Marsh Warbler Acrocephalus Palustris Research Articles

British Ornithologists' Union

The BOU is dependent upon a number of individuals whose contribution is scarcely visible, but without whom it would not be viable. Nigel Crocker is one such person, having served the Union in two key roles over many years: as Honorary Treasurer from 1984 to 2000, and subsequently as Chair of the trustees who look after the Union’s investments. Council is delighted to recognize Nigel’s 35-year contribution by the award of the Janet Kear Union Medal. Born in Devon, Nigel was brought up in Cornwall. His interest in birds was encouraged from an early age, both by a neighbour and his grandfather, who bought him his first pair of binoculars. At school he undertook a project on Barn Owls Tyto alba, exploring abandoned Cornish mine buildings to collect owl pellets, something that might not now be encouraged in an age of health and safety! After school, Nigel began a long career with the Trustee and Executorship department of National Westminster Bank, eventually reaching a senior management position. Like many bank employees he had to move around the country as he made his way up the bank hierarchy, with postings in Exeter, two spells in Gloucestershire, interrupted by a spell in Sussex where he met his wife Beryl. He eventually ended up working in Bristol and London, and they established the family home in Somerset near Chew Valley Lake and Blagdon Lake, where he and Beryl have lived for over 30 years Throughout, Nigel has contributed to ornithology in many capacities, notwithstanding the demands of career and family life. In Gloucestershire he undertook Marsh Warbler Acrocephalus palustris surveys for the Gloucestershire Trust for Nature Conservation (GTNC), was county wildfowl count organizer, RSPB and YOC group leader, and served on the Council of GTNC and the Gloucestershire Naturalists’ Society. In Sussex he ran birdwatching classes. He has participated in many BTO surveys and undertaken fieldwork for the Somerset Breeding Bird Atlas project. His particular interest is in waterbirds and waterside birds. Living in Somerset he has been able to witness close to home the colonization of Little Egretta garzetta, Great Ardea alba and Cattle Bubulcus ibis Egrets. Nigel joined the BOU at a time when membership applications were by nomination. One of Nigel's colleagues at National Westminster, Peter Wilkinson, was instrumental in Nigel's nomination, following Nigel's work on Marsh Warblers in the Severn Valley. It was Peter who persuaded Nigel to succeed him as Honorary Treasurer of the BOU in 1984. During Nigel's period as Treasurer, prudent action ensured that it was spared the effects of the Black Monday Stock Market crash in October 1987. In 1997, as Hon. Treasurer Nigel was part of the BOU's leadership team which was responsible for one of the most significant developments ever for the BOU; appointing a full-time administrator, Steve Dudley, when the then long-serving, part-time secretary, Gwen Bonham, chose to retire. The decision to invest more of the Union's resources in securing its long-term administration provided the platform on which all subsequent development and successes of the BOU have been founded. Nigel also served as the BOU’s representative on the UK Dependent Territories Conservation Forum. On his retirement as Hon. Treasurer in 2000, he kindly agreed to become one of the Union's investment trustees, and he has now served for over 20 years in this role. The Union is not alone in benefiting from Nigel's time and expertise. He has also served as a trustee of the Herbert Stevens Trust of the British Ornithologists’ Club and as Vice-chair of the Diocese of Bath and Wells and Chair of its Investment Committee. It is particularly appropriate that Nigel's service to the BOU is marked by the award of the Janet Kear Union Medal as Janet was one of the Presidents under whom Nigel served and they shared a lifelong association with waterbirds. Neil Bucknell

Energy crops affecting farmland birds in Central Europe: insights from a miscanthus-dominated landscape

The expansion of energy crops such as miscanthus Miscanthus x giganteus has changed the habitat of European farmland birds. However, most studies on the subject are based in Western Europe. We surveyed the avian community in a sample bioenergy landscape in Poland to investigate the pattern of use of the crop by birds in Central Europe. During a year-long survey, 80 species were noted, with 32 sighted in miscanthus. The number of bird sightings was negatively correlated with the area covered by miscanthus in study plots. In contrast to results from Western Europe, most woodland-generalist bird species tended to avoid miscanthus. Farmland species (e.g. the corn bunting Miliaria calandra; the tree sparrow Passer montanus; the starling Sturnus vulgaris; the yellowhammer Emberiza citrinella) were less frequently sighted in the crop than in other habitats. Only a few species were sighted more often in miscanthus than in other habitats, e.g. the marsh warbler Acrocephalus palustris; the reed bunting Emberiza schoeniclus; the whinchat Saxicola rubetra. The potential impact of expanded miscanthus cropping on bird communities in Central and Eastern Europe may diverge from predictions derived from studies based in Western Europe due to differing habitat preferences and bird densities between the regions. For a majority of farmland species, the crop may constitute only a suboptimal, supplementary habitat, with only a few birds potentially adapting to the exploitation of bioenergy plantations.

