Reed Bunting Emberiza Schoeniclus Research Articles

Three new species of the ectoparasitic mites of the genus Syringophiloidus Kethley, 1970 (Acari: Syringophilidae) from passeriform birds from Slovakia.

Three new quill mite species of the genus Syringophiloidus Kethley, 1970 (Acari: Syringophilidae) from Slovakia are described and figured: S. bombycillae sp. n. from the waxwing Bombycilla garrulus (L.) (Passeriformes: Bombycillidae), S. schoeniclus sp. n. from the reed bunting Emberiza schoeniclus L. (Passcriformes: Emberizidae) and S. montanus sp. n. from the tree sparrow Passer monlanus (L.) (Passeriformes: Ploceidae). A key to all known species of the genus Syringophiloidus is given.

Declines of ground-nesting birds in two areas of upland farmland in the south Pennines of England

CapsuleWe present evidence of large declines in numbers of breeding waders and passerines in some upland areas since the 1970s. Aims Changes in numbers of ground-nesting birds are documented for two areas of the Pennines and are qualitatively related to recent land-use history. Methods Territory mapping was used to estimate bird numbers on two areas (76 and 99 ha) in the Pennines for which more than 10 consecutive years of data were available from the BTO's Common Birds Census archives. Results At both sites there were large declines in Lapwing Vanellus vanellus, Snipe Gallinago gallinago, Skylark Alauda arvensis, Twite Carduelis flavirostris and Reed Bunting Emberiza schoeniclus. The two sites differed in the timing of the declines but for Twite the trends were almost identical. By the late 1990s, numbers of most ground-nesting birds were far lower than in the 1970s. There was relatively little change in numbers of species breeding at either site. Conclusions Progressive changes in land-use, involving loss of rough grassland and a switch from dairy to sheep farming, may have contributed to the declines at one of the sites. However, there was no obvious change in land-use or habitat loss at the other site where population declines began 5 to 10 years earlier. Such declines have probably occurred widely in moorland-edge areas during the last 30 years and multiple factors may be responsible.

The importance of arable habitat for farmland birds in grassland landscapes

Summary Over the last 25 years, populations of seed‐eating birds have declined severely over most of western Europe. Local extinctions have occurred in grassland‐dominated areas in western Britain, which may be influenced by loss in habitat diversity and a decline in the amount of arable cultivation. We used the large‐scale British Breeding Bird Survey of 1998 to investigate the importance of arable habitat within grassland landscapes for 11 common seed‐eating birds and four similar sized insectivores. Generalized linear models were used to model the number of birds recorded in agricultural habitat within survey squares as a function of the amount of arable habitat present. Numbers of grey partridge Perdix perdix, skylark Alauda arvensis, tree sparrow Passer montanus, corn Miliaria calandra and reed buntings Emberiza schoeniclus, yellowhammer Emberiza citrinella and whitethroat Sylvia communis increased with the amount of arable habitat present in a survey square; the numbers of house sparrow Passer domesticus, four finch species, dunnock Prunella modularis, robin Erithacus rubecula and blackcap Sylvia atricapilla did not. The positive association between numbers of some species and arable habitat within 1‐km squares was strongest where arable habitat was rare in the surrounding area, and weakest or even reversed when arable habitat was common. These results demonstrate the scale‐dependence of bird–habitat associations in agricultural landscapes, only demonstrable where data are available at fine grain over large geographical areas. These results support the hypothesis that range contractions (i.e. local extinctions) of some granivorous species have occurred because of contraction in arable cultivation. The loss of arable habitat where it is scarce may be causing declines in some areas, even though intensification of arable management is thought to be the main cause of declines elsewhere. Agri‐environment schemes may need to vary between regions, for example to encourage arable cultivation in pastoral areas.

