| 1. |
- Klaassen, M, et al.
(författare)
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Flight costs and fuel composition of a bird migrating in a wind tunnel
- 2000
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Ingår i: The Condor: ornithological applications. - 0010-5422. ; 102:2, s. 444-451
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Tidskriftsartikel (refereegranskat)abstract
- We studied the energy and protein balance of a Thrush Nightingale Luscinia luscinia, a small long-distance migrant, during repeated 12-hr long Eights in a wind tunnel and during subsequent two-day fueling periods. From the energy budgets we estimated the power requirements for migratory flight in this 26 g bird at 1.91 Watts. This is low compared to flight cost estimates in birds of similar mass and with similar wing shape. This suggests that power requirements for migratory flight are lower than the power requirements for nonmigratory Eight. From excreta production during Right, and nitrogen and energy balance during subsequent fueling, the dry protein proportion of stores was estimated to be around 10%. A net catabolism of protein during migratory flight along with that of fat may reflect a physiologically inevitable process, a means of providing extra water to counteract dehydration, a production of uric acid for anti-oxidative purposes, and adaptive changes in the size of Eight muscles and digestive organs in the exercising animal.
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| 2. |
- Lillandt, B G, et al.
(författare)
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Family structure in the Siberian Jay as revealed by microsatellite analyses
- 2003
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Ingår i: The Condor: ornithological applications. - 0010-5422. ; 105:3, s. 505-514
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Tidskriftsartikel (refereegranskat)abstract
- The Siberian Jay (Perisoreus infaustus) lives in resident, territorial family groups outside the breeding season, but does not breed cooperatively. Thereby it offers an opportunity to study the evolution of territorial group living, without confounding effects of reproductive cooperation. During a long-term study in Finland 1974-2000, we observed Siberian Jay group composition in autumn. Using microsatellite analysis based on feather or blood samples we clarified kin relations within the groups. We found that out of 311 groups that included at least one more individual than the territory holders, 74% were nuclear families, including breeding birds and 1-3 retained offspring. However, 26% of the groups were not families, but consisted of pairs accompanied only by individuals that were not their offspring. According to extensive pedigrees we found that 70% of the 82 immatures associated with a nonparent pair were not related to either territory holder. Of these 82 immatures, 91% were associated with pairs that had no offspring on their own, suggesting that they were failed breeders or newly established pairs. The composition of groups was mostly unchanged during the observation period within each season, regardless of kinship. Previous studies have reported apparent nepotism between parents and retained offspring in the Siberian Jay, and a high degree of aggression toward nonoffspring, so we did not expect to find such high frequency and remarkable within-season stability of nonfamily groups. These observations suggest that there are important fitness benefits to gain from territoriality and group living, regardless of kinship.
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| 3. |
- Lindström, Åke, et al.
(författare)
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High basal metabolic rates of shorebirds while in the arctic: A circumpolar view
- 2003
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Ingår i: The Condor: ornithological applications. - 0010-5422. ; 105:3, s. 420-427
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Tidskriftsartikel (refereegranskat)abstract
- The basal metabolic rate (BMR) of Old World long-distance-migrant shorebirds has been found to vary along their migration route. On average, BMR is highest in the Arctic at the start of fall migration, intermediate at temperate latitudes, and lowest on the tropical wintering grounds. As a test of the generality of this pattern, we measured the BMR of one adult and 44 juvenile shorebirds of 10 species (1-18 individuals of each species, body-mass range 19-94 g) during the first part of their southward migration in the Canadian Arctic (68-76degreesN). The interspecific relationship between BMR and body mass was almost identical to that found for juvenile shorebirds in the Eurasian Arctic (5 species), although only one species appeared in both data sets. We conclude that high BMR of shorebirds in the Arctic is a circumpolar phenomenon. The most likely explanation is that the high BMR reflects physiological adaptations to low ambient temperatures. Whether the BMR of New World shorebirds drops during southward migration remains to be investigated.
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| 4. |
- Arlt, Debora
(författare)
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RESEARCH NEEDS AND RECOMMENDATIONS FOR THE USE OF CONSPECIFIC-ATTRACTION METHODS IN THE CONSERVATION OF MIGRATORY SONGBIRDS
- 2010
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Ingår i: Condor. - : Oxford University Press (OUP). - 0010-5422. ; 112, s. 252-264
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Tidskriftsartikel (refereegranskat)abstract
- Numerous studies have confirmed that when selecting habitat birds can use social information acquired from observing other individuals, and many aspects of this social information can be capitalized upon to manage bird populations. The conservation implications of attraction to conspecifics are especially promising for management, and as research progresses it is important to consider how this behavior can be applied to conservation practice. The biological underpinnings of conspecific attraction and the repercussions of manipulating species' distributions with attraction methods are not well understood, but conservation decisions often cannot wait for scientific research. Here we synthesize the current research on manipulation of songbirds by conspecific-attraction methods and review our knowledge gaps critically. We reviewed the published literature on conspecific-attraction experiments in songbirds and found that of 24 studies in which they were attempted, 20 were successful in attracting birds. Although many experiments have been successful in attracting conspecifics with various cues, we outline issues to be considered before songbirds are manipulated by attraction methods, and we highlight areas of research necessary to enhance the understanding of conspecific attraction and its use in conservation.