Breeding phenology, reproductive traits and apparent survival of sympatric Marsh Warbler Acrocephalus palustris and Blyth’s Reed Warbler Acrocephalus dumetorum

ABSTRACTCapsule: Sympatric Marsh Warblers Acrocephalus palustris and Blyth’s Reed Warblers Acrocephalus dumetorum differ significantly in their life history traits.Aims: To provide a direct comparison of demographic parameters among two sympatric populations of the closely related Marsh Warbler and Blyth’s Reed Warbler.Methods: We examined breeding phenology and reproductive traits at a 25 ha study plot. We use program MARK to estimate daily nest survival and adult apparent survival rates.Results: On average, Marsh Warblers laid the first eggs 3 days later than Blyth’s Reed Warblers. Mean clutch size in the Marsh Warbler was significantly lower than in the Blyth’s Reed Warbler. There are no significant differences between the two species for nest daily survival, duration of incubation and nestling periods. Apparent survival of adults was slightly higher in Marsh Warblers than in Blyth’s Reed Warblers.Conclusion: Our findings suggest that two ecologically similar sympatric species differ significantly in terms of life history traits. We assume that observed differences could be the result of adaptations to environmental factors in the central parts of the species’ ranges or due to differences in mortality on migratory pathways or wintering grounds.

Moulting and Wintering Grounds of Marsh WarblersAcrocephalus palustris: Evidence from Stable Isotopes and Ring Recoveries

Abstract. We analysed stable carbon (δ13C) and nitrogen (δ15N) isotope ratios in Marsh Warbler Acrocephalus palustris feathers sampled in Europe and Africa to assess non-breeding habitat selection and location of wintering grounds of different breeding populations. Feather δ13C values showed that Marsh Warblers occupy a biome dominated by C4 vegetation during the stopover in northeastern Africa, whereas C3 habitats are used during the complete moult in southern Africa. East European Marsh Warblers differed in their stable isotope profiles from other European regions, suggesting a certain level of population segregation in southern Africa. A dual-isotope assignment approach confirmed this difference and helped us restrict the autumn staging areas to lower elevations of the Ethiopian Highlands west of the Rift valley. Available ring recoveries, however, suggested high levels of population mixing both on migration through East Africa and in the final wintering grounds.

Mitochondrial phylogeography of the Eurasian Reed Warbler Acrocephalus scirpaceus and the first genetic record of A. s. fuscus in Central Europe

The phylogeography and evolutionary history of the long‐distance migratory Eurasian Reed Warbler Acrocephalus scirpaceus were analysed using sequence data from the mitochondrial DNA COI gene of 405 individuals and cyt b sequences from a subset of those individuals from 20 breeding, migrating and wintering populations over its wide geographical range. Median‐joining network and Bayesian phylogenetic analyses recovered three lineages corresponding to three subspecies of A. scirpaceus that started to diverge approximately 480 000 years ago: one spanning Asia (Acrocephalus scirpaceus fuscus), one encompassing Europe and Northern Africa (Acrocephalus scirpaceus scirpaceus) and a third that included Eastern Africa and Southwestern Asia (Acrocephalus scirpaceus avicenniae). Phylogenetic analyses suggest that the third clade is basal and diverged from its sister species, the African Reed Warbler Acrocephalus baeticatus, around 700 000 years ago. This earliest subspecies (avicenniae) may have survived the Last Glacial Maximum in one of the African refugia, probably the low forest refugium of the Ethiopian Highlands. Sequences of 348 samples from Germany, which were captured for ringing, showed that one bird was genetically assigned to the subspecies fuscus, the first genetic evidence of this Asian subspecies in Central Europe. According to our DNA sequences, 6.8% of Eurasian Reed Warblers were misidentified at the species level, Marsh Warbler Acrocephalus palustris accounting for most of these misidentified specimens. At the subspecies level, of 22 fuscus identified by genetic analyses, only six had been correctly named by the ringers.

