Stable isotope ratios in winter‐grown feathers of Great Reed Warblers Acrocephalus arundinaceus,Clamorous Reed Warblers A. stentoreus and their hybrids in a sympatric breeding population in Kazakhstan

Analyses of the stable isotope composition of feathers can provide significant insight into the spatial structure of bird migration. We collected feathers from Great Reed Warblers Acrocephalus arundinaceus, Clamorous Reed Warblers A. stentoreus and a small sample of their hybrids in a sympatric breeding population in Kazakhstan to assess natural variation in stable isotope signatures and delineate wintering sites. The Great Reed Warbler is a long‐distance migrant that overwinters in sub‐Saharan Africa, whereas the Clamorous Reed Warbler performs a short‐distance migration to the Indian sub‐continent. Carbon (δ¹³C), nitrogen (δ¹⁵N) and deuterium (δD) isotope signatures were obtained from winter‐grown feathers of adult birds. There were highly significant differences in δD and less significant differences in δ¹³C between Great and Clamorous Reed Warblers. Thus, our results show that the stable isotope technique, and in particular the deuterium (δD) signal, resolves continental variation in winter distribution between these closely related Acrocephalus species with sympatric natal origin. The isotope signatures of hybrid Great × Clamorous Reed Warblers clustered with those of the Great Reed Warblers. Hence, a parsimonious suggestion is that the hybrids undergo moult in Afrotropical wintering grounds, as do the Great Reed Warblers. The observed δD values fell within the range of expected values based on available precipitation data collected at precipitation stations across the wintering continents of each species. However, the power to predict the winter origin of birds in our study system using these data was weak as the expected values ranged widely at this broad continental scale.     

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

Capsule: 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.     

The Genus Primula: Section Muscarioides

ABSTRACT

Background: Hybrid zones provide excellent opportunities for studying plant adaptation and speciation.

Aims: We tested whether two herbaceous species of Senecio, S. vernalis and S. glaucus, hybridise in the eastern Mediterranean region and form a hybrid zone across an aridity gradient in the Jordan Rift Valley.

Methods: Allozyme variation surveyed across both species was analysed by the programme STRUCTURE to assign individuals to genetic groups and determine levels of admixture. Populations in the Jordan Rift Valley were subsequently subjected to a cline analysis.

Results: STRUCTURE showed that interspecific hybrids were produced at low frequency along the Israeli coastal plain where S. glaucus is represented by ssp. glaucus. In contrast, hybrids were more commonly produced in central populations of the Jordan Rift Valley. Here, the two species form a hybrid zone with S. vernalis occurring in mesic sites to the north and S. glaucus (ssp. coronopifolius) in arid sites to the south. Cline analysis showed that the hybrid zone is centred towards the northern end of the Dead Sea, but the analysis failed to distinguish how it is maintained.

Conclusions: Future detailed genetic and ecological analysis of the Senecio hybrid zone should improve our understanding of plant adaptation and speciation across aridity gradients.     

Comparison of land cover and farming intensity-based models for mapping High Nature Value farmland in Cyprus

ABSTRACT

Capsule: Breeding bird survey data were used to compare biodiversity at sites defined as High Nature Value farmland (HNVf) under two different mapping models.

Aims: To examine whether farmland classified as HNVf was important for bird diversity and conservation of priority bird species in Cyprus, through comparison of two different HNVf maps. The HNV concept aims to define biodiversity-rich farmland and facilitate its protection and management. Heterogeneous, low-intensity cropping and grazing systems are important areas for biodiversity conservation in Europe and for birds in particular, but are threatened by abandonment and agricultural intensification. We compared two HNVf mapping systems, a simpler model based on land cover data (CLC map) and a more complex Cyprus Environment Department model (ED map) including layers relating to agricultural intensity.

Methods: Line transect bird surveys were carried out to compare bird diversity, abundance of farmland bird species of conservation priority and also of the endemic Cyprus Warbler Sylvia melanothorax, at sites classified as HNV or not.