Subspecies song discrimination in a Mediterranean population of the reed bunting Emberiza schoeniclus intermedia

Song represents one of the possible key factors influencing the interaction among songbird populations and can affect their evolution. We studied the effect of song differences between morphologically different subspecies of the reed bunting (Emberiza schoeniclus) on the territorial behaviour of males of the Mediterranean subspecies E. s. intermedia. Twenty males were presented with playback of different songs belonging to either their own or to the foreign subspecies, northern European E. s. schoeniclus, and their response behaviour was recorded. Both treatments elicited an aggressive approach to the loudspeaker, but the response to the foreign playback was slightly weaker. We conclude that the response of intermedia males seems close to that expected if the members of a demographically inferior subspecies need to defend resources from another, more abundant, subspecies. However, the hypothesis of song as an effective barrier between subspecies in territorial defence cannot be excluded.

Agricultural habitat-type and the breeding performance of granivorous farmland birds in Britain

Conservation concern about granivorous birds has led to the implication of changing agricultural practices as causes of widespread population decline. We investigate relationships between breeding performance and the agricultural environment for ten granivorous farmland bird species (Stock Dove Columba oenas, Skylark Alauda arvensis, Tree Sparrow Passer montanus, Chaffinch Fringilla coelebs, Greenfinch Carduelis chloris, Linnet C. cannabina, Bullfinch Pyrrhula pyrrhula, Reed Bunting Emberiza schoeniclus, Yellowhammer E. citrinella and Corn Bunting Miliaria calandra). We analyse long-term, extensive data from the British Trust for Ornithology's Nest Record Scheme on breeding performance per breeding attempt with respect to farmland type (arable, grazing or mixed) and time (pre- and post-1975–76). The influence of habitat is investigated at two different scales: within the nesting territory and at the landscape level. Relationships between farmland type and (temporal changes in) breeding performance tended to be species-specific, but a few patterns were each common to some species. Improvements in breeding performance occurred across all three farmland types for four declining species. Grazing farmland seems to have deteriorated as breeding habitat for Linnet and arable/mixed farmland for Reed Bunting. Mixed farming at the territory scale supported better breeding performance for four species, three of which (Bullfinch, Yellowhammer and Corn Bunting) have declined concurrently with mixed farming. Pastoral landscapes supported better breeding performance for up to seven species, six of which have undergone large declines. Arable landscapes supported better breeding only for the stable or increasing Chaffinch and Greenfinch. Different relationships between farming regime and breeding performance were found at the two scales considered.

Responses to playback of different subspecies songs in the Reed Bunting Emberiza schoeniclus

Populations of Reed Buntings Emberiza schoeniclus in the western Palearctic are classified in two major subspecies groups according to morphology: northern migratory schoeniclus and Mediterranean resident intermedia. Songs of the two groups differ mainly in complexity and syllable structure, with intermedia songs being more complex. We explored the possibilities of song as a subspecies isolating mechanism by testing if male schoeniclus Reed Buntings reacted differently to field playbacks of songs from their own subspecies group, from the foreign subspecies group and from a control species, the Yellowhammer Emberiza citrinella. We tested 30 different males, each with a different song belonging to one of the three categories: own, foreign and Yellowhammer. Unlike songs of the two subspecies groups, Yellowhammer song elicited no response. Differences between reactions to own and foreign subspecies group songs were not significant, even though differences in response type (singing vs approaching) suggested some degree of uncertainty in classification of foreign song. We conclude from these results that the subspecies may be only in the first stages of the isolation process.

Local extinctions and changes in species richness of lowland farmland birds in England and Wales in relation to recent changes in agricultural land-use

