| 1. |
- Abalos, Javier, et al.
(författare)
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No evidence for differential sociosexual behavior and space use in the color morphs of the European common wall lizard (Podarcis muralis)
- 2020
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 10:20, s. 10986-11005
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Tidskriftsartikel (refereegranskat)abstract
- Explaining the evolutionary origin and maintenance of color polymorphisms is a major challenge in evolutionary biology. Such polymorphisms are commonly thought to reflect the existence of alternative behavioral or life-history strategies under negative frequency-dependent selection. The European common wall lizard Podarcis muralis exhibits a striking ventral color polymorphism that has been intensely studied and is often assumed to reflect alternative reproductive strategies, similar to the iconic “rock–paper–scissors” system described in the North American lizard Uta stansburiana. However, available studies so far have ignored central aspects in the behavioral ecology of this species that are crucial to assess the existence of alternative reproductive strategies. Here, we try to fill this gap by studying the social behavior, space use, and reproductive performance of lizards showing different color morphs, both in a free-ranging population from the eastern Pyrenees and in ten experimental mesocosm enclosures. In the natural population, we found no differences between morphs in site fidelity, space use, or male–female spatial overlap. Likewise, color morph was irrelevant to sociosexual behavior, space use, and reproductive success within experimental enclosures. Our results contradict the commonly held hypothesis that P. muralis morphs reflect alternative behavioral strategies, and suggest that we should instead turn our attention to alternative functional explanations.
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| 2. |
- Abrego, Nerea, et al.
(författare)
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Higher host plant specialization of root-associated endophytes than mycorrhizal fungi along an arctic elevational gradient
- 2020
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 10:16, s. 8989-9002
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Tidskriftsartikel (refereegranskat)abstract
- How community-level specialization differs among groups of organisms, and changes along environmental gradients, is fundamental to understanding the mechanisms influencing ecological communities. In this paper, we investigate the specialization of root-associated fungi for plant species, asking whether the level of specialization varies with elevation. For this, we applied DNA barcoding based on the ITS region to root samples of five plant species equivalently sampled along an elevational gradient at a high arctic site. To assess whether the level of specialization changed with elevation and whether the observed patterns varied between mycorrhizal and endophytic fungi, we applied a joint species distribution modeling approach. Our results show that host plant specialization is not environmentally constrained in arctic root-associated fungal communities, since there was no evidence for changing specialization with elevation, even if the composition of root-associated fungal communities changed substantially. However, the level of specialization for particular plant species differed among fungal groups, root-associated endophytic fungal communities being highly specialized on particular host species, and mycorrhizal fungi showing almost no signs of specialization. Our results suggest that plant identity affects associated mycorrhizal and endophytic fungi differently, highlighting the need of considering both endophytic and mycorrhizal fungi when studying specialization in root-associated fungal communities.
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| 3. |
- Ah-King, Malin, et al.
(författare)
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A conceptual review of mate choice : stochastic demography, within-sex phenotypic plasticity, and individual flexibility
- 2016
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 6:14, s. 4607-4642
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Forskningsöversikt (refereegranskat)abstract
- Mate choice hypotheses usually focus on trait variation of chosen individuals. Recently, mate choice studies have increasingly attended to the environmental circumstances affecting variation in choosers' behavior and choosers' traits. We reviewed the literature on phenotypic plasticity in mate choice with the goal of exploring whether phenotypic plasticity can be interpreted as individual flexibility in the context of the switch point theorem, SPT (Gowaty and Hubbell ). We found >3000 studies; 198 were empirical studies of within-sex phenotypic plasticity, and sixteen showed no evidence of mate choice plasticity. Most studies reported changes from choosy to indiscriminate behavior of subjects. Investigators attributed changes to one or more causes including operational sex ratio, adult sex ratio, potential reproductive rate, predation risk, disease risk, chooser's mating experience, chooser's age, chooser's condition, or chooser's resources. The studies together indicate that choosiness of potential mates is environmentally and socially labile, that is, induced - not fixed - in the choosy sex with results consistent with choosers' intrinsic characteristics or their ecological circumstances mattering more to mate choice than the traits of potential mates. We show that plasticity-associated variables factor into the simpler SPT variables. We propose that it is time to complete the move from questions about within-sex plasticity in the choosy sex to between- and within-individual flexibility in reproductive decision-making of both sexes simultaneously. Currently, unanswered empirical questions are about the force of alternative constraints and opportunities as inducers of individual flexibility in reproductive decision-making, and the ecological, social, and developmental sources of similarities and differences between individuals. To make progress, we need studies (1) of simultaneous and symmetric attention to individual mate preferences and subsequent behavior in both sexes, (2) controlled for within-individual variation in choice behavior as demography changes, and which (3) report effects on fitness from movement of individual's switch points.