Mitochondrial evidence for genetic diversity and low phylogeographic differentiation in the Marsh Warbler Acrocephalus palustris (Aves: Acrocephalidae)

We analyzed the levels of genetic variability in a long-distance migratory reed warbler, the Marsh Warbler Acrocephalus palustris, by using nucleotide sequences of the mitochondrial cytochrome c oxidase subunit I gene (COI; 611 nucleotides [nt]). We obtained sequences from 229 individuals from ten sampling sites that include breeding, wintering, and migrating birds. Overall, 44 haplotypes were detected, which reflect high levels of genetic variation in this species, but most of this variation corresponds to individual differences within collecting sites. We also analyzed 829 nt of cytochrome b (cyt b) from 49 selected individuals of different sampling sites to evaluate the reliability of the COI results. Our analyses based on both mtDNA loci could not detect any population subdivision or phylogeographic structure, indicating high levels of gene flow between breeding sites (Nm = 13.69). The split between the Marsh Warbler and its sister species, the Eurasian Reed Warbler Acrocephalus scirpaceus, could be dated for the Lower Pliocene (about 3.8 million years ago). The time to the most recent common ancestor (TMRCA) among Marsh Warbler haplotypes was estimated as 0.45 million years, indicating their bottleneck during the last glacial periods. Low nucleotide diversity, a shallow phylogenetic tree, a star-like haplotype network, and a unimodal mismatch distribution point to a sudden increase of the effective population size (probably after the last glaciation period) and a recent range expansion likely from a single refuge.

Interesting sightings from Sierra Leone, including the first Tawny Pipit Anthus campestris and the first evidence of Marsh Warbler Acrocephalus palustris for West Africa

Interesting sightings from Sierra Leone, including the first Tawny Pipit Anthus campestris and the first evidence of Marsh Warbler Acrocephalus palustris for West Africa

Are cuckoos maximizing egg mimicry by selecting host individuals with better matching egg phenotypes?

BackgroundAvian brood parasites and their hosts are involved in complex offence-defense coevolutionary arms races. The most common pair of reciprocal adaptations in these systems is egg discrimination by hosts and egg mimicry by parasites. As mimicry improves, more advanced host adaptations evolve such as decreased intra- and increased interclutch variation in egg appearance to facilitate detection of parasitic eggs. As interclutch variation increases, parasites able to choose hosts matching best their own egg phenotype should be selected, but this requires that parasites know their own egg phenotype and select host nests correspondingly.Methodology/Principal FindingsWe compared egg mimicry of common cuckoo Cuculus canorus eggs in naturally parasitized marsh warbler Acrocephalus palustris nests and their nearest unparasitized conspecific neighbors having similar laying dates and nest-site characteristics. Modeling of avian vision and image analyses revealed no evidence that cuckoos parasitize nests where their eggs better match the host eggs. Cuckoo eggs were as good mimics, in terms of background and spot color, background luminance, spotting pattern and egg size, of host eggs in the nests actually exploited as those in the neighboring unparasitized nests.Conclusions/SignificanceWe reviewed the evidence for brood parasites selecting better-matching host egg phenotypes from several relevant studies and argue that such selection probably cannot exist in host-parasite systems where host interclutch variation is continuous and overall low or moderate. To date there is also no evidence that parasites prefer certain egg phenotypes in systems where it should be most advantageous, i.e., when both hosts and parasites lay polymorphic eggs. Hence, the existence of an ability to select host nests to maximize mimicry by brood parasites appears unlikely, but this possibility should be further explored in cuckoo-host systems where the host has evolved discrete egg phenotypes.

Egg phenotype differentiation in sympatric cuckooCuculus canorusgentes

The brood parasitic common cuckoo Cuculus canorus consists of gentes, which typically parasitize only a single host species whose eggs they often mimic. Where multiple cuckoo gentes co-exist in sympatry, we may expect variable but generally poorer mimicry because of host switches or inter-gens gene flow via males if these also contribute to egg phenotypes. Here, we investigated egg trait differentiation and mimicry in three cuckoo gentes parasitizing great reed warblers Acrocephalus arundinaceus, marsh warblers Acrocephalus palustris and corn buntings Miliaria calandra breeding in close sympatry in partially overlapping habitat types. The three cuckoo gentes showed a remarkable degree of mimicry to their three host species in some but not all egg features, including egg size, a hitherto largely ignored feature of egg mimicry. Egg phenotype matching for both background and spot colours as well as for egg size has been maintained in close sympatry despite the possibility for gene flow.

