| 1. |
- Barboutis, Christos, et al.
(author)
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From Mediterranean to Scandinavia – timing and body mass condition in four long distance migrants
- 2015
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In: Ornis Svecica. - 1102-6812 .- 2003-2633. ; 25, s. 51-58
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Journal article (peer-reviewed)abstract
- In spring, long-distance migrants are considered to adopta time-minimizing strategy to promote early arrival atbreeding sites. The phenology of spring migration wasexamined and compared between two insular stopoversites in Greece and Sweden for Icterine Warbler, WoodWarbler, Spotted Flycatcher and Collared Flycatcher. All of them migrate due north which means that some proportion of birds that pass through Greece are headingto Scandinavia. The Collared Flycatcher had the earliestand the Icterine Warbler the latest arrival time. Thedifferences in median dates between Greece and Swedenwere 3–4 weeks and the passages in Sweden weregenerally more condensed in time. The average overallspeed estimates were very similar and varied between129 and 137 km/d. In most of the species higher speedestimates were associated with years when birds arrivedlate in Greece. After crossing continental Europe birdsarrive at the Swedish study site with significantly higherbody masses compared to when they arrive in Greece andthis might indicate a preparation for arriving at breedinggrounds with some overload.
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| 2. |
- Barshep, Yahkat, et al.
(author)
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Non-breeding ecology of the Whinchat Saxicola rubetra in Nigeria
- 2012
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In: Ornis Svecica. - 1102-6812 .- 2003-2633. ; 22, s. 25-32
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Journal article (peer-reviewed)abstract
- This study on the non-breeding ecology of the Whinchat Saxicola rubetra was conducted in central Nigeria from February through April. The core site was at Gwafan (N09°53', E08°57'), an open scrubland located 10 km east of the city of Jos. The density of Whinchats at Gwafan was 0.58 individuals/ha, almost three times the overall density around Jos. Time budget observations of colour banded Whinchats, including six birds fitted with radio-transmitters, showed that they spent 80% of their time perching, 11% foraging, 7% preening, and 2% flying. The main method of catching insects was a swoop to the ground. There was no change in perching, preening or flying time but the time some Whinchats spent foraging increased towards the end of the study period. GPS positions of individuals showed that all birds held clearly demarcated territories and defended them against neighbours. Aggressive interactions were also recorded between Whinchats and other bird species. Three birds colour-ringed in 2006 returned to the study site in 2007 and one occupied almost the same territory, indicating site fidelity.
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| 3. |
- Bengtsson, Daniel, et al.
(author)
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Age and sex determination of mallards Anas platyrhynchos in autumn
- 2016
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In: Ornis Svecica. - 1102-6812 .- 2003-2633. ; 26, s. 61-81
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Journal article (peer-reviewed)abstract
- The mallard is a well-known and important species in migration ecology, game management,and epidemiology. Males and females are generally easily told apart, whereas ageing isproblematic, due to individual timing of the moult cycle and lack of easily defined agecriteria. From examination and photographic documentation of mallards caught within a longtermringing program at Ottenby Bird Observatory (56°12′N, 16°24′E), we describe ninecharacters of plumage and bare parts to be used for ageing mallards in autumn. The reliabilityof these characters was tested by letting experienced bird ringers determine putative age ofbirds from photos. Age determination from any single character proved to be uncertain, as therate of correctly assigned mallard photos of each character was in the range of 51-85% formales and 48-89% for females. For both sexes, the lowest figure represented post-humeralsand the highest represented tertials. Rectrices, tertial coverts, and greater coverts also hadreasonably high scores (71-85%). With all characters at hand, 91% of the males and 95% ofthe females were correctly identified to age. As young mallards, with the progress of prebreedingmoult (completed from October onwards), acquire tail and tertials identical to adults,untypical individuals are better not assigned to an age category.
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| 4. |
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| 5. |
- Betzholtz, Per-Eric, et al.
(author)
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What do population viability analyses tell about the future for Baltic Dunlin Calidris alpina schinzii and Montagu’s Harrier Circus pygargus on Öland?