Changes in agricultural land-use may have been responsible for contractions in range that have occurred in a number of bird species over the past three decades. This was considered by examining spatial change in the ranges of 21 farmland bird species at the scale of 10 km squares in relation to spatial change in agricultural land-use variables between the late 1960s and the late 1980s in lowland England and Wales. Seven species showed range declines (local extinction) exceeding 5% over this period and analyses focused on these: Grey Partridge Perdix perdix, Lapwing Vanellus vanellus, Turtle Dove Streptopelia turtur, Yellow Wagtail Motacilla flava, Tree Sparrow Passer montanus, Corn Bunting Miliaria calandra and Reed Bunting Emberiza schoeniclus. Individual species loss and change in species richness tended to be related to variables with strong regional trends, reflecting greater losses in western 10 km squares characterized by pastoral agriculture. It is unlikely that many of the variables selected in the regression models are, in themselves, the causal factors behind changes in the ranges of species and changes in species richness. Lapwing was an exception, agricultural variables associated with grassland being consistently selected. Principal Components Analysis (PCA) was applied to the agricultural variables. This identified a major gradient of change in cropping patterns, involving large increases in areas of wheat Triticum spp. and oilseed rape Brassica napus at the expense of barley Hordeum spp., bare fallow and grass. Local extinctions and change in species richness were consistently related to the first PCA axis, showing that local extinctions have occurred most in those squares where there had been relatively little change in crop types. The greater rate of local extinctions in pastoral regions may be associated with a number of factors, including changes in the management of grass and livestock, edge of range effects (where species in less favoured habitats are more likely to become locally extinct) and source-sink effects. These results highlight the need for further research into the effects of agricultural management on birds in pastoral systems.

Wing moult duration for the Reed Bunting Emberiza schoeniclus at Kvismaren, central Sweden, with regard to data representativeness and weather influence

I have analysed 1,777 moult records of the Reed Buntings Emberiza schoeniclus, collected at Kvismaren, central Sweden, in 1973–1995. When evaluating moult with regression techniques it is important that the data are representative primarily with respect to the start and the end of the moult period. Otherwise a too short period is obtained. The mean moult duration was estimated to be 63 days, starting on 10 July. The females started to moult 6 days later and finished moult 3 days later than the males. Weather conditions significantly affected the moult performance. The variation in mean annual onset of moult ranged from 3 to 17 July. The temperature in April, May and to some extent also in July had a significant influence on the onset. Warm versus cold summers introduced a variation of only about 3 days in the duration of the moult but under extreme conditions (snow in spring and warm summer versus warm spring and cold summer) the variation between years in the mean duration of the moult was as much as 10 days.

Long‐term changes in over‐winter survival rates explain the decline of reed buntings Emberiza schoeniclus in Britain

Summary 1. The reed bunting Emberiza schoeniclus is one of a suite of granivorous farmland bird species that suffered a major population decline in Britain during the late 1970s and early 1980s. Extensive monitoring data indicate a large increase in the abundance of reed buntings between 1963 and 1975, followed by a decline of 58% on farmland and 66% along linear waterways during the period 1975–83. Since 1983 numbers have remained relatively stable in both habitats. 2. During the population decline, breeding numbers declined rapidly on arable and mixed farms, but remained relatively stable on pastoral farms. The decline on farmland was greater in northern Britain than in the south‐east. 3. Extensive nest recording indicated that breeding performance was higher during the period of population decline (2·74 young per nesting attempt) than during the preceding period of population increase (2·65) or the recent period of population stability (2·17). 4. Minimum survival during the first year of life (estimated from mark–recapture data) declined during the 1970s and early 1980s, and increased strongly during the 1990s. The trend in first‐year survival was independent of a weak positive relationship with winter temperature. Although there was evidence of a similar temporal trend in adult survival, this disappeared when winter temperature was taken into account. 5. A demographic model indicated that the timing and magnitude of the observed changes in first‐year survival and adult survival were each sufficient alone to account for the observed changes in the abundance of reed buntings during the period 1969–87. A reduction in over‐winter survival was probably the main demographic cause of the reed bunting population decline, although loss of breeding habitat and a recent reduction in breeding performance may also have influenced numbers. 6. During winter reed buntings feed mainly on small grass and weed seeds. The observed declines in abundance and survival rates coincide with the widespread introduction of a range of efficient herbicides and the loss of winter stubbles from British farmland. Our findings are therefore consistent with the hypothesis that the decline of the British reed bunting population was caused primarily by a reduction in food availability outside the breeding season. Changes in agricultural practices that increase the abundance of small weed and grass seed on farmland during winter are likely to allow at least a partial recovery of the British reed bunting population.