Results: A greater diversity of breeding birds was found in sites classified as HNVf under combined ED and CLC maps. However, for the set of 12 priority bird species, neither HNV mapping approach encompassed their overall abundance, but a combined CLC and ED model did predict higher abundances of the Cyprus Warbler. Vineyard sites were found to be associated with high overall breeding bird diversity, but with low abundance of priority bird species.

Conclusion: We identified weaknesses in both mapping systems, with the ED model failing to capture all HNV grazing land and the CLC model defining some intensive farming systems as HNV. We conclude that the overlap between the two models best captures HNVf, but layers encompassing grazing land and priority habitats need to be added to better define HNVf in Cyprus and facilitate its protection and management.     

Song in two cryptic species: comparative analysis of Large-billed Reed Warblers Acrocephalus orinus and Blyth’s Reed Warblers Acrocephalus dumetorum

Capsule: Songs of Large-billed Reed Warblers Acrocephalus orinus and Blyth’s Reed Warblers Acrocephalus dumetorum differed in quantitative parameters. Blyth’s Reed Warbler used different modes of singing on breeding grounds and migration stopovers.

Aims: To compare the songs of two cryptic species of reed warblers. To compare Blyth’s Reed Warbler songs in different parts of the breeding range and on migration stopovers in central Asia. To investigate the status of Blyth’s Reed Warblers in central Asia.

Methods: We analysed song recordings of individual singing males and conducted field observations of singing behaviour at migration stopover and breeding sites. The status of Blyth’s Reed Warblers in central Asia was reviewed from the historical Russian literature and other sources.

Results: We found differences between six out of eight variables in songs of Large-billed and Blyth’s Reed Warblers on breeding sites. Blyth’s Reed Warbler songs recorded on migration stopovers showed differences in five variables from Large-billed Reed Warblers and in six variables from breeding Blyth’s Reed Warblers. On migration stopovers, Blyth’s Reed Warblers sang actively but did not stay more than 1–2 days. The evidence suggests that Blyth’s Reed Warbler does not breed in central Asia.

Conclusion: Songs of Large-billed and Blyth’s Reed Warblers could be distinguished by quantitative analysis. Blyth’s Reed Warblers used different modes of singing on breeding sites and migration stopovers. We believe vocalizations of Blyth’s Reed Warblers on migration to be plastic song.     

Signals of local adaptation across an environmental gradient among highly connected populations of the Dead Sea Sparrow Passer moabiticus in Israel

Populations found at the edge of a species range often have decreased genetic diversity, which together with high gene flow may reduce the ability of a species to adapt to local environmental conditions. The Dead Sea Sparrow Passer moabiticus occupies a disjointed range, where the Israeli populations are considered peripheral and fragmented. The species is also thought to have undergone a recent range expansion. We aimed to describe the genetic and morphological variation of the Israeli populations and to determine the extent of gene flow among them. We expected that because of the small latitudinal gradient across Israel and the recent range expansion of the species that Dead Sea Sparrow populations would show no significant morphological adaptation to local environmental conditions, and that considerable gene flow would be taking place among populations. Our findings indicate the existence of gene flow, suggesting high connectivity among populations, but recovered no support for a recent range expansion, possibly due to insufficient time since expansion for mutations to have accumulated. However, despite recurrent gene flow among populations, latitudinal variation in wing length (male and female) and body mass (male) was indicative of local adaptation across Israel, in accordance with Bergmann's rule.     

Ein Drossel- x Teichrohrs?nger-HybrideAcrocephalus arundinaceus xA. scirpaceus und der Nachweis seiner Elternschaft

