Bearded Tit Panurus Biarmicus Research Articles

A nest-box and colour-ringing study of Bearded Tits Panurus biarmicus at Leighton Moss, Lancashire

Since 1997, Bearded Tits Panurus biarmicus have successfully nested in reed nest boxes positioned in reed Phragmites australis growing in standing water at Leighton Moss RSPB Reserve. Before nest boxes were installed, the bulk of the breeding population nested in dry reed areas but the provision of nest boxes resulted in a shift to the wetter areas of reed. Nest boxes were used mainly for early nesting attempts, with the birds moving to natural sites as cover increased for later broods. In the 18 years of the study 309 nests were monitored of which 48.5% successfully produced young. Some colour-ringed birds showed considerable movement between nesting attempts, with the average distance being 203 m. The time between fledging and the first egg of a second brood averaged 9.6 days. Pair fidelity was high, with two pairs breeding together for three years. The advantages of nest boxes included attracting pairs to nest in the area with the highest abundance of invertebrates, well above any flood level.

Morphometric and allozymic differences between Bearded Tit Panurus biarmicus (Aves: Passeriformes) subpopulations in a large wetland and a small pond in central Anatolia, Turkey

The Bearded Tit (Panurus biarmicus) is a small passerine bird occurring only in wetland habitats. Three subspecies of the Bearded Tit are known from Turkey. The endemic subspecies Panurus biarmicus kosswigi has only been recorded from Amik Lake in Turkey. This subspecies is now considered extinct; the apparent cause of this extinction was the drought affecting the lake. Other subpopulations might be similarly threatened by habitat loss. Therefore, it is important to investigate the morphometric characteristics and genetic variation of these local subpopulations. In this study, body weights and 12 morphometric characters were measured for Bearded Tit individuals in the Eber Lake and Behiçbey reedbed subpopulations. Statistically significant differences were found in extended wing length, maximum wing chord, and weight between the 2 subpopulations. Allozymic variation was also studied in the 2 subpopulations. Genetic variation was assessed using isozyme systems, and 8 of 21 loci (Pgm, Me-I, Me-II, Fum, Est, Mpi, Pgd, and Acon-M) were found to be polymorphic. The percentage of polymorphic loci was higher at Eber Lake (P_{95%} = 38.1%) than in the Behiçbey reedbed (P_{95%} = 33.3%). The mean F_{ST} (0.048) and Nm (5.0) values showed high levels of gene flow between these subpopulations.

Conspecific brood parasitism and anti-parasite strategies in relation to breeding density in female bearded tits

Within the animal kingdom conspecific brood parasitism (CBP) is particularly frequent in birds and parasitic individuals mainly save parental costs. Host counterstrategies and their efficiency may be influenced by environmental or socio-ecological factors like breeding density. Breeding density in particular may influence the opportunities for parasitism and the number of parasites. Here we examine the rate and efficiency of parasitism in relation to breeding density in socially monogamous bearded tits Panurus biarmicus. We differentiate between CBP attempts and realized CBP which means genetic representation of parasitic chicks in a brood and relate these to breeding density. Furthermore we investigate anti-parasite strategies of female bearded tits including egg ejection, nest abandonment and manipulation of egg position. Almost 40% of the females suffer from conspecific brood parasitism but there is significant increase with breeding density. Finally, only half of all egg dumping attempts have been successful, which implies high costs for parasites as well. Hence CBP is a 'make the best of a bad job' strategy rather than a strategy to increase reproductive success. Females desert their nests especially when clutch size is larger than normal. Egg ejection occurs less frequently and host females do not move parasitic eggs to less favourable incubation positions.

Changes in eye colour of juvenile Bearded Tits Panurus biarmicus and its use in determining breeding productivity

IbisVolume 149, Issue 2 p. 407-411 Changes in eye colour of juvenile Bearded Tits Panurus biarmicus and its use in determining breeding productivity JOHN WILSON, JOHN WILSON 40 Church Hill Avenue, Warton, Carnforth, Lancashire LA5 9NU, UKSearch for more papers by this authorIAN R. HARTLEY, Corresponding Author IAN R. HARTLEY Biological Sciences, Lancaster University, Lancaster LA1 4YQ, UK *Corresponding author. Email: i.hartley@lancaster.ac.ukSearch for more papers by this author JOHN WILSON, JOHN WILSON 40 Church Hill Avenue, Warton, Carnforth, Lancashire LA5 9NU, UKSearch for more papers by this authorIAN R. HARTLEY, Corresponding Author IAN R. HARTLEY Biological Sciences, Lancaster University, Lancaster LA1 4YQ, UK *Corresponding author. Email: i.hartley@lancaster.ac.ukSearch for more papers by this author First published: 22 January 2007 https://doi.org/10.1111/j.1474-919X.2006.00630.xCitations: 7Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume149, Issue2April 2007Pages 407-411 RelatedInformation