Differences in wing shape between sedentary and migratory Reed Buntings Emberiza schoeniclus

In several species wing shape varies with migratory habit, population, age and/or sex. Several wing-shape indices are used in the literature, but until now no studies have applied multivariate statistical techniques to avoid the problem of allometry at an intraspecific level between migratory and sedentary individuals. In this study we apply a new technique to determine wing-shape differences between two subspecies of Reed Bunting, one migratory and the other sedentary, inhabiting the same area in autumn. Our results showed that the migratory subspecies has larger, more convex wings than the sedentary one. Wing morphology was accurately correlated with migratory habit when corrected for size differences.

Genetic variation and bill size dimorphism in a passerine bird, the reed bunting Emberiza schoeniclus.

In passerine birds morphological differentiation in bill size within species is not commonly observed. Bill size is usually associated with a trophic niche, and strong differences in it may reflect the process of genetic differentiation and, possibly, speciation. We used both mitochondrial DNA (mtDNA) and nuclear microsatellites to study genetic variation between two subspecies of reed bunting, Emberiza schoeniclus schoeniclus and E.s. intermedia, along their distributional boundary in western Europe. These two subspecies are characterized by a high dimorphism in bill size and, although breeding populations of the two subspecies are found very close to each other in northern Italy, apparently no interbreeding occurs. The observed morphological pattern between the two subspecies may be maintained by geographically varying selective forces or, alternatively, may be the result of a long geographical separation followed by a secondary contact. MtDNA sequences of cytochrome b and ND5 (515 bp) showed little variation and did not discriminate between the two subspecies, indicating a divergence time of less than 500 000 years. The analysis of four microsatellite loci suggested a clear, although weak, degree of genetic differentiation in the large- and small-billed populations, as indicated by FST and RST values and genetic distances. The correlation between bill size and genetic distance between populations remained significant after accounting for the geographical distances between sampling localities. Altogether, these results indicate a very recent genetic differentiation between the two bill morphs and suggest that a strong selection for large bills in the southern part of the breeding range is probably involved in maintaining the geographical differentiation of this species.

Reproductive Anatomy of the Reed Bunting: A Species Which Exhibits a High Degree of Sperm Competition through Extra-Pair Copulations

The morphology of the reproductive organs of both male and female Reed Buntings (Emberiza schoeniclus) are described in relation to the high level of sperm competition exhibited by the species as a result of extra-pair copulation behavior. In males, the volume of the cloacal protuberance in relation to body weight was 26.7 mm 3 g -1 , which is relatively large for a socially monogamous passerine. The weight of the testes was 23% greater than that expected for a bird of comparable size, and the spermatozoa were among the longest recorded for any avian species (mean length = 291 μm). The morphology of the female tract also showed adaptations associated with a high level of sperm competition: the sperm storage tubules were extremely long (mean length = 865 μm).

Different singing styles in mated and unmated Reed Buntings Emberiza schoeniclus

Ewin described two singing styles, “rapid” and “slow”, in the Reed Bunting Emberiza schoeniclus. My research has demonstrated that the prevalence of song styles is related to male mating status. Songs of mated and unmated males differed in the interval structure, number of syllables per song, number of frequency modulations per syllable and number of introductory syllables. Since both singing styles are uttered at the same intensity, it is not likely that they are parts of a continuous range and it is justified to treat them as two different song categories. After losing their mate, males sang like unpaired males and therefore a learning effect can be excluded. Both singing styles were directed to females, the slow one probably only to the mate. The use of these singing styles as a means of territory or mate defence cannot be excluded, but, if so used, it would seem to be of minor significance.

