| 1. |
- Sigvald, Roland, et al.
(författare)
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Molecular identification of bloodmeals and species composition in Culicoides biting midges
- 2013
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Ingår i: Medical and Veterinary Entomology. - : Wiley. - 0269-283X .- 1365-2915. ; 27, s. 104-112
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Tidskriftsartikel (refereegranskat)abstract
- Investigations of host preferences in haematophagous insects, including Culicoides biting midges (Diptera: Ceratopogonidae), are critical in order to assess transmission routes of vector-borne diseases. In this study, we collected and morphologically identified 164 blood-engorged Culicoides females caught in both light traps and permanent 12-m high suction traps during 20082010 in Sweden. Molecular analysis of the mitochondrial cytochrome c oxidase subunit I (COI) gene in the biting midges was performed to verify species classification, discern phylogenetic relationships and uncover possible cryptic species. Bloodmeal analysis using universal vertebrate cytochrome b primers revealed a clear distinction in host selection between mammalophilic and ornithophilic Culicoides species. Host sequences found matches in horse (n = 59), sheep (n = 39), cattle (n = 26), Eurasian elk (n = 1) and 10 different bird species (n = 18). We identified 15 Culicoides species previously recorded in Scandinavia and four additional species haplotypes that were distinctly different from the described species. All ornithophilic individuals (n = 23) were caught exclusively in the suction traps, as were, interestingly, almost all mammalophilic species (n = 41), indicating that many biting midge species may be able to cover long distances after completing a bloodmeal. These results add new information on the composition of Culicoides species and their host preferences and their potential long-distance dispersal while blood-engorged.
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| 2. |
- Sköld, Helen Nilsson, et al.
(författare)
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Hormonal regulation of female nuptial coloration in a fish.
- 2008
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Ingår i: Hormones and behavior. - : Elsevier BV. - 1095-6867 .- 0018-506X. ; 54:4, s. 549-56
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Tidskriftsartikel (refereegranskat)abstract
- Physiological color change in camouflage and mating is widespread among fishes, but little is known about the regulation of such temporal changes in nuptial coloration and particularly concerning female coloration. To better understand regulation of nuptial coloration we investigated physiological color change in female two-spotted gobies (Gobiusculus flavescens). Females of this species develop an orange belly that acts as an ornament. The orange color is caused by the color of the gonads combined with the chromathophore based pigmentation and transparency of the skin. Often during courtship and female-female competition, a rapid increase in orange coloration, in combination with lighter sides and back that increases skin and body transparency, gives the belly an intense 'glowing' appearance. To understand how this increased orange coloration can be regulated we analysed chromatic and transparency effects of neurohumoral agents on abdominal skin biopsies in vitro. We found prolactin and alpha-melanocyte stimulating hormone (MSH) to increase orange coloration of the skin. By contrast, melatonin and noradrenaline increased skin transparency, but had a negative effect on orange coloration. However, mixtures of melatonin and MSH, or melatonin and prolactin, increased both orange coloration and transparency. This effect mimics the chromatic 'glow' effect that commonly takes place during courtship and intra sexual aggression. Notably, not only epidermal chromatophores but also internal chromatophores lining the peritoneum responded to hormone treatments. There were no chromatic effects of the sex steroids 17beta-estradiol, testosterone or 11-ketotestosterone. We hypothesize that similar modulation of nuptial coloration by multiple hormones may be widespread in nature.
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| 3. |
- Witzgall, Peter, et al.
(författare)
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"This is not an Apple"-Yeast Mutualism in Codling Moth
- 2012
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Ingår i: Journal of Chemical Ecology. - : Springer Science and Business Media LLC. - 1573-1561 .- 0098-0331. ; 38:8, s. 949-957
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Tidskriftsartikel (refereegranskat)abstract
- The larva of codling moth Cydia pomonella (Tortricidae, Lepidoptera) is known as the worm in the apple, mining the fruit for food. We here show that codling moth larvae are closely associated with yeasts of the genus Metschnikowia. Yeast is an essential part of the larval diet and further promotes larval survival by reducing the incidence of fungal infestations in the apple. Larval feeding, on the other hand, enables yeast proliferation on unripe fruit. Chemical, physiological and behavioral analyses demonstrate that codling moth senses and responds to yeast aroma. Female moths are attracted to fermenting yeast and lay more eggs on yeast-inoculated than on yeast-free apples. An olfactory response to yeast volatiles strongly suggests a contributing role of yeast in host finding, in addition to plant volatiles. Codling moth is a widely studied insect of worldwide economic importance, and it is noteworthy that its association with yeasts has gone unnoticed. Tripartite relationships between moths, plants, and microorganisms may, accordingly, be more widespread than previously thought. It, therefore, is important to study the impact of microorganisms on host plant ecology and their contribution to the signals that mediate host plant finding and recognition. A better comprehension of host volatile signatures also will facilitate further development of semiochemicals for sustainable insect control.
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| 4. |
- Jelenkovic, A., et al.
(författare)
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Genetic and environmental influences on adult human height across birth cohorts from 1886 to 1994
- 2016
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Ingår i: eLIFE. - Cambridge, United Kingdom : eLife Sciences Publications. - 2050-084X. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Human height variation is determined by genetic and environmental factors, but it remains unclear whether their influences differ across birth-year cohorts. We conducted an individual-based pooled analysis of 40 twin cohorts including 143,390 complete twin pairs born 1886-1994. Although genetic variance showed a generally increasing trend across the birth-year cohorts, heritability estimates (0.69-0.84 in men and 0.53-0.78 in women) did not present any clear pattern of secular changes. Comparing geographic-cultural regions (Europe, North America and Australia, and East Asia), total height variance was greatest in North America and Australia and lowest in East Asia, but no clear pattern in the heritability estimates across the birth-year cohorts emerged. Our findings do not support the hypothesis that heritability of height is lower in populations with low living standards than in affluent populations, nor that heritability of height will increase within a population as living standards improve.
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| 5. |
- Blake, Chelsea A., et al.
(författare)
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Conspecific boldness and predator species determine predation-risk consequences of prey personality
- 2018
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Ingår i: Behavioral Ecology and Sociobiology. - : Springer-Verlag New York. - 0340-5443 .- 1432-0762. ; 72:8, s. 1-7
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Tidskriftsartikel (refereegranskat)abstract
- Abstract: Individual variation in the behavior of prey can influence predation risk in complex ways. We ran individual roach (Rutilus rutilus), a common freshwater fish, through a standard refuge emergence protocol to characterize their boldness, a key animal personality trait. We then paired a bold and a shy roach and exposed the pair to one of two predator species that have contrasting hunting modes to ascertain how personality traits shaped their survival during predator encounters. When a paired bold and shy prey fish interacted with a perch predator (active foraging mode), bold and shy prey were consumed in almost equal numbers. However, pike predators (ambush foraging mode) selectively consumed more shy prey, and prey body size and boldness score both contributed significantly to which prey fish was eaten. Our findings support the idea that multiple predators with different foraging modes, and hence differential selection on prey personality, could contribute to maintaining variation in personality in prey populations. Furthermore, for social species, including shoaling fish, the ultimate consequences of an individual’s personality may depend upon the personality of its nearby conspecifics. Significance statement: Animals of the same species often look similar, but individuals show differences in their behavior that can have important consequences, for instance when these individuals interact with predators. The common roach is a freshwater fish that shows inter-individual variation in its propensity to take risks, a key personality trait often termed boldness. Variation in boldness may affect the outcome when roach interact with predators, i.e., if they get eaten or survive. However, we found the impact of roachs’ personality type depends on what species of predatory fish they face. When we put a shy and a bold roach together with predatory perch, the roachs’ personality did not significantly affect which individual was eaten. But when the predator was a pike, the predators selectively ate more shy roach, and the likelihood an individual would be eaten depended on their body size.
