| 1. |
- Amininasab, Seyed Mehdi, et al.
(författare)
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Effect of tree logging on reproductive performance in Blue Tits (Cyanistes caeruleus)
- 2017
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Ingår i: Journal of Ornithology = Journal fur Ornithologie. - : SPRINGER. - 0021-8375 .- 1439-0361. ; 158:1, s. 339-344
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Tidskriftsartikel (refereegranskat)abstract
- For birds, habitat quality is largely determined by local vegetation, and reproductive performance can therefore be negatively influenced by anthropogenic activities. A tree logging event enabled us to examine the effect of removing trees of different maturities and types on the reproductive performance of Blue Tits (Cyanistes caeruleus). Against expectations, only the logging of small coniferous trees, but not larger and deciduous trees, was associated with a reduction in the number of eggs laid, whereas logging had no significant effect on lay date. Therefore, we conclude that modest logging activity has no or limited negative influence on Blue Tit reproductive performance.
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| 2. |
- Arzel, Céline, et al.
(författare)
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A flyway perspective on food resource abundance in a long-distance migrant, the Eurasian teal (Anas crecca)
- 2009
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Ingår i: Journal of Ornithology = Journal fur Ornithologie. - 0021-8375 .- 1439-0361. ; 150:1, s. 61-73
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Tidskriftsartikel (refereegranskat)abstract
- Two frequent assumptions about the evolution of long-distance migration in birds are that they travel long distances annually to reach food-rich areas for breeding, and that they time their migratory journey to be at staging sites when the latter provide the best feeding conditions. These assumptions have rarely been properly tested, and there is no study in which a species’ major food types have been measured by standardized methods throughout a flyway and over a large part of the year. We here present such data for Eurasian teal (Anas crecca), converted to a common energetic currency, and collected at wintering, spring staging and breeding sites. Teal did not time migration to maximize local food abundance; most birds left wintering and spring staging sites before a sharp increase in invertebrate food abundance occurred. On the other hand, hatching of ducklings coincided with a peak in invertebrate food abundance on boreal breeding lakes. Mean overall food abundance (invertebrates and seeds combined) did not differ between wintering sites in southern France and breeding sites in northern Sweden at the time of breeding. Our results are inconsistent with the hypothesis that long-distance migration in dabbling ducks has evolved because adult birds gain an immediate pay-off in increased food abundance by flying north in spring. However, our data confirm a selective advantage for breeding at higher latitudes, because hatching of ducklings may coincide with a peak in invertebrate emergence and because longer days may increase the duration of efficient foraging.
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| 3. |
- Arzel, Céline, et al.
(författare)
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Ecology of spring-migrating Anatidae : a review
- 2006
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Ingår i: Journal of Ornithology = Journal fur Ornithologie. - 0021-8375 .- 1439-0361. - 0021-8375 ; 147:2, s. 167-184
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Forskningsöversikt (refereegranskat)abstract
- Spring migration is generally considered as a crucial period of the year for many birds, not the least due to its supposed importance for subsequent breeding success. By reviewing the existing literature for Anatidae (ducks, geese, and swans), we show that little is known about their ecology in spring, although some goose species are exceptions. Another general pattern is that the ecology of Anatidae at staging sites is particularly neglected. Existing studies tend to focus on questions dealing with acquisition of nutrient reserves, whereas almost nothing has been published about stopover habitats, time use, microhabitat use, foraging behaviour, food availability, food limitation, diet selection, and interspecific relationships. Besides summarising present knowledge, we identify taxonomic groups and topics for which gaps of knowledge appear the most evident, thereby also highlighting research needs for the future.
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| 4. |
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| 5. |
- Corrales, Carolina, et al.
(författare)
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Maintenance of gene flow by female-biased dispersal of black grouse, Tetrao tetrix in northern Sweden
- 2012
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Ingår i: Journal of Ornithology = Journal fur Ornithologie. - : Springer Science and Business Media LLC. - 0021-8375 .- 1439-0361. ; 153:4, s. 1127-1139
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Tidskriftsartikel (refereegranskat)abstract
- Sex-biased dispersal is a common phenomenon in most birds. In general, males breed at or near their site of birth while most of the females disperse. We investigated the dispersal patterns and genetic structure of lekking Black Grouse Tetrao tetrix based on ten microsatellite loci. Data for 469 individuals from 25 localities spaced from 45 to 558 km apart revealed low levels of genetic differentiation and high connectivity among studied sites due to female-biased dispersal. The spatial distribution of the genetic variation did not follow an isolation by distance pattern neither for females nor for males. STRUCTURE identified three clusters of male individuals but without any geographical pattern. Only one cluster was identified for females. Several tests of sex-biased dispersal were executed. Most of them showed no difference between sexes, but the mean assignment index and F IS showed a statistically significant female-biased dispersal. Therefore, we consider that the northern Swedish Black Grouse population is a panmictic population. The amount of gene flow throughout time has been consistent with dispersal and with no strong effect of forest fragmentation in the region.
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| 6. |
- Corrales, Carolina, et al.