Impact of an exceptional winter flood on the population dynamics of bearded tits (Panurus biarmicus)

AbstractMark–recapture data are used to investigate the impact of an exceptional winter flood on the population dynamics of an isolated bearded tit Panurus biarmicus population in north‐west England. Adult numbers increased threefold (from 60 to 180 individuals) between 1992 and 2000, but declined by 94% during 2000/2001. This large reduction in numbers was caused by severe over‐winter mortality associated with a prolonged flood of the Phragmites litter layer, the main winter foraging habitat of bearded tits, followed immediately by cold weather. At the end of the flood, bearded tits were 20% lighter than during previous winters. Population changes in other years were accurately predicted by annual variation in recruitment, and there was evidence that recruitment was higher following the introduction of artificial nest boxes and was density dependent. This study highlights the potential threat to bearded tits in Europe of predicted increases in the frequency and extent of winter flooding, and the potential utility of measures like artificial nest boxes that aim to promote recruitment. Recent extensions of methodology now permit a detailed exploration of animal population dynamics from mark–recapture data alone.

A review of the European Harpirhynchidae (Acari, Prostigmata) with the description of a new species

AbstractRecords of the European Harpirhynchidae Dubinin, 1957 (Acari, Prostigmata) are summarized and briefly discussed. This family is represented in Europe by 23 species belonging to three subfamilies, Harpirhynchinae (18 species recorded), Harpypalpinae Fain, 1972 (4 species recorded), and Ophioptinae Southcott, 1956 (1 species recorded). A new species Harpirhynchus dusbabeki sp. nov. from the bearded tit Panurus biarmicus (L., 1758) (Passeriformes, Timaliidae) in Slovakia is described. This new species differs morphologically from the two similar congeneric species, H. nidulans Nitzsch, 1818 and H. galeridae Fain, Bochkov et Mironov, 1999, by having setae 3a and two setae on both genua I and II.

The effect of age and sex on wing morphology and body size of the Bearded Tit Panurus biarmicus in relation to complete moult

In sedentary birds, variation in wing morphology as a result of complete moult during the transition from juvenile to adult plumage is poorly understood. The aim of this study was to characterise sex‐ and age‐related differences in wing morphology resulting from a complete post‐juvenile moult in an isolated, sedentary population of the Bearded Tit Panurus biarmicus at El Hondo Natural Park reedbeds (SE Spain). Variation in wing morphology was evaluated by means of a Size‐Constrained Components Analysis (SCCA) of standardised primary lengths of 66 birds trapped for ringing. Wing traits representing size and shape showed differences among age and sex classes, adults having significantly greater wing sizes than juveniles and males less rounded or convex wings than females. Structural body size also varied significantly among sex classes, females being smaller than males. Sex‐ and age‐specific differences in wing morphology of these Bearded Tits may represent adaptations to the sedentary and colonial behaviour of the local population within constraints imposed by a reedbed microhabitat.

The importance of tail length for habitat use in the Bearded Tit Panurus biarmicus: an experimental study

The original function of the tail in birds is likely to be related to flight performance or bipedal locomotion. In this study, we examined the role of the long graduated tail of male Bearded Tits Panurus biarmicus, focusing on the function of the tail as a balancing organ when moving in reeds, the habitat in which this species spends its whole life. We performed an aviary experiment using males with shortened, elongated or control (unmanipulated) tails and recorded their use of different reed heights and preferences for different sitting postures. Tail manipulation did not change the use of different reed heights between treatments. The head‐up posture was the preferred sitting technique and was independent of tail length. We found that males with elongated tails showed less variation in the use of different sitting postures along the reed. In addition, the use of the ‘straddle’ sitting technique varied in relation to tail length, tending to be less frequent when tails were experimentally shortened. These results suggest that tail length influences how Bearded Tits move and may exploit their habitat. The role of the tail as a balancing organ when using small twigs or branches may have been underestimated.

Infestation by the mite Harpirhynchus nidulans in the Bearded Tit Panurus biarmicus

Capsule Mites sometimes induced voluminous subcutaneous cysts in featherless parts. Aims To describe the first reported infestation by the skin-dweller mite Harpirhynchus nidulans in Bearded Tits Panurus biarmicus and for the Timaliidae family, to detect possible fitness costs for the host and to determine the distribution of the parasite within the distribution range of the host. Methods Parasites were identified using a microscope. Wing-length and body mass were recorded on both uninfected and infected birds captured at different times during the year. We also considered historical data, and contact was made with 32 European ringing stations to identify the distribution range of the parasite. Results Subcutaneous reproduction of the mite Harpirhynchus nidulans induced the development of voluminous dermal nodules in Panurus biarmicus. There were no differences in body mass or wing-length with respect to infestation. In the south of France, prevalence changed from 10.6% in spring to 4.7% in autumn. Both sexes are equally parasitized. Occurrence of dermal cysts is reported from several southern European populations of Bearded Tits, whereas it seems to be absent from northern latitudes. Conclusion The occurrence of a Harpirhynchus mite in wild bird populations is reported for the first time. We consider aspects of its biology, host–parasite system, host-specificity, co-adaptation of the mite reproductive cycle to the social dynamics of its host and metapopulational host–parasite dynamics.

