| 1. |
- Pape Møller, Anders, et al.
(författare)
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Interaction of climate change with effects of conspecific and heterospecific density on reproduction
- 2020
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Ingår i: Oikos. - : Wiley. - 0030-1299 .- 1600-0706. ; 129:12, s. 1807-1819
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Tidskriftsartikel (refereegranskat)abstract
- We studied the relationship between temperature and the coexistence of great tit Parus major and blue tit Cyanistes caeruleus, breeding in 75 study plots across Europe and North Africa. We expected an advance in laying date and a reduction in clutch size during warmer springs as a general response to climate warming and a delay in laying date and a reduction in clutch size during warmer winters due to density‐dependent effects. As expected, as spring temperature increases laying date advances and as winter temperature increases clutch size is reduced in both species. Density of great tit affected the relationship between winter temperature and laying date in great and blue tit. Specifically, as density of great tit increased and temperature in winter increased both species started to reproduce later. Density of blue tit affected the relationship between spring temperature and blue and great tit laying date. Thus, both species start to reproduce earlier with increasing spring temperature as density of blue tit increases, which was not an expected outcome, since we expected that increasing spring temperature should advance laying date, while increasing density should delay it cancelling each other out. Climate warming and its interaction with density affects clutch size of great tits but not of blue tits. As predicted, great tit clutch size is reduced more with density of blue tits as temperature in winter increases. The relationship between spring temperature and density on clutch size of great tits depends on whether the increase is in density of great tit or blue tit. Therefore, an increase in temperature negatively affected the coexistence of blue and great tits differently in both species. Thus, blue tit clutch size was unaffected by the interaction effect of density with temperature, while great tit clutch size was affected in multiple ways by these interactions terms.
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| 2. |
- Vaugoyeau, Marie, et al.
(författare)
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Interspecific variation in the relationship between clutch size, laying date and intensity of urbanization in four species of hole-nesting birds
- 2016
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 6:16, s. 5907-5920
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Tidskriftsartikel (refereegranskat)abstract
- The increase in size of human populations in urban and agricultural areas has resulted in considerable habitat conversion globally. Such anthropogenic areas have specific environmental characteristics, which influence the physiology, life history, and population dynamics of plants and animals. For example, the date of bud burst is advanced in urban compared to nearby natural areas. In some birds, breeding success is determined by synchrony between timing of breeding and peak food abundance. Pertinently, caterpillars are an important food source for the nestlings of many bird species, and their abundance is influenced by environmental factors such as temperature and date of bud burst. Higher temperatures and advanced date of bud burst in urban areas could advance peak caterpillar abundance and thus affect breeding phenology of birds. In order to test whether laying date advance and clutch sizes decrease with the intensity of urbanization, we analyzed the timing of breeding and clutch size in relation to intensity of urbanization as a measure of human impact in 199 nest box plots across Europe, North Africa, and the Middle East (i.e., the Western Palearctic) for four species of hole-nesters: blue tits (Cyanistes caeruleus), great tits (Parus major), collared flycatchers (Ficedula albicollis), and pied flycatchers (Ficedula hypoleuca). Meanwhile, we estimated the intensity of urbanization as the density of buildings surrounding study plots measured on orthophotographs. For the four study species, the intensity of urbanization was not correlated with laying date. Clutch size in blue and great tits does not seem affected by the intensity of urbanization, while in collared and pied flycatchers it decreased with increasing intensity of urbanization. This is the first large-scale study showing a species-specific major correlation between intensity of urbanization and the ecology of breeding. The underlying mechanisms for the relationships between life history and urbanization remain to be determined. We propose that effects of food abundance or quality, temperature, noise, pollution, or disturbance by humans may on their own or in combination affect laying date and/or clutch size.
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| 3. |
- Forsman, Jukka T., et al.
