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J. K. Blakey - One of the best experts on this subject based on the ideXlab platform.

  • Evidence for cuckoldry in the Great Tit Parus Major
    Ibis, 2008
    Co-Authors: K. J. Norris, J. K. Blakey
    Abstract:

    We estimated the frequency of cuckoldry (the proportion of offspring resulting from extra-pair copulations) in Great Tits Parus Major using heritability estimates based on the resemblance of offspring tarsus-length to that of their parents. Our results suggest that cuckoldry occurs and may be relatively common in certain years.

  • Genetic evidence for extra-pair fertilizations in a monogamous passerine, the Great Tit Parus Major
    Ibis, 2008
    Co-Authors: J. K. Blakey
    Abstract:

    The incidence of extra-pair paternity in a Great Tit Parus Major population at Wytham Wood, Oxford, in 1985–1987 was determined using two polymorphic allozymes. In 831 nestlings from 94 broods, 27 genetic exclusions were detected in 25 (3%) nestlings from 16 broods. Seven (44%) of these broods contained offspring that excluded the putative male parent from being the genetic parent. The distribution of exclusion types indicated that excluded offspring were the result of fertilizations by extra-pair males and not of egg-dumping. The true frequency of extra-pair paternity was estimated as 14% of offspring. These results suggest a mixed reproductive strategy for males in which they breed mo-nogamously whilst simultaneously seeking extra-pair matings with females of other pairs.

  • Is variation in brood sex ratios adaptive in the great tit (Parus Major)
    Behavioral Ecology, 2000
    Co-Authors: Andrew N. Radford, J. K. Blakey
    Abstract:

    Life-history theory predicts skewed offspring sex ratios in a range of situations in which the costs and benefits of producing the two sexes differ. In recent years, many studies have demonstrated biased sex ratios in a variety of bird species. However, many of these investigations have been based on small sample sizes, on data from a single year, or both. Using a recently developed polymerase chain reaction-based molecular DNA technique, 912 great tit (Parus Major) nestlings from 118 broods in 5 different years were sexed. As found in a number of previous studies on the same species, there were significant predictors of offspring sex ratio in individual years. However, there were no consistent trends across years, and none of the measured variables significantly predicted sex ratio over all years combined. Furthermore, brood sex ratio of the population did not depart from the expected binomial distribution. Although there are theoretical advantages to manipulating the sex ratio in this and other species, the physiological mechanism by which it is achieved in birds remains obscure. We argue that data from several years are needed to confirm whether facultative sex ratio manipulation is a consistent breeding strategy used by birds. Key words: great tits, molecular sexing, Parus Major, sex ratios. [Behav Ecol 11:294–298 (2000)]

Jerzy Banbura - One of the best experts on this subject based on the ideXlab platform.

  • Subtle differences in breeding performance between Great Tits Parus Major and Afrocanarian Blue Tits Cyanistes teneriffae in the peripheral zone of the species geographic ranges in NE Algeria
    The European Zoological Journal, 2020
    Co-Authors: Ala-eddine Adamou, Miroslawa Banbura, Jerzy Banbura
    Abstract:

    Because of the geological history of North Africa, populations of Great Tits Parus Major existing in this region experienced less geographical isolation from populations of continental Europe than ...

  • Long-term variation in hemoglobin concentration in nestling great tits Parus Major.
    Comparative biochemistry and physiology. Part A Molecular & integrative physiology, 2015
    Co-Authors: Adam Kalinski, Miroslawa Banbura, Joanna Skwarska, Michal Glądalski, Piotr Zieliński, Marcin Markowski, Jarosław Wawrzyniak, Iwona Cyżewska, Jerzy Banbura
    Abstract:

    Abstract Several studies have previously proposed that blood hemoglobin concentration in nestling passerines is a reliable index of individual condition and nutritional state. In this paper we present results concerning variation in hemoglobin concentration in the blood of ca. 14-day-old nestling great tits Parus Major in central Poland in an 11-year-long period, 2003–2013, in two distinct habitat types: urban park and deciduous forest. The most important findings of the study were: (i) variation in hemoglobin concentration was consistent within broods, (ii) hemoglobin concentration of nestlings varied markedly across years, (iii) hemoglobin concentration was significantly higher in the forest study site which is richer in terms of food abundance during the short period of tits breeding season and (iv) high hemoglobin level was a predictor of nestling survival from hatching to fledging.

