| 1. |
- Amininasab, Seyed Mehdi, et al.
(author)
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Effect of tree logging on reproductive performance in Blue Tits (Cyanistes caeruleus)
- 2017
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In: Journal of Ornithology = Journal fur Ornithologie. - : SPRINGER. - 0021-8375 .- 1439-0361. ; 158:1, s. 339-344
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Journal article (peer-reviewed)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.
(author)
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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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In: Journal of Ornithology = Journal fur Ornithologie. - : Springer Science and Business Media LLC. - 0021-8375. ; 150:1, s. 61-73
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Journal article (peer-reviewed)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.
(author)
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Ecology of spring-migrating Anatidae : a review
- 2006
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In: Journal of Ornithology = Journal fur Ornithologie. - : Springer Science and Business Media LLC. - 0021-8375. ; 147:2, s. 167-184
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Research review (peer-reviewed)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. |
- Cardinale, Massimiliano
(author)
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Effects of body condition and food intake on stop-over decisions in Garden Warblers and European Robins during spring migration
- 2017
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In: Journal für Ornithologie. - : Springer Science and Business Media LLC. - 0021-8375 .- 2193-7192 .- 2193-7206. ; 158, s. 989-999
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Journal article (peer-reviewed)abstract
- During migration, birds need to optimize their time and/or energy management, especially during stop-overs. Previous studies with caged birds under controlled condition support the notion that departure decisions are condition-dependent, but they did not take into account the availability or the actual intake of food. In the study reported here we investigated whether food intake interacts with condition in influencing migratory disposition in temporarily caged wild migrants. We conducted the study on Garden Warblers (Sylvia borin) and European Robins (Erithacus rubecula) at a spring stop-over site that is reached after a long non-stop flight over the Mediterranean Sea. The birds were held in cages during the day and the first night following capture, and their locomotor activity, food intake, and body mass change were recorded. In both species, food intake was positively correlated with body mass change. Body condition was positively correlated with migratory restlessness (Zugunruhe) in both species and was also negatively related to diurnal activity in Garden Warblers. Food intake was negatively correlated with diurnal activity in Garden Warblers. When only birds with low fat scores were considered, we found a positive effect of food intake on Zugunruhe in Garden Warblers. In general, European Robins consumed less food than Garden Warblers and no significant effects on Zugunruhe were found. Our results show that food intake interacts with condition in affecting migratory behavior during stop-overs. In particular, food intake may induce Garden Warblers with low fat stores at arrival to leave a stop-over site earlier. The large individual variability in food consumption supports the notion that birds vary in their capacity to refuel soon after arrival at a stop-over site. Overall, our work suggests that the decision to stay at the stop-over site or to resume migration depends on the interaction of condition, refueling capacity and rate, and migratory strategy.
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| 5. |
- Corrales, Carolina, et al.
(author)
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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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In: 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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Journal article (peer-reviewed)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.
(author)
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Phylogeography and subspecies status of Black Grouse
- 2014
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In: 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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Journal article (peer-reviewed)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.
(author)
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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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In: Journal of Ornithology = Journal fur Ornithologie. - : Springer Science and Business Media LLC. - 0021-8375 .- 1439-0361. ; 152, s. S539-S554
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Journal article (peer-reviewed)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, et al.
(author)
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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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In: Journal of Ornithology = Journal fur Ornithologie. - : Springer Science and Business Media LLC. - 0021-8375. ; 155:3, s. 571-579
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Research review (peer-reviewed)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 usedonly 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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| 9. |
- Enemar, Anders, 1926, et al.
(author)
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Early onset of reduced reproductive performance with age in the Treecreeper ( Certhia familiaris )
- 2008
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In: Journal of Ornithology. - : Springer Science and Business Media LLC. - 0021-8375 .- 2193-7192 .- 2193-7206. ; 149:1, s. 117-121
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Journal article (peer-reviewed)abstract
- Reductions in reproductive performance with age have been predicted to result from a general deterioration of performance, i.e. senescence. Variation among species in the onset and rate of this deterioration depends on the age-independent extrinsic mortality rate. If few individuals reach a specific age, the strength of selection for mechanisms that retard senescence will be reduced. The aim of this study was to investigate the age-dependent variation in two reproductive traits in a species, the Treecreeper (Certhia familiaris), with a low between-year survival rate. Clutch size did not vary with age, but egg size decreased from the first to the second breeding season. Compared with published age-dependent reductions in egg size, Treecreepers demonstrate the earliest onset of senescence, but they also have the highest total mortality rate, corroborating the predictions from the evolutionary theory of senescence. Production of eggs seems to be demanding for female Treecreepers, as egg size is also positively dependent on ambient temperature, further stressing the vulnerability of this trait for small reductions in female performance.
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| 10. |
- Fjeldså, Jon, et al.
(author)
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Molecular data reveal some major adaptational shifts in the early evolution of the most diverse avian family, the Furnariidae
- 2005
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In: Journal of Ornithology = Journal fur Ornithologie. - : Springer Science and Business Media LLC. - 0021-8375 .- 1439-0361. ; 146:1, s. 1-13
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Journal article (peer-reviewed)abstract
- A robust phylogeny estimate for the family Furnariidae (sensu lato) was obtained using sequences of two nuclear introns and one mitochondrial gene (cyt b). Contrary to the widely accepted sister-group relationship of ovenbirds (Furnariinae) and woodcreepers (Dendrocolaptinae), a basal clade is suggested for Sclerurus and Geositta, while Xenops, hitherto considered an aberrant ovenbird, was found to occupy a basal position on the woodcreeper lineage. The morphological variation is re-interpreted in view of this revised phylogenetic hypothesis. Presumably, the remarkable adaptive radiation in this family started as primitive, Sclerurus-likes forms, which used the tail as a prop during terrestrial feeding, lured up to seek food on tree-trunks. The two basal woodcreeper genera, Xenops and then Glyphorynchus, show strong cranial specializations for hammering in wood, thus presenting a remarkable parallelism with the family Picidae, Xenops resembling a piculet, Glyphorynchus, a diminutive woodpecker. However, this specialization was lost in other woodcreepers, which show a more normal passerine skull, adapted for probing and prying in tree-trunk crevices and sallying for escaping insects. The ovenbirds developed a more flexible (rhynchokinetic) bill, well suited for probing and retrieving hidden prey in dead-leaf clusters and debris suspended in the vegetation, and in epiphyte masses. Adaptations to live in open terrain are secondary.
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