(författare)
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Mechanisms and fitness effects of interspecific information use between migrant and resident birds
- 2007
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Ingår i: Behavioral Ecology. - : Oxford University Press (OUP). - 1045-2249 .- 1465-7279. ; 18:5, s. 888-894
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Tidskriftsartikel (refereegranskat)abstract
- Interactions with potential competitors are an important component of habitat quality. Due to the costs of coexistence with competitors, a breeding habitat selection strategy that avoids competitors is expected to be favored. However, many migratory birds appear to gain benefits from an attraction to the presence of resident birds, even though residents are assumed to be competitively dominant. Thus far the mechanisms of this habitat selection process, heterospecific attraction, are unknown, and the consequences for resident birds of migrant attraction remain untested. Through heterospecific attraction, migrants may gain benefits if the density or territory location of residents positively reflects habitat quality, and/or they gain benefits through increased frequency of social interactions with residents in foraging or predator detection. In this experiment, we examined the reciprocal effects of spatial proximity on fitness-related traits in migrant pied flycatcher (Ficedula hypoleuca) and resident great tit (Parus major) by experimentally forcing them to breed either alone or in close proximity to each other. Surprisingly, great tits bore all the costs of coexistence while flycatchers were unaffected, even gaining slight benefits. In concert with an earlier study, these results suggest that flycatchers use tits as information about good-quality nest-site locations while benefits from social interactions with tits are possible but less important. We suggest that utilizing interspecific social information may be a common phenomenon between species sharing similar resource needs. Our results imply that the effects of interspecific information use can be asymmetric and may therefore have implications for the patterns and consequences of species coexistence.
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| 4. |
- Seppänen, Janne-Tuomas, et al.
(författare)
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Interspecific social learning : Novel Preference Can Be Acquired from a Competing Species
- 2007
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Ingår i: Current Biology. - : Elsevier BV. - 0960-9822 .- 1879-0445. ; 17:14, s. 1248-1252
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Tidskriftsartikel (refereegranskat)abstract
- Nongenetic transmission of behavioral traits via social learning allows local traditions in humans, and, controversially, in other animals [1], [2], [3] and [4]. Social learning is usually studied as an intraspecific phenomenon (but see [5], [6] and [7]). However, other species with some overlap in ecology can be more than merely potential competitors: prior settlement and longer residence can render them preferable sources of information [8]. Socially induced acquisition of choices or preferences capitalizes upon the knowledge of presumably better-informed individuals [9] and should be adaptive under many natural circumstances [10] and [11]. Here we show with a field experiment that females of two migrant flycatcher species can acquire a novel, arbitrary preference of competing resident tits for a symbol attached to the nest sites. The experiment demonstrates that such blind acquisition of heterospecific traits can occur in the wild. Even though genetic variation for habitat preferences exists in many taxa [12] and overlap between bird species likely induces costs [13], this result shows that interspecific social learning can cause increased overlap in nest-site preferences. Conventional, negative species interactions push ecological niches of species apart, but the use of competing species as a source of information counters that force and may lead to convergence.
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| 5. |
- Sysi-Aho, Marko, et al.
(författare)
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Metabolic regulation in progression to autoimmune diabetes
- 2011
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Ingår i: PloS Computational Biology. - : Public Library of Science (PLoS). - 1553-734X .- 1553-7358. ; 7:10
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Tidskriftsartikel (refereegranskat)abstract
- Recent evidence from serum metabolomics indicates that specific metabolic disturbances precede β-cell autoimmunity in humans and can be used to identify those children who subsequently progress to type 1 diabetes. The mechanisms behind these disturbances are unknown. Here we show the specificity of the pre-autoimmune metabolic changes, as indicated by their conservation in a murine model of type 1 diabetes. We performed a study in non-obese prediabetic (NOD) mice which recapitulated the design of the human study and derived the metabolic states from longitudinal lipidomics data. We show that female NOD mice who later progress to autoimmune diabetes exhibit the same lipidomic pattern as prediabetic children. These metabolic changes are accompanied by enhanced glucose-stimulated insulin secretion, normoglycemia, upregulation of insulinotropic amino acids in islets, elevated plasma leptin and adiponectin, and diminished gut microbial diversity of the Clostridium leptum group. Together, the findings indicate that autoimmune diabetes is preceded by a state of increased metabolic demands on the islets resulting in elevated insulin secretion and suggest alternative metabolic related pathways as therapeutic targets to prevent diabetes.
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