The use of sympatric Reed Warblers <I>Acrocephalus scirpaceus</I> and Marsh Warblers <I>Acrocephalus palustris</I> as breeding hosts: parasitism rates and breeding success of Common Cuckoos <I>Cuculus canorus</I>

We investigated the level of parasitism, rejection rates and breeding success of the Common Cuckoo Cuculus canorus parasitising two sympatric species of Acrocephalus warblers breeding in western Poland. In both hosts the fre- quency of Cuckoo parasitism was fairly constant throughout the breeding season. The parasitism rate (defined as the proportion of nests parasitised by the Cuckoo) was significantly higher in Reed Warblers Acrocephalus scirpaceus (12%) than in Marsh Warblers Acrocephalus palustris (4.6%). The rejection rate in Reed Warblers (7.4%) was the lowest ever reported for this species, while Marsh Warblers rejected 57.1% of Cuckoo eggs. As a result, the hatching success of the Cuckoo in Reed Warbler nests was higher than in Marsh Warbler nests (74.1% and 28.6%, respectively). The fledging success of Cuckoo chicks in the nests of the two host species was similar. Nest survival was significantly lower in para- sitised nests than in non-parasitised ones. The breeding success of the Cuckoo (proportion of fledged young to the total number of eggs laid) was higher in the nests of Reed Warblers (29.6%) than in those of Marsh Warblers (7.1%), but the difference was not statistically significant. In 2001-2003 both host species were parasitised at a similar rate, but in 2004-2008 the level of parasitism dropped dramatically in Marsh Warblers. We discuss possible explanations for this phenomenon.

Identification of Blood Parasites in Old World Warbler Species from the Danube River Delta

Warbler species of the families Sylviidae and Acrocephalidae occurring in the Danube river delta are frequently exposed to blood-sucking arthropods that transmit avian blood parasites. We investigated infections by three genera of hemosporidian parasites in blood samples from six warbler species. Altogether in 17 (32.6%) of 52 blood samples, a PCR product was amplified. The great reed warbler (Acrocephalus arundinaceus) had the highest prevalence, with 63.6% (7/11) infected individuals, whereas no infection was detected in marsh warbler (Acrocephalus palustris). The most common parasite genus was Haemoproteus, which was found in 15.4% (8/52) of individuals. Seven known parasite lineages (five Haemoproteus and two Plasmodium) and two new lineages were recorded (one Leucocytozoon and one Plasmodium).

Migration speeds among eleven species of long‐distance migrating passerines across Europe, the desert and eastern Africa

Based on phenology, passage and median dates gathered from large number of study sites, we measured autumn and spring migration speeds of eleven long distance migratory passerines in four different ecogeographic sectors: Europe, desert, north‐eastern and eastern Africa. Results demonstrate that, during the southward autumn migration, late‐departing species, such as lesser whitethroat Sylvia curruca, garden warbler S. borin, spotted flycatcher Muscicapa striata, whitethroat S. borin, and willow warbler Phylloscopus trochilus cover their migration route with a slower average migration speed across Europe than do early migrating species. During spring migration, late‐departing species (marsh warbler Acrocephalus palustris, garden warbler, spotted flycatcher, red‐backed shrike Lanius collurio) across north‐eastern Africa showed a higher speed than early migrating species. Our results show overall shorter migration duration estimates in spring than autumn. Sector‐wise seasonal comparisons of duration indicate that migration journey in the African and desert sectors are covered in a relatively shorter time in spring than in autumn. Periods required to cover the distance between northern latitude breeding grounds and desert during both seasons were equivalent.

Fugler i Norge i 2006 - Rapport fra Norsk faunakomité for fugl (NFKF)