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| 6. |
- Eggers, Sönke, et al.
(författare)
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Differential demographic responses of sympatric Parids to vegetation management in boreal forest
- 2014
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 319, s. 169-175
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Tidskriftsartikel (refereegranskat)abstract
- Large-scale removal of small-diameter trees (i.e. thinning from below) in boreal forest can diminish niche diversity for birds that rely on a well-developed understory for nesting and foraging. Yet, few studies have examined how reduced niche diversity in managed forests affects fitness measures in closely-related species and the ability of competing species to co-exist. We related forest thinning to population trends of the willow tit Poecile montana (declining) and its dominant competitor the crested tit Lophophanes cristatus (stable), and conducted a 3-year comparative study to determine how variation in understory spruce density differentially influences survival and reproduction in these species. In line with our prediction that crested tits would gain resource priority under conditions of reduced forest understory complexity, willow tits and their nestlings suffered a disproportionate decline in both nest and adult survival prospects relative to crested tits as understoiy spruce density declined. Willow tits also had increased numbers of tail feather fault bars with decreasing understory complexity, further supporting the idea that willow tits suffer from food shortage and increased predation risk in areas of reduced understory. The long-term population declines of willow tits in boreal forest appears linked to large scale harvest of small-diameter spruce trees that provide important understory vegetation. A patchy arrangement of different thinning treatments through 'Understory Retention Thinning' (URT) may provide a cost-effective way to restore long-term structural complexity and biodiversity in densely stocked conifer stands. (C) 2014 Elsevier B.V. All rights reserved.
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| 7. |
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| 8. |
- Kvarnemo, Charlotta, 1963, et al.
(författare)
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Gravida hanar och konkurrerande honor
- 2014
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Ingår i: Havsutsikt. - 1104-0513. ; 2014:1, s. 6-7
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Hos fisken tångsnälla blir pappan gravid. Hanen förser ungarna med syre och näring under utvecklingen, men han kan också själv ta upp näring som kommer från äggen. Honor konkurrerar om att få para sig med hanar som har plats för hennes ägg, och de gillar särskilt att para sig med stora hanar. Trots det ger de ägg med mer näring till små hanar.
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| 9. |
- Sundman, Ann-Sofie, et al.
(författare)
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Similar recent selection criteria associated with different behavioural effects in two dog breeds
- 2016
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Ingår i: Genes, Brain and Behavior. - : Wiley-Blackwell Publishing Inc.. - 1601-1848 .- 1601-183X. ; 15:8, s. 750-756
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Tidskriftsartikel (refereegranskat)abstract
- Selection during the last decades has split some established dog breeds into morphologically and behaviourally divergent types. These breed splits are interesting models for behaviour genetics since selection has often been for few and well-defined behavioural traits. The aim of this study was to explore behavioural differences between selection lines in golden and Labrador retriever, in both of which a split between a common type (pet and conformation) and a field type (hunting) has occurred. We hypothesized that the behavioural profiles of the types would be similar in both breeds. Pedigree data and results from a standardized behavioural test from 902 goldens (698 common and 204 field) and 1672 Labradors (1023 and 649) were analysed. Principal component analysis revealed six behavioural components: curiosity, play interest, chase proneness, social curiosity, social greeting and threat display. Breed and type affected all components, but interestingly there was an interaction between breed and type for most components. For example, in Labradors the common type had higher curiosity than the field type (F1,1668 = 18.359; P < 0.001), while the opposite was found in goldens (F1,897 = 65.201; P < 0.001). Heritability estimates showed considerable genetic contributions to the behavioural variations in both breeds, but different heritabilities between the types within breeds was also found, suggesting different selection pressures. In conclusion, in spite of similar genetic origin and similar recent selection criteria, types behave differently in the breeds. This suggests that the genetic architecture related to behaviour differs between the breeds.
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| 10. |
- Trona, Federica, et al.
(författare)
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Neural coding merges sex and habitat chemosensory signals in an insect herbivore
- 2013
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Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 280:1760, s. 20130267-
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the processing of odour mixtures is a focus in olfaction research. Through a neuroethological approach, we demonstrate that different odour types, sex and habitat cues are coded together in an insect herbivore. Stronger flight attraction of codling moth males, Cydia pomonella, to blends of female sex pheromone and plant odour, compared with single compounds, was corroborated by functional imaging of the olfactory centres in the insect brain, the antennal lobes (ALs). The macroglomerular complex (MGC) in the AL, which is dedicated to pheromone perception, showed an enhanced response to blends of pheromone and plant signals, whereas the response in glomeruli surrounding the MGC was suppressed. Intracellular recordings from AL projection neurons that transmit odour information to higher brain centres, confirmed this synergistic interaction in the MGC. These findings underscore that, in nature, sex pheromone and plant odours are perceived as an ensemble. That mating and habitat cues are coded as blends in the MGC of the AL highlights the dual role of plant signals in habitat selection and in premating sexual communication. It suggests that the MGC is a common target for sexual and natural selection in moths, facilitating ecological speciation.
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| 11. |
- Emami, S. Noushin, et al.
(författare)
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A key malaria metabolite modulates vector blood seeking, feeding, and susceptibility to infection
- 2017
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 355:6329
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Tidskriftsartikel (refereegranskat)abstract
- Malaria infection renders humans more attractive to Anopheles gambiae sensu lato mosquitoes than uninfected people. The mechanisms remain unknown. We found that an isoprenoid precursor produced by Plasmodium falciparum, (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP), affects A. gambiae s. l. blood meal seeking and feeding behaviors as well as susceptibility to infection. HMBPP acts indirectly by triggering human red blood cells to increase the release of CO2, aldehydes, and monoterpenes, which together enhance vector attraction and stimulate vector feeding. When offered in a blood meal, HMBPP modulates neural, antimalarial, and oogenic gene transcription without affecting mosquito survival or fecundity; in a P. falciparum-infected blood meal, sporogony is increased.
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| 12. |
- Näslund, Joacim, 1985, et al.
(författare)
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Performance of wild brown trout in relation to energetic state and lab-scored activity during the early-life survival bottleneck
- 2017
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Ingår i: Behavioral Ecology and Sociobiology. - : Springer Science and Business Media LLC. - 0340-5443 .- 1432-0762. ; 71:11
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Tidskriftsartikel (refereegranskat)abstract
- The early life stage is typically a selective bottleneck during which individual performance is important for survival. We investigated size, energetic state, and activity, in relation to recapture probability in the youngest free-swimming stage of a territorial fish, the brown trout. In two experiments, we induced compensatory growth in wild-caught brown trout fry, using a restriction-refeeding protocol. Upon refeeding in the laboratory, the restricted trout showed compensatory growth in mass, but not in length. During this compensatory growth phase, we released the fish into their native stream habitat and then recaptured them after 1 month to assess survival and growth. Despite not having fully compensated body size at release, restricted fish did not show continued growth compensation in the stream, indicating that the natural environment limits growth capacity during early life. Individual baseline activity was scored in open-field tests before and after food restriction and was found repeatable but not significantly affected by growth manipulations. Under natural conditions, we found a positive association between open-field activity and survival (as indicated by recapture probability), but no significant differences between food-restricted and control fish. Initial body length positively influenced survival in the first experiment (early summer), but not in the second (late summer). These results contrast with the assumption that high baseline activity should be riskier in natural environments. For territorial animals, we hypothesize that activity is associated with high aggression and territoriality, which facilitates access to high-quality territories providing both shelter from predation and reduced starvation risk, which reduces mortality risk. In the early critical life stage, more active brown trout are better survivors. This finding, which contradicts general assumptions about the balance between predator exposure and food intake, could possibly be due to trout being highly territorial species in which active individuals can claim the best territories. We also find that young trout are likely limited in growth rate by environmental conditions in the wild, as growth compensation following food restriction is possible in the lab, but not realized in natural streams.
