Emberiza Cirlus Research Articles

Countryside stewardship delivers cirl buntings ( Emberiza cirlus) in Devon, UK

Enhancement of farmland biodiversity is a key objective of agri-environment schemes in Europe, and conservation of the rare and threatened cirl bunting ( Emberiza cirlus) has been a key objective for the Countryside Stewardship Scheme (CSS) in south Devon, UK. Cirl bunting numbers increased by 83% on land entering CSS management agreements between 1992 and 1998, compared with an increase of just 2% on adjacent countryside not managed under CSS. The increase in cirl buntings on stewardship land was part of a wider regional increase in abundance rather than a redistribution of birds away from land not under stewardship. In 1998, 22% of all UK cirl buntings were breeding on land under CSS agreements and a further 16% of birds were within 0.5 km of land under stewardship. All but one of the 27 agreements that gained cirl buntings were within 2 km of cirl bunting breeding sites in 1992, with more distant agreements failing to be colonised even if they offered a range of potentially beneficial prescriptions. Agreements providing grass margins around arable fields, weedy winter stubbles and open patches of grassland next to scrub tended to gain additional cirl buntings. Grass margins and weedy winter stubbles constitute important food-rich habitats for cirl buntings and other farmland birds, and should be encouraged in future agri-environment agreements and schemes.

The status of the Cirl Bunting Emberiza cirlus in the UK and the Channel Islands in 1998

A survey of breeding Cirl Buntings in the United Kingdom and the Channel Islands was undertaken in 1998. An estimated 453 (95% CI, 415–504) territories were recorded in 103 tetrads in Devon. This amounts to an increase of 29% in the Devon population since the last full survey in 1993, when 352 territories were recorded in 95 tetrads. In addition, nine territories were located on the island of Jersey in 1998 although none were found elsewhere. In 1993 there were 18 singing males on Jersey with a further two in both Cornwall and Somerset. The Cirl Bunting population in Devon seems to be consolidating rather than expanding as the only significant increase in numbers between 1993 and 1998 was from those tetrads occupied in both years. This paper also summarizes the results of surveys during 1989–97 and assesses the changes in the Cirl Bunting population over that period.

Blood parasites, leucocytes and plumage brightness in the Cirl Bunting,Emberiza cirlus

1.Although a female preference for pairing with brightly plumaged males has been reported in many species, the reasons for this choice are not fully understood.2.Parasites have been proposed as playing an important role in shaping these preferences because, by pairing with brightly coloured individuals, females can obtain parasite‐free and/or more healthy mates.3.In this paper one of the predictions of this hypothesis is tested, namely a higher health level in brightly coloured individuals, by analysing the relationships among blood parasites, leucocyte levels and plumage brightness in the Cirl Bunting,Emberiza cirlus.4.Two species of blood parasites were detected. Whereas a lower body condition was detected in individuals infected byLeucocytozoon cambournaci,no such differences were associated withPlasmodium relictuminfections. Infected individuals showed higher total leucocyte counts than non‐infected individuals.5.Colour intensity of carotenoid derived colorations was negatively correlated to the relative proportion of lymphocytes and positively correlated to the relative presence of heterophils. Furthermore, the size of yellow feathered areas was positively correlated with the absolute number of leucocytes and the relative presence of heterophils. Only some of these relationships were found for non‐carotenoid derived traits.6.These results suggest that male plumage yellow coloration in the Cirl Bunting is a reliable indicator of health status and supports the hypothesis that females obtain more parasite‐free mates if they pair with brightly coloured individuals.

Agri‐environment schemes and their contribution to the conservation of biodiversity in England

SUMMARYAgri‐environment schemes were first launched in England in 1987. A number of schemes are now operated by the Ministry of Agriculture, Fisheries and Food that invite farmers and landowners to enter formal agreements to change their management practices in order to achieve a range of nature, landscape and archaeological conservation objectives. Agreements are based on payments to compensate for loss of income incurred by adopting less intensive, low‐input practices that offer potential benefits for biodiversity conservation within agricultural landscapes. The UK Government's response to the Convention on Biological Diversity has included producing a list of priority species and habitats for conservation action. Each of these has its own detailed action plan, including time‐limited targets. A significant proportion of these targets can at least in part be met through the agri‐environment schemes; the way this is being done is illustrated through examples of lowland heathland and a bird, the cirl bunting Emberiza cirlus. Linking of biodiversity and agri‐environment objectives is an important step towards achieving a more sustainable agriculture.

