Migrant waders using freshwater habitats are hypothesized to have slower primary moult than waders using coastal habitats. We chose the Wood Sandpiper Tringa glareola as a representative species using the freshwater habitats and compare its moult pattern with a range of fresh-water and coastal wader species to test the habitat hypothesis. Only fragmentary descriptions of Wood Sandpipers' primary moult in their sub-Saharan non-breeding quarters had existed. We analysed the primary moult formulae of 1496 adult Wood Sandpipers obtained in southern Africa. The Underhill & Zucchini moult model was used to estimate the timing and duration of moult for all 10 primaries combined and for each primary individually. We also estimated the rate of production of feather material during moult. Adult Wood Sandpipers arrive in southern Africa between late July and November, and depart from mid-March to April. Suspension of moult was observed in 56 birds (7.5%) after two to nine primaries had been replaced. The remaining birds performed a continuous complete primary moult, with average start and completion dates of 21 August and 30 December, respectively; estimated duration was 131 days. The overall rate of production of primary feather material was uniform, achieved by growing up to five small inner primaries simultaneously at the beginning of the moult but only one or two simultaneously while the large outer primaries were growing. Primary moult of adult Wood Sandpipers took longer but ended earlier than in similar-sized waders using coastal habitats. Compared with waders using coastal habitats, Wood Sandpipers prolonged moult by shedding their primaries at longer intervals and by extending the growth period of each primary. The longer primary moult and its earlier ending compared with coastal waders are probably adaptations to Wood Sandpipers' use of freshwater habitats, which in southern Africa provide unpredictable food supplies and might require nomadic movements between ephemeral inland wetlands.

To explore migration patterns of Lesser Black-backed Gulls Larus fuscus breeding in northern Norway, this study presents resightings of 16 adult and 83 juvenile birds marked in this region. Adults of the endangered nominate sub-species L. f. fuscus had a low probability of being observed (only 3.5% of marked birds were observed), probably because the adults winter in areas with few observers, such as eastern and central Africa. In contrast, birds of the greyish-mantled subspecies L. f. intermedius or L. f. graellsii had a high probability of being observed (45.5%). Adults of intermedius/graellsii had a western migration route and wintered mainly in western Europe and northwest Africa, Adults exhibited a high site fidelity to wintering areas. Birds marked as juveniles had two different migration routes. (1) 30% of the observed birds crossed the Scandinavian Peninsula to Finland and the Baltic countries, and then migrated to the eastern Mediterranean (Israel and Egypt) down to eastern and central Africa (Kenya and Cameroon). (2) The other 70% followed the European coast and overwintered in UK, the Iberian Peninsula, Morocco, Mauritania and Senegal. There were no indications that juvenile migration patterns differed among subspecies as juveniles from mixed and pure fuscus colonies exhibited similar patterns. The apparent differences in migration patterns between adult and juvenile fuscus may be a result of juvenile exploratory migration.

We analysed satellite tracking data to reveal the daily travel schedules of Hobbles Falco subbuteo migrating between northern Europe and southern Africa. By comparing movements during short-time intervals of 1–8 h at different times of the day between the three different regions Europe, Sahara Desert and tropical Africa, we found significant higher hourly speeds in the Sahara compared to the other two regions. The migration started early in the morning and continued throughout the day, resulting in daily travel time exceeding that of typical thermal soaring migrants. Due to fast hourly speeds in combination with the long travel days during Sahara crossings, the Hobbies exceeded daily travel distances recorded for soaring migrants. In Europe and tropical Africa, the speed was highly variable during the day, and lower flight speeds, especially during afternoons, suggest a fly-and-forage strategy. Our predictions about regular occurrence of nocturnal flight especially across geographical barriers as the desert were not fulfilled. In the Sahara, the Hobbies restricted their movement to diurnal migration. Nevertheless, 10% of the flight segments in tropical Africa were partly or completely during night hours and Hobbies often started their daily flight before or at sunrise. We attribute the special characteristics of the daily travel schedules of Hobbies primarily to their use of a fly-and-forage strategy, possibly in combination with preparedness for exploiting thermals during the daily thermal time window. Further studies are needed to understand why Hobbies do not increase daily travelling hours to include regular nocturnal flight in the Sahara Desert. We suggest that the daily travel schedules of the Hobby, which were distinctly different from those of other diurnal migrants like large raptors (which mainly exploit thermal soaring migration) or pipits, wagtails, finches and pigeons (which mainly travel during the morning hours) may be typical for bird species that primarily use a fly-and-forage migration strategy.