  • does the threat of european pine marten martes martes predation influence the height of nests built by blue tits cyanistes caeruleus and great tits Parus Major
    Avian Biology Research, 2014
    Co-Authors: Adam Kalinski, Jaroslaw Wawrzyniak, Miroslawa Banbura, Joanna Skwarska, Michal Glądalski, Piotr Zieliński, Jerzy Banbura
    Abstract:

    The Major aim of this study was to examine the influence of the European Pine Marten (Martes martes) predation on the heights of nests of Blue Tits (Cyanistes caeruleus) and Great Tits (Parus Major...

  • Body condition parameters of nestling Great Tits Parus Major in relation to experimental food supplementation
    Acta Ornithologica, 2011
    Co-Authors: Jerzy Banbura, Adam Kalinski, Miroslawa Banbura, Joanna Skwarska, Jerzy Nadolski, Marcin Markowski, M. Gladalski, Marek Michalski, Piotr Zieliński
    Abstract:

    Amount of food supplied to nestlings by their parents is considered to affect the development of nestling physiological condition. In this study we supplied parental Great Tits Parus Major with extra food, larvae of Tenebrio molitor, put into feeders close to nest-boxes, assuming that this should facilitate parental care and, as a consequence, nestling nutrition. The following nestling characteristics measured 13 days after hatching were analysed: body mass, haematocrit, blood concentrations of haemoglobin, glucose and triglycerides, heterophil-to-lymphocyte ratio (H/L), and patagium swelling after PHA injection. Nestlings from extra food broods were significantly heavier than control ones. They also had lower H/L, which indicated lower stress. No other variable was significantly affected by the experiment. Possibly, the rainy weather and non-restrictive natural trophic conditions during the experiment caused weakening of the net benefits from extra food.

  • Blood parameters as consistent predictors of nestling performance in great tits (Parus Major) in the wild.
    Comparative biochemistry and physiology. Part A Molecular & integrative physiology, 2005
    Co-Authors: Jerzy Nadolski, Adam Kalinski, Miroslawa Banbura, Joanna Skwarska, R. Śniegula, Jerzy Banbura
    Abstract:

    Fourteen blood profile variables were analysed in 12-day-old nestlings of great tits (Parus Major) in the wild. Except for plateletocrit and platelet distribution width, the traits showed a consistent pattern of variation, with significant intra-brood repeatabilities; they were shown to be significant predictors of nestling performance as measured by survival from hatching to fledging. It is concluded that all blood characteristics that show consistent within-brood variation may be useful as indicators of some aspects of nestling condition/health status in wild birds.

Marcel E. Visser - One of the best experts on this subject based on the ideXlab platform.

  • activity patterns during food provisioning are affected by artificial light in free living great tits Parus Major
    PLOS ONE, 2012
    Co-Authors: Mieke Titulaer, Kamiel Spoelstra, Cynthia Y M J G Lange, Marcel E. Visser
    Abstract:

    Artificial light may have severe ecological consequences but there is limited experimental work to assess these consequences. We carried out an experimental study on a wild population of great tits (Parus Major) to assess the impact of light pollution on daily activity patterns during the chick provisioning period. Pairs that were provided with a small light outside their nest box did not alter the onset, cessation or duration of their working day. There was however a clear effect of artificial light on the feeding rate in the second half of the nestling period: when provided with artificial light females increased their feeding rate when the nestlings were between 9 and 16 days old. Artificial light is hypothesised to have affected the perceived photoperiod of either the parents or the offspring which in turn led to increased parental care. This may have negative fitness consequences for the parents, and light pollution may thus create an ecological trap for breeding birds.