Seasonal variation in breeding performance and nestling diet of Cirl Buntings Emberiza cirlus in England

The survival rates and outcomes of Cirl Bunting nests were recorded over a four-year period. Significant annual variations in nest survival were found at both the egg and the young stage. Significant seasonal variations in survival rates were found, with late nests being over twice as likely to produce fledglings as early ones. Most losses occurred at the chick stage early in the season and were due to predation and starvation. Chicks in poor condition through food shortage may have been more likely to be predated as a result of increased begging activity. Late season chicks had a very different diet to those hatched early in the season, being fed a much higher proportion of Orthoptera. They also enjoyed higher growth rates and survival. Rainfall had a small detrimental effect on growth rates, probably as a result of insect prey becoming hard to find. Loss of arthropods due to intensification of livestock farming and loss of diversity in the agricultural landscape may have contributed to the decline of the species in the UK.

Population changes and breeding ecology of the Cirl BuntingEmberiza cirlusin eastern Spain

The number of Cirl Bunting Emberiza cirlus breeding pairs was recorded from 1976 to 1993 in orange plantations in eastern Spain, and some aspects of the breeding ecology of this species were studied from 1989 to 1993. Breeding densities varied from 0.6 to 10.1 pairs per 10 ha, being highest during the last 5 years. Breeding density each year was positively correlated with rainfall during the previous December–March period, but not to winter temperatures. The mean laying date was 17 April, and between-year variation was almost entirely determined (97% of the variation) by rainfall during December–March. The last clutches were laid by early July. Mean clutch size was 3.5 eggs. Clutch size increased during the first part of the season and then declined. About half of the nests were successful and half of the eggs laid produced fledglings. Predation accounted for most (35%) of the individual losses and was heavier early in the season. A logistic model was fitted to the weight data of the nestlings. Growth rate was 0.58 g day-1 g-1 and asymptotic weight was 15.6 g, which is about 65% of the adult weight. We suggest that the increase of the breeding population during the last years is related to the increase in winter rainfall, probably increasing food supply.

Isospora Normanlevinei N. Sp. and Isospora Coluzzii N. Sp. (Apicomplexa: Eimeriidae) In Emberiza Cirlus (Cirl Bunting) (Passeriformes‐Emberizidae)

ABSTRACT. The morphological characteristics of two new species of Isospora observed in Emberiza cirlus (Cirl Bunting) from Italy are reported. the oocysts of Isospora normanlevinei n. sp. are spherical or sub‐spherical, with a smooth double‐layered wall, and measure 24.2 times 23.7 (21.0‐26.5 times 21.5‐25.5) μm; each oocyst contains 2 to 10 polar granules. No micropyle or residuum was observed. the piriform sporocysts measure 19.4 times 11.2 (17.0‐21.0 times 10.0‐12.5) μm and contain a dispersed residuum. the Stieda body is flat; the substiedal body, with scattered clear and dark granules, may be either symmetrical or asymmetrical. the oocysts of I. coluzzii n. sp. are asymmetrical and rounded shape and measure 28.6 times 24.2 (25.0‐31.5 times 21.5‐26.0) μm. the oocyst has a double‐layered wall and 2 to 3 polar granules. Neither micropyle nor residuum is present. the sub‐ellipsoidal sporocyst, measuring 18.2 times 10.0(16.5‐20.0 times 9.0‐11.0) μm, has a dispersed sporocyst residuum. the Stieda complex is symmetrical.

