Jahreszeitliche Aspekte der Biologie der Bartmeise(Panurus biarmicus)

Phenotypic flexibility of structure and function of the digestive system of Japanese quail

“…It has also been shown that the gizzard of birds adjusts to changes in diet composition (Spitzer, 1972;Starck, 1999b;Dekinga et al, 2001). After switching the diet from soft to hard food, the gizzard doubled in size within 6 days in Japanese quail (Starck, 1999b) and within 6-8.5 days in red knots Calidris canutus (Dekinga et al, 2001).…”

A Survey of the Bearded TitPanurus biarmicusDuring the Non-Breeding Season in a Landscape of Western Poland

“…Some of them, temporary disappear while others colonize brand new areas (Wilson 1993, Strehlow 1997, Bertoli & Leo 1998. Climatic conditions during the non-breeding season are among the main factors affecting dynamic pattern of Bearded Tit distribution (Spitzer 1972). Although the species is sedentary in general, it shows a wide variety of wintering strategies; from short-distance migrations to staying in breeding areas over the whole winter (Dürr et al 1999).…”

“…Dürr et al (1999) found that 20% of the juveniles and 12.1% of the adults do not return to their natal and former breeding sites in spring. On the other hand, many Bearded Tits which stayed for a winter could die due to unfavorable weather conditions to which they are particularly vulnerable (Spitzer 1972). The decrease of mean flock size at the end of winter (Fig.…”

The Behavioural Ecology, Local Population Dynamics and Conservation of the Bearded Reedling <i>Panurus Biarmicus</i> in “El Hondo Natural Park” (SE Spain)

“…Bearded Reedlings were aged as juveniles according plumage features [84] and birds of longer age as immatures and/or adults in autumn according iris colour [21,85] and sexed by bill colouration before or during post-juvenile moult in summer and autumn following [84]. In the analysis of social structures, captures from March to October were assumed be in summer and from November to February as in winter, upcoming resemblances with the seasonal habitat distinction of this species [23] and also appropriate to the diet turnover of this species [26]. For the analyses of daytime activity of the flocks, morning sampling alone does not give an accurate estimate of relative abundance and age structure of reed passerines in mist-netting [86], so sampling included evening birds and all of them were grouped in morning-catches (7-10 hours GMT) and evening-catches (11-21 hours GMT).…”

“…The social behaviour indicates that the level of influence that males exert on social cohesion is not related to ornamental traits so Bearded Reedlings are likely to have a consistent social position within their flocks. Pioneer works on the behavioural ecology of the Bearded Reedling are based primarily in observations [21,24,[26][27]. However, few studies in wild using data inferred from mist-netting have been performed [28][29][30].…”