  • Spring phenology does not affect timing of reproduction in the great tit (Parus Major)
    Journal of Experimental Biology, 2011
    Co-Authors: Sonja V. Schaper, Carolina Rueda, Peter J. Sharp, Alistair Dawson, Marcel E. Visser
    Abstract:

    Many seasonal breeders adjust the timing of reproduction in response to year-to-year variations in supplementary environmental cues, amongst which ambient temperature is thought to be most influential. However, it is possible that for species such as the great tit (Parus Major L.), phenological cues from sprouting vegetation and the consequent abundance of invertebrate prey, although dependent on temperature, may provide supplementary environmental cues per se. This hypothesis was investigated in breeding pairs of great tits kept in outdoor aviaries. In spring, experimental pairs were provided with access to leafing birch branches and caterpillars as a visual food cue, while control pairs were provided with non-leafing branches. Observations were made on the onset of laying and on concentrations of plasma luteinizing hormone (LH) at regular intervals to monitor changes in reproductive function. The onset of egg laying was not advanced by the presence of leafing branches and caterpillars. LH concentrations increased during the course of the study, but phenological cues did not affect plasma LH levels in females and males. Early spring vegetation, such as the leafing of birch branches, and the appearance of caterpillar prey do not appear to play a significant role in fine-tuning the onset of egg laying in great tits

  • The costs of egg production and incubation in great tits (Parus Major)
    Proceedings. Biological sciences, 2001
    Co-Authors: Marcel E. Visser, C. M. Lessells
    Abstract:

    The costs of egg production and incubation may have a crucial effect on avian reproductive decisions, such as clutch size and the timing of reproduction. We carried out a brood-size enlargement experiment on the great tit (Parus Major), in which the birds had to lay and incubate extra eggs (full costs), only incubate extra eggs (free eggs) or did not pay any extra cost (free chicks) in obtaining a larger brood. We used female fitness (half the recruits produced plus female survival) as a fitness measure because it is the female which pays the costs of egg production and incubation, and because clutch size is under female control. Female fitness decreased with increasing costs (fitness of free chicks females is higher than that of free eggs females which is higher than that of full costs females). These fitness differences were due to differences in female survival rather than in the number of recruits produced. This is the first time that the costs of egg production and incubation have been estimated using such a complete fitness measure, including, as our measure does, the local survival to the following year of both the female and her offspring. Our results emphasize that reproductive decisions cannot be understood without taking egg production and incubation costs into account.

  • Great Tit Parus Major survival and the beech-crop cycle.
    Ardea, 2000
    Co-Authors: Albert C. Perdeck, Marcel E. Visser, J.h. Van Balen
    Abstract:

    The single most important environmental variable correlating with annual survival of both juvenile and adult Great Tits Parus Major is the beech crop index (BCI). This index is a measure for the amount of seeds of beeches present in the winter, and correlates with crop size of several other tree species. Two, not mutually exclusive, hypotheses exist to explain the correlation between BCI and annual survival. The first is that the amount of seeds directly affects survival (winter-food limitation hypothesis). To test this hypothesis we re-analysed a supplemental food experiment of Van Balen (1980), extended with three more years of previously unpublished data. We found that supplemental food increased survival of both juveniles and adults, mainly in low BCI years, confirming the winter-food limitation hypothesis. The second hypothesis states that winters with a high BCI are preceded by springs with high densities of caterpillars (the breeding-season food limitation hypothesis). Using data of three long term studies of Dutch Great Tit populations we show that this hypothesis does not hold because (1) high BCI winters are not preceded by springs with high caterpillar densities, (2) annual mean juvenile fledging mass increased with increasing caterpillar densities, but no effect on parental mass was found, and (3) the annual survival of juveniles was not affected by the annual mean fledging mass, nor was annual adult survival affected by their mean mass during chick rearing. Finally we show that, despite the fact that the level of BCI probably can be predicted at the time of the breeding season and that both juvenile and adult survival is affected by BCI, reproductive decisions (clutch size, laying date and percentage second broods) are not affected by the BCI levels in the following winter. [KEYWORDS: Parus Major; food limitation; food provisioning; population dynamics; survival Winter; population; food; fluctuations; density]