Zusammenfassung Im Juni 1995 wurde im Fränkischen Weihergebiet ein mittelgroßer Rohrsänger gefangen, den wir nach seinen Merkmalen zunächst nicht bestimmen konnten. Er hielt ein Revier zwischen zwei Drosselrohrsängern und reagierte auf Gesang dieser Art. Mit Hilfe molekulargenetischer Methoden (PCR mit Mikrosatelliten-Primern) konnte der Vogel als ein Hybride zwischen Drossel- x Teichrohrsänger identifiziert werden. Eine Sequenzanalyse der mtDNA (Cytochrom b-Gen) belegt, daß die Mutter des Mischlings ein Drosselrohrsängerweibchen war. Körpermaße und Gefiedermerkmale des Hybriden waren intermediär. Der Vogel brachte Mischgesang: 37% der Strophen waren drosselrohrsängertypisch, 28% enthielten kurze Teichrohrsänger-Passagen, die übergangslos eingeschoben wurden; der Rest der Strophen wich unterschiedlich stark von Drosselrohrsängergesang ab. Der Hybride könnte entweder auf eine Mischbrut oder auf eine EPC zurückgehen. Die Elternarten unterscheiden sich u. a. in der Körpergröße (um den Faktor 2,7) und in ihren Paarungssystemen. Bei der Bestimmung problematischer Rohrsänger sollte stärker die Möglichkeit von Hybriden berücksichtigt werden.

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A Great Reed x Reed Warbler (Acrocephalus arundinaceus xA. scirpaceus) hybrid and its parentage

A medium sizedAcrocephalus Warbler which initially could not be identified was captured in Bavaria in June 1995. The bird held a territory between two Great Reed Warbler males and responded to playback of Great Reed Warbler song. Using PCR with microsatellite primers sequence the bird could be identified as a Great Reed x Reed Warbler hybrid (Fig. 1). Based on mt DNA sequence analysis the hybrid's mother was a Great Reed Warbler (Fig. 2). With respect to the hybridization process the main difference between the parental species occur in body size (Great Reed Warbler being 2.7 times larger than Reed Warbler) and mating systems. Whether the hybrid resulted from an extra-pair copulation or a mixed pairing is unknown. External morphology of the hybrid was intermediate between the parental species (Tab). The bird sang a mixed song incorporating both parent species' songs (predominantly Great Reed Warbler) as well as intermediate songs into its own (Fig. 3).

     

Structural heterogeneity of linear habitats positively affects Barred Warbler Sylvia nisoria,Common Whitethroat Sylvia communis and Lesser Whitethroat Sylvia curruca in farmland of Western Poland

Capsule Structural heterogeneity was the most important factor influencing the distribution of Barred Warbler Sylvia nisoria, Common Whitethroat S. communis and Lesser Whitethroat S. curruca in linear habitats in farmland of Western Poland.

Aims To investigate the occurrence of three species of Sylvia warblers in relation to the spatial structure of linear habitats in the agricultural landscape of Western Poland where, in contrast to Western Europe, field boundaries are not managed in terms of their size or spatial structure.

Methods In 2008, the distribution of breeding territories of Sylvia warblers in linear habitats was estimated in farmland of Western Poland. Redundancy detrended analysis was used to assess the relationship between bird abundance and seven linear habitat variables in ninety-four 150?m sections.

Results Sylvia warblers differed in habitat requirements, however heterogeneity affected their distribution to the greatest extent. In addition, Barred Warbler preferred high shrub volume and wider sections, whereas Common Whitethroat was attracted by brambles and nettles and Lesser Whitethroat favoured shrubs. All species avoided a high proportion of low vegetation.

Conclusion Structural heterogeneity resulted in highly preferred linear habitats for Sylvia warblers. Thus, maintaining or increasing structural heterogeneity of linear habitats may be a very effective tool for the conservation of farmland bird populations.     

Seed food preferences of granivorous farmland passerines

Capsule Large buntings prefer cereal grains whilst sparrows also take oily seeds.

Aims To determine seed food preferences of Tree Sparrow Passer montanus and Corn Bunting Emberiza calandra.

Methods Forty seed choice experiments were conducted at two sites over two winters. In each experiment, two seed types were provided and the number of visits made by birds to each type was recorded over a set period. At one site, Tree Sparrows were colour-ringed, allowing choices made by individual birds to be recorded. Data were also collected for House Sparrow Passer domesticus, Yellowhammer Emberiza citrinella and Reed Bunting E. schoeniclus.

