| 1. |
- Karpestam, Einat, et al.
(author)
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Detection experiments with humans implicate visual predation as a driver of colour polymorphism dynamics in pygmy grasshoppers
- 2013
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In: BMC Ecology. - : Springer Science and Business Media LLC. - 1472-6785. ; 13, s. Article number 17-
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Journal article (peer-reviewed)abstract
- Background: Animal colour patterns offer good model systems for studies of biodiversity and evolution of local adaptations. An increasingly popular approach to study the role of selection for camouflage for evolutionary trajectories of animal colour patterns is to present images of prey on paper or computer screens to human 'predators'. Yet, few attempts have been made to confirm that rates of detection by humans can predict patterns of selection and evolutionary modifications of prey colour patterns in nature. In this study, we first analyzed encounters between human 'predators' and images of natural black, grey and striped colour morphs of the polymorphic Tetrix subulata pygmy grasshoppers presented on background images of unburnt, intermediate or completely burnt natural habitats. Next, we compared detection rates with estimates of capture probabilities and survival of free-ranging grasshoppers, and with estimates of relative morph frequencies in natural populations. Results: The proportion of grasshoppers that were detected and time to detection depended on both the colour pattern of the prey and on the type of visual background. Grasshoppers were detected more often and faster on unburnt backgrounds than on 50% and 100% burnt backgrounds. Striped prey were detected less often than grey or black prey on unburnt backgrounds; grey prey were detected more often than black or striped prey on 50% burnt backgrounds; and black prey were detected less often than grey prey on 100% burnt backgrounds. Rates of detection mirrored previously reported rates of capture by humans of free-ranging grasshoppers, as well as morph specific survival in the wild. Rates of detection were also correlated with frequencies of striped, black and grey morphs in samples of T. subulata from natural populations that occupied the three habitat types used for the detection experiment. Conclusions: Our findings demonstrate that crypsis is background-dependent, and implicate visual predation as an important driver of evolutionary modifications of colour polymorphism in pygmy grasshoppers. Our study provides the clearest evidence to date that using humans as 'predators' in detection experiments may provide reliable information on the protective values of prey colour patterns and of natural selection and microevolution of camouflage in the wild.
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| 2. |
- Avril, Alexis, et al.
(author)
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Exploration forays in juvenile European hares (Lepus europaeus) : dispersal preludes or hunting-induced troubles?
- 2014
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In: BMC Ecology. - : Springer Science and Business Media LLC. - 1472-6785. ; 14
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Journal article (peer-reviewed)abstract
- Background: Movements of animals have important consequences, at both the individual and population levels. Due to its important implications in the evolutionary dynamics of populations, dispersal is one of the most studied types of movement. In contrast, non-permanent extra home-range movements are often paid less attention. However, these movements may occur in response to important biological processes such as mating or predation avoidance. In addition, these forays are often preludes to permanent dispersal, because they may help individuals gain cues about their surroundings prior to settlement in a new place. In the European hare, exploration forays occur predominantly in juveniles, the time at which most hares disperse. In France, the timing of dispersal also overlaps with the hare hunting period. However, the determinants of such behaviour have not yet been studied. Herein, we investigate whether these non-permanent explorations are dispersal attempts/preludes or, in contrast, whether they are triggered by other factors such as disturbances related to hunting. Results: Contrary to natal dispersal, we did not find strong male-bias in the propensity to engage in explorations. Exploration forays occurred less in juveniles than in adults and later in the season than natal dispersal. This was the case both for philopatric movements and for movements occurring after dispersal and settlement. These movements were also more likely to occur during the hare hunting period and the mating season. Conclusions: We suggest that explorations in hares are triggered by factors other than dispersal and that hares may respond to hunting disturbances. Overall, we emphasize the need to account for human-related predation risk as a factor driving space-use in harvested species.
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| 3. |
- Danilov, Roman, et al.
(author)
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Effects of Cu2+, Ni2+, Pb2+, Zn2+ and pentachlorophenol on photosynthesis and motility in Chlamydomonas reinhardtii in short-term exposure experiments.