  • Warmer springs lead to mistimed reproduction in great tits (Parus Major)
    Proceedings of the Royal Society of London. Series B: Biological Sciences, 1998
    Co-Authors: Marcel E. Visser, Joost M. Tinbergen, A. J. Van Noordwijk, C. M. Lessells
    Abstract:

    In seasonal environments, the main selection pressure on the timing of reproduction (the ultimate factor) is synchrony between offspring requirements and food availability. However, reproduction is initiated much earlier than the time of maximum food requirement of the offspring. Individuals should therefore start reproduction in response to cues (the proximate factors), available in the environment of reproductive decision making, which predict the later environment of selection. With increasing spring temperatures over the past decades, vegetation phenology has advanced, with a concomitant advancement in the reproduction of some species at higher trophic levels. However, a mismatch between food abundance and offspring needs may occur if changes in the environment of decision making do not match those in the environment of selection. Date of egg laying in a great tit (Parus Major) population has not advanced over a 23-year period, but selection for early laying has intensified. We believe that this is the first documented case of an adaptive response being hampered because a changing abiotic factor affects the environment in which a reproductive decision is made differently from the environment in which selection occurs.

Caroline Isaksson - One of the best experts on this subject based on the ideXlab platform.

  • Urban environment shortens telomere length in nestling great tits, Parus Major
    Biology letters, 2016
    Co-Authors: Pablo Salmón, Johan Nilsson, Andreas Nord, Staffan Bensch, Caroline Isaksson
    Abstract:

    Urban environments are expanding rapidly, and with urbanization come both challenges and opportunities for wildlife. Challenges include combating the anthropogenic disturbances such as light, noise and air pollution and lower availability of natural food sources. The benefits are many, including the availability of anthropogenic food sources, breeding boxes and warmer temperatures. Thus, depending on the context, urbanization can have both positive and negative effects on fitness related traits. It is well known that early-life conditions can have lifelong implications on fitness; little is however known about development in urban environments. We reciprocally cross-fostered urban and rural nestling great tits (Parus Major L.) to study how growing up in an urban versus rural habitat affected telomere length (TL)-a suggested biomarker of longevity. We show, for the first time, that growing up in an urban environment significantly shortens TL, independently of natal origin (i.e. urban or rural). This implies that the urban environment imposes a challenge to developing birds, with potentially irreversible effects on lifespan.

  • Sexual, seasonal, and environmental variation in plasma carotenoids in great tits, Parus Major.
    Biological Journal of the Linnean Society, 2007
    Co-Authors: Caroline Isaksson, Maria Von Post, Staffan Andersson
    Abstract:

    In many birds, carotenoids have dual functions as irreversible plumage pigments and as physiologically essential vitamins and antioxidants. They must be obtained through the diet and may therefore be a limiting resource, a constraint that is likely to vary with factors such as sex, habitat, and time of year. In the present study, we investigated signs of carotenoid limitation in great tits, Parus Major, in relation to sex, season, year, and within an urban versus a rural habitat. The two main carotenoids, lutein and zeaxanthin, were analysed by high-performance liquid chromatography in the plasma and in the yellow carotenoid-based breast feathers. We found that plasma carotenoid concentrations were significantly influenced by sex, season, and year, but not by urban versus rural habitat. At moult, plasma concentration was positively correlated with feather pigmentation, independent of body condition and sex. During the breeding season, however, circulating carotenoid concentrations were negatively related to the feather pigmentation (i.e. from previous autumn moult). We suggest that great tits are carotenoid deprived before leaf emergence, and that carotenoid utilization and limitations are sex-specific, but that there are neither any obvious honesty-maintaining costs of pigmentation, nor any fitness consequences of the colour variation. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society, 2007, 92, 521–527.