Results All five species fed intensively on cereal grain, and wheat and oats were consistently preferred to barley. Sparrows and Reed Buntings also took maize, which was avoided by Corn Bunting and Yellowhammer. Tree Sparrow exhibited a broad diet, selecting cereal grain and oily seeds including sunflower and oilseed rape, but rye-grass seed was almost completely avoided.

Conclusion Cereal grain should be a key component of over-winter provision of seed for farmland passerines, especially when targeted at Corn Bunting and Yellowhammer. Oily seeds such as brassicas and sunflower will benefit species with more generalist diets, including Tree Sparrows.     

Interspecific song imitation by a Prairie Warbler

Song development in oscine songbirds relies on imitation of adult singers and thus leaves developing birds vulnerable to potentially costly errors caused by imitation of inappropriate models, such as the songs of other species. In May and June 2012, we recorded the songs of a bird that made such an error: a male Prairie Warbler (Setophaga discolor) in western Massachusetts that sang songs seemingly acquired by imitating the songs of a Field Sparrow (Spizella pusilla). Another song type in the bird's repertoire was a near‐normal Group A Prairie Warbler song, but the bird used this song in contexts normally reserved for Group B songs. Despite its abnormal singing behavior, the aberrant bird successfully defended a territory and attracted a mate that laid two clutches of eggs. Results of playbacks of the focal bird's heterospecific song suggested that neighboring conspecific males learned to associate the Field Sparrow‐like song with the focal male, and responded to the song as if it were a Prairie Warbler song. Our evidence suggests that the focal bird's aberrant singing evoked normal responses from potential mates and rivals. If such responses are widespread among songbirds, the general failure of heterospecific songs, once acquired, to spread through populations by cultural transmission is probably not attributable to a lack of recognition by conspecifics of the songs of heterospecific singers.     

Geographic variation in parasitism rates of two sympatric cuckoo hosts in China

Rates of brood parasitism vary extensively among host species and populations of a single host species. In this study, we documented and compared parasitism rates of two sympatric hosts, the Oriental Reed Warbler (Acrocephalus orientalis) and the Reed Parrotbill (Paradoxornis heudei), in three populations in China. We found that the Common Cuckoo (Cuculus canorus) is the only parasite using both the Oriental Reed Warbler and Reed Parrotbill as hosts, with a parasitism rate of 22.4%-34.3% and 0%-4.6%, respectively. The multiple parasitism rates were positively correlated with local parasitism rates across three geographic populations of Oriental Reed Warbler, which implies that higher pressure of parasitism lead to higher multiple parasitism rate. Furthermore, only one phenotype of cuckoo eggs was found in the nests of these two host species. Our results lead to two conclusions: (1) The Oriental Reed Warbler should be considered the major host of Common Cuckoo in our study sites; and (2) obligate parasitism on Oriental Reed Warbler by Common Cuckoo is specialized but flexible to some extent, i.e., using Reed Parrotbill as a secondary host. Further studies focusing on egg recognition and rejection behaviour of these two host species should be conducted to test our predictions.     

Avian brood parasitism in a Mediterranean region: hosts and habitat preferences of Common Cuckoos Cuculus canorus

Capsule Cuckoos in Italy support the ‘host preference’ hypothesis.

Aims To identify the species parasitized in a Mediterranean area, in Italy; to quantify the frequency of parasitism on each host species; and to determine whether some species and/or habitat types are parasitized more than expected from a homogeneous distribution.

Methods Nest records dating from 1865 were compiled from literature, nest card programmes, and personal communication with ornithologists working in the region. Comparisons of parasitism frequencies were made among and within habitats for all cuckoo hosts.

Results The most frequently parasitized hosts were Great Reed Warbler, European Robin, Marsh Warbler, Redstart, and Reed Warbler. The highest number of parasitized species was in anthropic areas (15 host species), whereas wetlands supported the highest number of parasitized nests (471).

Conclusion Cuckoos select a different suite of hosts in Italy from those in continental Europe, but this was not always explained on the basis of different geographical distribution. Results support the ‘host preference’ hypothesis. We suggest further analyses to avoid over‐ or underestimates of parasitism on each host species when parasite preferences are examined.     