THE NORWEGIAN BIRD REPORT 2006 -  a report on locally uncommon and scarce birds in Norway in 2006, by the Norwegian Birds Records Committee (NFKF) The basis of this report is the annual reports produced by the county rarities committees. For 2006 all the counties on the mainland are represented in the report, although Finnmark, Troms, Sogn & Fjordane, Rogaland, Vest-Agder and Oppland counties did not publish own county reports. Svalbard archipelago and Jan Mayen did not contribute to this report. We believe this report reflects fairly well observations from Norway in 2006. Readers should take care to note the geographical or time delimitation of the records stated for the different species, as stated in codes immediately after the scientific name of the species. Letters in the tables stated in the beginning of the review of the different species should not be cited as real occurrences. The Norwegian Birds Records Committee (NFKF) has been publishing annual reports since 1991. The occurrence of Bewick’s Swan Cygnus columbianus was the poorest in NFKFs history, and the occurence of Lesser White-fronted Geese Anser erythropus at the traditional feeding and roosting site Valdakmyra, Porsanger (FI) continued to be very low. Bean Geese Anser fabalis had a record high occurrence while Bar-headed Geese Anser indicus had the third best occurrence since 1991. Record high numbers of Dark-bellied Brent Geese Branta bernicla bernicla were observed in southern parts of the Norway during the autumn. Gadwall Anas strepera have occurred in steadily increasing numbers in Norway in recent years, and 2006 was the third best year to date for this species. Garganey Anas quequedula occurred in record high number, while the occurrence of Smew Mergellus albellus was the second best since 1991. Quail Coturnix coturnix occurred in good numbers for the fifth year in succession. Yellow-billed Diver Gavia adamsii experienced the third best year since 1991. Many Rough-legged Buzzards Buteo lagopus were seen during the winter months. The Eurasian Hobby Falco subbuteo is a raptor that has occurred in high numbers in recent years, and 2006 was the best year ever. The occurrence of Corncrakes Crex crex wasthe poorest since 1998 and the occurrence of Avocets Recurvirostra avosetta was the second poorest since 1991. Jack Snipes Lymnocryptes minima were recorded in record high numbers during January to March and the number of spring migrating Great Snipes Gallinago media were record high. The occurrence of Little Gulls Larus minutus reached record high numbers while the occurrence of Sandwich Terns Sterna sandvicensis was very poor. In northern parts of its distribution range many Stock Doves Columba oenas were observed in 2006. Wood Larks Lullula arborea occurred in second best numbers since 1991. The negative trend relatedto migrating Horned Larks Eremophila alpestris was broken in 2006 and this year was the third best since 1991. Stonechats Saxicola torquata occurred in good numbers and eleven confirmed breeding pairs were recorded from the coastal areas of Sogn og Fjordane county. The number of singing Common Grasshopper Warblers Locustella naevia and Marsh Warblers Acrocephalus palustris was the third best since 1991. The occurrence of Yellow-browed Warblers Phylloscopus inornatus was the best ever recorded. The number of Golden Orioles Oriolus oriolus was very poor. The occurrence of Arctic Redpolls Carduelis hornemanni was the third best since 1991, and in late autumn a major influx of Pine Grosbeaks Pinicola enucleator took place in many parts of southern Norway. Many Lapland Buntings Calcarius lapponicus were observed during the winter months. The number of Ortolan Bunting Emberiza hortulana continued to drop and Rustic Bunting Emberiza rustica was observed in record low numbers.

Fugler i Norge 2003 – Rapport fras Norsk faunakomité for fugl (NFKF)

THE NORWEGIAN BIRD REPORT 2003 - a report on locally uncommon and scarce birds in Norway in 2003, by the Norwegian Bird Records Committee (NFKF) The basis of this report is the annual reports produced by the county rarities committees. All counties contributed to the report for 2003, although the Svalbard archipelago and Jan Mayen as well as Finnmark, Troms, Sogn & Fjordane and Vest-Agder counties did not publish own county reports. We believe this report reflects fairly well observations from Norway in 2003. Readers should take care to note the geographical or time delimitation of the records stated for the different species, as stated in codes immediately after the scientific name of the species. The Norwegian Bird Records Committee (NFKF) has published annual reports since 1991. The occurrence of Bewick’s Swan Cygnus columbianus was the best in NFKFs history, while the occurence of Lesser White-fronted Geese Anser erythropus at the traditional feeding and roosting site Valdakmyra, Porsanger (FI) continued to be low. One breeding pair of Pink-footed Goose Anser brachyrhynchus at Grindøya, Troms county was the first breeding attempt on the Norwegian mainland (excepting an attempt by a hybrid pair). Bar-headed Goose Anser indicus was seen in exceptionally good numbers. Gadwalls Anas strepera have occurred in steadily increasing numbers in Norway in recent years, and 2003 was the best year to date for this species. One breeding record of Smew Mergellus albellus from Vikna, Nord-Trøndelag county was the first breeding record in Norway outside Finnmark. The occurrence of Common Quail Coturnix coturnix and Corncrake Crex crex was the second best, while the occurrence of Spotted Crake Porzana porzana was the third best in NFKFs history. The Eurasian Hobby Falco subbuteo is a raptor that has occurred in high numbers in recent years, and 2003 was the best year ever. The occurrence of Avocets Recurvirostra avosetta and Black-tailed Godwits Limosa limosa was the best ever in NFKFs history, while the occurrence of migrating Broad-billed Sandpiper Limicola falcinellus was poor with only one individual during the autumn migration period. Migrating Pomarine Skuas Stercorarius pomarinus and Long-tailed Skuas Stercorarius longicaudus were seen in good numbers and the occurrence of Glaucous Gulls Larus hyperboreus was the best in NFKFs history. Also the occurrence of Little Gulls Larus minutus was very good, givingc the second best year ever. Turtle Doves Streptopelia turtur had a very good year during both spring and autumn, giving the best year in NFKFs history. The number of Hoopoes Upupa epops was the third best since 1991. The occurrences of Wood Larks Lullula arborea and Richard’s Pipits Anthus richardi was the third best, while the occurrence of Red-throated Pipits Anthus cervinus was very low. The number of Pied Wagtails Motacilla alba yarrellii, singing Grasshopper Warblers Locustella naevia, Yellow-browed Warblers Phylloscopus inornatus and Red-breasted Flycatchers Ficedula parva was the highest ever recorded, while Marsh Warbler Acrocephalus palustris, Barred Warblers Sylvia nisoria and Great Grey Shrikes Lanius excubitor experienced second best numbers since 1991. The number of Golden Oriole Oriolus oriolus was the lowest ever recorded in NFKFs history. Two-barred Crossbills Loxia leucoptera continued to occur in good numbers after the autumn 2002 influx, but very few individuals remained after the summer. The Hawfinch Coccothraustes coccothraustes still show a marked increase in the north of its distribution range, especially in the Trøndelag counties. The Ortolan Bunting Emberiza hortulana continued to occur in low numbers while the occurrence of Little Buntings Emberiza pusilla was the second best in NFKFs history.