- 2010
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In: Ornis Svecica. - Lund : Swedish Ornithological Society. - 1102-6812 .- 2003-2633. ; 20, s. 93-102
-
Journal article (peer-reviewed)abstract
- Population viability analysis (PVA) has become an important tool in conservation biology. Even though detailed outcomes of PVA:s are constrained by data quality, it is a useful approach when the objective is exploratory, aiming to identify important parameters for viability or to guide future field work on endangered species. In this study we perform PVA:s based on scarce data to explore viability of two endangered bird species, Baltic Dunlin and Montagu’s Harrier, on Öland. Our simulation results underline that both species are under severe threats, with a median time to extinction of 24 years in Baltic Dunlin and 63 years in Montagu’s Harrier. Sensitivity analyses show that population growth rate is the most important factor for the model outcome in both species. Since there are no apparent threats for adult birds on Öland, this suggests that conservation measures should focus on improving conditions for successful breeding on the island. In additional simulations we explore some threats in more detail. In the case of Baltic Dunlin nest predation of eggs and chicks increase the extinction risk. In Montagu’s Harrier viability increases if breeding attempts within agricultural areas are detected and safeguarded. In order to enhance the PVA model, and build a stage-structured model, we suggest that detailed data on fecundity and survival should be collected.
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| 6. |
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| 7. |
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| 8. |
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| 9. |
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| 10. |
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| 11. |
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| 12. |
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| 13. |
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| 14. |
- Ekblom, Robert
(author)
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Evaluation of the analysis of distance sampling data : a simulation study
- 2010
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In: Ornis Svecica. - 1102-6812 .- 2003-2633. ; 20, s. 43-53
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Journal article (peer-reviewed)abstract
- Distance sampling is used to estimate number of indi- viduals in an area of interest. The idea is that with known distances to the observed individuals, one can model the probability of detection in relation to distance and thereby account for individuals that were not detected. Distances can be recorded either exactly or in discrete categories. In this study I validated the method using simulated dis- tance sampling data for two hypothetical bird species and compared the estimated density values to the known true densities. Generally the true densities and numbers of individuals were very similar to (and always within the 95% confidence interval of) the parameter estimates from the analysis of the simulated data. The analyses were also robust to modifications of the data such as truncation andgrouping of the distances into discrete categories. The confidence intervals increased, however, when using only two distance groups. Given that critical assumptions of the model can be met in the field situation, distance data can thus be used in a wide range of bird studies to calculate reliable density estimates.
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| 15. |
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| 16. |
- Engvall, Emma, et al.
(author)
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Diet and prey size preference in Razorbills Alca torda breeding at Stora Karlsö, Sweden; [Vilken typ och storlek av bytesdjur föredrar häckande tordmular Alca torda vid Stora Karlsö?]
- 2022
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In: Ornis Svecica. - : University of Lund. - 1102-6812 .- 2003-2633. ; 32, s. 87-98
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Journal article (peer-reviewed)abstract
- The Razorbill Alca torda is one of three auk species breeding in Sweden, often occurring in colonies with Common Guillemot Uria aalge. The largest colony in the Baltic Sea is situated on the island Stora Karlsö west of Gotland. During the chick-rearing phase, Razorbills forage at sea and return to feed the young with single or multiple prey carried sideways in the bill, unlike Common Guillemots that carry a single fish in the middle of the bill. Clupeids, especially sprat Sprattus sprattus, are the main prey of Baltic Sea Razorbills, but studies are scarce. Here, we investigate the diet preference of Razorbills at Stora Karlsö with regard to prey taxonomy and size, analysing photographs and applying morphometric equations. We show that most feeding attempts involved a single clupeid (88% of known fish taxonomy), in most cases likely sprat. The average prey size (115 mm) and prey species was similar to that of Common Guillemots in the same colony. The variation in size was much smaller in the Razorbill diet than the size distribution of clupeids at sea, indicating a strong prey size selectivity. The Razorbills’ high specialisation underlines the importance of maintaining strong populations of clupeids in their foraging area, as these fish are also targeted by industrial fisheries.