Nest defence,enemy recognition and nest inspection behaviour of experimentally parasitized Reed Warblers Acrocephalus scirpaceus

Capsule Reed Warblers in a regularly parasitized population do not recognize Cuckoo Cuculus canorus as a special enemy and do not change their behaviour at nest immediately after being parasitized.

Aims To assess if an intruder near the nest influences the behaviour of the Cuckoo host.

Methods Host responses to Cuckoo, control Pigeon dummies and human intruder were observed. Host behaviour at 71 nests was video-recorded for 30 minutes at four experimental groups of nests: Cuckoo dummy, Cuckoo dummy + Cuckoo egg, Pigeon dummy, human intruder.

Results Reed Warblers did not respond differently to the Cuckoo and the control species. The experimental procedure had no significant effect on the behaviour of hosts during the study period. We were unable to find any differences in the time spent at the nest, clutch inspection behaviour and nest defence behaviour between morning and afternoon experimental groups. Our results do not support the hypothesis that afternoon laying by the Cuckoo is maintained by a selection pressure from the host. We observed no ejection or egg-pecking during the 30-min period after the experimental parasitism.

Conclusions Low aggression and non-specificity of host responses in our study area are in line with the fact that the Reed Warbler is an intermediate rejecter of Cuckoo eggs as expected from the spatial habitat structure hypothesis.     

Habitat associations and communities of breeding birds in the highlands of south-west Jordan

Abstract

Habitat associations and communities of breeding birds were studied for the first time in a semi-arid region in the southern highlands of Jordan. Birds were censused and habitat variables estimated in different habitat types, ranging from steppe to open, Mediterranean-type woodland. The variation of abundance of several species was explained adequately with multiple regressions of up to five habitat variables. A distinct bird community was identified by using principal component analysis on the highland plateau (e.g. Short-toed Lark, Isabelline Wheatear), in steppe habitats modified by dry farming methods. The plateau was identified as a transition zone of Palaeoxeric/Turkestanian and Mediterranean faunal types. The remainding cluster included species of diverse origins (Palaearctic, Mediterranean, Saharo-Sindian, Afrotropical and others). It was subdivided into three bird assemblages with preferences for following habitat types: Mediterranean-type open woodlands (e.g. Syrian Serin), dwarf shrub formations of higher altitudes (e.g. Spectacled Warbler), dwarf shrub formations, including clearings and the edge of woodlands at lower altitudes (e.g. Scrub Warbler).     

Confirmation of Acrocephalus scirpaceus avicenniae (Aves: Acrocephalidae) from mangroves on the Red Sea coast near Jazan,southwest Saudi Arabia

Members of the Eurasian (or Common) Reed Warbler complex, Acrocephalus scirpaceus, are widespread across much of Europe, Africa, the Middle East and Central Asia. With its relatively complex taxonomy, the identity of several local (and sometimes remote) populations remains somewhat unresolved. In Saudi Arabia, populations of reed warblers were first identified in mangroves at Yanbu’ on the Red Sea coast in 1984, with several subsequent records up to 900 km further south toward the Yemen border. We took morphological data from 51 individuals and genetic material from three individuals captured near Jazan in southwest Saudi Arabia. Both genetic and morphometric data confirmed that these birds belong to the taxon A. scirpaceus avicenniae, sometimes referred to as the Mangrove or Red Sea Reed Warbler.     

Pellet contents of the Barn Owl,Tyto alba,near Samandag,Turkey

Summary

Weights and standard measurements are given of 568 individuals of 52 bird species ringed in various localities in Turkey in July and August 1973. The Melodious Warbler, Hippolais polyglotta, was recorded in Turkey for the first time.     

Habitat preference of endangered Eastern Iberian Reed Buntings Emberiza schoeniclus witherbyi

Capsule Careful management is required to maintain or create habitats with the correct proportions of rush with reeds that are preferred by this subspecies.