Fugler i Norge 2004 – Rapport fra Norsk faunakomite for fugl (NFKF)

THE NORWEGIAN BIRD REPORT 2004 - a report on locally uncommon and scarce birds in Norway in 2004, by the Norwegian Birds Records Committee (NFKF)The basis of this report is the annual reports produced by the county rarities committees. For 2004 all the counties contributed to the report, although Finnmark, Troms, Sogn & Fjordane, Rogaland and Vest-Agder counties did not publish own county reports. We believe this report reflects fairly well observations from Norway in 2004. Readers should take care to note the geographical or time delimitation of the records stated for the different species, as stated in codes immediately after the scientific name of the species. The Norwegian Birds Records Committee (NFKF) has been publishing annual reports since 1991. The occurrence of Bewick’s Swan Cygnus columbianus was one of the poorest in NFKFs history, and the occurence of Lesser White-fronted Geese Anser erythropus at the traditional feeding and roosting site Valdakmyra, Porsanger (FI) continued to be very low. White-fronted Geese Anser albifrons was seen in good numbers. Mandarin Ducks Aix galericulata occurredin record high numbers. Gadwalls Anas strepera have occurred in steadily increasing numbers in Norway in recent years, and 2004 was the second best year to date for this species. Quails Coturnix coturnix occurred in good numbers for the third year in succession. Yellowbilled Divers Gavia adamsii experienced the second best year since 1991. Leach’s Storm Petrel Oceanodroma leucorhoa was seen in record high numbers in Rogaland in September. Many Common Kestrels Falco tinnunculus were seen during the winter months. The Eurasian Hobby Falco subbuteo is a raptor that has occurred in high numbers in recent years, and 2004 was the second best year ever. The occurrence of Avocets Recurvirostra avosetta was the best ever in NFKFs history. Several shorebirds, such as European Golden Plovers Pluvialis apricaria, Northern Lapwings Vanellus vanellus, Great Knots Calidris canutus, SanderlingsCalidris alba and Woodcocks Scolopax rusticola wintered in low numbers. The number of migrating Broad-billed Sandpipers Limicola falcinellus was the second best in NFKFs history. Migrating Pomarine Skuas Stercorarius pomarinus and Long-tailed Skuas Stercorarius longicaudus were seen in good numbers, and the occurrence of Little Gulls Larus minutus was the second best in NFKFs history. Compared to the last three years, Glaucous Gulls Larus hyperboreus occurred in considerable lower numbers in 2004. Also the occurrence of Snowy Owls Bubo scandiaca and Great Grey Owls Strix nebulosa were very poor. The negative trend related to migrating Horned Larks Eremophila alpestris continued in 2004, and the last five years represent the five poorest years for this species. The occurrence of Red-throated Pipits Anthus cervinus was one of the poorest in NFKFs history, while Yellow Wagtails Motacilla flava flavissima and Pied Wagtails Motacilla alba yarrellii occurredin near record numbers. Many breeding attempts of Waxwings Bombycilla garrulus were recorded, especially in Nordland county. Stonechats Saxicola torquata occurred in record high numbers, and nine confirmed breeding pairs were recorded. The number of singing Common Grasshopper Warblers Locustella naevia was the highest ever recorded, and the number of Marsh Warblers Acrocephalus palustris and Redbreasted Flycatchers Ficedula parva continued to be high. Many breeding attempts of Red-backed Shrikes Lanius collurio were recorded in Rogaland county, and Great Grey Shrikes Lanius excubitor had another good year throughout the country. The Eurasian Tree Sparrow Passer montanus still show a marked increase in the north of its distribution range, especially in Nord- Trøndelag county. In November, the southernmost parts of Norway experienced a major influx of Pine Grosbeaks Pinicola enucleator producing record numbers in the history of NFKF. In October, Norway also had a major influx of Bullfinches Pyrrhula pyrrhula. These Bullfinches probably came from other parts of Europe than Fennoscandia. The Ortolan Bunting Emberiza hortulana continued to occur in low numbers and the Rustic Bunting Emberiza rustica experienced the poorest year in NFKFs history. The occurrence of Little Buntings Emberiza pusilla was very good.