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| 4. |
- Alerstam, Thomas, et al.
(författare)
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Hypotheses and tracking results about the longest migration : The case of the arctic tern
- 2019
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 9:17, s. 9511-9531
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Tidskriftsartikel (refereegranskat)abstract
- The arctic tern Sterna paradisaea completes the longest known annual return migration on Earth, traveling between breeding sites in the northern arctic and temperate regions and survival/molt areas in the Antarctic pack-ice zone. Salomonsen (1967, Biologiske Meddelelser, Copenhagen Danske Videnskabernes Selskab, 24, 1) put forward a hypothetical comprehensive interpretation of this global migration pattern, suggesting food distribution, wind patterns, sea ice distribution, and molt habits as key ecological and evolutionary determinants. We used light-level geolocators to record 12 annual journeys by eight individuals of arctic terns breeding in the Baltic Sea. Migration cycles were evaluated in light of Salomonsen's hypotheses and compared with results from geolocator studies of arctic tern populations from Greenland, Netherlands, and Alaska. The Baltic terns completed a 50,000 km annual migration circuit, exploiting ocean regions of high productivity in the North Atlantic, Benguela Current, and the Indian Ocean between southern Africa and Australia (sometimes including the Tasman Sea). They arrived about 1 November in the Antarctic zone at far easterly longitudes (in one case even at the Ross Sea) subsequently moving westward across 120–220 degrees of longitude toward the Weddell Sea region. They departed from here in mid-March on a fast spring migration up the Atlantic Ocean. The geolocator data revealed unexpected segregation in time and space between tern populations in the same flyway. Terns from the Baltic and Netherlands traveled earlier and to significantly more easterly longitudes in the Indian Ocean and Antarctic zone than terns from Greenland. We suggest an adaptive explanation for this pattern. The global migration system of the arctic tern offers an extraordinary possibility to understand adaptive values and constraints in complex pelagic life cycles, as determined by environmental conditions (marine productivity, wind patterns, low-pressure trajectories, pack-ice distribution), inherent factors (flight performance, molt, flocking), and effects of predation/piracy and competition.
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| 5. |
- Alexandre, Ana, et al.
(författare)
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Effects of CO2 enrichment on photosynthesis, growth, and nitrogen metabolism of the seagrass Zostera noltii
- 2012
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 2:10, s. 2620-2630
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Tidskriftsartikel (refereegranskat)abstract
- Seagrass ecosystems are expected to benefit from the global increase in CO2 in the ocean because the photosynthetic rate of these plants may be C-i-limited at the current CO2 level. As well, it is expected that lower external pH will facilitate the nitrate uptake of seagrasses if nitrate is cotransported with H+ across the membrane as in terrestrial plants. Here, we investigate the effects of CO2 enrichment on both carbon and nitrogen metabolism of the seagrass Zostera noltii in a mesocosm experiment where plants were exposed for 5 months to two experimental CO2 concentrations (360 and 700 ppm). Both the maximum photosynthetic rate (Pm) and photosynthetic efficiency (alpha) were higher (1.3- and 4.1-fold, respectively) in plants exposed to CO2-enriched conditions. On the other hand, no significant effects of CO2 enrichment on leaf growth rates were observed, probably due to nitrogen limitation as revealed by the low nitrogen content of leaves. The leaf ammonium uptake rate and glutamine synthetase activity were not significantly affected by increased CO2 concentrations. On the other hand, the leaf nitrate uptake rate of plants exposed to CO2-enriched conditions was fourfold lower than the uptake of plants exposed to current CO2 level, suggesting that in the seagrass Z. noltii nitrate is not cotransported with H+ as in terrestrial plants. In contrast, the activity of nitrate reductase was threefold higher in plant leaves grown at high-CO2 concentrations. Our results suggest that the global effects of CO2 on seagrass production may be spatially heterogeneous and depend on the specific nitrogen availability of each system. Under a CO2 increase scenario, the natural levels of nutrients will probably become limiting for Z. noltii. This potential limitation becomes more relevant because the expected positive effect of CO2 increase on nitrate uptake rate was not confirmed.