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| 13. |
- Amundin, Mats, et al.
(författare)
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A proposal to use distributional models to analyse dolphin vocalisation
- 2017
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Ingår i: Proceedings of the 1st International Workshop on Vocal Interactivity in-and-between Humans, Animals and Robots, VIHAR 2017. - 9782956202905 ; , s. 31-32
-
Konferensbidrag (refereegranskat)abstract
- This paper gives a brief introduction to the starting points of an experimental project to study dolphin communicative behaviour using distributional semantics, with methods implemented for the large scale study of human language.
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| 14. |
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| 15. |
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| 16. |
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| 17. |
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| 18. |
- De Jong, Adriaan
(författare)
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Övervakning av vårrastande gäss, svanar och tranor i Norrbottens och Västerbottens kustland 2012
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Stora mängder gäss, svanar och tranor rastar om våren på jordbruksmarkerna längs norra norrlandskusten. I denna rapport redovisas första årets resultat från ett nytt övervakningsprogram finansierat av Trafikverket Region Nord och länsstyrelserna i Norrbotten och Västerbotten. Studien bygger vidare på räkningarna som genomförts sedan 2004. Samtliga arter gäss, svanar och tranor räknades varannan dag inom fyra undersökningsområden (Umedeltat, Brånsjön, Skellefteå och Luleå), var och ett uppdelat i ett antal delområden. Varje delområde räknades och bokfördes separat. Fåglarnas räknades under dagtid då de söker föda eller vilar på jordbruksfälten. Förekomsten av taiga- och tundrasädgäss studerdeas särskilt med hjälp av sädgåsexperten Thomas Heinicke, Tyskland. Resultaten av årets räkningar visar att det under perioden 25 mars - 6 maj fanns mer än 2000 individer av de berörda arterna inom studieområdet medan antalet var cirka 10 000 individer mellan 16 och 26 april. I Umedeltat räknades 68% av alla dessa fåglar, kring Skellefteå och Luleå cirka 12% vardera. Brånsjön är en blygsam rastlokal i jämförelse med de övriga men kunde ändå husera upp till ett tusental fåglar samtidigt. De olika arterna var ojämnt fördelade över de fyra undersökningsområdena. Sångsvanar och kanadagäss rastade i huvudsak i Umedeltat medan tranor var särskilt talrika kring Skellefteå. Grågäss var generellt fåtaliga medan sädgässen utgjorrde ett betydande inslag inom alla områden och var efter sångsvanen den talrikaste arten. Andelen tundrasädgäss bland sädgässen var betydande, speciellt senare på säsongen och då speciellt kring Luleå. Även i Umedeltat observerades dock upp till ett tusen rastande tundrasädgäss samtidigt.
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| 19. |
- De Jong, Adriaan
(författare)
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Övervakning av vårrastande gäss, svanar och tranor i Norrbottens och Västerbottens kustland 2013
- 2014
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Stora mängder gäss, svanar och tranor rastar om våren på jordbruksmarkerna längs norra norrlandskusten. I denna rapport redovisas andra årets resultat från ett övervakningsprogram finansierat av Trafikverket Region Nord och länsstyrelserna i Norrbotten och Västerbotten. Studien bygger vidare på räkningarna som genomförts sedan 2004. Samtliga arter gäss, svanar och tranor räknades varannan dag inom fyra undersökningsområden (Umedeltat, Brånsjön, Skellefteå och Luleå), var och ett uppdelat i ett antal delområden. Varje delområde räknades och bokfördes separat. Fåglarnas räknades under dagtid då de söker föda eller vilar på jordbruksfälten. Förekomsten av taiga- och tundrasädgäss studerades särskilt med hjälp av sädgåsexperten Thomas Heinicke, Tyskland. Totalt inräknades närmare 38 tusen individer (mot närmare 127 tusen våren 2012). Fler än 2000 individer av de berörda arterna per dag räknades in endast under perioden 20 april - 2 maj, en mycket kortare period än 2012 (25 mars - 6 maj). De totala dagssummorna nådde under våren 2013 aldrig över 6000 individer medan det räknades som mest 11659 individer i 2012 (22 april). Dessa låga antal (speciellt för Umedeltat) kan med all sannolikhet förklaras av den sena våren söder om och avsaknaden av bromsande förhållanden norr om studieområdet. Detta i kombination med stora arealer oskördade sädesfält och riklig förekomst av svämpölar på jordbruksmarkerna i hela kustlandet. I Umedeltat räknades 33% av fåglarna (68% i 2012), kring Brånsjön och Skellefteå cirka 15% vardera medan Luleå ledde med 37%. Högsta antalet sädgäss som räknades kring Brånsjön var i år nästan lika högt som i Umedeltat: 984 mot 1090. De olika arterna var ojämnt fördelade över de fyra undersökningsområdena. Merparten (46%) av sädgässen räknades kring Luleå medan Umedeltat stod för endast 19%, vilket var mindre än andelen för Brånsjön (24%). Sångsvanar och kanadagäss rastade i huvudsak i Umedeltat medan tranor i huvudsak nyttjade markerna kring Brånsjön och Skellefteå. Grågäss utgjorde 20-40 % av alla inräknade fåglar inom alla undersökningsområden utom Brånsjön där andelen var knappt 11 %. Andelen tundrasädgäss bland sädgässen var betydande (över 80%), speciellt senare på säsongen och då speciellt kring Luleå. Även i Umedeltat observerades dock upp till drygt 300 rastande tundrasädgäss samtidigt och mot slutet av sträckperioden (27 april) utgjorde tundrasädgäss 40% av sädgässen i Umedeltat.
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| 20. |
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| 21. |
- Uller, Tobias, 1977, et al.
(författare)
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Direct exposure to corticosterone during embryonic development influences behaviour in an ovoviviparous lizard
- 2006
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Ingår i: ETHOLOGY. - : Wiley. - 0179-1613 .- 1439-0310. ; 112:4, s. 390-397
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Tidskriftsartikel (refereegranskat)abstract
- It is becoming increasingly clear that conditions experienced during embryonic development can be of major importance for traits subsequent to parturition or hatching. For example, in mammals, offspring from stressed mothers show a variety of changes in behavioural, morphological, and life-history traits. The effects of maternal stress on trait development are believed to be mediated via transfer of glucocorticoids, the main hormones released during the stress response, from mother to offspring. However, also other physiological maternal responses during stress could be responsible for changes in offspring phenotype. We investigated the direct effects of corticosterone on offspring development, without other confounding factors related to increased maternal stress, by injection of corticosterone in eggs of the ovoviviparous lizard Lacerta vivipara. Corticosterone-manipulated offspring did not show impaired development, reduced body size or body condition at parturition. However, corticosterone-treated offspring showed altered anti-predator behaviour, as measured by the time required to emerge from shelter after a simulated predator attack. Differential steroid exposure during development, possibly mediated by maternal stress response, may explain some of the variation in behaviour among individuals in natural populations.
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| 22. |
- Larsson, Kjell, 1958-, et al.
