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Nest Box Use for Winter Roosting within a Flock of Tits

Typiak Jakub A., Typiak Marlena J., Mazgajski Tomasz D.

Polish Journal of Ecology

2019

Vol. 67, nr 2

148--158

Roosting in various shelters allows saving energy, especially in winter, thus hole nesting birds, like tits, search for places suitable to spend cold nights. Because the environment probably does not provide enough shelters for all birds from a winter flock to roost, a competition for best sites, as nest boxes, probably occurs. Therefore, the aim of this study was to describe the pattern of using the nest boxes by birds for roosting during three consecutive winter seasons and to determine the structure of a group of roosting birds in relation to the winter flock. Tits were captured and marked; daily controls of nest boxes were performed to find out which of them the tits used for roosting and subsequently, birds entering these boxes were caught at night. Great tits Parus major were the most abundant species roosting in the studied boxes with proportion of blue tits Cyanistes caeruleus differed between years. Young individuals prevailed among the birds roosting in nest boxes. However the age and sex structure of great tits roosting in nest boxes was similar to that observed in winter flocks, which was in contrast to earlier studies that found that the males and older individuals, high in the social hierarchy of the flock, will take over these boxes. The size of winter flock differs strongly among winters, thus it is possible that the level of competition for these roosting sites also varies between the years.

Variation in the Timing of Reproduction and Clutch Size of Afrocanarian Blue Tits Cyanistes teneriffae ultramarinus in the Saharan Atlas of Algeria

Adamou A.-L., Kouidri M., Bańbura A., Ouakid M. L., Chabi Y., Bańbura J.

Polish Journal of Ecology

2015

Vol. 63, nr 4

599--607

We examined the variation in the date of the onset of egg laying and clutch size in three peripheral populations of the Afrocanarian Blue Tits Cyanistes teneriffae ultramarinus at the edge of the species and subspecies geographic range. This study was carried out in three study sites, 130–290 km apart, in similar geographic conditions of the South Border Range of the Saharan Atlas in Algeria. Mean altitudes of nesting territories were between 1327 and 1437 m a.s.l. Habitats of the study sites were covered by the secondary, human-modified vegetation, ranging from a maquis shrubland, with the Holm oak Quercus ilex shrubs to woodlands dominated by the Atlas cedar Cedrus atlantica or by the Aleppo pine Pinus halepensis. 169 wooden nest-boxes were monitored for breeding parameters (laying dates and clutch sizes) during the breeding seasons 2007–2009 and 2011–2013. The timing of egg laying was relatively late for the latitude of the study sites, with overall mean laying dates varying between the study sites from 4 to 13 May. The laying date was influenced by the altitude of nesting sites, with the dates being delayed with increasing altitude. Overall mean clutch size differed between the study sites from 5.91 at Djelfa to 8.43 at Aflou. Clutch size tended to decrease with the advance of the breeding season. Because the study populations inhabit areas of similar physical conditions (climate and altitude), the main inter-population source of variation in the breeding parameters studied was probably variation in habitat quality.