(författare)
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Phylogeography and subspecies status of Black Grouse
- 2014
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Ingår i: Journal of Ornithology = Journal fur Ornithologie. - : Springer Science and Business Media LLC. - 0021-8375 .- 1439-0361. ; 155:1, s. 13-25
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Tidskriftsartikel (refereegranskat)abstract
- The cold periods of the Pleistocene have had a striking impact on the diversification of most organisms in temperate regions. Phylogeographic patterns and postglacial expansion are poorly understood in the Black Grouse (Tetrao tetrix). This species is widely distributed across Eurasia, and has been divided into a number of subspecies on the basis of morphological differences and geographic isolation. To investigate the evolutionary history of the species, 143 samples from different regions were examined for a mtDNA control region fragment. Overall, analyses of mtDNA gave support for the divergence between Tetrao tetrix tetrix, T. t. ussuriensis and T. t. mongolicus. The analyses reveal the effects of colonisation out of glacial refugia on the genetic diversity and genetic structure of Black Grouse. The phylogeographical results are consistent with a demographic population expansion following a bell-shaped mismatch distribution, a star-shaped phylogeny and low nucleotide diversity. Patterns of postglacial dispersal imply that Black Grouse from southern Europe have been restricted to this area, and did not contribute to the genetic diversity of northern Europe. Instead, Black Grouse spread out to northern Europe from a refugium in the east and a possible one in western Europe, following the retreat of glacial ice sheets, although both refugia remain unidentified. We suggest that T. t. britannicus and T. t. viridanus correspond to northern T. t. tetrix, and that this lineage has diverged from the other subspecies. This division is tentative due to limited sampling, but it will facilitate the management of different evolutionary significant units of the species.
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| 7. |
- Doligez, Blandine, et al.
(författare)
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Estimation and comparison of heritability and parent-offspring resemblance in dispersal probability from capture-recapture data using different methods : the Collared Flycatcher as a case study
- 2012
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Ingår i: Journal of Ornithology = Journal fur Ornithologie. - : Springer Science and Business Media LLC. - 0021-8375 .- 1439-0361. ; 152, s. S539-S554
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the evolution of a trait requires analysing its genetic basis. Many studies have therefore estimated heritability values of different traits in wild populations using quantitative genetic approaches on capture-recapture data of individuals with known parentage. However, these models assume perfect individual detection probability, a hidden hypothesis that is rarely met in natural populations. To what extent ignoring imperfect detection may bias heritability estimates in wild populations needs specific investigation. We give a first insight into this question using dispersal probability in a patchy population of Collared Flycatchers Ficedula albicollis as an example. We estimate and compare heritability and parent-offspring resemblance in dispersal obtained from (1) quantitative genetic approaches ("classical'' parent-offspring regressions and more recent animal models) and (2) multi-state capture-recapture models accounting for individual detection probability. Unfortunately, current capture-recapture models do not provide heritability estimates, preventing a full comparison of results between models at this stage. However, in the study population, detection probability may be expected to be lower for dispersing compared to philopatric individuals because of lower mating/breeding success and/or higher temporary emigration, making the use of capture-recapture models particularly relevant. We show significant parent-offspring resemblance and heritable component of between-patch dispersal probability in this population. Accounting for imperfect detection does however not seem to influence the observed pattern of parent-offspring resemblance in dispersal probability, although detection probability is both sensibly lower than 1 and heterogeneous among individuals according to dispersal status. We discuss the problems encountered, the information that can be derived from, and the constraints linked to, each method. To obtain unbiased heritability estimates, combining quantitative genetic and capture-recapture models is needed, which should be one of the main developments of capture-recapture models in the near future.
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| 8. |
- Elmberg, Johan, 1960-, et al.
(författare)
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Interpreting seasonal range shifts in migratory birds : a critical assessment of 'short-stopping' and a suggested terminology
- 2014
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Ingår i: Journal of Ornithology = Journal fur Ornithologie. - 0021-8375 .- 1439-0361. ; 155:3, s. 571-579
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Forskningsöversikt (refereegranskat)abstract
- The term 'short-stopping' is increasingly used in ecology to describe spatio-temporal changes in occurrence of migratory species. Spurred by the insight that it has been used in a variety of contexts, we reviewed its use in avian ecology. A literature search yielded 59 papers explicitly treating short-stopping in birds, most of them in peer-reviewed journals. The term was first used in 1967 to describe a northward shift in wintering Canada Geese in North America and has been used with increasing frequency to the present day. Geese dominate the short-stopping literature, which is confined to the northern hemisphere. Short-stopping has been used to describe (1) a shortened autumn migration that results in a wintering distribution closer to breeding areas, (2) a shortened spring migration that results in a breeding distribution closer to wintering areas, and (3) a delay in autumn migration that leads to a perceived reduced abundance in some part of the winter range. We advocate that short-stopping should be used only to describe (1) range shifts that involve shortening of the migratory corridor, and that they are qualified explicitly by season (i.e. breeding/winter) and degree (i.e. full or partial range shift). In other cases of breeding, wintering or entire range shifts where the migratory corridor is elongated or remains the same, we recommend using the term 'range shift', qualified by season, geography and orientation (i.e. the direction of the range shift). We also discuss the need for spatially explicit avian count monitoring mechanisms (rather than capture-recapture or hunting bag data) designed specifically to track such changes in distribution in the future.
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