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| 17. |
- Eriksson, Mats O. G., et al.
(author)
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Vattenkemi och fiskbeståndens sammansättning i storlommens Gavia arctica häckningssjöar, samt en jämförelse med smålommens Gavia stellata fiskesjöar
- 2010
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In: Ornis Svecica. - : Sveriges Ornitologiska förening. - 1102-6812 .- 2003-2633. ; 20:1, s. 3-30
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Journal article (peer-reviewed)abstract
- Breeding performance of Black-throated Diver Gavia arctica was compared to water chemistry, light penetration and density of fish in 122 breeding lakes in Sweden with a total of 184 pairs (1.5 pairs per lake, about 3% of the national population). The breeding lakes were on average nutrient-poor, and 12% of them had a low buffering capacity (alkalinity <0.10 meq/l). Perch Perca fluviatilis, roach Rutilus rutilus and pike Esox lucius, three species characteristic for nutrient-poor lakes, were found in more than 90% of the lakes. Salmonid fish occurred in half of the lakes, compared to >90% of the fishing lakes used by Red-throated Diver. Reproduction was related to high abundance of Perch, and the survival of chicks to light penetration. Poor nutrient status in combination with low pH or alkalinity in approximatively 10% of the breeding lakes of Black-throated Diver and probably more than 30% of the fishing lakes of Red-throated Diver, indicate susceptibility of exposure to methylmercury. This finding should be considered in relation to recent reports of increased contents of mercury in freshwater fish.
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| 18. |
- Ferry, Björn, et al.
(author)
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Ökande antal övervintrande skogsfåglar i lappland 1986–2017 visar starkare samband med skogens utveckling än lokalt väder
- 2020
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In: Ornis Svecica. - : Ornis Svecica. - 1102-6812 .- 2003-2633. ; 30, s. 13-30
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Journal article (peer-reviewed)abstract
- After a long period of decline, the number of forest birds has increased in Sweden in recent decades. Whether this trend is due to an increase in forested area, forest quality, climate change, or a combination of these factors, remains unclear. Here, we compared forest bird data from a local winter point count route around Storuman in Swedish Lapland between 1986 and 2017, with the development of regional forest composition and local weather conditions. We suggest that rather than changes in average annual, winter, or summer local temperatures or precipitation, the main drivers behind increasing numbers of wintering forest birds in this part of Sweden are an increase in the area of denser forest and dead wood volume, and a decrease in open ground area without forest vegetation. While there may be supplementary explanations behind the increasing numbers of forest birds, such as reduced agriculture, decreasing local human population, or stronger photosynthesis, our results indicate that local land use has been favourable for forest birds in recent decades in this area.
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| 19. |
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| 20. |
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| 21. |
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| 22. |
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| 23. |
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| 24. |
- Hjernquist, Måns, et al.
(author)
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Behaviour and survival of Common Guillemot Uria aalge chicks at departure from a nest site in the Baltic Sea
- 2012
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In: Ornis Svecica. - 1102-6812 .- 2003-2633. ; 22
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Journal article (peer-reviewed)abstract
- Common Guillemots Uria aalge often breed high up in cliffs, forcing the juveniles to jump down to the beach or sea sea when leaving their nests. We studied survival of Common Guillemot chicks at time of nest departure on the island Lilla Karlsö in the Baltic Sea. All jumps were conducted either together with one of the parents, or, more commonly, the parent few down shortly before the chick jumped. At this point, the parent was always found waiting for the chick directly underneath the nest, either on the beach or in the water, and never farther out than fve meters if there was no beach below the cliff. If separated, all observed parents and juveniles reunited within one minute and then swam close together out to sea. Juvenile mortality was very low, only 0.5% in 2011, with 2 of 426 chicks dying. In both cases hitting a lower cliff ledge caused the mortality. No case of predation was observed. The high survival rates are most likely due to the chicks’ close proximity to their male parent at all times.
