Tag: all of Parus

How great tits maintain synchronization of their hatch date with food supply in response to long-term variability in temperature

Great Tit (Parus major) Science Article 28 abstract Breeding birds increase their fitness by synchronizing their production of chicks with a peak of food abundance. Synchronization is primarily achieved by varying first egg date, but yearly temperature variations may delay or accelerate the food peak after the first egg has been laid. We tested the […]

Breeding territory size affects fiitness: an experimental study on competition at the individual level

Great Tit (Parus major) Science Article 11 abstract 1. Descriptive studies have shown that the annual mean fecundity and survival in bird populations decline as density increases. Experimental studies in which breeding density has been manipulated show that density causally a.ects reproduction in some but not other species. 2. In a 3-year study on great […]

Food, reproductive success and multiple breeding in the Great Tit Parus major.

Great Tit (Parus major) Science Article 23 abstract We studied the reproductive success of facultatively double brooded Great Tits Parus major in relation to (seasonal) variation in abundance of their main food supply: caterpillars in Oak Quercus robur. Data were collected in two mixed woods (Vlieland and Hoge Veluwe, from 1985-1996). The caterpillar food stock […]

Size and parental effort in the Great Tit Parus major.

Great Tit (Parus major) Science Article 19 abstract We experimentally reduced clutch size of Great Tits Parus major to investigate the effects on parental care (including Daily Energy Expenditure, DEE, measured with doubly labelled water). and the relationship between DEE and the residual reproductive value. The length of a working day was not affected. but […]

Information, predation risk and foraging decisions during mobbing in great tits Parus major

Great Tit (Parus major) Science Article 26 abstract Tomaximise survival during foraging animalsmust decide when and for how long foraging should be interrupted in order to avoid predators. Previous experiments have shown that birds that hear other individuals’alarm calls resume feeding later than those that see a flying predator.However, the responses of prey animals to […]

Maternal yolk testosterone does not modulate parasite susceptibility or immune function in great tit nestlings

Great Tit (Parus major) Science Article 31 abstract Maternal yolk hormones can enhance the development and phenotypic quality of nestling birds. Nevertheless, within species large differences in yolk androgen concentrations among clutches are observed. This differential allocation of maternal yolk hormones might be explained by a trade-off between beneficial effects of yolk androgens and their […]

Delays of the hatching dates in Great Tits Parus major: Effects on breeding performance

Great Tit (Parus major) Science Article 21 abstract The effects of delays of hatching date, caused by temporary interruptions or lengthening of breeding activities such as nest building, laying or incubation, on several fitness-related components were studied in a Great Tit Parus major population in eastern Spain. Hatching delays were relatively more frequent during an […]

Are unseen effects of early environment negligible? Threeexamples in great tits (Parus major)

Great Tit (Parus major) Science Article 9 abstract Three case studies failed to demonstrate impacts of early environment or maternal effects on breeding in situationswhere they could have been expected. This leads to a number of methodological questions about the resolving power requiredto detect such impacts, but above all else to the conclusion that maternal […]