The roles of temperature, nest predators and information parasites for geographical variation in egg covering behaviour of tits (Paridae) (original) (raw)
Related papers
Journal of Ornithology, 2007
It has been suggested that a bird's clutch size is not limited by the amount of resources available at the time of laying but that differences in the availability of food for nestlings is the ultimate underlying factor determining spatio-temporal variations in clutch size. However, habitat-related variations in egg production ability has yet to be investigated explicitly. We studied the breeding of Great Tits Parus major in deciduous and coniferous forests in the same area. The sizes of both the clutches and the eggs were, on average, larger in the former habitat than in the latter. A number of females were induced to lay more eggs than usual by removing four eggs from designated experimental clutches early in the laying period. These manipulated females laid approximately one egg more than control females, with the number of additional eggs laid not differing between the habitats. However, in both study years the relative size of the extra eggsrelative to the mean size of earlier laid eggs of the same clutch -was smaller in the coniferous habitat than in the deciduous habitat, while there was no habitat-related difference in the relative size of the last-laid eggs of control clutches. This result indicates that some form of proximate limitation during egg-laying period can contribute to the relatively small clutches and eggs in the coniferous habitat. Our results emphasize the need to take egg production costs into account when attempting to account for spatial variation in the reproductive behaviour of birds.
International Journal of Zoology, 2011
Nest ectoparasites have been linked previously to patterns of nest-site choice and breeding success in birds. Recent research has shown nestboxes facing south-southwest are occupied less frequently by great tits (Parus major) than identical boxes facing other directions, and are associated with reduced offspring condition. Here, we investigate the hypothesis that these findings are due to ectoparasite load being directionally nonuniform, possibly because of nonuniformity in nestbox internal temperature. Nests contained, in order of prevalence, hen fleas (Ceratophyllus gallinae), haematophagous blowflies (Protocalliphoraspp.), biting lice (Ischnocera), and ticks/mites (Acari). Although southwest-facing nestboxes were significantly warmer than other boxes, there was no directional difference in total ectoparasite load or abundance of particular species. Similarly, there was no relationship between abundance of any ectoparasite species (either per-nest or per-chick) and avian offspring...
Standardized long-term multi-plot investigations of variation in nest size in free-ranging model species are rare, despite their value for understanding how the environment influences plastic traits such as nest size. Here, we report the results of an 18-yr descriptive study of nest size in first clutches produced by secondary-cavity nesting great tits (Parus major) and blue tits (Cyanistes caeruleus) in the Mediterranean, whilst also taking individual (lay-date, clutch size, age, species) and environmental characteristics (e.g. weather, oak habitat, region) into account. Nests of both species were built in relatively small standardized boxes erected in habitat patches that differed in the presence of the dominant oak species which was either summergreen deciduous or evergreen sclerophyllous. Nest size showed strong differences between species, and also in relation to environmental factors. Great tits built smaller nests than blue tits, Corsican birds had larger nests than mainland ones, nests tended to be larger in evergreen oak-habitat, and larger nests were built during drier weather. None of the individual-specific traits most often considered in long-term studies (lay-date, clutch size, and female age) were related to nest size in either species. Experimental approaches will be required to identify the underlying mechanisms that caused the observed phenotypic diversity for nest size in our study system.
