Nest Weight and Female Health in the Blue Tit (Cyanistes Caeruleus) (original) (raw)
Related papers
Acta Ornithologica, 2013
Physiological functions of growing nestlings are thought to be traded-off in relation to rearing conditions, with the resulting physiological state of fledglings having important long-lasting consequences for their fitness. By manipulating brood size up and down, and, separately, by supplying additional food (mealworms -larvae of Tenebrio molitor) we tested if alterations of the rearing conditions would influence nestling performance in Blue Tits Cyanistes caeruleus and Great Tits Parus major. Brood size manipulation affected body mass, heterophil-to-lymphocyte ratio (H:L) and fledging probability in both species and the level of triglycerides in nestling Great Tits. Extra food supply influenced only fledging probability, with no other effect on indicators of nestling performance. An effect on nestling body mass and a lack of effect on cell-mediated immune response in the brood-size experiment suggest that nestlings in enlarged broods sacrificed growth to maintain immunity. In general, effects of both types of experiments were probably to some extent masked by specific character of the study site -an urban parkland with high human-induced disturbance.
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.
Royal Society open science, 2018
The potential for animals to respond to changing climates has sparked interest in intraspecific variation in avian nest structure since this may influence nest microclimate and protect eggs and offspring from inclement weather. However, there have been relatively few large-scale attempts to examine variation in nests or the determinates of individual variation in nest structure within populations. Using a set of mostly pre-registered analyses, we studied potential predictors of variation in the size of a large sample (803) of blue tit () nests across three breeding seasons at Wytham Woods, UK. While our pre-registered analyses found that individual females built very similar nests across years, there was no evidence in follow-up () analyses that their nest size correlated to that of their genetic mother or, in a cross-fostering experiment, to the nest where they were reared. In further pre-registered analyses, spatial environmental variability explained nest size variability at rela...
Experimental manipulation of Blue Tit nest height does not support the thermoregulation hypothesis
Ornis Fennica, 2017
Birds show immense variation in nest sizes within species. At least six different hypotheses have been forwarded to explain intraspecific variation in nest size in cavity nesting species, but very few of those hypotheses have been tested experimentally. In our study, when nestlings were 2 days old, we manipulated the height of 182 Blue Tit (Cyanistes caeruleus) nests to either 5 cm or 11 cm while standardising their ectoparasite load and genetic and maternal background. In line with the hypothesis that larger nests provide thermoregulatory benefits, we expected experimentally enlarged nests to show increased growth of nestlings compared to shallow nests, or to improve female somatic condition. We found that the nest height manipulation affected the tail length of 16-day old nestlings, but did not affect any other morphometric measure (tarsus length, body mass, head size and wing length). In addition, nest height manipulation had no impact on nestling survival and did not affect female body condition. Our results do not therefore provide strong support for the thermoregulatory hypothesis and suggest regional differences in the relationship between nest size and reproductive success.
Animal Behaviour, 2007
Research on the costs of nest reuse is central to understanding the population ecology and evolution of cavity-nesting birds. We explored the consequences of nest reuse by offering blue tits three types of nestboxes in which to breed: nestboxes with an old nest (O), empty nestboxes (E) and nestboxes with an old nest fumigated with insecticide (F). The experimental groups differed in ectoparasitism level: the O nestboxes had the most and the F nestboxes the fewest ectoparasites. Blue tits using nestboxes that contained old nests from the previous season paid a cost caused by the presence of nest ectoparasites: both reproductive success and female body mass at the end of the nestling period were reduced. Haematozoan infections in females also increased with the level of ectoparasitism. The costs of nest reuse would be reduced in areas and/or seasons with few ectoparasites, as shown by the results from the group with fumigated old nests.
International Journal for Parasitology: Parasites and Wildlife
Although different predictive models forecast that climate change will alter the distribution and incidence of parasitic diseases, few studies have investigated how microclimatic changes may affect host-parasite relationships. In this study, we experimentally increased the temperature inside nest boxes of the blue tit Cyanistes caeruleus during the nestling period at two different latitudes (central Spain and central Germany) to determine its effect on parasite abundance. The two localities have contrasting climate conditions: the southern one in Spain is warmer and drier than the northern one in Germany. Consistent with this, we observed that the parasitic fauna in nests at the two localities differs. The flea species Ceratophyllus gallinae was more abundant in the northern locality, while the blowfly species Protocalliphora azurea and biting midge species of the genus Culicoides were more abundant in the southern one, as were blood parasites. Moreover, dermanyssid mites and blackflies (Simuliidae) were observed only in the southern locality. The temperature inside nest boxes was increased using heat mats placed underneath the nest material during the nestling period (day 3 to day13 post-hatching). Compared with control nests, the average temperature in heated nests increased by 2.24 • C and 1.35 • C at night in Spain and Germany, respectively. Consequently, the average relative humidity in heated versus control nests decreased 4.93 and 0.82 units in Spain and Germany, respectively. The abundance of blowfly pupae in the heated nests was significantly lower than that of control nests at both localities. The abundance of larval fleas was also lower in the heated nests, but only at the Spanish locality. Infection by the blood parasites Haemoproteus/Plasmodium was higher in males attending the heated nests in Germany, and the control nests in Spain. Moreover, both male body mass and nestling wing length were negatively related to the abundance of larval fleas. In conclusion, our results indicate that increased temperature at the nestling stage may affect the fitness of blue tits by altering parasite prevalence rates.