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| 5. |
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| 6. |
- De Ruyck, Chris, et al.
(författare)
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n Appraisal of the use of Hydrogen-Isotope Methods to Delineate Origins of Migratory Saw-Whet Owls in North America
- 2013
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Ingår i: The Condor: ornithological applications. - : Oxford University Press (OUP). - 0010-5422 .- 1938-5129. ; 115:2, s. 366-374
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Tidskriftsartikel (refereegranskat)abstract
- Northern Saw-whet Owls (Aegolius acadicus) breed throughout the boreal forest of North America, but little is known about their population trends or distribution within this region. Analysis of stable hydrogen isotopes (delta H-2) in feathers can delineate origins of a variety of avian migrants, but raptors are reported to have high infra-feather isotopic variance and mean delta H-2 values higher than predicted from delta H-2 isoscapes specific to raptor feathers, making assignment of geographic origin sometimes difficult. We examined the applicability of delta H-2 analysis of saw-whet owl feathers to delineating origins of migrants and to assessing differences in the migratory behavior of adult and young owls by using multiple generations of feathers from owls captured during fall migration at the Delta Marsh Bird Observatory, Manitoba, 2006-2007. Values of delta H-2 in saw-whet owl feathers were higher than predicted from a delta H-2 isoscape specific to raptor feathers and from patterns of movements inferred from analysis of band recoveries. This effect was pronounced in adults, while values of delta H-2 in feathers of hatching-year owls fell primarily within the range predicted for the boreal forest northwest of Delta Marsh. Significant differences in delta H-2 values among feather generations suggest that physiological or behavioral differences between adults and young give rise to greater H-2 enrichment in adult feathers. These results indicate that current delta H-2 isoscapes for feathers cannot be used to track adult saw-whet owls reliably and further research into the mechanisms of H-2 enrichment in owl feathers is required.
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| 7. |
- Hou, Lianhai, et al.
(författare)
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A middle Eocene shorebird from China
- 2002
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Ingår i: The Condor. - 0010-5422 .- 1938-5129. ; 104, s. 896-899
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Tidskriftsartikel (refereegranskat)abstract
- We describe a new species of shorebird, tentatively referred to the family Charadriidae, from the Huadian Formation (Middle Eocene) in Jilin Province, China. In general morphology the specimen closely matches that of an extant charadriid, and correspondsin size to the Killdeer (Charadrius vociferus). If correctly identified this is the oldest record of the Charadriidae. The Middle Eocene paleoenvironment of the Huadian region is thought to have resembled a subtropical swamp.
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| 8. |
- Härdling, Roger, et al.
(författare)
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Memory for hoarded food : An aviary study of the european nuthatch
- 1997
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Ingår i: The Condor: ornithological applications. - : Oxford University Press (OUP). - 0010-5422. ; 99:2, s. 526-529
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Tidskriftsartikel (refereegranskat)abstract
- In an aviary study, each of six male European Nuthatches Sitta europaea was allowed to hoard 30 sunflower seeds in natural hoarding substrates. After eight days, each bird was allowed to search for its cached seeds and its performance compared with that of a bird without previous experience of the specific aviary. In all but one case, the hoarder found significantly more seeds than did the naive bird and the hoarder also found the first seed significantly sooner. Furthermore, hoarders found a fixed number of seeds more quickly than did naive birds. These results suggest memory of cache sites.
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| 9. |
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| 10. |
- Lindström, Åke, et al.
(författare)
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A Puzzling Migratory Detour: Are Fueling Conditions In Alaska Driving The Movement Of Juvenile Sharp-Tailed Sandpipers?
- 2011
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Ingår i: The Condor: ornithological applications. - : Oxford University Press (OUP). - 0010-5422. ; 113:1, s. 129-139
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Tidskriftsartikel (refereegranskat)abstract
- Making a detour can be advantageous to a migrating bird if fuel-deposition rates at stopover sites along the detour are considerably higher than at stopover sites along a more direct route. One example of an extensive migratory detour is that of the Sharp-tailed Sandpiper (Calidris acuminata), of which large numbers of juveniles are found during fall migration in western Alaska. These birds take a detour of 1500-3400 km from the most direct route between their natal range in northeastern Siberia and nonbreeding areas in Australia. We studied the autumnal fueling rates and fuel loads of 357 Sharp-tailed Sandpipers captured in western Alaska. In early September the birds increased in mass at a rate of only 0.5% of lean body mass day(-1). Later in September, the rate of mass increase was about 6% of lean body mass day(-1), among the highest values found among similar-sized shorebirds around the world. Some individuals more than doubled their body mass because of fuel deposition, allowing non-stop flight of between 7100 and 9800 km, presumably including a trans-oceanic flight to the southern hemisphere. Our observations indicated that predator attacks were rare in our study area, adding another potential benefit of the detour. We conclude that the most likely reason for the Alaskan detour is that it allows juvenile Sharp-tailed Sand-pipers to put on large fuel stores at exceptionally high rates.