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| 25. |
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| 26. |
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| 27. |
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| 28. |
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| 29. |
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| 30. |
- Kylin, Henrik
(author)
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Birds and mammals off the northern coast of Argentina: first report of an association between birds and a feeding Pygmy Right Whale Caperea marginata
- 2013
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In: Ornis Svecica. - : Sveriges Ornitologiska Förening. - 1102-6812 .- 2003-2633. ; 23:3-4, s. 117-122
-
Journal article (peer-reviewed)abstract
- When the icebreaker Oden passed between 39°36’S, 57°46’W and 39°59’S, 58°11’W on 20 November 2007, an extraordinary observation was made. A feeding Pygmy Right Whale Caperea marginata, a species rarely seen, was attended by eight Grey Phalaropes Phalaropus fulicarius, two Slender-billed Prions Pachyptila belcheri, and four Wilson’s Storm Petrels Oceanites oceanicus. The birds returned to feed around the head of the whale every time it surfaced, presumably copepod plankton straining out between the baleen. The site is off Rio de la Plata estuary where nutrient rich freshwater meets cold water of the Malvinas (Falkland) Current, creating a hotspot with high levels of plankton food. The conditions were extraordinarily favourable for observation with a calm sea, no wind and only a very weak swell. Six multispecies feeding groups were seen with a total of 42 species of birds, eleven species of whales, dolphins and porpoises, and three species of seals. Dusky Dolphins Lagenorhynchus obscurus and Great Shearwaters Puffinus gravis were predominant in the groups.
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| 31. |
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| 32. |
- Kylin, Henrik
(author)
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Juvenile Black-legged Kittiwakes Rissa tridactyla with deformed bills and clubfeet in the Barents Sea
- 2005
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In: Ornis Svecica. - : Sveriges Ornitologiska Förening. - 1102-6812 .- 2003-2633. ; 15, s. 149-152
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Journal article (peer-reviewed)abstract
- Juvenile Black-legged Kittiwakes Rissa tridactyla with deformed bills and feet were observed in the Barents Sea in 1996, first while passing between Franz Josef Land and Novaya Zemlya on 21–24 July (at least 10 birds) and then off the West Coast of Svalbard 20–21 September (at least 2 birds). Deformities were manifest as prolonged upper or lower mandible, hooked or crocked upper mandible, crossed bill and clubfeet. This paper reports the circumstances of the observations and discusses possible causes. Among the possible causes are nutritional deficiencies, epizootic events, environmental pollutants (persistent organic pollutants, heavy metals or radioactivity), or combinations of these.
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| 33. |
- Kylin, Henrik
(author)
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Short-tailed Shearwaters Puffinus tenuirostris forage in Grey Whale Eschrichtius robustus Mud Plumes
- 2013
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In: Ornis Svecica. - : Sveriges Ornitologiska Förening. - 1102-6812 .- 2003-2633. ; 23, s. 114-116
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Journal article (peer-reviewed)abstract
- Greay Whales Eschristius robustus are the only large whales that are specialized bottom feeders, foraging on bottom sediments. When surfacing after a feeding dive a mud plume is formed at the surface as remaining sediment is strained out between the baleen. In the Chukchi Sea, Short-tailed Shearwaters Puffinus tenuirostris are attrackted to these mud plumes in search of food particles.
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| 34. |
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| 35. |
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| 36. |
- Larsson, Kjell, Professor, 1958-
(author)
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Age and sex ratios of wintering Long-tailed Ducks Clangula hyemalis can be determined by analysis of photos of flying flocks at sea : A method description
- 2023
-
In: Ornis Svecica. - : BirdLife Sweden. - 1102-6812 .- 2003-2633. ; 33, s. 1-20
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Journal article (peer-reviewed)abstract
- The West Siberian / North European population of Long-tailed Duck Clangula hyemalis that breeds in Fennoscandia and Northwestern Russia, and winters in the Baltic Sea, has declined by at least 65 % since the 1990s and is classified as globally vulnerable. To propose effective management actions to stop the decline, knowledge about demographic parameters is required. A photo survey method by which it is possible, in winter, to collect data on sex ratios and production of first-winter birds is presented here. The plumage traits and bill patterns, which are detectable in photos taken at a distance, are described. The traits can be used to discriminate between three categories of birds: adult males, first-winter males, and females. To extrapolate results from several photo surveys and obtain population-wide estimates of demographic parameters, knowledge about non-random distributions of different bird categories is needed. It was found that different age and sex categories were distributed differently across flocks of different sizes. The required sample sizes and the possible constraints and biases related to the photo survey method are discussed.