(författare)
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Nest parasitism in the barnacle goose : evidence from protein fingerprinting and microsatellites
- 2009
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Ingår i: Animal Behaviour. - London : Academic Press. - 0003-3472 .- 1095-8282. ; 78:1, s. 167-174
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Tidskriftsartikel (refereegranskat)abstract
- Geese are often seen as one of nature's best examples of monogamous relationships, and many social pairs stay together for life. However, when parents and young are screened genetically, some chicks do not match their social parents. Although this has often been explained as adoption of foreign young after hatching, conspecific nest parasitism is another possibility. We used nondestructive egg albumen sampling and protein fingerprinting to estimate the frequency and success of nest parasitism in a Baltic Sea population of barnacle geese, Branta leucopsis. Among the 86 nests for which we had the most complete information, 36% were parasitized, and 12% of the eggs were parasitic. Almost 80% of the parasitic eggs were laid after the host began incubation. Hatching of these eggs was limited to the few cases where the host female incubated longer than normally because her own eggs failed to hatch. Conspecific nest parasitism in this population therefore seems mainly to be an alternative reproductive tactic of lower fitness than normal nesting. Comparison with DNA profiling of chicks (with 10–14 microsatellites) and other evidence confirmed the suitability of protein fingerprinting for analysis of nest parasitism. It can often provide more data than microsatellites, if eggs are albumen-sampled soon after being laid, before most losses occur.
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| 23. |
- Barber, I., et al.
(författare)
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Behavioural responses to simulated avian predation in female three spined sticklebacks the effect of experimental Schistocephalus solidus infections
- 2004
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Ingår i: Behaviour. - 0005-7959 .- 1568-539X. ; 141, s. 1425-1440
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Tidskriftsartikel (refereegranskat)abstract
- Plerocercoid larvae of Schistocephalus solidus are common parasites of three-spined sticklebacks that require the ingestion of stickleback hosts by birds to complete their life cycle. Amongst wild-caught sticklebacks, infection is associated with a reduction in antipredator behaviour; however, to date no study has examined the escape responses of experimentally infected sticklebacks, and thus assigning causality remains difficult. Here, we compare aspects of the antipredator behaviour of five experimentally infected female sticklebacks with shamexposed controls over a 16 post-exposure week period. During weeks 1-7 post-exposure, the escape responses of infected fish did not differ significantly from those of sham-exposed fish. However, over weeks 9-15, when infected fish had developed plerocercoids of >50 mg—the size at which they become infective to birds —a lower proportion of infected fish performed directional responses and reached cover within 2 s of the strike. Infected fish also performed a lower frequency of ‘staggered dashes’, and a higher frequency of ‘slow swims’, than shamexposed fish over weeks 9-15. Amongst sham-exposed fish, re-emergence from cover was uncommon throughout the study, but infected fish regularly left cover during weeks 9-15. Our results support those of previous studies examining behavioural change in naturally infected fish and, although other explanations remain possible, our finding that behaviour change in experimentally-infected fish is limited to hosts harbouring single infective parasites provides further evidence that the behaviour changes may be parasite adaptations.
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| 24. |
- Barber, I., et al.
(författare)
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Effects of experimental Schistocephalus solidus infections on growth, morphology and sexual development of female three-spined sticklebacks, Gasterosteus aculeatus
- 2003
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Ingår i: Parasitology. - 0031-1820 .- 1469-8161. ; 126, s. 359-367
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Tidskriftsartikel (refereegranskat)abstract
- The use of naturally infected hosts in studies attempting to identify parasite-induced changes in host biology is problematical because it does not eliminate the possibility that infection may be a consequence, rather than a cause, of host trait variation. In addition, uncontrolled concomitant infections may confound results. In this study we experimentally infected individual laboratory-bred female three-spined sticklebacks Gasterosteus aculeatus L. with the pseudophyllidean cestode Schistocephalus solidus [Muller], and compared the morphology and growth patterns of infected females with sham-exposed controls over a 16-week period. Fish were fed a ration of 8% body weight per day. Non-invasive image analysis techniques allowed the growth of individual plerocercoids to be tracked in vivo throughout the course of infection, and patterns of host and parasite growth were determined. Females that developed infections diverged morphometrically from unexposed control females and exposed-uninfected females at 6 weeks post-infection, with the width of the body at the pectoral fins giving the earliest indication of infection success. When including the plerocercoid, infected females gained weight more quickly than controls, but when plerocercoid weight was removed this trend was reversed. There was no effect of infection on the increase in fish length. Plerocercoids grew at different rates in individual hosts, and exhibited measurable sustained weight increases of up to 10% per day. Final estimates of plerocercoid weight from morphometric analysis prior to autopsy were accurate to within +/-17% of actual plerocercoid weight. At autopsy, infected female sticklebacks had significantly lower perivisceral fat reserves but had developed significantly larger ovaries than controls. The results are discussed in relation to previous studies examining natural infections, and the value of utilizing experimental infections to examine ecological aspects of host-parasite interactions is discussed.
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| 25. |
- Brand, Jack A., et al.
(författare)
-
Temperature change exerts sex-specific effects on behavioural variation
- 2023
-
Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - 0962-8452 .- 1471-2954. ; 290:2002
-
Tidskriftsartikel (refereegranskat)abstract
- Temperature is a key factor mediating organismal fitness and has important consequences for species' ecology. While the mean effects of temperature on behaviour have been well-documented in ectotherms, how temperature alters behavioural variation among and within individuals, and whether this differs between the sexes, remains unclear. Such effects likely have ecological and evolutionary consequences, given that selection acts at the individual level. We investigated the effect of temperature on individual-level behavioural variation and metabolism in adult male and female Drosophila melanogaster (n = 129), by taking repeated measures of locomotor activity and metabolic rate at both a standard temperature (25°C) and a high temperature (28°C). Males were moderately more responsive in their mean activity levels to temperature change when compared to females. However, this was not true for either standard or active metabolic rate, where no sex differences in thermal metabolic plasticity were found. Furthermore, higher temperatures increased both among- and within-individual variation in male, but not female, locomotor activity. Given that behavioural variation can be critical to population persistence, we suggest that future studies test whether sex differences in the amount of behavioural variation expressed in response to temperature change may result in sex-specific vulnerabilities to a warming climate.
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| 26. |
- Lehtonen, Topi K., et al.
(författare)
-
Adjustment of brood care behaviour in the absence of a mate in two species of Nicaraguan crater lake cichlids
- 2011
-
Ingår i: Behavioral Ecology and Sociobiology. - : Springer Science and Business Media LLC. - 0340-5443 .- 1432-0762. ; 65:4, s. 613-619
-
Tidskriftsartikel (refereegranskat)abstract
- In many taxa, parental strategies can vary among individuals. This is especially true in species with biparental care, with males, more often than females, deserting their mates. While there is an abundance of theoretical predictions and empirical data on factors inducing mate abandonment by males, much less is known about what consequences this may have on female behaviour, particularly in the field and in non-avian systems. Here, we compared brood defence rate, behavioural defence types, and brood success of solitary and paired females in two species of Neotropical cichlid fish in their natural habitat. In terms of the rate of territorial aggression towards potential brood predators, solitary females were able to fully compensate in the absence of a male but, in so doing, ended up maintaining smaller territories, which appeared to compromise offspring fitness in at least one of the two species. Hence, our results suggest that even extensive quantitative compensation in parental effort by solitary females may not be enough to ensure adequate qualitative compensation for the lack of male participation, highlighting the importance of distinguishing between these two aspects of compensatory parental care.
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| 27. |
- Svensson, P. A., et al.
(författare)
-
Chromatic interaction between egg pigmentation and skin chromatophores in the nuptial coloration of female two-spotted gobies
- 2005
-
Ingår i: Journal of Experimental Biology. - : The Company of Biologists. - 0022-0949 .- 1477-9145. ; 208:23, s. 4391-4397
-
Tidskriftsartikel (refereegranskat)abstract
- In two-spotted gobies (Gobiusculus flavescens Fabricius 1779), females develop an orange belly as they approach sexual maturity. Bright belly coloration is preferred by males and has been suggested to act as a female ornament. This coloration is unusual in that it originates partly from pigmentation of the abdominal skin but also from strongly pigmented gonads directly visible through the skin. In addition, females have been observed to temporarily become more colourful during courtship and competition. To understand how gonad and skin pigmentation interact in this nuptial coloration, the potential for colour modification via regulation of skin chromatophores was investigated. Noradrenaline caused aggregation of chromatophore pigment and was used to experimentally reduce the contribution of skin chromatophores to the nuptial coloration. Chromatophore pigment aggregation caused bellies to become less colourful and abdominal skin biopsies to become less colourful and more transparent. There was a strong positive relationship between belly coloration and the coloration of the underlying gonads. This shows that belly coloration honestly reflects egg pigmentation, mainly because the transparency of the abdominal skin allows other fish to see the gonads directly. Interestingly, when noradrenaline caused pigment to aggregate and thereby increased the transparency of the skin, the relationship between belly and gonad coloration weakened. We conclude that female G. flavescens have a potential to use skin chromatophores to rapidly alter their nuptial coloration, thereby affecting the efficacy with which information about gonad coloration is conveyed.
