scholarly journals Size matters but hunger prevails—begging and provisioning rules in blue tit families

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5301 ◽  
Author(s):  
Nolwenn Fresneau ◽  
Arne Iserbyt ◽  
Carsten Lucass ◽  
Wendt Müller

It is commonly observed in many bird species that dependent offspring vigorously solicit for food transfers provided by their parents. However, the likelihood of receiving food does not only depend on the parental response, but also on the degree of sibling competition, at least in species where parents raise several offspring simultaneously. To date, little is known about whether and how individual offspring adjusts its begging strategy according to the entwined effects of need, state and competitive ability of itself and its siblings. We here manipulated the hunger levels of either the two heaviest or the two lightest blue tit (Cyanistes caeruleus) nestlings in a short-term food deprivation experiment. Our results showed that the lightest nestlings consistently begged more than the heaviest nestlings, an effect that was overruled by the tremendous increase in begging behaviour after food deprivation. Meanwhile, the amplified begging signals after food deprivation were the only cue for providing parents in their decision process. Furthermore, we observed flexible but state-independent begging behaviour in response to changes in sibling need. As opposed to our expectations, nestlings consistently increased their begging behaviour when confronted with food deprived siblings. Overall, our study highlights that individual begging primarily aims at increasing direct benefits, but nevertheless reflects the complexity of a young birds’ family life, in addition to aspects of intrinsic need and state.


Behaviour ◽  
2007 ◽  
Vol 144 (4) ◽  
pp. 447-470 ◽  
Author(s):  
Thomas Dijkstra ◽  
Peter Korsten ◽  
Jan Komdeur

Structurally-based ultraviolet (UV) coloration of plumage can signal male quality and plays a role in female mate choice in many bird species. UV-reflecting badges could also be important signals in male-male competition. We tested if territorial blue tit ( Cyanistes caeruleus ) males discriminate between conspecific male intruders which differ in the UV reflectance of their crown feathers. To this aim, we used a new experimental approach in which we simultaneously (instead of sequentially) introduced two male blue tit taxidermic mounts in the territories of resident males during the female fertile period; one mount with natural crown UV reflectance and one mount with reduced crown UV. The two mounts provoked strong aggressive reactions from resident males. Males specifically directed their aggression to conspecific intruders, as a male blue tit mount received substantially more aggression than a mount of a European robin ( Erithacus rubecula ). However, aggression of resident males did not vary between the UV-reduced and the control mount. Furthermore, the variation in natural crown UV reflectance of the resident males did not predict the intensity of their aggressive response. Contrary to previous findings our results suggest that UV signals play only a limited role in male-male interactions during territorial intrusions in the female fertile period.



2020 ◽  
Author(s):  
Jorge García-Campa ◽  
Wendt Müller ◽  
Judith Morales

AbstractIn bi-parental species, reproduction is not only a crucial life-history stage where individuals must take fitness-relevant decisions, but these decisions also need to be adjusted to the behavioural strategies of a partner. Hence, communication is required, which could be facilitated by condition-dependent signals of parental quality. Yet, these traits have (co-)evolved in multiple contexts within the family, as during reproduction different family members may coincide and interact at the site of breeding. In this study we explore whether a condition-dependent trait acts a quality signal and regulates intra-family interactions in a bird species, the blue tit (Cyanistes caeruleus). As a family is a complex network where signals could be perceived by multiple receivers, we expected that experimentally blocking the reflectance of an adult’s UV/yellow colouration of breast feathers may affect the behavioural strategies of all family members. We found an increase of parental investment in nests with an UV-blocked adult, as the partner compensated for the perceived lower rearing capacity. As the UV-blocked adult did not change its provisioning behaviour, as was to be expected, their partner must have responded to the (manipulated) signal but not to a behavioural change. However, offspring did not co-adjust their begging intensity to a signal of parental quality. Opposite to adults, we propose that offspring respond to the behaviour but not to the parental signal. Overall, our results show experimentally at the first time that UV/yellow colouration of blue tits acts as a quality signal revealing the rearing capacity to mates.



2021 ◽  
Vol 288 (1951) ◽  
pp. 20210480
Author(s):  
Jack D. Shutt ◽  
Urmi H. Trivedi ◽  
James A. Nicholls

Supplementary feeding of wildlife is widespread, being undertaken by more than half of households in many countries. However, the impact that these supplemental resources have is unclear, with impacts largely considered to be restricted to urban ecosystems. We reveal the pervasiveness of supplementary foodstuffs in the diet of a wild bird using metabarcoding of blue tit ( Cyanistes caeruleus ) faeces collected in early spring from a 220 km transect in Scotland with a large urbanization gradient. Supplementary foodstuffs were present in the majority of samples, with peanut ( Arachis hypogaea ) the single commonest (either natural or supplementary) dietary item. Consumption rates exhibited a distance decay from human habitation but remained high at several hundred metres from the nearest household and continued to our study limit of 1.4 km distant. Supplementary food consumption was associated with a near quadrupling of blue tit breeding density and a 5-day advancement of breeding phenology. We show that woodland bird species using supplementary food have increasing UK population trends, while species that do not, and/or are outcompeted by blue tits, are likely to be declining. We suggest that the impacts of supplementary feeding are larger and more spatially extensive than currently appreciated and could be disrupting population and ecosystem dynamics.



2020 ◽  
Author(s):  
Katarzyna Janas ◽  
Paulina Gaweł ◽  
Anna Łatkiewicz ◽  
Dorota Lutyk ◽  
Lars Gustafsson ◽  
...  