- 2001
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In: BMC Ecology. - : Springer Science and Business Media LLC. - 1472-6785. ; 1:1
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Journal article (peer-reviewed)abstract
- Background: Heavy metals, especially copper, nickel, lead and zinc, have adverse effects on terrestrial and in aquatic environments. However, their impact can vary depending on the nature of organisms. Taking into account the ability of heavy metals to accumulate in sediments, extended knowledge of their effects on aquatic biota is needed. In this context the use of model organisms (often unicellular), which allows for rapid assessment of pollutants in freshwater, can be of advantage. Pentachlorophenol has been extensively used for decades as a bleaching agent by pulpand paper industry. Pentachlorophenol tends to accumulate in the nature. We aim to determine if photosynthesis and motility can be used as sensitive physiological parameters in toxicological studies of Chlamydomonas reinhardtii, a motile green unicellular alga. It is discussed if photosynthesis and motility can be used as sensitive physiological parameters in toxicological studies. Results: The concentrations studied ranged from 0.1 to 2.0 mg l-1 for copper, nickel, lead and zinc, and from 0.1 to 10.0 mg l-1 for pentachlorophenol. Exposure time was set to 24 h. Copper and pentachlorophenol turned out to be especially toxic for photosynthetic efficiency (PE) in C. reinhardtii. Conclusion: Copper and pentachlorophenol turned out to be especially toxic for PE in C. reinhardtii. Zinc has been concluded to be moderately toxic while nickel and lead had stimulatory effects on the PE. Because of high variance, motility was not considered a reliable physiological parameter when assessing toxicity of the substances using C. reinhardtii. © 2001 Danilov and Ekelund, licensee BioMed Central Ltd.
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| 4. |
- Hardisty, Alex, et al.
(author)
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A decadal view of biodiversity informatics: challenges and priorities.
- 2013
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In: BMC ecology. - : Springer Science and Business Media LLC. - 1472-6785. ; 13
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Journal article (peer-reviewed)abstract
- Biodiversity informatics plays a central enabling role in the research community's efforts to address scientific conservation and sustainability issues. Great strides have been made in the past decade establishing a framework for sharing data, where taxonomy and systematics has been perceived as the most prominent discipline involved. To some extent this is inevitable, given the use of species names as the pivot around which information is organised. To address the urgent questions around conservation, land-use, environmental change, sustainability, food security and ecosystem services that are facing Governments worldwide, we need to understand how the ecosystem works. So, we need a systems approach to understanding biodiversity that moves significantly beyond taxonomy and species observations. Such an approach needs to look at the whole system to address species interactions, both with their environment and with other species.It is clear that some barriers to progress are sociological, basically persuading people to use the technological solutions that are already available. This is best addressed by developing more effective systems that deliver immediate benefit to the user, hiding the majority of the technology behind simple user interfaces. An infrastructure should be a space in which activities take place and, as such, should be effectively invisible.This community consultation paper positions the role of biodiversity informatics, for the next decade, presenting the actions needed to link the various biodiversity infrastructures invisibly and to facilitate understanding that can support both business and policy-makers. The community considers the goal in biodiversity informatics to be full integration of the biodiversity research community, including citizens' science, through a commonly-shared, sustainable e-infrastructure across all sub-disciplines that reliably serves science and society alike.
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| 5. |
- Heyman, Erik, 1977, et al.
(author)
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Management effect on bird and arthropod interaction in suburban woodlands.
- 2011
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In: BMC ecology. - : Springer Science and Business Media LLC. - 1472-6785. ; 11
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Journal article (peer-reviewed)abstract
- Background: Experiments from a range of ecosystems have shown that insectivorous birds are important in controlling the populations of their invertebrate prey. Here, we report on a large field experiment testing the hypothesis that management for enhancing recreational values in suburban woodlands affects the intensity of bird predation on canopy-living arthropods. Bird exclosures were used in two types of management (understory clearance and dense understory) at two foraging heights in oak Quercus robur canopies and the experiment was replicated at two sites. Results: The biomass and abundance of arthropods were high on net-enclosed branches but strongly reduced on control branches in both types of management. In woods with dense understory, the effect of bird predation on arthropod abundance was about twice as high as in woods with understory clearance. The effect of bird predation on arthropod biomass was not significantly affected by management. Conclusions: Our data provide experimental evidence to support the idea that bird predation on arthropods can be affected by forest management. We suggest that the mechanism is twofold: reduction of bird abundance and shift of foraging behaviour. In urban woodlands, there may be a management trade-off between enhancing recreational values and promoting bird predation rates on arthropods.