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| 6. |
- Alfieri, James M., et al.
(författare)
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Genomic investigation refutes record of most diverged avian hybrid
- 2023
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- The most diverged avian hybrid that has been documented (Numida meleagris × Penelope superciliaris) was reported in 1957. This identification has yet to be confirmed, and like most contemporary studies of hybridization, the identification was based on phenotype, which can be misleading. In this study, we sequenced the specimen in question and performed analyses to validate the specimen's parentage. We extracted DNA from the specimen in a dedicated ancient DNA facility and performed whole-genome short-read sequencing. We used BLAST to find Galliformes sequences similar to the hybrid specimen reads. We found that the proportion of BLAST hits mapped overwhelmingly to two species, N. meleagris and Gallus gallus. Additionally, we constructed phylogenies using avian orthologs and parsed the species placed as sister to the hybrid. Again, the hybrid specimen was placed as a sister to N. meleagris and G. gallus. Despite not being a hybrid between N. meleagris and P. superciliaris, the hybrid still represents the most diverged avian hybrid confirmed with genetic data. In addition to correcting the “record” of the most diverged avian hybrid, these findings support recent assertions that morphological and behavioral-based identifications of avian hybrids can be error-prone. Consequently, this study serves as a cautionary tale to researchers of hybridization.
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| 7. |
- Allen, Andrew, et al.
(författare)
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Habitat-performance relationships of a large mammal on a predator-free island dominated by humans
- 2017
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 7, s. 305-319
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Tidskriftsartikel (refereegranskat)abstract
- The demographic consequences of changes in habitat use driven by human modification of landscape, and/or changes in climate, are important for any species. We investigated habitat-performance relationships in a declining island population of a large mammal, the moose (Alces alces), in an environment that is predator-free but dominated by humans. We used a combination of demographic data, knowledge of habitat selection, and multiannual movement data of female moose (n = 17) to understand how space use patterns affect fecundity and calf survival. The calving rate was 0.64 and was similar to calving rates reported in other populations. Calf survival was 0.22 (annually) and 0.32 (postsummer), which are particularly low compared to other populations where postsummer survival is typically above 0.7. Home ranges were mainly composed of arable land (>40%), and selection for arable land was higher in winter than in summer, which contrasts with previous studies. Females that spent more time in broadleaf forest in the summer prior to the rut had higher fecundity rates, while more time spent in arable land resulted in lower fecundity rates. Females that spent more time in thicket/scrubland habitats during winter had lower calf survival, while females that had higher use of mixed forests tended to have higher calf survival. The dominance, and subsequent use, of suboptimal foraging habitats may lead to poor body condition of females at parturition, which may lower calf body weights and affect the mother's ability to lactate. In addition, our results indicated that the growing season has advanced significantly in recent decades, which may be causing a mismatch between parturition and optimal resource availability. These effects may exacerbate the female's ability to meet the energetic demands of lactation. Therefore, the observed low calf survival appears to be caused by a combination of factors related to current land use and may also be due to changing vegetation phenology. These results have important implications for the management of species in human-dominated landscapes in the face of climate change, and for an increased understanding of how species may adapt to future land use and climate change.
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| 8. |
- Alshwairikh, Yara A., et al.