Achromatic patches are a common element of plumage patterns in many bird species and there is growing body of evidence that in many avian taxa they can play a signaling role in mate choice. Although the blue tit is a well-established model species in the studies on colouration, its white wing patch has never been examined in the context of sex-specific trait expression. In this exploratory study, we examined sexual size dimorphism and dichromatism of greater covert’s dots creating white wing patch and analysed its correlations with current body condition and crown colouration - a trait with established role in sexual selection. Further, we qualitatively analysed microstructural barb morphology underlying covert’s colouration. We found significant sexual dimorphism in the dot size independent of covert size, and sexual dichromatism in both white dot and blue outer covert’s vane spectral characteristics. Importantly, UV chroma of covert’s vane was positively correlated with crown UV chroma, which suggests that coverts colouration might be also an ornament assessed by females during courtship display. Internal structure of covert barbs within the white dot was similar to the one found in barbs from the blue part, i.e. with a medullary area consisting of dead keratinocytes containing channel-type ß-keratin spongy nanostructure and centrally located air cavities. However, it lacked melanosomes which was the main observed difference. Together with marked sexual dimorphism, it suggests that white dots may have emerged under sexual selection as an apomorphic trait on previously uniformly coloured feathers.



2021 ◽  
Author(s):  
Jack D Shutt ◽  
Urmi H Trivedi ◽  
James A Nicholls

AbstractSupplementary feeding of wildlife is widespread, being undertaken by more than half of households in many countries. However, the impact that these supplemental resources have is unclear, with impacts assumed to be restricted to urban ecosystems. We reveal the pervasiveness of supplementary foodstuffs in the diet of a wild bird using metabarcoding of blue tit (Cyanistes caeruleus) faeces collected in early spring from a 220km transect in Scotland with a large urbanisation gradient. Supplementary foodstuffs were present in the majority of samples, with peanut (Arachis hypogaea) the single commonest (either natural or supplementary) dietary item. Consumption rates exhibited a distance decay from human habitation but remained high at several hundred metres from the nearest household and continued to our study limit of 1.4km distant. Supplementary food consumption was associated with a near quadrupling of blue tit breeding density and a five-day advancement of breeding phenology. We show that woodland bird species using supplementary food have increasing UK population trends, while species that don’t, and/or are outcompeted by blue tits, are likely to be declining. We suggest that the impacts of supplementary feeding are larger and more spatially extensive than currently appreciated and could be disrupting population and ecosystem dynamics.



2014 ◽  
Vol 217 (21) ◽  
pp. 3775-3778 ◽  
Author(s):  
D. Gomez ◽  
A. Gregoire ◽  
M. Del Rey Granado ◽  
M. Bassoul ◽  
D. Degueldre ◽  
...  


2014 ◽  
Vol 27 (10) ◽  
pp. 2258-2264 ◽  
Author(s):  
J. Sudyka ◽  
A. Arct ◽  
S. Drobniak ◽  
A. Dubiec ◽  
L. Gustafsson ◽  
...  


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Liisa Hämäläinen ◽  
William Hoppitt ◽  
Hannah M. Rowland ◽  
Johanna Mappes ◽  
Anthony J. Fulford ◽  
...  

AbstractSocial transmission of information is taxonomically widespread and could have profound effects on the ecological and evolutionary dynamics of animal communities. Demonstrating this in the wild, however, has been challenging. Here we show by field experiment that social transmission among predators can shape how selection acts on prey defences. Using artificial prey and a novel approach in statistical analyses of social networks, we find that blue tit (Cyanistes caeruleus) and great tit (Parus major) predators learn about prey defences by watching others. This shifts population preferences rapidly to match changes in prey profitability, and reduces predation pressure from naïve predators. Our results may help resolve how costly prey defences are maintained despite influxes of naïve juvenile predators, and suggest that accounting for social transmission is essential if we are to understand coevolutionary processes.



2021 ◽  
Vol 68 (1) ◽  
Author(s):  
Luisa Fischer ◽  
Franca Möller Palau-Ribes ◽  
Silke Kipper ◽  
Michael Weiss ◽  
Conny Landgraf ◽  
...  

AbstractMycoplasma spp. are important pathogens in poultry and cause high economic losses for poultry industry worldwide. In other bird species (e.g. white storks, birds of prey, and several waterfowl species), Mycoplasma spp. are regularly found in healthy individuals, hence, considered apathogenic or part of the microbiota of the upper respiratory tract. However, as Mycoplasma spp. are absent in healthy individuals of some wild bird species, they might play a role as respiratory pathogen in these bird species, e.g. Mycoplasma gallisepticum in house finches. The knowledge on the occurrence of Mycoplasma spp. in wild birds is limited. To evaluate the relevance of Mycoplasma spp. in free-ranging nightingales and tits, 172 wild caught birds were screened for the presence of mycoplasmas. The birds were sampled via choanal swabs and examined via molecular methods (n = 172) and, when possible, via culture (n = 142). The Mycoplasma sp. was determined by sequencing the 16S rRNA gene and 16S-23S Intergenic Transcribed Spacer Region. All birds were tested negative for mycoplasmas via PCR and/or mycoplasmal culture. Hence, free-ranging nightingales and tits do not show any mycoplasma in their microbial flora of the respiratory tract. Therefore, these songbird species may suffer from clinical mycoplasmosis when being infected. We hypothesize that birds relying on their vocal ability for reproduction have excluded mycoplasmas from their respiratory flora compared to other bird species.



2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Cristina-Maria Valcu ◽  
Richard A. Scheltema ◽  
Ralf M. Schweiggert ◽  
Mihai Valcu ◽  
Kim Teltscher ◽  
...  


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