Fugler i Norge 2001 – Rapport fra Norsk faunakomité for fugl (NFKF)

THE NORWEGIAN BIRD REPORT 2001 - a report on locally uncommon and scarce birds in Norway in 2001, by the Norwegian Birds Records Committee (NFKF) The basis of this report is the annual reports produced by the county rarities committees. For 2001 all the counties contributed to the report, although the Svalbard archipelago and Jan Mayen as well as Finnmark, Troms and Sogn & Fjordane countiesdid not produce own county reports. With the exception of the northernmost counties the report thus reflects fairly well observations from Norway in 2001. Readers should take care to note the geographical or time delimitation of the records stated for the different species, as stated in codes immediately after the scientific name of the species. The Norwegian Birds Records Committee (NFKF) has been publishing annual reports since 1991. Bewick’s Swan Cygnus columbianus numbers were the lowest since 1991, and also the occurrence of Lesser White-fronted Geese Anser erythropus at the traditional feeding and roosting site Valdakmyra, Porsanger (FI) were particularly scarce this spring (lowest since 1993). However, this could partly be explained by early arrival at the breeding sites due to unusually early snow melting. Gadwalls Anas strepera have occurred in steadily increasing numbers in Norway in recent years, and 2001 was the best year to date for this species. The number of White-billed Divers Gavia adamsii was the highest reported since 1991. This species is probably a common winter guest from Nord-Trøndelag county and northwards. Manx Shearwaters Puffinus puffinus were also recorded in good numbers in 2001, the third best year since 1991. There was a further increase in numbers at the recently established colonies of Great Cormorant Phalacrocorax carbo of the subspecies sinensis at Øra (ØF), where the first confirmed breeding was in 1997. White-tailed Eagles Haliaeetus albicilla have steadily increased in numbers and also expanded their breeding distribution southwards. Breeding is now documented in both Rogaland and Vest-Agder counties and a further expansion is expected. The Osprey Pandion haliaetus is another species that is steadily expanding its range in Norway. Avocets Recurvirostra avosetta, however, is now very unusual, with only one individual in 2001, a record low number. Several shorebirds, such as Northern Lapwings Vanellus vanellus, Great Knots Calidris canutus, Sanderlings Calidris alba, Jack Snipes Lymnocryptes minimus, Woodcocks Scolopax rusticola and Bar-tailed Godwits Limosa lapponica wintered in higher numbers than usual in 2001, probably due to winter temperatures above normal. Pomarine Skuas Stercorarius pomarinus occurred in record numbers in 2001, and also Long-tailed Skuas Stercorarius longicaudus were recorded in good numbers on migration. Furthermore, numbers of Iceland Gulls Larus glaucoides recorded were the highest since 1991, while Turtle Doves Streptopelia turtur experienced another poor year. Good numbers of Snowy Owls Bubo scandiaca were still present in 2001 after the record setting year of 2000. Kingfishers Alcedo atthis also had a good year with one breeding attempt recorded. The number of Hoopoes Upupa epops was the second best since 1991. The occurrences of Richard’s Pipits Anthus richardi, Barred Warblers Sylvia nisoria and Marsh Warblers Acrocephalus palustris were the highest ever recorded, and Red-throated Pipits Anthus cervinus showed another good year, equalling the record numbers of 2000. Blackcaps Sylvia atricapilla wintered in record numbers. Stonechats Saxicola torquata, Red-breasted Flycatchers Ficedula parva, Great Grey Shrikes Lanius excubitor and Arctic Redpolls Carduelis hornemanni all experienced second best numbers since 1991. However, traditional winter invasion species such as Pine Grosbeaks Pinicola enucleator and Two-barred Crossbills Loxia leucoptera appeared in low numbers in 2001. The Hawfinch Coccothraustes coccothraustes still shows a marked increase in the north of its distribution, especially in the Trøndelag counties, while the situation is not as bright for Ortolan Buntings Emberiza hortulana, which continues to decline in numbers and now are in danger of becoming lost as a member of the Norwegian avifauna.