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| 28. |
- Ericsson, Philip, et al.
(författare)
-
Personality-dependent inter- and intraspecific foraging competition in the invasive round goby, Neogobius melanostomus
- 2021
-
Ingår i: Journal of Fish Biology. - : Wiley-Blackwell. - 0022-1112 .- 1095-8649. ; 98:5, s. 1234-1241
-
Tidskriftsartikel (refereegranskat)abstract
- This study examines the impact of boldness on foraging competition of the highly invasive round goby Neogobius melanostomus Pallas 1815. Individual risk tolerance, or boldness, was measured as the time to resume movement after a simulated predation strike. Fish that resumed movement faster were categorized as "bold," fish that took more time to resume movement were categorized as "shy" and those that fell in between these two categories were determined to have "intermediate" boldness. Competitive impacts of boldness in N. melanostomus were determined in a laboratory foraging experiment in which interspecific (juvenile Atlantic cod Gadus morhua Linnaeus 1758) and intraspecific (intermediate N. melanostomus) individuals were exposed to either bold or shy N. melanostomus competitors. G. morhua consumed fewer prey when competing with bold N. melanostomus than when competing with shy N. melanostomus, whereas intermediately bold N. melanostomus foraging was not affected by competitor boldness. Bold and shy N. melanostomus consumed similar amounts of prey, and the number of interactions between paired fish did not vary depending on the personality of N. melanostomus individuals. Therefore, intraspecific foraging competition was not found to be personality dependent. This study provides evidence that individual differences in boldness can mediate competitive interactions in N. melanostomus; nonetheless, results also show that competition is also governed by other mechanisms that require further study.
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| 29. |
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| 30. |
- Braga Gonçalves, Inês, et al.
(författare)
-
Effects of female mating order and male size on embryo survival in a pipefish.
- 2015
-
Ingår i: Biological Journal of the Linnean Society. - : Oxford University Press (OUP). - 0024-4066 .- 1095-8312. ; 114:3, s. 639-645
-
Tidskriftsartikel (refereegranskat)abstract
- In species that provide parental care, individuals should invest adaptively in their offspring in relation to the preand post-zygotic care provided by their partners. In the broad-nosed pipefish, Syngnathus typhle L., females transfer large, nutrient-rich eggs into the male brood pouch during mating. The male broods and nourishes the embryos for several weeks before independent juveniles emerge at parturition. Given a choice, females clearly prefer large partners. Yet, females provide protein-richer eggs when the same individual mates with a smaller than a larger male. In the present study, we allowed each female to mate with one small and one large male, in alternated order. We found a strong effect of female mating order, with larger clutches and higher embryo mortality in first- than second-laid broods, which may suggest that eggs over-ripen in the ovaries or reflect the negative effects of high embryo density in the brood pouch. In either case, this effect should put constraints on the possibility of a female being selective in mate choice. We also found that small and large males produced embryos of similar size and survival, consistent with the reproductive compensation hypothesis, suggesting that, in this species, larger males provide better nourishment to the embryos than smaller males.
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| 31. |
- Hambäck, Peter, et al.
(författare)
-
Mating affects resource selection and modulates associational effects between neighbouring resources
- 2017
-
Ingår i: Oikos. - : Wiley. - 0030-1299 .- 1600-0706. ; 126, s. 1708-1716
-
Tidskriftsartikel (refereegranskat)abstract
- Associational effects occur when the attack rate on a resource depends on neighbouring resources in the environment. These effects are predicted to result from mismatches experienced by the consumer organism in resource selection along hierarchical search levels. As resource selection depends on sensory information used during search behaviour, we expected that different physiological states of an insect might modulate the outcome of associational effects due to differences in resource selection. We used Drosophila melanogaster, as a model organism for olfactory-guided behaviour in insects, to study the effects of mating induced behavioural changes on associational effects between two alternative resources. We found that mating has no effect on the ability of D. melanogaster to locate resource patches, but rather affects the perception of the resources within the patch. Consequently, we only found associational effects in the experiments with unmated females and not in the experiments with mated females. Our results suggest that the lack of associational effects for mated females resulted from changes in the use of short-range olfactory cues, leading to random selection among the resources. In conclusion, our results suggest that the physiological state of an insect modulates associational effects by affecting resource selection rates within the patch.
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| 32. |
- Kuijper, D. P. J., et al.
(författare)
-
Paws without claws? Ecological effects of large carnivores in anthropogenic landscapes
- 2016
-
Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 283:1841
-
Tidskriftsartikel (refereegranskat)abstract
- Large carnivores are frequently presented as saviours of biodiversity and ecosystem functioning through their creation of trophic cascades, an idea largely based on studies coming primarily out of relatively natural landscapes. However, in large parts of the world, particularly in Europe, large carnivores live in and are returning to strongly human-modified ecosystems. At present, we lack a coherent framework to predict the effects of large carnivores in these anthropogenic landscapes. We review how human actions influence the ecological roles of large carnivores by affecting their density or behaviour or those of mesopredators or prey species. We argue that the potential for density-mediated trophic cascades in anthropogenic landscapes is limited to unproductive areas where even low carnivore numbers may impact prey densities or to the limited parts of the landscape where carnivores are allowed to reach ecologically functional densities. The potential for behaviourally mediated trophic cascades may be larger and more widespread, because even low carnivore densities affect prey behaviour. We conclude that predator-prey interactions in anthropogenic landscapes will be highly context-dependent and human actions will often attenuate the ecological effects of large carnivores. We highlight the knowledge gaps and outline a new research avenue to study the role of carnivores in anthropogenic landscapes.
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| 33. |
- Larson, Keith W., 1968-
(författare)
-
Hybrid zone dynamics, assortative mating, and migratory programmes in a willow warbler migratory divide
- 2012
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis I will compare and contrast the two willow warbler subspecies (Phylloscopus trochilus trochilus and P. t. acredula) with differing migratory phenotypes (or "migratype") in the context of their migratory divide and hybrid zone in central Sweden. Their migratory programs differ in the direction and distance traveled during migration. The "northern" willow warblers migrate south-southeast through the Balkan Peninsula to winter in eastern Africa. The "southern" willow warbler migrates southwest through the Iberian Peninsula to winter in western Africa. In this thesis I will also explore the consequences of hybridization for these two very closely related subspecies where they meet in central Sweden. In the first paper I investigate the role of population abundance in determining the location of the hybrid zone. Specifically, is there a region of low abundance associated with the hybrid zone? Further, is the hybrid zone located on an environmental gradient which might suggest that breeding ground environmental conditions are responsible for the lower abundance? This lower abundance may reflect the unsuitability of habitats along the environmental gradient for either parental or hybrid offspring. In my second paper, I ask if there are population specific differences in their wintering moult ecology that can be elucidated from diet derived stable isotope patterns in their winter moulted primary flight feathers? The third paper addresses the important question, does assortative mating lead to reproductive isolation or do these very similar subspecies hybridize and produce offspring? In my fourth paper, I ask does local adaptation to environmental conditions, such as temperature extremes and the short growing season, in mountain populations of willow warblers explain the apparent distribution of the “northern-allele” for the AFLP derived genetic marker WW1? Finally, in the fifth paper, I conduct a detailed analysis of phenotypic traits at 50 sites across the hybrid zone, including 35 sites visited more than once. Here I ask, does lower abundances in the west of the hybrid zone predict the zone to be wider in the west than in the east? Further, using data from repeated visits to sites across the zone, we predict low repeatabilities for migratory associated traits that would suggest that high annual turn-over in migratypes occupying the zone. For future efforts to understand hybrid zone dynamics, it will be essential to develop genetic markers that allow one to separate each parental migratypes, hybrids, and back-crosses. Once genetic markers allow the identification of hybrid offspring, orientation experiments should be conducted to elucidate migratory directional preferences that would support our hypothesis that hybrids take an intermediate migratory direction to their parental migratypes. This intermediate direction could be a significant cost to hybrid fitness, as this route would require they cross the Mediterranean Sea and Sahara Desert at their widest points.