Ibis, 2002
Bird nests are often heavily infested with several haematophagous ectoparasite species that drain energy and other essential resources needed for the development of the rapidly growing chicks. The nutritional requirements of altricial chicks can only be satisfied by the parents frequently bringing prey to the nest. In a 3-year study, we tested experimentally whether a parasite-induced change in the nutritional budgets of the chicks in an Algerian population of the Blue Tit, could be compensated by a response in parental food provisioning behaviour. We found that nestling body mass and size did not differ between heat-treated 'parasitefree' nests and heavily infested control nests. However, after controlling for potential confounding variables (laydate, clutch size, chick age, year), we found that broods of heavily infested control nests were more frequently visited and fed than broods that received antiparasite treatment. The results are discussed in the framework of theory related to behavioural responses of hosts to parasites.
Sex and environmental sensitivity in blue tit nestlings
Oecologia, 2005
In birds and mammals with sexual size dimorphism (SSD), the larger sex is typically more sensitive to adverse environmental conditions, such as food shortage, during ontogeny. However, some recent studies of altricial birds have found that the larger sex is less sensitive, apparently because large size renders an advantage in sibling competition. Still, this effect is not an inevitable outcome of sibling competition, because several studies of other species of altricial birds have found the traditional pattern. We investigated if the sexes differ in environmental sensitivity during ontogeny in the blue tit, a small altricial bird with c. 6% SSD in body mass (males larger than females). We performed a cross-fostering and brood size manipulation experiment during 2 years to investigate if the sexes were differently affected as regards body size (body mass, tarsus and wing length on day 14 after hatching) and pre-fledging survival. We also investigated if the relationship between body size and post-fledging survival differed between the sexes. Pre-fledging mortality was higher in enlarged than in reduced broods, representing poor and good environments, respectively, but the brood size manipulation did not affect the mortality rate of males and females differently. In both years, both males and females were smaller on day 14 after hatching in enlarged as compared to reduced broods. In one of the years, we also found significant Sex · Experiment interactions for body size, such that females were more affected by poor environmental conditions than that of males. Body size was positively correlated with post-fledging survival, but we found no interactive effects of sex and morphological traits on survival. We conclude that in the blue tit, females (the smaller sex) are more sensitive to adverse environmental conditions which, in our study, was manifest in terms of fledgling size. A review of published studies of sex differences in environmental sensitivity in sexually size-dimorphic altricial birds suggests that the smaller sex is more sensitive than the larger sex in species with large brood size and vice versa.
Vector abundance determines Trypanosoma prevalence in nestling blue tits
Parasitology, 2013
SUMMARYThe effect of insect vectors on avian exposure to infection by pathogens remains poorly studied. Here, we used an insect repellent treatment to reduce the number of blood-sucking flying insects in blue tit Cyanistes caeruleus nests and examined its effect on nestling health status measured as body mass, nestling phytohaemagglutinin (PHA) response and blood parasite prevalence. We found that (i) the insect repellent treatment significantly reduced the number of blood-sucking flying insects in nests and (ii) the number of blood-sucking flying insects had a significant effect on the prevalence of the blood parasite Trypanosoma independently of the treatment. In addition, we found support for an adverse effect of parasite infections on nestling PHA response. Nestlings infected by Trypanosoma mounted a weaker response against PHA than non-parasitized ones. In addition, the number of blowflies in the nest was negatively associated with nestling PHA response. Overall, we found suppo...
Acta Oecologica, 2012
Patterns of territory selection and sources of variation for reproductive performance in a Blue Tit Cyanistes caeruleus population breeding in nest-boxes during years 2007 and 2008 in a holm oak forest are analyzed. Territory selection has been assessed as a function of two fixed effect factors: territory location (peripheral vs. interior in the nestbox patch) and nestbox type (entrance hole: 26 mm vs. 32 mm). Breeding density was independent of these factors. Pairs nesting in periphery nest-boxes and in smallholed nestboxes owned territories bigger than those nesting in interior and large-holed nestboxes, respectively. The breeding traits studied were laying date, clutch size, hatching success, fledgling success and breeding success. Egg laying was earlier in periphery territories and small-holed nestboxes.