  • carotenoid diet and nestling provisioning in urban and rural great tits Parus Major
    Journal of Avian Biology, 2007
    Co-Authors: Caroline Isaksson, Staffan Andersson
    Abstract:

    Considering the importance of dietary constraints for the widely held view of carotenoid pigmentation as an honest quality indicator, there is surprisingly little data on carotenoid availability in different natural diets or along environmental gradients. Here we investigate the carotenoid availability in the main diet of breeding great tits Parus Major, living in urban and rural environments with known differences in carotenoid pigmentation. Carotenoid availability for nestling great tits was investigated in two respects: (1) quantity and quality of diet (i.e., caterpillar abundance and their carotenoid concentration), and (2) parental feeding frequency. First, caterpillars were generally more abundant in the urban environment and the four common Lepidoptera (i.e., caterpillars) genera studied were also heavier here. Second, as determined by HPLC analysis of the caterpillar genera, carotenoid concentration was significantly lower in the urban caterpillars. Furthermore, all except one of the caterpillar genera had higher lutein/zeaxanthin ratio in urban areas, which is in accordance with earlier studies of carotenoid composition in great tit yolk. Third, parental feeding frequency was about twice as high to urban broods compared to rural broods. This result may simply reflect the higher caterpillar abundance (shorter search time) in the urban environment. Poor food quality (low carotenoid concentration) seems therefore to be compensated by quantity in the urban environment. As a consequence the carotenoid availability seems to be similar for nestlings in the two environments.

Tapio Eeva - One of the best experts on this subject based on the ideXlab platform.

  • Metal pollution does not bias offspring sex ratio in great tit (Parus Major)
    Environmental science and pollution research international, 2012
    Co-Authors: Tapio Eeva, Saila Sillanpää, Esa Lehikoinen
    Abstract:

    Purpose We measured offspring sex ratios in a resident insectivorous passerine bird, the Great tit Parus Major, to find out whether metal pollution around a Finnish copper smelter would bias sex ratios in this territorial forest bird species. Besides a direct effect of pollutants, we were interested in possible indirect effects of pollution-related resource limitation, i.e., changes in food quality and quantity, on sex ratio.

  • Breeding success and lutein availability in great tit (Parus Major)
    Acta Oecologica, 2009
    Co-Authors: Saila Sillanpää, Juha-pekka Salminen, Tapio Eeva
    Abstract:

    The relationship among temporal variation in the availability of carotenoid-rich food, tissue carotenoid levels and breeding success are poorly known. We studied how diet quality and quantity affect the carotenoid profile and fledging success of great tit (Parus Major) nestlings along a pollution gradient. We found declining seasonal trend in lutein concentration of caterpillars, which may be the explanation for the declining trend in nestlings' lutein concentration of plasma with season, despite the increase in caterpillar biomass. This may be because the biomass of most lutein-rich caterpillars (autumnal moths) decreased and less lutein-rich caterpillars (sawflies) increased during the breeding season. The temporal difference in occurrence of different caterpillar species means that peak lutein availability does not coincide with peak caterpillar abundance. However the positive association between total larval biomass and the number of great tit fledglings may suggest that fledging success depends more on total caterpillar availability than on lutein concentration of caterpillars.

  • Local survival rates of the pied flycatchers (Ficedula hypoleuca) and the great tits (Parus Major) in an air pollution gradient
    Écoscience, 1998
    Co-Authors: Tapio Eeva, Esa Lehikoinen
    Abstract:

    We studied the local survival of pied flycatcher (Ficedula hypoleuca) and great tit (Parus Major) females under heavy air pollution stress. Females were trapped from three distance zones around a c...