(författare)
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Influence of environmental conditions at spawning sites and migration routes on adaptive variation and population connectivity in Chinook salmon
- 2021
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Ingår i: Ecology and Evolution. - : John Wiley & Sons. - 2045-7758. ; 11:23, s. 16890-16908
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Tidskriftsartikel (refereegranskat)abstract
- Many species that undergo long breeding migrations, such as anadromous fishes, face highly heterogeneous environments along their migration corridors and at their spawning sites. These environmental challenges encountered at different life stages may act as strong selective pressures and drive local adaptation. However, the relative influence of environmental conditions along the migration corridor compared with the conditions at spawning sites on driving selection is still unknown. In this study, we performed genome–environment associations (GEA) to understand the relationship between landscape and environmental conditions driving selection in seven populations of the anadromous Chinook salmon (Oncorhynchus tshawytscha)—a species of important economic, social, cultural, and ecological value—in the Columbia River basin. We extracted environmental variables for the shared migration corridors and at distinct spawning sites for each population, and used a Pool-seq approach to perform whole genome resequencing. Bayesian and univariate GEA tests with migration-specific and spawning site-specific environmental variables indicated many more candidate SNPs associated with environmental conditions at the migration corridor compared with spawning sites. Specifically, temperature, precipitation, terrain roughness, and elevation variables of the migration corridor were the most significant drivers of environmental selection. Additional analyses of neutral loci revealed two distinct clusters representing populations from different geographic regions of the drainage that also exhibit differences in adult migration timing (summer vs. fall). Tests for genomic regions under selection revealed a strong peak on chromosome 28, corresponding to the GREB1L/ROCK1 region that has been identified previously in salmonids as a region associated with adult migration timing. Our results show that environmental variation experienced throughout migration corridors imposed a greater selective pressure on Chinook salmon than environmental conditions at spawning sites.
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| 9. |
- Amundin, Mats, et al.
(författare)
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Estimating the abundance of the critically endangered Baltic Proper harbour porpoise (Phocoena phocoena) population using passive acoustic monitoring
- 2022
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 12:2
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Tidskriftsartikel (refereegranskat)abstract
- Knowing the abundance of a population is a crucial component to assess its conservationstatus and develop effective conservation plans. For most cetaceans, abundanceestimation is difficult given their cryptic and mobile nature, especially when thepopulation is small and has a transnational distribution. In the Baltic Sea, the numberof harbour porpoises (Phocoena phocoena) has collapsed since the mid-20thcenturyand the Baltic Proper harbour porpoise is listed as Critically Endangered by the IUCNand HELCOM; however, its abundance remains unknown. Here, one of the largestever passive acoustic monitoring studies was carried out by eight Baltic Sea nationsto estimate the abundance of the Baltic Proper harbour porpoise for the first time. Bylogging porpoise echolocation signals at 298 stations during May 2011–April2013,calibrating the loggers’ spatial detection performance at sea, and measuring the clickrate of tagged individuals, we estimated an abundance of 71–1105individuals (95% CI,point estimate 491) during May–Octoberwithin the population's proposed managementborder. The small abundance estimate strongly supports that the Baltic Properharbour porpoise is facing an extremely high risk of extinction, and highlights theneed for immediate and efficient conservation actions through international cooperation.It also provides a starting point in monitoring the trend of the populationabundance to evaluate the effectiveness of management measures and determine itsinteractions with the larger neighboring Belt Sea population. Further, we offer evidencethat design-basedpassive acoustic monitoring can generate reliable estimatesof the abundance of rare and cryptic animal populations across large spatial scales.
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| 10. |
- Andersson, Matilda L., et al.
(författare)
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The interaction between metabolic rate, habitat choice, and resource use in a polymorphic freshwater species
- 2022
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Ingår i: Ecology and Evolution. - : John Wiley & Sons. - 2045-7758. ; 12:8
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Tidskriftsartikel (refereegranskat)abstract
- 1. Resource polymorphism is common across taxa and can result in alternate ecotypes with specific morphologies, feeding modes, and behaviours that increase performance in a specific habitat. This can result in high intraspecific variation in the expression of specific traits and the extent to which these traits are correlated within a single population. Although metabolic rate influences resource acquisition and the overall pace of life of individuals it is not clear how metabolic rate interact with the larger suite of traits to ultimately determine individual fitness.2. We examined the relationship between metabolic rates and the major differences (habitat use, morphology, and resource use) between littoral and pelagic ecotypes of European perch (Perca fluviatilis) from a single lake in Central Sweden.3. Standard metabolic rate (SMR) was significantly higher in pelagic perch but did not correlate with resource use or morphology. Maximum metabolic rate (MMR) was not correlated with any of our explanatory variables or with SMR. Aerobic scope (AS) showed the same pattern as SMR, differing across habitats, but contrary to expectations was lower in pelagic perch.4. This study helps to establish a framework for future experiments further exploring the drivers of intraspecific differences in metabolism. In addition, since metabolic rates scale with temperature and determine predator energy requirements, our observed differences in SMR across habitats will help determine ecotype-specific vulnerabilities to climate change and differences in top-down predation pressure across habitats.
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