Influence of Photoperiod Duration on Fecal Androgen Content in Migratory Reed Bunting Emberiza schoeniclus and Non-migra tory Meadow Bunting Emberiza cioides Males

Fecal androgen levels of migratory reed bunting Emberiza schoeniclus and non-migratory meadow bunting Emberiza cioides males were measured by radioimmunoassay after extraction with ether.When the photoperiod conditions were changed stepwise from 10 h light/14 h darkness (LD 10:14) to LD 15:9, in the migratory reed bunting the fecal androgen contents increased significantly at LD 12:12, and these relative high levels were maintained at LD 14:10.The photoperiod conditions resulting in high fecal androgen contents were similar to those resulting in nocturnal migratory restlessness.On the other hand, no significant change was observed in the non-migratory meadow bunting.The fecal androgen content would reflect the levels circulating in the plasma, as has been reported for the Japanese Quail.It has been suggested that androgen may be an endocrine regulator of vernal migration.Thus, androgen may be involved in the control of the vernal migration in the reed bunting.

Flycatching behaviour in some passerines during the late breeding season at Ammarnäs, Swedish Lapland

Many passerines have been recorded flycatching in the late breeding season in northern Swedish forests. In this paper, I analyze how flight energy costs according to Minimum Energy Power (sensu Pennycuick 1989) correlated with flycatching behaviour. Species included are (with increasing rank of flight energy cost): Spotted Flycatcher Muscicapa striata, Whinchat Saxicola rubetra, Yellow Wagtail Motacilla flava, Reed Bunting Emberiza schoeniclus, Brambling Fringilla montifringilla, and White Wagtail Motacilla alba. On average, birds performed 0.6–2.3 flights/30s and captured from 0 up to 10 prey per flight. Number of prey captured per flight varied significantly among species (from 0.8 to 1.1 prey). The efficiency of capturing prey (percentage of successful single capture flights) also varied between species, from 72% in the Whinchat to 97% in the White Wagtail. The percentage of multi-capture flights did not, however, vary. In two species, the multi-capture flights significantly reduced the time spent flying per prey. Flight energy costs were positively correlated with flycatching rate and number of prey captured per flight. The extensive use of flycatching is interpreted as an opportunistic response to local super-abundance of highly rewarding prey, mostly insects Isoperla grammatica, O. Plecoptera, during a period of presumed high energetic demands by birds.

Responses of Some Rare Cuckoo Hosts to Mimetic Model Cuckoo Eggs and to Foreign Conspecific Eggs

Reactions of Willow Warblers Phylloscopus trochilus, Reed Buntings Emberiza schoeniclus, Blackcaps Sylvia atricapilla and Bluethroats Luscinia svecica, towards mimetic model Cuckoo Cuculus canorus eggs were tested by exchanging one of their eggs for a model plastic egg. Reactions of Willow Warblers, Reed Buntings and Bluethroats towards a foreign conspecific egg were also tested. Some Willow Warblers were also tested with Great Tit Parus major eggs. The Willow Warblers, Reed Buntings and Blackcaps rejected mimetic model eggs at a high rate (90-100%), while the Bluethroats showed a lower (but not statistically significant) rejection rate (63%). The Willow Warblers and the Bluethroats accepted conspecific eggs, but the Reed Buntings rejected some of these eggs (3 of 8 trials). Great Tit eggs, which resemble Willow Warbler eggs in colour and pattern but are bigger (although considerably smaller than Cuckoo eggs), were rejected in 5 of 6 trials. The responses of the above species towards mimetic model eggs were similar to those previously reported for non-mimetic eggs. This behaviour pattern is important in providing an explanation for their present status as only rare hosts of the Cuckoo.