Our aim was to assess to what extent detection of differential timing of passage in migrant birds depends on the sampling frequency (SF). We determined if Blackcaps Sylvia atricapilla performed differential migration by age and sex when passing over N Iberia. We mist netted and ringed migrating Blackcaps at a stopover site, both during the autumn (2005) and the spring (2006) migrations. During autumn, adult female Blackcaps passed later than juvenile birds and adult males. In spring, however, migration differed mainly by sex rather than by age. In particular, males passed over earlier than females, likely due to the pressure on males to earlier arrival at their breeding areas. A simulation based on daily captures at the Constant Effort Site showed that the ability to detect differential timing of passage was affected by SF, with P-values being higher with decreasing SF. However, the proportion of variance explained by differences in timing of passage between sex or age classes was not affected by SF. This implies that at Constant Effort Sites a low SF may be adequate to detect differential timing of passage if a higher sampling effort per day (e.g. by sampling with more mist nets, and/or for a longer period) is maintained.

Survival and reproductive rates often decrease with increasing population density. Such negative density dependence reflects a changing net balance between the benefits and costs of presence of others with increasing density. When densities are low, however, survival and reproductive rates might increase rather than decrease with increasing density (Allee effect), for example in colonial species. Relationships between fitness and density are therefore expected to change with population density. We studied the relationship between apparent annual survival and population density in a population of Mediterranean Gulls Larus melanocephalus from establishment onwards for a period of 13 years, using capture-recapture techniques. The results confirmed our expectation: apparent survival increased with density at low densities (i.e. an Allee effect), but survival decreased with density at high densities. Post-hoc analyses revealed that the Allee effect could only be shown for juveniles, not for adults, suggesting that the Allee effect might have been age-specific. These patterns in apparent survival reflect the combined effects of density on true survival and on permanent emigration, and both mechanisms are discussed.

Ring recoveries of dead individuals from all over Europe and covering a period of 57 years were collected to study survival of Great Crested Podiceps cristatus (n = 433), Black-necked P. nigricollis (n = 95) and Little Grebes Tachybaptus ruficollis (n = 295). Survival rates of adult birds were estimated by fitting simple mark-recapture models via maximum-likelihood. Realizing that the samples were extremely heterogeneous and possibly biased, it was further investigated how the survival data conformed to information from literature on fledging success, age at first breeding, and long-term population trends. In the Great Crested Grebe, ring recoveries were biased towards young birds, as indicated by a marked, untypical increase in apparent survival after the age of 3 years. Also, the whole-sample estimate of 0.66 was too low to match the other demographic parameters. The survival rate of 0.75 (95% CI 0.69–0.80) estimated for birds of 4 years and older conformed well with the breeding performance established for Great Crested Grebes and is thus considered as a realistic estimate for adult birds. The survival rate estimate of 0.63 (95% CI 0.55–0.70) for the Black-necked Grebe seemed a slight underestimate given estimates for the other demographic parameters. Apart from a possible, albeit undetected, sample bias towards younger birds, some influence of ring loss cannot be excluded, because in contrast to the other two species, the Black-necked Grebe sample contained a high proportion of aluminium rings. The survival rate of Little Grebe was estimated at 0.60 (95% CI: 0.55–0.64), which corresponded well with other demographic data.

The Ortolan Bunting Emberiza hortulana has suffered a general decline across much of Western Europe in recent decades. In Switzerland, only one population remains in sub-Mediterranean shrub-steppe on the south-facing slopes of the Rhône Valley (Valais). We aimed to collect data on foraging ecology of the last Swiss Ortolan Buntings during reproduction. However, this population underwent a considerable decline, with no breeding confirmed in Switzerland in 2007. We investigated foraging habitat selection of four unpaired males at the habitat and microhabitat scales, and compared patterns of foraging habitat use with patterns of terrestrial invertebrate abundance. All radio-tracked birds foraged exclusively on the plain. The adjacent slope, which harboured the former breeding grounds, was used only for territorial song displays. All males showed a disproportionate use of conventional maize fields that had been treated with herbicides, while also exhibiting an avoidance of meadows and riparian vegetation. These observed patterns of habitat use may be driven by unavailability of optimal foraging habitat, with birds being forced to use the best of a poor set of options. Structurally, it was shown that birds foraged in areas with a high proportion of bare ground, as well as moderately dense overhead vegetation. These areas did not support higher arthropod abundance, suggesting that food accessibility (and/or cover) rather than food abundance dictated habitat selection. It remains to be seen whether these patterns of microhabitat use also apply to breeding Ortolan Buntings. Further work in southern European breeding grounds should be envisioned to gain crucial information about the ecological requirements of Ortolan Buntings in Mediterranean and sub-Mediterranean habitats. Additionally, effort needs to be focused on identifying factors affecting the species on the wintering grounds, which may assist in explaining the observed declines in the breeding areas.