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| 6. |
- Johannesson, Kerstin, 1955, et al.
(author)
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Phenotypic variation in sexually and asexually recruited individuals of the Baltic Sea endemic macroalga Fucus radicans : in the field and after growth in a common-garden
- 2012
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In: BMC Ecology. - : Springer Science and Business Media LLC. - 1472-6785. ; 12, s. 2-
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Journal article (peer-reviewed)abstract
- BACKGROUND: Most species of brown macroalgae recruit exclusively sexually. However, Fucus radicans, a dominant species in the northern Baltic Sea, recruits new attached thalli both sexually and asexually. The level of asexual recruitment varies among populations from complete sexual recruitment to almost (> 90%) monoclonal populations. If phenotypic traits have substantial inherited variation, low levels of sexual activity will decrease population variation in these traits, which may affect function and resilience of the species. We assessed the level of inherited variation in nine phenotypic traits by comparing variation within and among three monoclonal groups and one group of unique multilocus genotypes (MLGs) sampled in the wild.RESULTS: Of the nine phenotypic traits, recovery after freezing, recovery after desiccation, and phlorotannin content showed substantial inherited variation, that is, phenotypic variation in these traits were to a large extend genetically determined. In contrast, variation in six other phenotypic traits (growth rate, palatability to isopod grazers, thallus width, distance between dichotomies, water content after desiccation and photochemical yield under ambient conditions) did not show significant signals of genetic variation at the power of analyses used in the study. Averaged over all nine traits, phenotypic variation within monoclonal groups was only 68% of the variation within the group of different MLGs showing that genotype diversity does affect the overall level of phenotypic variation in this species.CONCLUSIONS: Our result indicates that, in general, phenotypic diversity in populations of Fucus radicans increases with increased multilocus genotype (MLG) diversity, but effects are specific for individual traits. In the light of Fucus radicans being a foundation species of the northern Baltic Sea, we propose that increased MLG diversity (leading to increased trait variation) will promote ecosystem function and resilience in areas where F. radicans is common, but this suggestion needs experimental support.
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| 7. |
- Langenheder, Silke, et al.
(author)
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Role of functionally dominant species in varying environmental regimes : evidence for the performance-enhancing effect of biodiversity
- 2012
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In: BMC Ecology. - : Springer Science and Business Media LLC. - 1472-6785. ; 12, s. 14-
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Journal article (peer-reviewed)abstract
- Background: Theory suggests that biodiversity can act as a buffer against disturbances and environmental variability via two major mechanisms: Firstly, a stabilising effect by decreasing the temporal variance in ecosystem functioning due to compensatory processes; and secondly, a performance enhancing effect by raising the level of community response through the selection of better performing species. Empirical evidence for the stabilizing effect of biodiversity is readily available, whereas experimental confirmation of the performance-enhancing effect of biodiversity is sparse. Results: Here, we test the effect of different environmental regimes (constant versus fluctuating temperature) on bacterial biodiversity-ecosystem functioning relations. We show that positive effects of species richness on ecosystem functioning are enhanced by stronger temperature fluctuations due to the increased performance of individual species. Conclusions: Our results provide evidence for the performance enhancing effect and suggest that selection towards functionally dominant species is likely to benefit the maintenance of ecosystem functioning under more variable conditions.
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| 8. |
- Nielsen, Scott E., et al.