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| 34. |
- Ljungberg, Peter, et al.
(författare)
-
Effects of small-scale habitat fragmentation on predator–prey interactions in a temperate sea grass system
- 2013
-
Ingår i: Marine Biology. - : Springer Science and Business Media LLC. - 0025-3162 .- 1432-1793. ; 160:3, s. 667-675
-
Tidskriftsartikel (refereegranskat)abstract
- During the last decades, fragmentation has become an important issue in ecological research. Habitat fragmentation operates on spatial scales ranging over several magnitudes from patches to landscapes. We focus on small-scale fragmentation effects relevant to animal foraging decision making that could ultimately generate distribution patterns. In a controlled experimental environment, we tested small-scale fragmentation effects in artificial sea grass on the feeding behaviour of juvenile cod (Gadus morhua). Moreover, we examined the influence of fragmentation on the distribution of one of the juvenile cod’s main prey resources, the grass shrimp (Palaemon elegans), in association with three levels of risk provided by cod (no cod, cod chemical cues and actively foraging cod). Time spent by cod within sea grass was lower in fragmented landscapes, but total shrimp consumption was not affected. Shrimp utilised vegetation to a greater extent in fragmented treatments in combination with active predation. We suggest that shrimp choose between sand and vegetation habitats to minimize risk of predation according to cod habitat-specific foraging capacities, while cod aim to maximize prey-dependent foraging rates, generating a habitat-choice game between predator and prey. Moreover, aggregating behaviour in grass shrimp was only found in treatments with active predation. Hence, we argue that both aggregation and vegetation use are anti-predator defence strategies applied by shrimp. We therefore stress the importance of considering small-scale behavioural mechanisms when evaluating consequences from habitat fragmentation on trophic processes in coastal environments.
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| 35. |
- Näslund, Joacim, 1985, et al.
(författare)
-
State-dependent behavior and alternative behavioral strategies in brown trout (Salmo trutta L.) fry
- 2016
-
Ingår i: Behavioral Ecology and Sociobiology. - : Springer Science and Business Media LLC. - 0340-5443 .- 1432-0762. ; 70:12, s. 2111-2125
-
Tidskriftsartikel (refereegranskat)abstract
- © 2016, The Author(s).Abstract: Animals generally adjust their behavior in response to bodily state (e.g., size and energy reserves) to optimize energy intake in relation to mortality risk, weighing predation probability against the risk of starvation. Here, we investigated whether brown trout Salmo trutta adjust their behavior in relation to energetic status and body size during a major early-life selection bottleneck, when fast growth is important. Over two consecutive time periods (P1 and P2; 12 and 23days, respectively), food availability was manipulated, using four different combinations of high (H) and low (L) rations (i.e., HH, HL, LH, and LL; first and second letter denoting ration during P1 and P2, respectively). Social effects were excluded through individual isolation. Following the treatment periods, fish in the HL treatment were on average 15–21% more active than the other groups in a forced open-field test, but large within-treatment variation provided only weak statistical support for this effect. Furthermore, fish on L-ration during P2 tended to be more actively aggressive towards their mirror image than fish on H-ration. Body size was related to behavioral expression, with larger fish being more active and aggressive. Swimming activity and active aggression were positively correlated, forming a behavioral syndrome in the studied population. Based on these behavioral traits, we could also distinguish two behavioral clusters: one consisting of more active and aggressive individuals and the other consisting of less active and aggressive individuals. This indicates that brown trout fry adopt distinct behavioral strategies early in life. Significance statement: This paper provides information on the state-dependence of behavior in animals, in particular young brown trout. On the one hand, our data suggest a weak energetic state feedback where activity and aggression is increased as a response to short term food restriction. This suggests a limited scope for behavioral alterations in the face of starvation. On the other hand, body size is linked to higher activity and aggression, likely as a positive feedback between size and dominance. The experiment was carried out during the main population survival bottleneck, and the results indicate that growth is important during this stage, as 1) behavioral compensation to increase growth is limited, and 2) growth likely increases the competitive ability. However, our data also suggests that the population separates into two clusters, based on combined scores of activity and aggression (which are positively linked within individuals). Thus, apart from an active and aggressive strategy, there seems to be another more passive behavioral strategy.
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| 36. |
- Van Deurs, M., et al.
(författare)
-
Using accelerometry to quantify prey attack and handling behaviours in piscivorous pike Esox lucius
- 2017
-
Ingår i: Journal of Fish Biology. - Oxford : Wiley. - 0022-1112 .- 1095-8649. ; 90:6, s. 2462-2469
-
Tidskriftsartikel (refereegranskat)abstract
- Accelerometer technology was used to evaluate behaviours in the teleost ambush predator pike Esox lucius foraging on crucian carp Carassius carassius. Automated rule-based estimates of prey-size determined handling time were obtained and are compared with video-recorded behaviours. Solutions to tag attachment and the limitations imposed by battery-time and data-logging capacities are evaluated.
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| 37. |
- Schötz, Susanne, et al.
(författare)
-
Phonetic Characteristics of Domestic Cat Vocalisations
- 2017
-
Ingår i: Proceedings of the 1st International Workshop on Vocal Interactivity in-and-between Humans, Animals and Robots, VIHAR 2017. - 9782956202905 ; , s. 5-6
-
Konferensbidrag (refereegranskat)abstract
- The cat (Felis catus, Linneaus 1758) has lived around or with humans for at least 10,000 years, and is now one of the most popular pets of the world with more than 600 millionindividuals. Domestic cats have developed a more extensive, variable and complex vocal repertoire than most other members of the Carnivora, which may be explained by their social organisation, their nocturnal activity and the long period of association between mother and young. Still, we know surprisingly little about the phonetic characteristics of these sounds, and about the interaction between cats and humans.Members of the research project Melody in human–cat communication (Meowsic) investigate the prosodic characteristics of cat vocalisations as well as the communication between human and cat. The first step includes a categorisation of cat vocalisations. In the next step it will be investigated how humans perceive the vocal signals of domestic cats. This paper presents an outline of the project which has only recently started.
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| 38. |
- Jensen, Mikael, 1969
(författare)
-
Lekteorier
- 2013
-
Bok (övrigt vetenskapligt/konstnärligt)
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| 39. |
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| 40. |
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| 41. |
- Andersson, Claes, 1973, et al.