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| 37. |
- Larsson, Kjell, et al.
(author)
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Effekter av oljeutsläpp på övervintrande alfågel Clangula hyemalis vid Hoburgs bank i centrala Östersjön mellan 1996/97 och 2003/04 : Effects of oil spills on wintering Long-tailed Ducks Clangula hyemalis at Hoburgs bank in central Baltic Sea between 1996/97 and 2003/04
- 2005
-
In: Ornis Svecica. - : Sveriges Ornitologiska Förenening. - 1102-6812 .- 2003-2633. ; 15, s. 161-171
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Journal article (peer-reviewed)abstract
- The Baltic Sea is an important marine area for wintering birds. Surveys in the 1990s showed that more than 25 % of the European Long-tailed Duck Clangula hyemalis population wintered at Hoburgs bank and east of Gotland. A shipping route with very frequent traffic goes from southwest Baltic Sea via Öland, Hoburgs bank and east of Gotland to the Gulf of Finland. In year 2000 about 58 500 ships passed east of Öland along this route. Hundreds of oils spills are registered along the route each year. Weekly surveys of oiled birds at southern Gotland and analyses of birds that had drown in fish nets showed that tens of thousands of ong-tailed Ducks were injured by oil each year in central Baltic Sea. Of 998 birds that drowned in fish nets at Hoburgs bank 11.8 % were found to have oil in the plumage. There was no clear relationship between the number of oiled birds observed and the number of registered oil spills in different years. Many sea duck have a life history in which variable or low productivity is compensated for by relatively high adult survival. This makes sea duck populations very susceptible to extra adult mortality caused by oil spills.
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| 38. |
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| 39. |
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| 40. |
- Lerner, Henrik, et al.
(author)
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What knowledge is "jizz"?
- 2012
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In: Ornis Svecica. - : Sveriges Ornitologiska Förening. - 1102-6812 .- 2003-2633. ; 22, s. 73-79
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Journal article (peer-reviewed)abstract
- Jizz is used by many birders to identify bird species. The definition of jizz differs between authors, but concerns aspects of the bird that are not always easy to define scientifically or describe in objective terms. Rather, impressions of the bird are favoured, including size, shape, behavior and appearance. Here we try to show that jizz is a term worth studying in detail, since its use offers insights in how to identify species, why there are differences among observers in bird surveys and why traditional knowledge about biological diversity might be worth saving when preserving species.
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| 41. |
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| 42. |
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| 43. |
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| 44. |
- Nilsson, Leif
(author)
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Changes in local distribution and numbers of staging and wintering bean geese anser fabalis in scania, south Sweden 1977/1978–2016/2017
- 2017
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In: Ornis Svecica. - : Ornis Svecica. - 1102-6812 .- 2003-2633. ; 27:2-4, s. 110-120
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Journal article (peer-reviewed)abstract
- Scania in southern Sweden is an important staging and wintering province for the Bean Goose Anser fabalis, especially for the Taiga form A. f. fabalis. Based on counts in October, November and January 1977/1978– 2016/2017, and observations of neck-banded individuals, the changes in local distribution are described. When the counts started, large numbers were counted already in October, but autumn numbers steadily decreased as the geese stayed further north in Sweden. The January counts on the other hand increased as the geese wintered in Scania in successively larger numbers rather than leaving Sweden. In January 2017, more than 40 000 or two- thirds of the global population of Taiga Bean Goose were counted in Scania. Within the province, more and more geese concentrated to inland areas and instead of using the Öresund coastal region as in earlier years. Birds from different breeding areas, e.g. from Finland and Sweden, used different parts of Scania. In recent years 3000–9000 of Tundra Bean Geese Anser f. rossicus have been wintering in a small area in northeast Scania.