(author)
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Environmental, biological and anthropogenic effects on grizzly bear body size : temporal and spatial considerations
- 2013
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In: BMC Ecology. - : Springer Science and Business Media LLC. - 1472-6785. ; 13, s. 31-
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Journal article (peer-reviewed)abstract
- Background: Individual body growth is controlled in large part by the spatial and temporal heterogeneity of, and competition for, resources. Grizzly bears (Ursus arctos L.) are an excellent species for studying the effects of resource heterogeneity and maternal effects (i.e. silver spoon) on life history traits such as body size because their habitats are highly variable in space and time. Here, we evaluated influences on body size of grizzly bears in Alberta, Canada by testing six factors that accounted for spatial and temporal heterogeneity in environments during maternal, natal and 'capture' (recent) environments. After accounting for intrinsic biological factors (age, sex), we examined how body size, measured in mass, length and body condition, was influenced by: (a) population density; (b) regional habitat productivity; (c) inter-annual variability in productivity (including silver spoon effects); (d) local habitat quality; (e) human footprint (disturbances); and (f) landscape change. Results: We found sex and age explained the most variance in body mass, condition and length (R-2 from 0.48-0.64). Inter-annual variability in climate the year before and of birth (silver spoon effects) had detectable effects on the three-body size metrics (R-2 from 0.04-0.07); both maternal (year before birth) and natal (year of birth) effects of precipitation and temperature were related with body size. Local heterogeneity in habitat quality also explained variance in body mass and condition (R-2 from 0.01-0.08), while annual rate of landscape change explained additional variance in body length (R-2 of 0.03). Human footprint and population density had no observed effect on body size. Conclusions: These results illustrated that body size patterns of grizzly bears, while largely affected by basic biological characteristics (age and sex), were also influenced by regional environmental gradients the year before, and of, the individual's birth thus illustrating silver spoon effects. The magnitude of the silver spoon effects was on par with the influence of contemporary regional habitat productivity, which showed that both temporal and spatial influences explain in part body size patterns in grizzly bears. Because smaller bears were found in colder and less-productive environments, we hypothesize that warming global temperatures may positively affect body mass of interior bears.
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| 9. |
- Puettker, Thomas, et al.
(author)
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Responses of five small mammal species to micro-scale variations in vegetation structure in secondary Atlantic Forest remnants, Brazil
- 2008
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In: BMC Ecology. - : Springer Science and Business Media LLC. - 1472-6785. ; 8, s. 9-Article No.: 9
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Journal article (peer-reviewed)abstract
- Background: The Brazilian Atlantic Forest is highly endangered and only about 7% of the original forest remains, most of which consists of fragments of secondary forest. Small mammals in the Atlantic Forest have differential responses to this process of fragmentation and conversion of forest into anthropogenic habitats, and have varying abilities to occupy the surrounding altered habitats. We investigated the influence of vegetation structure on the micro-scale distribution of five small mammal species in six secondary forest remnants in a landscape of fragmented Atlantic Forest. We tested whether the occurrence of small mammal species is influenced by vegetation structure, aiming to ascertain whether species with different degrees of vulnerability to forest fragmentation (not vulnerable: A. montensis, O. nigripes and G. microtarsus; vulnerable: M. incanus and D. sublineatus; classification of vulnerability was based on the results of previous studies) are associated with distinct vegetation characteristics.Results: Although vegetation structure differed among fragments, micro-scale distribution of most of the species was influenced by vegetation structure in a similar way in different fragments. Among the three species that were previously shown not to be vulnerable to forest fragmentation, A. montensis and G. microtarsus were present at locations with an open canopy and the occurrence of O. nigripes was associated to a low canopy and a dense understory. On the other hand, from the two species that were shown to be vulnerable to fragmentation, M. incanus was captured most often at locations with a closed canopy while the distribution of D. sublineatus was not clearly influenced by micro-scale variation in vegetation structure.Conclusion: Results indicate the importance of micro-scale variation in vegetation structure for the distribution of small mammal species in secondary forest fragments. Species that are not vulnerable to fragmentation occurred at locations with vegetation characteristics of more disturbed forest, while one of the species vulnerable to fragmentation was found at locations with older forest characteristics. Results suggest that micro-habitat preferences may be an important factor influencing the capacity of small mammals to occupy altered habitats and, consequently, their vulnerability to forest fragmentation at a larger spatial scale.
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| 10. |
- Souter, Petra, et al.
(author)
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Patterns of genetic structuring in the coral Pocillopora damicornis on reefs in East Africa.
- 2009
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In: BMC Ecology. - : Springer Science and Business Media LLC. - 1472-6785. ; 9, s. 19-
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Journal article (peer-reviewed)abstract
- This study showed that population differentiation in P. damicornis varied over spatial scales and that this variability occurred at both evolutionary and ecological time scales. This paradox is discussed in light of stochastic recruitment and small scale population structures found in other species of coral. The study also identifies potential source reefs, such as those within Mnemba Conservation area near Zanzibar and genetically isolated reefs such as those within Malindi Marine National Park and Reserve in northern Kenya.
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