Cuckoo Host Interactions in Norwegian Mountain Areas

The host interactions of the European Cuckoo Cuculus canorus were studied in highland regions of Central Norway. Over a 12-year period, 17 potential host species were investigated for evidence of nest parasitism by the Cuckoo. Only three species were actually parasitized (Meadow Pipit Anthus pratensis, Reed Bunting Emberiza schoeniclus, and Lapland Bunting Calcarius lapponicus). These species have similar eggs and also had similar parasitism rates, viz. about 6% in the higher lying areas, and 25% (only Meadow Pipits) in the lower areas. This indicates that individual female Cuckoos have the opportunity to use several species as hosts, depending on the colour and shape of the host's eggs. Breeding success for the Cuckoo was 56%. Deserted host nests contained significantly more eggs than undeserted nests, a fact which may indicate that one mechanism for the host to detect parasitism is to assess the number of eggs. It is therefore important for the Cuckoo to remove at least one of the host eggs when laying its own, This study shows that a mean of 1.5 eggs were probably removed per parasitized host nest.

Severe Eggshell Defects and Impaired Reproductive Capacity in Small Passerines in Swedish Lapland

The breeding biology of the Pied Flycatcher Ficedula hypoleuca Pallas was studied, 1965-76, in a subalpine woodland on a mountain in the Ammarnas area, Swedish Lapland. In nestboxes placed near the shore of Lake Tjultrdsk, the reproductive capacity was significantly decreased as compared with that in nestboxes more distant from the lake. The eggshell quality, clutch size, hatching success, incubation, and the health of the breeding birds were highly impaired in the vicinity of the shore. It was shown that deficient breeding in the Pied flycatcher also occurred at another lake in the Ammarnas area, indicating that the breeding deficiencies were an expression of a general lake-effekt in the area. Similar impaired breeding was observed in three other small passerine birds species. Bluethroat Luscinia svecica L., Reed Bunting Emberiza schoeniclus (L.) and Willow Warbler Phylloscopus trochilus (L.) breeding near Lake Tjultrask. The symptomes indicate that the affected birds were poisoned.

Foraging-sites of Reed Bunting Emberiza schoeniclus and Ussurian Yellow-breasted Bunting E. aureola in the breeding season

1. This paper describes nesting- and foraging-sites of Reed Bunting E. schoeniclus and Ussurian Yellow-breasted Bunting E. aureola in the breeding season. Observations were made in the summer 1974 at Koshimizu in eastern Hokkaido. The area of study was about 11 ha.2. The vegetation-type of the study area was as follows: A; pached willows (1.2m average hight), B': fallen reed near waters, B: reed (average hight 1.8m), C: mixture of reed and other forbs (hight 0.6-1.4m), D: mugworts (hight 0.8-1.5m), E: low grass (average hight 0.4m), F: Alymus mollis grass (hight 0.5-0.8m), G: Rosa rugosa bush (hight 0.5-1.2m), H: Malus baccata bush (hight 1.8-3.0m), I: bareground and J: pasture.3. The arrival of E. schoeniclus at study area was two weeks earlier than thatof E. aureola, but the breeding started at almost the same date.4. The nesting-site of the two species were in or near B-type of vegetation (E. schoeniclus) and in the C-type (E. aureola), respectively.5. The spatial distribution of foraging sites E. schoeniclus tended to concentrate in B-type (dominant reed Phragmites), while E. aureola foraged extensively over the study area and relatively large portions of E-type of vegetation (low grasses).6. Both species foraged on the ground where therewere a lot of deadplant cover (E. schoeniclus 90.3%, E. aureola 94.5%). However, there was a great the difference between the vegetation types that both unilized for foraging was great. The extent of utilization of type B by E. schoeniclus was extremely great (59.50%), while the type E was used much less. In contrast, E. aureola frequented the foraging grounds to utilize B and C types to a similar extent.Foraging on plants were frequently seen (E. schoeniclus 9.7%, E. aureola 5.5%). E. schoeniclus alone foraged on Aand B types. This species showed a behavior of moving up and down on the stem of B-type plants, while such a movement was never recognized in case of E. aureola. The difference in the extent of utilization of B-type between E. schoeniclus and E. aureola might be attributed to thedifference of the foraging habit.