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| 45. |
- Nilsson, Leif
(author)
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Flyttning hos grågäss enligt återfynd av fåglar märkta med traditionella metallringar i Sverige
- 2017
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In: Ornis Svecica. - : Ornis Svecica. - 1102-6812 .- 2003-2633. ; 27:2-4, s. 132-138
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Journal article (peer-reviewed)abstract
- Traditional recoveries of ringed Greylag Geese Anser anser from different regions in Sweden have been analyzed to compare the migration patterns from a number of different areas. During the years up to and including 2012, 7210 Greylag Geese were marked with metal rings from the Swedish Ringing Centre, yielding 1398 recoveries. After exclusion of local recoveries in the ringing area, 924 recoveries were used in the present analysis. The majority of recoveries were from the Western European flyway along the Atlantic coast but some Greylag Geese marked in the province of Södermanland migrated south through Eastern Europe even reaching Northern Africa. A number of records of Greylag Geese marked during the moult on Gotland were probably recruited from Eastern Europe. Later about 25% of these birds migrated south through central Europe. In general, the geese marked in different parts of the country showed the same migration patterns as geese neck-banded in SW Scania and Södermanland.
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| 46. |
- Nilsson, Leif
(author)
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Förändringar i antal och lokal utbredning hos övervintrande sjöfåglar vid den skånska sydkusten under 55 vintrar, 1964–2018
- 2020
-
In: Ornis Svecica. - : Ornis Svecica. - 1102-6812 .- 2003-2633. ; 30, s. 38-52
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Journal article (peer-reviewed)abstract
- THE SOUTH COAST of Scania, southernmost Sweden, has long been an important wintering and staging area for waterbirds. A large part of the coast was surveyed annually as a part of the international midwinter counts for 55 years (1964–2018). The total number of wintering waterbirds showed an increasing trend but there was much variation between years. Common Goldeneye Bucephala clangula, followed by Mallard Anas platyrhynchos, Tufted Duck Aythya fuligula and—during the early years—Long-tailed Duck Clangula hyemalis, dominated the community. Great Cormorant Phalacrocorax carbo, Mallard, Common Goldeneye and Eurasian Coot Fulica atra increased in numbers, reflecting the national and international trends related to milder winters and a northward shift of the winter distribution. Eurasian Wigeon Mareca penelope and Great Crested Grebe Podiceps cristatus established wintering traditions in the area during the study period. Tufted Duck and Common Merganser Mergus merganser decreased locally due to a northward shift of the wintering distribution northwards within the country. The Long-tailed Duck was an important winter guest in the first years but was only seen in very small numbers in later years, reflecting the general and large-scale decrease of the Baltic wintering population.
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| 47. |
- Nilsson, Leif, et al.
(author)
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Livslång häckningsframgång för grågäss anser anser häckande i södra Sverige.
- 2018
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In: Ornis Svecica. - : Ornis Svecica. - 1102-6812 .- 2003-2633. ; 28:1, s. 39-47
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Journal article (peer-reviewed)abstract
- During 1984–2009, 664 adults and 1,944 goslings of Greylag Geese Anser anser were neck-banded in south-west Scania, Sweden. After hatching the area was careful-ly searched for marked geese, giving more than 100,000 re-sightings. Of those marked as goslings 71% survived the first year, 52% the second year, and the oldest bird recorded was 25 years. About 50% of the survivors were recruited into the breeding population when two to three years old. Of 1,187 geese that survived for at least two years, 25% produced at least one brood of small young, and 18% at least one fledged young. The maximum lifetime number of broods with fledged young was nine, but 50% of the geese known to have bred successfully pro- duced only one brood of fledged young. Ten percent of the geese seen with small goslings produced 47% of all fledged young. The maximum number of fledged young for a goose of known age was 32 (age 15 years), but two geese marked as adults and followed for 16 and 17 years produced 40 fledglings each.