(författare)
-
Zooming out the microscope on cumulative cultural evolution: ‘Trajectory B’ from animal to human culture
- 2023
-
Ingår i: Humanities and Social Sciences Communications. - 2662-9992. ; 10, s. 1-20
-
Tidskriftsartikel (refereegranskat)abstract
- It is widely believed that human culture originated in the appearance of Oldowan stone-tool production (circa 2.9 Mya) and a primitive but effective ability to copy detailed know-how. Cumulative cultural evolution is then believed to have led to modern humans and human culture via self-reinforcing gene-culture co-evolution. This outline evolutionary trajectory has come to be seen as all but self-evident, but dilemmas have appeared as it has been explored in increasing detail. Can we attribute even a minimally effective know-how copying capability to Oldowan hominins? Do Oldowan tools really demand know-how copying? Is there any other evidence that know-how copying was present? We here argue that this account, which we refer to as “Trajectory A”, may be a red herring, and formulate an alternative “Trajectory B” that resolves these dilemmas. Trajectory B invokes an overlooked group-level channel of cultural inheritance (the Social Protocell) whereby networks of cultural traits can be faithfully inherited and potentially undergo cumulative evolution, also when the underpinning cultural traits are apelike in not being transmitted via know-how copying (Latent Solutions). Since most preconditions of Trajectory B are present in modern-day Pan, Trajectory B may even have its roots considerably before Oldowan toolmaking. The cumulative build-up of networks of non-cumulative cultural traits is then argued to have produced conditions that both called for and afforded a gradual appearance of the ability to copy know-how, but considerably later than the Oldowan.
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| 42. |
- Allen, Andrew, et al.
(författare)
-
Scaling up movements: from individual space use to population patterns
- 2016
-
Ingår i: Ecosphere. - : Wiley. - 2150-8925. ; 7, s. 1-16
-
Tidskriftsartikel (refereegranskat)abstract
- Studying multiple individuals from multiple populations would add knowledge about the proportion of different movement strategies (migratory vs. resident) and how space use patterns vary within and across populations. This allows for effective conservation or management of partially migratory animal populations by identifying the appropriate size of management units and temporal interventions. However, this knowledge is often lacking as only a few individuals from a single population are tracked in space and time. To understand the drivers of intraspecific variation in movement patterns across a broad scale, we analyzed the multiannual space use of 307 moose (Alces alces), containing 544 single-year trajectories, from 10 study areas that are spread over a 1500-km latitudinal gradient. Using a novel approach, we quantified within-and among-population variation in movement and space use patterns. We identified the movement strategy (migratory, sedentary, nomadic, or dispersal) of moose and computed annual and seasonal home ranges. Individuals demonstrated variable movement strategies from migration to year-round residence. Summer home ranges were larger in northern study areas, whereas no geographical trends were detected among populations in winter home ranges. Individual-level traits, such as sex and age, along with factors related to the landscape, such as land use and habitat, explained variation within populations, whereas climatic factors such as temperature and vegetative productivity explained variation among populations. Importantly, the variables that explained individual-level variation in space use within populations were different for all our populations. We demonstrate the intricate interplay between individual life history and landscape scale variables and how they may determine the observed movement patterns and influence the scale of management.
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| 43. |
- Alström, Per
(författare)
-
Recent northward range expansion promotes song evolution in a passerine bird, the Light-vented Bulbul
- 2013
-
Ingår i: Journal of Evolutionary Biology. - : Wiley. - 1010-061X .- 1420-9101. ; 26, s. 867-877
-
Tidskriftsartikel (refereegranskat)abstract
- In common with human speech, song is culturally inherited in oscine passerine birds (songbirds'). Intraspecific divergence in birdsong, such as development of local dialects, might be an important early step in the speciation process. It is therefore vital to understand how songs diverge, especially in founding populations. The northward expansion of the Light-vented Bulbul Pycnonotus sinensis (J. F. Gmelin, 1789) into north China in the last 30years provides an excellent opportunity to study birdsong evolution. We compared similar to 4400 songs from newly established northern populations with similar to 2900 songs from southern populations to evaluate song divergence after recent expansion. The total pool of syllables and especially song types was considerably smaller in the north than in the south, indicating founder effects' in the new population. The ancestral pattern of mosaic song dialects changed into a pattern of wide geographical sharing of a few song types and syllables, likely the result of fewer geographical barriers to meme flow', and the recent spread across a large area in the north. Our results suggest that song evolution and vocal trait shifts can arise rapidly after range expansion, and that in the Light-vented Bulbul founder effects', geographical isolation, and recent rapid expansions played important roles in the evolution of song dialects.
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| 44. |
- Andersson, Marica, et al.
(författare)
-
Increased noise levels cause behavioural and distributional changes in Atlantic cod and saithe in a large public aquarium—A case study
- 2023
-
Ingår i: Aquaculture, Fish and Fisheries. - : John Wiley & Sons. - 2693-8847.
-
Tidskriftsartikel (refereegranskat)abstract
- Abstract Investigating the effects of underwater noise on aquatic animals is a research field that is receiving rapidly increasing attention. Despite this, surprisingly few studies have addressed the potential impacts of noise in a marine animal husbandry setting. In this regard, the behaviour of fish in public aquariums can be used as an indicator of well-being, and noise is known to cause behavioural changes. This case study investigates the behaviour of cod (Gadus morhua) and saithe (Pollachius virens) in a large public aquarium when exposed to increased noise levels originating from an aquarium renovation carried out by construction divers. Swimming behaviour, group formation and vertical distribution, along with yawning and scratching frequencies of the fish, were analysed from video recordings made before, during and after the exposure to increased noise levels. The same parameters were also analysed to evaluate potential effects of the presence of divers when not making renovation noise, compared to fish behaviour prior to the renovation. There was a slight change in the depth distribution of both species and a decrease in the number of scratches in cod due to the presence of divers that were not making renovation noise. In the presence of construction noises in the tank, however, both cod and saithe showed a wider array of behavioural changes, including increased swimming speed, changes in depth distribution and increased yawning frequencies. The results from this case study demonstrate that an underwater renovation with increased noise levels impacts fish behaviour and suggests that underwater noise should be considered during the management of aquatic environments, including public aquaria.
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| 45. |
- Behrens, Jane W., et al.
(författare)
-
Personality- and size-related metabolic performance in invasive round goby (Neogobius melanostomus)
- 2020
-
Ingår i: Physiology and Behavior. - : Elsevier. - 0031-9384 .- 1873-507X. ; 215, s. 1-6
-
Tidskriftsartikel (refereegranskat)abstract
- Differences between individuals in behavioral type (i.e. animal personality) are ecologically and evolutionarily important because they can have significant effects on fitness components such as growth and predation risk. In the present study we are used the invasive round goby (Neogobius melanostomus) from an established population in controlled experiments to examine the relationships among personality, metabolic performance, and growth rate (inferred as size-at-age). Boldness was measured as the time to return to normal behavior after a simulated predator attack, where fish with shorter freezing times were categorized as "bold" and fish with longer times were categorized as "shy." We show that bold fish have significantly higher standard metabolic rate (SMR) than their shy conspecifics, whereas there was no difference between personality types in their maximum metabolic rate (MMR) or aerobic scope (AS). Bold fish furthermore had a smaller size-at-age as compared to shy fish. Together this provides evidence of a metabolic underpinning of personality where the high-SMR bold fish require more resources to sustain basic life functions than their low-SMR shy conspecifics, indicating that bold round goby from established populations with high densities (and high competition for food) pay a price of reduced growth rate.
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| 46. |
- Corral-López, Alberto, 1984-, et al.