Song syllable variation tolerance and motor theory of song perception: the territorial reaction of cirl bunting Emberiza cirlus to homologue syllables

The extent of syllable variation tolerance was tested using synthetic homologue syllables. A synthetic copy of a common syllable type of cirl bunting Emberiza cirlus song was used as control. Homologue syllables, in the same frequency range but shorter or longer, were created by multiplying (2/3, 5/3, 7/3) the time scale of the control syllable. By this way the specificity of homologue syllables inside (2/3) and outside (5/3 and 7/3) the syllable duration range (mean ± 2 SD) of the species were tested. Results do not support a hypothesis for syllable variation tolerance founded on motor perception theory. Processes free from production occur in syllable recognition.

Bird phonology and species recognition: minimal song units are cues inducing strong reactions in male cirl buntings (Emberiza cirlus)

Cirl bunting (Emberiza cirlus) songs consist of identical repetitions of the same syllable. A syllable is an arrangement of minimal acoustic units, which I call elements. A limited number of elements characterizes the different kinds of syllables found in the repertoires of individuals from different areas. The three most frequent element categories (a, b and c) represent 80% of all syllable elements. I demonstrate that minimal song units from these three categories are strong cues for species recognition because (1) songs composed of repetitions of only one of these elements (a or b or c) induced strong responses, while the repetition of a heterospecific element induced very weak responses; and (2) a song composed of the elements a, b, and c ordered at random without the usual syllable syntax induced the same reactions as a normal control song with the same elements ordered in a normal syntactical pattern. These results also demonstrated that while normal syntax is not required, normal variety appears to...

Diversité et spécificité des chants du Bruant zizi (Emberiza cirlus)

The diversity and specificity of the vocal repertoire of the Cirl bunting (Emberiza cirlus ) is studied, making use of 2180 song recordings of 89 individual birds from different parts of Europe. Cirl bunting songs are composed of the repetition of a single syllabe. On the average, each male repertoire is made of 2.4 song types (or syllabes). However, neighbouring conspecifics very often have different repertoires ; consequently, there is a great variety of syllabe types. Such a diversity is nevertheless limited, as syllabe types consist of a combination of smaller acoustic units, the elements, whose number is much smaller than that of the syllabes. Only five categories of elements can indeed be distinguished, and the species’ «phonology » is therefore limited. Two atypical songs were recorded in natural conditions. In the first case, the song syntax was atypical, whereas it was the shape of the elements, and the syllabe pattern, which were unusual in the second case — though the song of the latter bird was similar to that developped by a Cirl bunting reared in acoustic isolation. Acoustic imitation and social contacts between conspecifics can be considered as basic requirements f or the transmission of the specific song repertoire from one generation to the other in this species.

Assessing population trends of scarce birds using information in a county bird report and archive

Casual birdwatching results in the accumulation of large volumes of data in county archives, but it has received little systematic analysis. It could potentially be used to examine trends in populations of scarce birds not otherwise regularly censused. Population trends for 16 species are produced for the years 1943–1987 inclusive from data in the county bird reports and the data archive for Leicestershire, England. The species considered are buzzard, hen harrier, peregrine, hobby, quail, corncrake, barn owl, nightjar, lesser spotted woodpecker, stonechat, black redstart, nightingale, grasshopper warbler, wood warbler, hawfinch and cirl bunting. The trends are consistent with what is known elsewhere of population changes of these species. A cost-effective method of deriving a national index of population is presented for locally scarce species using records collected by birdwatchers at the county level. These indices could be invaluable in detecting trends to assist in conservation planning.

Reactions of cirl buntings (Emberiza cirlus) to playback of an atypical natural song: The use of own and neighbors' repertoires for song recognition.

Reactions of cirl buntings (Emberiza cirlus) to playback of an atypical natural song: The use of own and neighbors' repertoires for song recognition.

Reactions of cirl buntings (Emberiza cirlus) to playback of an atypical natural song: The use of own and neighbors' repertoires for song recognition.

Reactions of cirl buntings (Emberiza cirlus) to playback of an atypical natural song: The use of own and neighbors' repertoires for song recognition.

Cirl Buntings in Britain in 1982

This 7982 enquiry confirmed that the long-term Cirl Bunting decline is continuing, with the species becoming increasingly concentrated in Devon (78% of registrations). Possible reasons for the trend are discussed.