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| 48. |
- Nyholm, Erik
(author)
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Dynamics and reproduction of a nest-box breeding population of Pied Flycatcher Ficedula hypoleuca in a subalpine birch forest in Swedish Lapland during a period of 46 years
- 2011
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In: Ornis Svecica. - Stockholm : Sveriges ornitologiska förening. - 1102-6812 .- 2003-2633. ; 21:2-4, s. 133-156
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Journal article (other academic/artistic)abstract
- A nest-box breeding population of Pied Flycatcher Ficedula hypoleuca in subalpine birch forest at Ammarnäs in northern Sweden was studied in 1965–2010. The population showed on average a significantly decreasing trend during the initial 25 years, after which it remained on a static level. The yearly variation of the population size was significantly correlated with breeding result in preceding years, which in turn was affected by e.g. nest predation, adverse climatic factors, clutch size, and incidence of defective egg shell formation. It is also suggested that the population decline during the initial 10–15 study years followed from over-establishment of the breeding habitat. The average breeding result was 2.3 fledglings per pair, which is far below the number needed for the population to be self-reproducing. The occurrence of unusually high rates of nest predation and defective egg shells seems to be passing phenomena, predicted to approach zero after about 30 and 60 years, respectively, after the start of the study. But even with these factors eliminated and with other conditions remaining unchanged, the Ammarnäs population will continue to be a sink population.
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| 49. |
- Nyholm, N. Erik I., 1940-
(author)
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Return rates of nest box breeding pied flycatchers ficedula hypoleuca to their breeding site in subalpine birch forest in Swedish Lapland, during 1965-2018 : [Andelar holkhäckande svartvit flugsnappare Ficedula hypoleuca som återvände till häckningsplatsen i fjällbjörkskog i Lappland, 1965-2018]
- 2019
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In: Ornis Svecica. - : Ornis Svecica. - 1102-6812 .- 2003-2633. ; 29, s. 53-68
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Journal article (peer-reviewed)abstract
- RETURN RATES of 4,178 female and 1,565 male breeding Pied Flycatchers ringed in 1965-2017 were studied near the species’ upper elevation and climatic limit in northern Sweden. Female return rate was 7.5 % in the season subsequent to the first breeding season. Having returned once, 38 % continued to return the next three seasons. Corresponding return rates of males were 27 % and 39 %. Female return rate decreased with more than 30 % during the study period whereas that of males did not decrease. This difference was probably due to increased mortality during the non-breeding season that selectively struck females after the 1970s. Local factors affected return rates in both sexes. Return rate was positively correlated with breeding success in females but negatively in males, whereas it was correlated with nest predation in the opposite way. Predation by mustelids accounted for a significant part of female return rate. Females that had returned once were continuously faithful to the former breeding site. Males showed faithfulness only after having returned twice.
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| 50. |
- Ottvall, Richard
(author)
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Boöverlevnad hos strandängshäckande vadare : den relativa betydelsen av predation och trampskador av betesdjur
- 2005
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In: Ornis Svecica. - Stockholm : Sveriges ornitologiska förening. - 1102-6812 .- 2003-2633. ; 15, s. 89-96
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Journal article (peer-reviewed)abstract
- Nest survival among eight wader species Charadrii in relation to densities of grazing livestock (0–2 livestock/day/ha) was investigated on Öland, southeastern Sweden in 2004. When analysing a pooled data set of 173 nests, nest survival was not related to densities of livestock. Only six nests were destroyed from trampling by livestock and the estimated trampling risk of nests was low. Another analysis of 122 nests produced significantlynegative relationships between nest survival and initiation of incubation. Nests were depredated more oftenlater in the season. Nest survival was not related to livestock density or to vegetation height at nests. Mayfieldestimates of hatching success were 2–21% for four of the different wader species. The highest hatching success was found in Lapwing Vanellus vanellus (21%) and Ringed Plover Charadrius hiaticula (20%), and the lowest in Oystercatcher Haematopus ostralegus (2%), while Redshank Tringa totanus had intermediate hatchingsuccess (11%). This study indicates that, at current grazing management, predation has a higher relative impact on nest survival of waders breeding on coastal meadows compared to direct and indirect effects of grazing animals.
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