(författare)
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Functional convergence of genomic and transcriptomic architecture underlies schooling behaviour in a live-bearing fish
- 2024
-
Ingår i: Nature Ecology and Evolution. - : Springer Nature. - 2397-334X. ; 8:1, s. 98-110
-
Tidskriftsartikel (refereegranskat)abstract
- The organization and coordination of fish schools provide a valuable model to investigate the genetic architecture of affiliative behaviours and dissect the mechanisms underlying social behaviours and personalities. Here we used replicate guppy selection lines that vary in schooling propensity and combine quantitative genetics with genomic and transcriptomic analyses to investigate the genetic basis of sociability phenotypes. We show that consistent with findings in collective motion patterns, experimental evolution of schooling propensity increased the sociability of female, but not male, guppies when swimming with unfamiliar conspecifics. This finding highlights a relevant link between coordinated motion and sociability for species forming fission–fusion societies in which both group size and the type of social interactions are dynamic across space and time. We further show that alignment and attraction, the two major traits forming the sociability personality axis in this species, showed heritability estimates at the upper end of the range previously described for social behaviours, with important variation across sexes. The results from both Pool-seq and RNA-seq data indicated that genes involved in neuron migration and synaptic function were instrumental in the evolution of sociability, highlighting a crucial role of glutamatergic synaptic function and calcium-dependent signalling processes in the evolution of schooling.
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| 47. |
- Griffith, Simon C., et al.
(författare)
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Variation in reproductive success across captive populations: Methodological differences, potential biases and opportunities
- 2017
-
Ingår i: Ethology. - : Wiley. - 1439-0310 .- 0179-1613. ; 123:1, s. 1-29
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Tidskriftsartikel (refereegranskat)abstract
- Our understanding of fundamental organismal biology has been disproportionately influenced by studies of a relatively small number of ‘model’ species extensively studied in captivity. Laboratory populations of model species are commonly subject to a number of forms of past and current selection that may affect experimental outcomes. Here, we examine these processes and their outcomes in one of the most widely used vertebrate species in the laboratory – the zebra finch (Taeniopygia guttata). This important model species is used for research across a broad range of fields, partly due to the ease with which it can be bred in captivity. However despite this perceived amenability, we demonstrate extensive variation in the success with which different laboratories and studies bred their subjects, and overall only 64% of all females that were given the opportunity, bred successfully in the laboratory. We identify and review several environmental, husbandry, life-history and behavioural factors that potentially contribute to this variation. The variation in reproductive success across individuals could lead to biases in experimental outcomes and drive some of the heterogeneity in research outcomes across studies. The zebra finch remains an excellent captive animal system and our aim is to sharpen the insight that future studies of this species can provide, both to our understanding of this species and also with respect to the reproduction of captive animals more widely. We hope to improve systematic reporting methods and that further investigation of the issues we raise will lead both to advances in our fundamental understanding of avian reproduction as well as to improvements in future welfare and experimental efficiency.
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| 48. |
- Kvarnemo, Charlotta, 1963
(författare)
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Why do some animals mate with one partner rather than many? A review of causes and consequences of monogamy.
- 2018
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Ingår i: Biological Reviews of the Cambridge Philosophical Society. - : Wiley. - 1469-185X. ; 93, s. 1795-1812
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Forskningsöversikt (refereegranskat)abstract
- Why do some animals mate with one partner rather than many? Here, I investigate factors related to (i) spatial constraints (habitat limitation, mate availability), (ii) time constraints (breeding synchrony, length of breeding season), (iii) need for parental care, and (iv) genetic compatibility, to see what support can be found in different taxa regarding the importance of these factors in explaining the occurrence of monogamy, whether shown by one sex (monogyny or monandry) or by both sexes (mutual monogamy). Focusing on reproductive rather than social monogamy whenever possible, I review the empirical literature for birds, mammals and fishes, with occasional examples from other taxa. Each of these factors can explain mating patterns in some taxa, but not in all. In general, there is mixed support for how well the factors listed above predict monogamy. The factor that shows greatest support across taxa is habitat limitation. By contrast, while a need for parental care might explain monogamy in freshwater fishes and birds, there is clear evidence that this is not the case in marine fishes and mammals. Hence, reproductive monogamy does not appear to have a single overriding explanation, but is more taxon specific. Genetic compatibility is a promising avenue for future work likely to improve our understanding of monogamy and other mating patterns. I also discuss eight important consequences of reproductive monogamy: (i) parentage, (ii) parental care, (iii) eusociality and altruism, (iv) infanticide, (v) effective population size, (vi) mate choice before mating, (vii) sexual selection, and (viii) sexual conflict. Of these, eusociality and infanticide have been subject to debate, briefly summarised herein. A common expectation is that monogamy leads to little sexual conflict and no or little sexual selection. However, as reviewed here, sexual selection can be substantial under mutual monogamy, and both sexes can be subject to such selection. Under long-term mutual monogamy, mate quality is obviously more important than mate numbers, which in turn affects the need for pre-mating mate choice. Overall, I conclude that, despite much research on genetic mating patterns, reproductive monogamy is still surprisingly poorly understood and further experimental and comparative work is needed. This review identifies several areas in need of more data and also proposes new hypotheses to test.
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| 49. |
- Lebreton, Sebastien, et al.
(författare)
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Feeding regulates sex pheromone attraction and courtship in Drosophila females
- 2015
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- In Drosophila melanogaster, gender-specific behavioural responses to the male-produced sex pheromone cis-vaccenyl acetate (cVA) rely on sexually dimorphic, third-order neural circuits. We show that nutritional state in female flies modulates cVA perception in first-order olfactory neurons. Starvation increases, and feeding reduces attraction to food odour, in both sexes. Adding cVA to food odour, however, maintains attraction in fed females, while it has no effect in males. Upregulation of sensitivity and behavioural responsiveness to cVA in fed females is paralleled by a strong increase in receptivity to male courtship. Functional imaging of the antennal lobe (AL), the olfactory centre in the insect brain, shows that olfactory input to DA1 and VM2 glomeruli is also modulated by starvation. Knocking down insulin receptors in neurons converging onto the DA1 glomerulus suggests that insulin-signalling partly controls pheromone perception in the AL, and adjusts cVA attraction according to nutritional state and sexual receptivity in Drosophila females.
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| 50. |
- Mansourian, Suzan
(författare)
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Drosophila Sensory Neuroethology
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Animals, like humans, need to perceive their surroundings via their senses in order to make sensible behavioral decisions, reproduce successfully, and survive. Animals are equipped with audition, vision, thermosensation, hygrosensation, mechanosensation, magnetoception, gustation, and olfaction, which detects physical and chemical changes in their habitats. Among these senses, olfaction is likely the most ancient sensory modality. Insects, the most abundant and successful group of the animal kingdom, predominantly use olfaction to find food, mates, breeding sites, and to avoid dangers. Moreover, hygrosensation is vital for insects to find a suitable habitat and to avoid risks of dehydration. Our understanding of the molecular, neuronal, and morphological organization of the insect olfactory system is today substantial, in large parts thanks to Drosophila melanogaster (vinegar fly) and the wealth of sophisticated genetic tools available in this classic model system. Our knowledge regarding the functional and molecular basis of insect hygrosensation, is, however, limited. In this thesis, I show that the vinegar fly olfactory system do not detect odor molecules randomly, but capture and process specific odors associated with needs and dangers. I demonstrate how the olfactory system cope with toxic and harmful matters in the natural habitat and I identify an olfactory circuit that mediates repellency towards phenol, which is produced by pathogenic bacteria, predominantly present in carnivore feces. Furthermore, I show that flies have an innate and species-specific ability to find suitable humidity levels, related to their native habitat. Vinegar flies can sense humidity changes in their environment through a trio of ionotropic receptors expressed in the sacculus of the antennae. Although D. melanogaster is known as a generalist, I show that wild populations of D. melanogaster from a mopane forest within the potential ancestral habitat have a strong breeding preference towards marula fruit. This fruit is seasonally abundant, native to Southern Africa, and is presumably the ancestral host of the vinegar fly. I also argue that marula drove the D. melanogaster to become a human commensal. In summary, the research presented in my thesis enhances our understanding of how the olfactory system operates, the behavior of wild flies, and introduces the genetic and neural basis underlying humidity sensation in insects. These findings might lead us to better strategies for controlling insect pests, as well as human disease vectors.
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