Eurasian Oystercatchers Haematopus ostralegus ostralegus are a classic example of individual feeding specialization. Feeding specialization causes morphological differentiation in Oystercatchers' bill shapes due to varying degrees of abrasion associated with specific handling techniques for each prey species. Consequently, the Oystercatcher's bill shape has been used as a proxy for diet specialization, as it provides a quick and easy way to assess the diet choice of this marine top-predator. However, bill shapes of Oystercatchers are categorized visually in distinct types, while it has been argued that the relevant variation is continuous. Also, it is unclear how comparable the bill-shape classification is among studies and between the sexes and how universal bill shape-diet relationships are. Here we investigate the usefulness of bill-shape types as a proxy for diet choice in Oystercatchers, using four new and two published datasets. We show that quantitative bill-morphometrics provide no evidence that bill-shape types are discrete entities. Additionally, the dimensions of the same bill-shape type differ across studies. This difference is unlikely to be caused by methodology and might reflect subtle additional feeding specialization among birds with the same bill-shape type. Moreover, we show that the tip of the bill of males is typically 7% higher than that of females with the same bill-shape type. A higher — and probably stronger — bill tip in males may explain why males had more shellfish in their diet than females with the same bill-shape type. Finally, a literature-review shows that the exact bill shape-diet relationship differs between studies and the sexes. We conclude that the interpretation of bill-shape type as a proxy for diet choice in Oystercatchers is context dependent. We propose that quantitative bill dimensions are a better proxy for feeding specialization than bill-shape types.

Many waterbird species assemble in large aggregations during winter. In most species, these aggregations are generally thought to be composed of individuals not familiar to each other. In this study, we analysed mark-recapture data of Tufted Ducks Aythya fuligula and Common Pochard A. ferina from four wintering places in Switzerland to assess whether individual birds were recaptured non-independently of each other one or more years later, We found that individual Tufted Ducks caught together during a previous winter were re-caught together more often than expected by chance. Our results suggest that winter flocks of Tufted Ducks may be socially structured to an extent unknown so far. We discuss a number of hypotheses that could explain our observations, but clearly, much more work needs to be done to confirm our observation and to understand its causes.

We studied collision rate of birds with modern, large 1.65 MW wind turbines in three wind farms in The Netherlands during three months in autumn and winter. Collision rate, after correction for retrieval and disappearance rate, was 0.08 birds per turbine per day on average (range 0.05–0.19). Collision risk, i.e. the number of victims relative to the flight intensity of birds at the wind farms, was 0.14% on average. For nocturnal migrants, risk was as low as 0.01%, while the risk was 0.16% for local birds flying at night. In absolute numbers, the overall collision risk was similar to the 0.06–0.28% found for earlier-generation lower turbines that have a smaller rotor surface. However, given the comparatively large rotor surface and altitude range of the modern turbines, the risk was c. threefold lower than for smaller turbines. A large fraction of collision victims were diurnally active and local birds that were foraging in the area, rather than nocturnal migrants. Flight intensities of this group should be taken into account as well as that of nocturnal migrants, when calculating collision rate.

We report two recordings of Great-tailed Grackles Quiscalus mexicanus in the Chamela Biosphere Reserve, which is an important conservation area for pristine tropical dry forests in West Mexico. These recordings are important for three main reasons: (1) they reveal the recent encroachment of the reserve by human-disturbed areas; (2) the recorded grackles fought with West Mexican Chachalacas Ortalis poliocephala, and won, underlining their possible negative effects towards other native bird species; and (3) if Great-tailed Grackles successfully invade the conservation area, it could turn into an unmanageable scenario with possible negative consequences within an important area for bird conservation in the dry tropics.

In a Danish landscape with relatively high (134/km²) but variable human density, 86% of 213 incubating Common Buzzards Buteo buteo flushed from the nest at distances of 0–200 m in response to a person approaching on foot. Flight distances were not conditional on nest site parameters despite considerable variation in human disturbance variables, lending no support for the hypothesis that Common Buzzards are more tolerant of humans in disturbed locations.

This is the third update on the taxonomy of species and higher taxa on the Dutch List since Voous (1977). It summarizes decisions made by the Commissie Systematiek Nederlandse Avifauna (CSNA) between Jan 2004 and Dec 2008. Changes in this report fall into five categories: (1) the sequence within and among some groups is changed to reflect their phylogenetic relationships (flamingos and grebes, eagles, shanks, gulls, terns, swallows and tits); (2) 20 scientific names are changed due to generic revisions (Aquila pennata, A. fasciata, Chroicocephalus genei, C. Philadelphia, C. ridibundus, Hydrocoloeus minutus, Onychoprion anaethetus, Sternula albifrons, Hydroprogne caspia, Megaceryle alcyon, Cecropis daurica, Geokichla sibirica, Cyanistes caeruleus, Lophophanes cristatus, Periparus ater, Poecile montanus, P. palustris, Pastor roseus, Agropsar sturninus, Melospiza melodia); (3) two scientific names replace others presently on the list due to the recognition of extralimital taxa as species (Turdus eunomus, T. atrogularis); (4) one species is added because of a split from a species already on the Dutch List (Sylvia subalpina); (5) two species become monotypic due to the recognition of an extralimital taxon as species (Tarsiger cyanurus, Oenanthe pleschanka).