Aims To determine the habitat requirements of Eastern Iberian (Western Iberian Reed Buntings were not included in the study) Reed Buntings Emberiza schoeniclus witherbyi, a subspecies endemic to a few marshes in France, Spain and Morocco, with a population of 254–360 breeding pairs.

Methods Twenty-five wetlands in Spain were surveyed and presence/absence of Iberian Reed Buntings was deteremined together with data on 41 environmental variables. The relationships between the birds and habitat data were investigated using glm.

Results Proportion of rush with reeds, proportion of reed–bulrush patches and perimeter length of rush–reed patches, were the variables that primarily explained the present distribution of Eastern Iberian Reed Buntings. Other vegetation classes traditionally associated with the presence of the Eastern Iberian Reed Buntings, such as sedges, were not found to be important in the selected models.

Conclusion Conservation planning and management guidelines for this subspecies should focus on encouraging these specific-vegetation parameters. Flood control and grazing are proposed as the best practices that will favour these vegetation variables and avoid simplification of the plant community.     

Diversity and ecology of algae from the Lower Jordan River,Israel

Abstract

The Lower Jordan River stretches from the outlet of Lake Kinneret till the Dead Sea and is one of the most polluted rivers in Israel. In order to estimate the aquatic ecosystem of the northern part of the Lower Jordan River we used algal communities as biological indicators in the rainy and dry seasons of 2005 and 2007. We found 152 species of algae and cyanoprokaryotes from seven taxonomic divisions, which were mostly dominated by diatoms accompanied by the greens, blue‐greens and euglenoids. The xanthophycean species Heterococcus viridis, a red freshwater alga Audouinella hermannii, and a cyanobacterium Microcrocis marina were found for the first time in Israel. In the ecological analysis we revealed groups of freshwater algae according to pH, salinity, and saprobity as well as temperature, streaming and oxygenation. Quantitative information on the relationship between species and environmental variables was obtained using CCA analysis, emphasizing the major seasonal parameters. The extent of association of species with the environmental variables vector allowed us to determine the bio‐sensors and bio‐indicators, which may be relevant for monitoring of pollutants in the Lower Jordan River. The combination of bio‐indicational methods and statistics were effective in the determination of the main factors influencing algal diversity, as well as in revealing the indicators or bio‐sensing species for the most important environmental variables.     

The use and function of snake skins in the nests of Great Reed Warblers Acrocephalus arundinaceus

We documented and experimentally tested the use of snake skins in construction of nests in a Great Reed Warbler Acrocephalus arundinaceus population in southwestern Slovakia. There was no difference in predation rates of artificial nests that did or did not contain sloughs. We suggest that snake skins in Great Reed Warbler nests may serve as a post‐pairing signal revealing female parental quality.     

Mate guarding in the Linnet Carduelis cannabina

Capsule?House Sparrow (Passer domesticus) populations in south Swedish farmland are not affected by supplemental winter feeding, irrespective of agricultural landscape type or presence of animal husbandry, although winter populations declined more in mixed farmland and when farms contained animal husbandry.

Aims?To investigate whether food limitation of House Sparrow population size during the winter varied spatially in relation to agricultural landscape intensification and farm management.

Methods?We experimentally increased the winter food supply for populations on farmsteads in replicated landscapes that differed in agricultural intensification (open plains versus mixed farming) and/or farm management (crop farming versus animal husbandry), and estimated possible differences in effects on winter population change.

Results?We found no effect of supplementary winter feeding on changes in House Sparrow population sizes over the winter, irrespective of agricultural landscape type or presence of animal husbandry at the farm. However, we found a significantly larger winter population decline in mixed farmland and when farms contained animal husbandry.

Conclusions?The results suggest that House Sparrow populations in south Swedish farmland are not primarily limited by winter food availability. Alternatively, supplemental winter feeding may augment interspecific competition or attracts predators, offsetting any positive effect on population change. However, the stronger population decline in landscapes in which more breeding resources may be available (animal husbandry farms, mixed farmland), suggests stronger intraspecific competition during the winter in line with the resource separation hypothesis.