographically variable niche divergence is generated by local processes in different contact zones. By varying the absolute and relative densities of Leptidea sinapis and Leptidea juvernica in large outdoor cages, we show that female mating success is unaffected by conspecific density, but strongly negatively affected by the density of the other species. Whereas 80% of the females mated when a conspecific couple was alone in a cage, less than 10% mated when the single couple shared the cage with five pairs of the other species. The heterospecific courtships can thus affect the population fitness, and for the species in the local minority, the suitability of a habitat is likely to depend on the presence or absence of the locally interacting species. If the local relative abundance of the different species depends on the colonization order, priority effects might determine the ecological roles of interacting species in this system.
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| 20. |
- Friberg, Magne, et al.
(författare)
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Host plant induced larval decision-making in a habitat/host plant generalist butterfly
- 2010
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Ingår i: Ecology. - : Wiley. - 0012-9658 .- 1939-9170. ; 91, s. 15-21
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Tidskriftsartikel (refereegranskat)abstract
- Phenotypic plasticity can be a passive response to fluctuating environmental conditions or an active and presumably adaptive (evolved) response selected for in different environments. Here we ask if the larval decision to enter diapause when reared on a host plant associated with a colder habitat is an active or a passive response to host plant quality or suitability. We compare plasticity in larval propensity to enter diapause of the habitat generalist butterfly Leptidea sinapis and the meadow specialist Leptidea reali in a range of temperatures and long daylength on a forest plant, Lathyrus linifolius, and a meadow-associated plant, Lathyrus pratensis. The warmer meadow habitat promotes direct development whereas the colder forest habitat is conducive to diapause. Larvae of L. sinapis had a higher propensity to enter diapause when reared on the forest plant L. linifolius across all temperatures. Conversely, the propensity of L. reali to enter diapause was consistently lower and did not differ between host plants. Larval growth rates were similar between and within butterfly species and between host plants. Hence, we conclude that larval pathway decision-making in L. sinapis is an active response mediated by information from their host plants.
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