Stable isotope analyses of feathers help identify autumn stopover sites of three long‐distance migrants in northeastern Africa

The potential use of stable nitrogen (δ15N), carbon (δ13C) and hydrogen (δD) isotope ratios in feathers of marsh warblers Acrocephalus palustris, river warblers Locustella fluviatilis and whitethroats Sylvia communis was evaluated as a means to help identify the location and isotopic composition of autumn stopover sites in northeast Africa. Feather δD values were compared with regional precipitation δD maps averaged over autumn months. Compared with whitethroats, feather δ15N, δ13C, and δD values of marsh warblers and river warblers suggest the two warblers occupy and grow their feathers in geographic locations with relatively mesic environments, and with higher proportions of C3 (vs. C4) plants. However, δ13C values of marsh and river warblers were distinct enough to indicate use of different foodwebs. From previous studies, it is evident that during autumn stopover, river warblers moult their primaries in Ethiopia. It is likely that marsh warblers, like river warblers, stay in Ethiopia and/or in neighbouring regions. Based on feather δD values and regional δD precipitation maps, this region should lie between southeast Sudan and southwest Ethiopia. However, without additional regional isotopic maps in Africa, more precise locations of the stopover sites remain unclear. The relatively enriched δ15N and δ13C values of whitethroat feathers compared with the two other species, reflect the fact that whitethroats moult in relatively drier environments and/or with a lower proportion of C3 vs. C4 plants.

Breeding success of common cuckoosCuculus canorusparasitising four sympatric species ofAcrocephaluswarblers

We investigated the level of parasitism, egg mimicry and breeding success of cuckoos parasitising four sympatric species ofAcrocephaluswarblers in southern Moravia, Czech Republic. The parasitism rate was highest in the marsh warblerAcrocephalus palustris(44.8%) followed by great reed warblerA. arundinaceus(33.8%), sedge warblerA. schoenobaenus(26.5%) and reed warblerA. scirpaceus(11.6%). Although the cuckoo eggs showed a high level of mimicry the eggs of the marsh warbler this host species rejected 72% of the cuckoo eggs, resulting in a cuckoo breeding success of only 4.3%. Cuckoo eggs laid in great reed warbler and reed warbler nests showed a similar hatching success, but the cuckoo chicks survived better in great reed warbler nests, resulting in a breeding success of 30.4%, as compared to 16.4% in nests of the reed warbler. The relationship between the level of parasitism, host rejection of cuckoo eggs, cuckoo chick survival and breeding success is discussed for the four host species.

Notch factor ‐ a technique for separating Marsh Warblers Acrocephalus palustris from Reed Warblers A. scirpaceus on spring migration

Using measurements which are regularly collected on Reed Acrocephalus scirpaceus and Marsh Warblers Acrocephalus palustris, a new method was tested which appears to give better separation than the currently available biometric techniques. The length of the notch on the inner web of the second primary is multiplied by the number of the primary whose tip it falls adjacent to (numbering ascendently) to calculate the ‘notch factor’. This factor successfully separated (on biometrics alone) 1,574 out of 1,577 birds trapped in the spring migration through Kuwait. Reed Warblers trapped represented individuals from both the scirpaceus and fuscus races.

The orientation system and migration pattern of long‐distance migrants: conflict between model predictions and observed patterns

The requirements of the orientation system of naïve long‐distance night migrants were analysed by comparing data on Barred Warbler Sylvia nisoria, Marsh Warbler Acrocephalus palustris and Spotted Flycatcher Muscicapa striata with data from a computer model of a clock‐and‐compass system. These species show, respectively, a rather restricted winter distribution in East Africa, migration through a very narrow corridor in East Africa, and rather widely distributed recoveries in the Mediterranean with more concentrated recoveries south of the Sahara. For all three species, to obtain the observed concentrations either a very high directional migratory concentration was needed in computer simulations to bring the birds successfully to their wintering areas or misorientating individuals would be subjected to a very high mortality. Neither the very high directional concentration nor the high mortality amongst misorientating individuals fit the empirical data sets. On the basis of the present study, the observed patterns seem difficult to explain by a simple clock‐and‐compass system only, and to account for the exceptionally precise migratory routes shown in this study it is proposed that first‐time migrants might be able to use landscape topography on a regional scale in combination with corrections of directional mistakes/wind displacements.