Scientific Reports
In seasonal environments, a temporal decline in breeding performance (e.g. clutch size, nestling condition, and fledging success) of altricial bird species is a well-known phenomenon. In this study, we present the effect of laying phenology on the physiological condition of nestling great tits (Parus major) in 14 consecutive breeding seasons. We used blood haemoglobin and baseline glucose concentrations as indicators of nestling physiological condition. Nestling blood haemoglobin reflects food base quality and availability during the breeding period. Blood glucose concentration can be used as a supplementary reverse index of condition, since it is negatively related to environmental quality. It might be indicative of the stress caused by unfavourable extrinsic factors, though, due to potential confounding factors such as adverse weather conditions, low food quality, or feeding interruptions, glucose levels should be used in this ecological context with caution. Great tit nestlings from earlier broods were characterised by higher mean haemoglobin concentrations, indicating a seasonal decline in food quality and availability. the blood glucose concentration displayed an opposite pattern, with nestlings from earlier broods being characterised by lower mean concentrations than those from later broods. However, very little of the variation in blood glucose concentration can be explained by the variation in laying date, which suggests that blood glucose concentration is of little importance in the context of breeding phenology. our results show that the physiological condition of nestlings of this species decreases as the breeding season progresses, most probably due to environmental factors. Proper timing of breeding is crucial in highly seasonal environments at temperate latitudes, and is primarily determined by the prevailing weather and trophic conditions 1-3. Environmental factors influencing the onset of reproduction have been widely studied across various avian taxa 4-6. Breeding phenology is affected by selective pressures acting on different life history stages 7. In birds, photoperiodic cues together with the rise in temperature in spring appear to be key proximate factors activating breeding behaviour 8-11. The match-mismatch hypothesis suggests that the timing of breeding activity evolved to match the timing of maximum food demands of nestlings with the period of peak food availability, and fitness is lower for birds that breed both earlier and later than the seasonal food peak 12,13. However, in general, selection is thought to favour an earlier onset of reproduction, which might be beneficial for parents, enabling them to access rich food sources and proper feeding conditions for their nestlings; this is caused mainly by seasonally deteriorating external conditions, including predation or intra-and inter-specific competition 14,15. Early-breeders then benefit from access to rich food sources, which is particularly important for resident species in temperate zones, including the European tits Paridae, where there might be inter-and intra-specific competition for nesting sites and good-quality territories 16. Breeding early also allows parents to raise more than one clutch and produce more offspring per season 17,18. The seasonal decline in reproductive performance might be caused by variation in quality between early breeding high-quality birds and
Geographic variation in egg ejection rate by great tits across 2 continents
Behavioral Ecology, 2016
Hosts of brood parasites may vary geographically in their ability to resist parasitism. In contrast, geographic variation in defenses, such as egg rejection, is not expected to be present or vary geographically in unsuitable hosts. We examined spatial patterns of resistance in the great tit Parus major, a passerine that is a textbook example of an unsuitable host for brood parasites because of its hole-nesting habits. We experimentally tested for spatial variation in foreign egg rejection in 395 nests across latitudinal gradients in China (5 populations) and Europe (7 populations). In China, egg rejection rates were very high but showed a latitudinal gradient from 100% in the south to 52% in the north. In Europe, rejection rates were very low (on average only 4%) and did not vary latitudinally. The egg ejection rate patterns matched geographic patterns of parasitism risk with rejection probabilities decreasing with latitude (a surrogate measure of the diversity of brood parasites). The present study for the first time challenges the idea that hole-nesting birds did not evolve resistance mechanisms against brood parasites and highlights the importance of large-scale geographic comparisons in ecological research.
Journal of Avian Biology, 2021
Birds build nests primarily as a receptacle to lay their eggs in, but they can also provide secondary benefits including structural support, camouflage and adjustment of the microclimate surrounding the eggs and offspring. The factors underlying intraspecific variation in nest characteristics are poorly understood. In this study, we aim to identify the environmental factors that predict nest height variation and the duration of nest building in blue tits Cyanistes caeruleus, evaluating latitude, elevation, temperature and the timing of egg-laying as predictors of nest height, while also taking into account female and male parental identity. Using 713 nest height observations collected over a period of five years along a 220 km transect in Scotland, we found that if the annual mean timing of egg-laying was earlier, nests were taller. However, there was no correlation between nest height and elevation, latitude, the minimum temperature in the 14 days pre-egg-laying or the phenology of birds within a year. Female parental identity accounted for a large amount of variation in nest height, suggesting that individual behaviour has an influence on nest structure. We also found that nest building duration was shorter when egg laying occurred earlier in the year, and that across all observations taller nests took longer to build. Overall, our results show that blue tits are able to alter their nest characteristics based on environmental gradients like latitude (in the case of building duration) and the annual mean phenological variation of egg laying, and that birds build relatively taller nests faster.
2011
The breeding ecology of the Blue Tit (Cyanistes caeruleus) and Great Tit (Parus major) was studied for 18 years in three different neighbouring habitats in Sicily, comprising oakwoods, reforested pine and a reforested mix of pine and broad-leaved trees. Both Blue and Great Tits laid eggs up to two weeks earlier in oakwoods than in the reforested areas. Our results indicate a statistically greater breeding success for both species in the oakwoods compared to reforested habitats, with the mixed reforested habitat having a greater success than that of reforested pine habitat. We also correlated reproductive characteristics with local air temperature to verify if the laying date of tits advanced over a long period of years. Even though a variable egg-laying trend was recorded in the three habitats, an overall negative trendline was obtained indicating that the onset of nesting advanced through the 18-year study period. On the other hand, the air temperature trend was positive over the s...