| 1. |
- Abdilzadeh, R., et al.
(författare)
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Molecular assessment of the distribution and taxonomy of the Lesser Whitethroat Sylvia curruca complex in Iran, with particular emphasis on the identity of the contentious taxon, zagrossiensis Sarudny, 1911
- 2020
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Ingår i: Journal of Ornithology. - : Springer Science and Business Media LLC. - 2193-7192 .- 2193-7206. ; 161, s. 665-676
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Tidskriftsartikel (refereegranskat)abstract
- The Lesser Whitethroat Sylvia curruca complex continues to provide challenges for ornithologists and taxonomists. One of the remaining outstanding questions concerns the taxonomic identity of the different breeding populations in Iran and in particular zagrossiensis, which inhabits the Zagros mountains. We here used the three mitochondrial genes cyt b, COI and ND2, to evaluate samples of the Lesser Whitethroat complex from Iran. Our data include predominantly samples from the breeding season, and we find evidence of three taxa from Iran, of which two are certainly breeding; althaea from Kopet Dagh in NE Iran and the Kerman mountains, east of the Zagros mountains, SE Iran; and curruca from central Zagros mountains and northwestern Iran. Three samples of halimodendri from the south of Iran were migrating or wintering birds. The taxonomically contentious population from the Zagros mountains is here identified as belonging to the curruca clade, and evidence to recognize zagrossiensis based on molecular data is deemed insufficient.
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| 2. |
- Alerstam, Thomas
(författare)
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Optimal bird migration revisited
- 2011
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Ingår i: Journal of Ornithology. - : Springer Science and Business Media LLC. - 2193-7206 .- 2193-7192. ; 152, s. 5-23
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Forskningsöversikt (refereegranskat)abstract
- Using optimality perspectives is now regarded as an essential way of analysing and understanding adaptations and behavioural strategies in bird migration. Optimization analyses in bird migration research have diversified greatly during the two recent decades with respect to methods used as well as to topics addressed. Methods range from simple analytical and geometric models to more complex modeling by stochastic dynamic programming, annual routine models and multiobjective optimization. Also, game theory and simulation by selection algorithms have been used. A wide range of aspects of bird migration have been analyzed including flight, fuel deposition, predation risk, stopover site use, transition to breeding, routes and detours, daily timing, fly-and-forage migration, wind selectivity and wind drift, phenotypic flexibility, arrival time and annual molt and migration schedules. Optimization analyses have proven to be particularly important for defining problems and specifying questions and predictions about the consequences of minimization of energy, time and predation risk in bird migration. Optimization analyses will probably also be important in the future, when predictions about bird migration strategies can be tested by much new data obtained by modern tracking techniques and when the importance of new trade-offs, associated with, e.g., digestive physiology, metabolism, immunocompetence and disease, need to be assessed in bird migration research.
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| 3. |
- Alerstam, Thomas, et al.
(författare)
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Optimal central place foraging flights in relation to wind
- 2019
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Ingår i: Journal of Ornithology. - : Springer Science and Business Media LLC. - 2193-7192 .- 2193-7206. ; 160:4, s. 1065-1076
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Tidskriftsartikel (refereegranskat)abstract
- Many flying animals, like birds feeding their young, make commuting flights between a central place and foraging areas in the surroundings. Such central place foraging (CPF) represents a special case of foraging theory. We use simple geometry and trigonometry to analyse CPF flight performance (a round-trip cycle of outward flight from the central place and inward flight back along the reverse track) in relation to wind. In addition to considering the situation of a constant and uniform wind field, we take into account two factors that are likely to apply in many CPF situations under natural conditions: (a) that animals carry a load that will increase the energy expenditure during the inward flight and (b) that they may fly at different altitudes during out- and inward flights in the wind gradient above the ground or sea surface. Four main predictions emerge: (1) efficiency of CPF flights will be reduced with increasing wind speed, and foraging at the longest ranges is expected under low wind speeds. (2) A preference for CPF flights in crosswinds is expected in a constant and uniform wind field. (3) Carrying a load during the inward flight makes it optimal to fly with a small component of following winds during this flight while the outward flight will have a corresponding component of opposed winds. (4) With a steep wind gradient (e.g. over rough terrain) providing much shelter from wind at the lowest altitudes, predicted behaviour may change from crosswind preference to a preference for flights along the head/tailwind axis (at low altitude into headwinds and high altitude in tailwinds). Detailed tests of predictions for CPF flights in relation to wind will be important for understanding constraints and adaptations in animal responses to wind and for evaluating consequences of changing wind regimes in animal movement ecology.
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| 4. |
- Alström, Per, Professor, et al.
