Experimental evidence that UV/yellow colouration functions as a signal of parental quality in the blue tit

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.

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Is UV signalling involved in male-male territorial conflict in the blue tit (Cyanistes caeruleus)? A new experimental approach

Behaviour ◽

10.1163/156853907780756030 ◽

2007 ◽

Vol 144 (4) ◽

pp. 447-470 ◽

Cited By ~ 22

Author(s):

Thomas Dijkstra ◽

Peter Korsten ◽

Jan Komdeur

Keyword(s):

Experimental Approach ◽

Bird Species ◽

Female Mate Choice ◽

Blue Tit ◽

Cyanistes Caeruleus ◽

Fertile Period ◽

Territorial Conflict ◽

Uv Reflectance ◽

Aggressive Reactions ◽

Uv Coloration

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.

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Sibling competition in Blue Tits (Cyanistes caeruleus) is stronger in homozygous broods

The Auk ◽

10.1093/auk/ukz030 ◽

2019 ◽

Vol 136 (3) ◽

Author(s):

Judith Morales ◽

Iván Acevedo ◽

Annie Machordom

Keyword(s):

Mate Selection ◽

Brood Size ◽

Decision Rules ◽

Family Members ◽

Sibling Competition ◽

Family Interactions ◽

Sibling Conflict ◽

Cyanistes Caeruleus ◽

Behavioral Parameter ◽

Affected Parent

Abstract Heterozygosity affects mate selection and can modulate interactions among family members and their fitness-related decisions. We studied whether nestling heterozygosity affected parent–offspring interactions and sib–sib competition in the Blue Tit (Cyanistes caeruleus) while controlling for the degree of relatedness among nestlings. Demanding environmental conditions might make the detection of heterozygosity-fitness correlations easier. Thus, we also investigated whether the decision rules of family members according to offspring heterozygosity were affected by brood size, as a proxy of the strength of sibling conflict. We found that chick individual heterozygosity was positively although weakly associated with individual body mass. Mean brood heterozygosity did not predict fledging success, but broods that fledged more chicks showed a higher number of less common alleles. Interestingly, fathers, but not mothers, favored heterozygous broods with many nestlings, that is, heterozygous broods with higher potential for sibling conflict. Moreover, the lower the mean brood heterozygosity the stronger the begging intensity when parents were absent, regardless of brood size. Finally, the degree of relatedness among nestlings was not associated with any behavioral parameter, supporting a more prominent role for heterozygosity in shaping intra-family interactions. Our findings suggest that offspring heterozygosity determines sex-specific rules of parental care and that genetic diversity is associated with lower sibling competition.

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Faecal metabarcoding reveals pervasive long-distance impacts of garden bird feeding

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2021.0480 ◽

2021 ◽

Vol 288 (1951) ◽

pp. 20210480

Author(s):

Jack D. Shutt ◽

Urmi H. Trivedi ◽

James A. Nicholls

Keyword(s):

Bird Species ◽

Urban Ecosystems ◽

Early Spring ◽

Supplementary Feeding ◽

Ecosystem Dynamics ◽

Blue Tit ◽

Cyanistes Caeruleus ◽

Long Distance ◽

Supplementary Food ◽

The Impact

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.

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Sexual dichromatism, size dimorphism and microscale anatomy of white wing stripe in blue tit (Cyanistes caeruleus)

10.32942/osf.io/pnq2b ◽

2020 ◽

Author(s):

Katarzyna Janas ◽

Paulina Gaweł ◽

Anna Łatkiewicz ◽

Dorota Lutyk ◽

Lars Gustafsson ◽

...

Keyword(s):

Sexual Selection ◽

Sexual Dimorphism ◽

Spectral Characteristics ◽

Bird Species ◽

Common Element ◽

Sexual Dichromatism ◽

Blue Tit ◽

Cyanistes Caeruleus ◽

Size Dimorphism ◽

Wing Patch

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.

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

PeerJ ◽

10.7717/peerj.5301 ◽

2018 ◽

Vol 6 ◽

pp. e5301 ◽

Cited By ~ 6

Author(s):

Nolwenn Fresneau ◽

Arne Iserbyt ◽

Carsten Lucass ◽

Wendt Müller

Keyword(s):

Food Deprivation ◽

Competitive Ability ◽

Bird Species ◽

Blue Tit ◽

Cyanistes Caeruleus ◽

Parental Response ◽

Begging Behaviour ◽

Direct Benefits ◽

Individual Offspring ◽

Provisioning Rules

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.

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Faecal metabarcoding reveals pervasive long-distance impacts of garden bird feeding

10.1101/2021.01.31.429015 ◽

2021 ◽

Author(s):

Jack D Shutt ◽

Urmi H Trivedi ◽

James A Nicholls

Keyword(s):

Bird Species ◽

Urban Ecosystems ◽

Early Spring ◽

Supplementary Feeding ◽

Ecosystem Dynamics ◽

Blue Tit ◽

Cyanistes Caeruleus ◽

Long Distance ◽

Supplementary Food ◽

The Impact

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.

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‘Look it Daddy’

Research on Children and Social Interaction ◽

10.1558/rcsi.32576 ◽

2018 ◽

Vol 2 (1) ◽

pp. 98-119

Author(s):

Darcey K. Searles

Keyword(s):

Young Children ◽

Family Life ◽

American English ◽

Video Conferencing ◽

Family Members ◽

Family Interactions ◽

Life Data ◽

To Receive

Video-mediated technologies enable families with young children to participate in interactions with remote family members. This article examines how a family with young children uses the affordances of video conferencing to 'show' items or themselves. Findings indicate that there are two types of shows in these remote family interactions: those that are designed to receive identification, and those that are designed to receive appreciation and/or assessment. These shows are also often collaboratively produced between a child and her co-present parent. Finally, this paper considers the implications of these shows for our understanding of how families remotely participate in family life. Data are in American English.

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Family Interactions Regarding Fathers’ Smoking and Cessation in Shanghai, China

The Journal of Smoking Cessation ◽

10.1017/jsc.2014.25 ◽

2014 ◽

Vol 11 (4) ◽

pp. 199-202 ◽

Cited By ~ 3

Author(s):

Carla J. Berg ◽

Pinpin Zheng ◽

Michelle C. Kegler

Keyword(s):

Smoking Prevalence ◽

Family Members ◽

Spousal Support ◽

Gender Disparities ◽

Work Culture ◽

Family Interactions ◽

Structured Interviews ◽

Small Children ◽

Marital Interactions ◽

The Family

Introduction: Spousal support predicts smoking cessation. China is the world's largest consumer of tobacco, with drastic differences in smoking prevalence among men and women. Thus, understanding marital interactions around husbands’ smoking has implications for cultures with similarly large gender disparities in smoking.Aims: We examined interactions among family members regarding husbands’ smoking in homes with small children in Shanghai.Methods: In Spring 2013, we conducted in-person semi-structured interviews among 13 male smokers and 17 female nonsmokers recruited from an urban and a suburban community in Shanghai.Results/Findings: To encourage husbands’ cessation or reduction, some women reported intervening either directly or indirectly through their children, emphasizing the health consequences for the smoker and the family. Some women reported not conversing about cessation due to concern about conflict, tolerance, or resignation. Women reported that their husbands’ responses to anti-smoking messages from family members included promises to quit in the future or noting the strength of the nicotine addiction and the disadvantages of quitting. Men reported the importance of smoking in work/culture and argued against the research about the harms of smoking.Conclusions: Interventions targeting motivators for cessation among men and to support women in encouraging their husbands’ cessation should be developed.

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