Area Requirements Of Passerine Birds In The Reed Archipelago Of Lake Velence, Hungary

I studied the area requirement of reedbed breeding passerine birds on 109 reed islands in Lake Velence, Hungary, in the breeding seasons of 1993 and 1994. The size of the smallest occupied reed island for the observed 8 passerine bird species varied from 0.02 ha (Savi’s Warbler Locustella luscinioides) to 4.14 ha (Bluethroat Luscinia svecica). Three species occupied reed islands which were 8–18 times larger than their territory sizes (Sedge Warbler Acrocephalus schoenobaenus, Moustached Warbler A. melanopogon, and Bluethroat), three species occurred on reed islands 4–4.5 times larger than territory sizes (Great Reed Warbler A. arundinaceus, Reed Warbler A. scirpaceus, and Reed Bunting Emberiza schoeniclus), and two species occurred on islands half the size of their territory sizes in continuous reedbeds (Bearded Tit Panurus biarmicus, Savi’s Warbler). This may suggest that the latter two species can utilise groups of small patches within a territory. The incidence functions showed that the probability of occurrence of the Moustached Warbler and the Bluethroat was not 1 even on the largest reed islands (7–25.7 ha), while it was 1 for the other 6 species. The importance of landscape matrix type in determining minimum area requirements was demonstrated using data on the occurrence of bird species in reed marshes within an agricultural landscape in the Po Plain (Italy). In this landscape much larger minimum areas were found than at Lake Velence.

An alternative route to coloniality in the bearded tit: females pursue extra-pair fertilizations

We combine behavioral studies with DNA-fingerprinting of a population of bearded tits Panurus biarmicus and test the idea that the pursuit of extra-pair copulations by females acts as selective pressure that may contribute to the formation of colonies in this socially monogamous species. We show that the rate of extra-pair paternity in colonial breeding pairs is very high, whereas no extra-pair chicks were detected in solitary nests. We found no cases of extra-pair maternity and intraspecific brood parasitism in solitary nests, whereas it did occur in dense breeding situations. We further found no difference in die quality of males between colonial and solitary individuals. However, colonial females were of significantly higher quality in terms of body size and condition. We propose that high-quality females settle in colonies to increase their opportunities to adjust the choice of their social partner by obtaining extra-pair copulations. We suggest that colony formation enables high-quality females to incite male-male competition for extra-pair copulations and consequently secure extra-pair fertilizations by high-quality males and that high-density nesting is controlled by female bearded tits. Kty words: Aves, coloniality, extra-pair fertilization, F. Paradoxornithidae, female quality, nest site choice. [Behav Ecol 8:113-119 (1997)]

Age dependent variation in wing length of Bearded Tits Panurus biarmicus

I have studied the increase of wing length among Bearded Tits from their juvenile plumage to their autumn plumage. The increase is large, 8.5% for males and 7.3% for females. During 1992 I obtained data on several other feather measurements of these two plumages in order to find the ecological background of the increase in wing length. From juvenile plumage to autumn plumage tail length increased with 14–16%. There were also an increase in feather mass. The average mass of the innermost primary was 3.32 mg in juveniles and 4.10 mg in their autumn plumage. Indices of wing pointedness and aspect ratio show that adults grow a more pointed wing than juveniles. Different hypotheses to explain the age related increase in wing length are discussed. I argue that the shorter wings in juveniles is an evolutionary adaptation. The reason should be to bring down the time until fledging in order to reduce the risk of predation. I could find no data in favour of the alternative hypothesis, that starvation of nestlings reduces the growth rate of feathers. Moreover there might also be different wing length optima for juvenile and adult birds.

Geographical Variation and Distribution of the Bearded Tit Panurus Biarmicus (Linnaeus, 1758) (Aves)

The breeding distribution of the Bearded Tit Panurus biarmicus is not disjunct but continuous from western Europe to Manchuria (fig. 4).

Bearded TitsPanurus biarmicus in The Netherlands and England: comments on the hybridization theory

It is discussed whether the hybridization theory ofSpitzer (1973) with respect to the Bearded Tit populations of The Netherlands and England has been posed on accurate grounds.