(författare)
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Mongolian Short-toed LarkCalandrella dukhunensis, an overlooked East Asian species
- 2021
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Ingår i: Journal of Ornithology. - : Springer. - 2193-7192 .- 2193-7206. ; 162:1, s. 165-177
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Tidskriftsartikel (refereegranskat)abstract
- The eastern subspecies of Greater Short-toed LarkCalandrella brachydactyla dukhunensishas recently been considered a separate species,Calandrella dukhunensis, by several authors based on molecular data. We present supporting evidence for this treatment based on studies of morphology, vocalisations and song-flight, and also present new data on other aspects of its biology based on field studies. We show that its breeding distribution is considerably smaller than previously thought, and is restricted to the eastern half of Mongolia and, marginally, neighbouring parts of China and perhaps Russia.
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| 5. |
- Alström, Per
(författare)
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New locality for the endangered Blackthroat Calliope obscura
- 2016
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Ingår i: Journal of Ornithology. - : Springer Science and Business Media LLC. - 2193-7192 .- 2193-7206. ; 157, s. 371-372
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Tidskriftsartikel (refereegranskat)abstract
- This study provides new distributional and morphological data for one of the world's most poorly known species, the Blackthroat Calliope obscura, which, until recently, was only known from fewer than ten museum specimens and a few field observations. Three previously mis-labelled male specimens collected during the breeding season at a presumed breeding site slightly further to the northwest of the formerly known range were recently found.
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| 6. |
- Alström, Per
(författare)
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Rediscovery of an enigmatic Chinese passerine, the Blackthroat Calliope obscura: plumage, vocalizations, distribution, habitat choice, nesting and conservation
- 2014
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Ingår i: Journal of Ornithology. - : Springer Science and Business Media LLC. - 2193-7192 .- 2193-7206. ; 155, s. 347-356
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Tidskriftsartikel (refereegranskat)abstract
- The Blackthroat (or Blackthroated Blue Robin) Calliope obscura (previously Luscinia obscura) is one of the world's rarest "robins". It is extremely poorly known, with only a handful of records since it was firstly described in the 1890s. In 2011-2012, a series of field investigations were carried out in nature reserves in the Qinling Mountains, Shaanxi Province, China. During these surveys, a total of 14 males were found in 2011 and 24 males and 2 females in 2012 in the national nature reserves of Foping and Changqing. Based on these observations, we here describe the Blackthroat's vocalizations and habitat choice and review its distribution and conservation status. We also provide some notes on the plumage, especially of the female, and the nesting behaviour of this species. The present report confirms that the Blackthroat breeds on the southern slope of the Qinling Mountains in large, dense expanses of dwarf bamboo with scattered coniferous and broadleaved trees above 2,100 m. Our observations suggest that it is more numerous than previously believed, although it appears to be highly localized. The locally dense populations found in 2011 and 2012 and the vast expanses of suitable habitat suggest that the breeding population might be healthy.
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| 7. |
- 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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| 8. |
- Arct, Aneta, et al.
(författare)
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Effects of elevated nest box temperature on incubation behaviour and offspring fitness-related traits in the Collared Flycatcher Ficedula albicollis
- 2022
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Ingår i: Journal of Ornithology. - : Springer Nature. - 2193-7192 .- 2193-7206. ; 163, s. 263-272
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Tidskriftsartikel (refereegranskat)abstract
- Ambient temperature experienced by an animal during development or subsequently as an adult can affect many aspects of its behaviour and life-history traits. In birds, egg incubation is a vital component of reproduction and parental care. Several studies have suggested that environmental factors (such as nest microclimate) can influence the ability of incubating parents to maintain suitable conditions for embryo development. Here, we manipulated the developmental conditions of embryos through a modification of nest box thermal microclimate to investigate female incubation behaviour and its impact on offspring fitness-related traits in a wild population of the Collared Flycatcher (Ficedula albicollis). The temperature in experimental nests was increased using a heat-pack placed under the roof of a nest box, resulting in an average temperature increase of 2.5 degrees C, which corresponds to projected climate change scenarios. We demonstrated that females from nests with elevated temperature spent less time in the nest box during egg incubation and had more off-bouts than females from control nests. Moreover, we found that offspring from the experimentally heated nests had larger body mass at fledging in comparison to the control ones. Our study indicates that nest microclimate during the incubation period affects female incubation behaviour and offspring quality, indicating that environmental variation in nest temperature early in ontogeny can have important and long-lasting fitness consequences.
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| 9. |
- 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. - : Springer Science and Business Media LLC. - 0021-8375. ; 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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| 10. |
- 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. - : Springer Science and Business Media LLC. - 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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