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| 11. |
- Merilä, Juha, et al.
(författare)
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Interspecific Competition for Nest Holes Causes Adult Mortality in the Collared Flycatcher
- 1995
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Ingår i: The Condor. - : Oxford University Press (OUP). - 0010-5422 .- 1938-5129. ; 97:2, s. 445-450
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Tidskriftsartikel (refereegranskat)abstract
- Interspecific competition for nest sites between tits (Parus spp.) and Collared Flycatchers (Ficedula albicollis) was responsible for the death of 23 flycatchers during one breeding season. Eighteen (78%) of the killed flycatchers were males, and nineteen (83%) of the kills took place in nest boxes occupied by Great Tits (Parus major), and two (9%) in boxes occupied by Blue Tits (P. caeruleus). The number of casualties in different plots increased with increasing proportion of nest boxes occupied by tits (r = 0.76), and decreased with increasing density of nest boxes (r = -0.43). The number of casualties equalled up to 17% of all flycatcher individuals breeding in a given plot, indicating that interspecific competition for nest sites may constitute a significant source of adult mortality in the Collared Flycatcher population studied.
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| 12. |
- Olsson, O, et al.
(författare)
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Changes in King Penguin breeding cycle in response to food availability
- 1997
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Ingår i: CONDOR. - : COOPER ORNITHOLOGICAL SOC. - 0010-5422. ; 99:4, s. 994-997
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- From 1991 to 1996 we investigated how the breeding cycle of King Penguins Aptenodytes patagonicus, in a small colony at South Georgia, was affected by variation in food availability between years. During the first (1992) and third (1996) of the three succ
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| 13. |
- Saracura, Valeria, et al.
(författare)
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Genetic parentage and variable social structure in breeding southern lapwings
- 2008
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Ingår i: The Condor. - : Oxford University Press (OUP). - 0010-5422 .- 1938-5129. ; 110:3, s. 554-558
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Tidskriftsartikel (refereegranskat)abstract
- We examined the genetic mating system and social breeding structure of the Southern Lapwing (Vanellus chilensis), a shorebird that breeds in Brazil in secluded pairs or groups (3–4 adults). We never observed copulation between males or females of primary pairs with additional adults in groups; all recorded copulations were between primary pair members. Where DNA from primary males was available, we found mixed paternity in 18.8% of the broods (3 of 16), comprising 9.8% of the chicks (4 of 41). All broods containing young sired by different males occurred in groups. One chick had a DNA fingerprint with four novel bands but shared a high proportion of bands with both primary pair members of its group. One explanation is that the chick's mother copulated with a relative of her social mate. However, quasi parasitism (i.e., nest-sharing by two females) cannot be excluded. Our study demonstrates a flexible social and genetic mating system in Southern Lapwings.
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| 14. |
- Smith, Henrik, et al.
(författare)
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Extra-Pair Paternity in the European Starling: The Effect of Polygyny
- 1993
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Ingår i: The Condor: ornithological applications. - 0010-5422. ; 95:4, s. 1006-1015
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Tidskriftsartikel (refereegranskat)abstract
- We determined the frequency of extra-pair paternity and intraspecific brood parasitism in European Starlings (Sturnus vulgaris) by performing multilocus DNA fingerprinting on 22 complete families from a population in southern Sweden. Among 92 nestlings, we did not detect any successful intraspecific brood parasitism. This confirms observational data that successful intraspecific brood parasitism is rare in this population. We detected eight extra-pair young. Except for one case, where all (two) nestlings were fathered by another male than the one attending the nest, no more than one nestling in each nest was fathered by an extra-pair male. Although the degree of extra-pair paternity was higher in nests of secondary females than in those of primary and monogamous females, this difference was not significant. There was no relationship between a male's paternity with his primary and secondary female during the same reason. There was a tendency for males to loose paternity in the broods of secondary females when the fertile periods of his females overlapped considerably. We suggest that the relative ease by which female Starlings can be mate-guarded, the fact that mate-attraction and mate-guarding do not have to be exclusive activities and the high within pair copulation frequency in Starlings may keep the degree of extra-pair paternity low.
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| 15. |
- Svensson, E, et al.
(författare)
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Molt and migratory condition in Blue Tits: A serological study
- 1996
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Ingår i: CONDOR. - : COOPER ORNITHOLOGICAL SOC. - 0010-5422. ; 98:4, s. 825-831
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Migration and molt are both energy demanding activities and can be expected to conflict with each other in migratory birds. We studied autumn migrating juvenile Blue Tits (Parus caeruleus) and investigated whether molting birds showed signs of diseases or
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