scholarly journals A fixed agreement—consequences of brood size manipulation on alternation in blue tits

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6826 ◽  
Author(s):  
Maaike Griffioen ◽  
Wendt Müller ◽  
Arne Iserbyt
Keyword(s):  
Sexual Conflict ◽  
Experimental Studies ◽  
Mass Gain ◽  
Blue Tit ◽  
Conditional Cooperation ◽  
Cyanistes Caeruleus ◽  
Directional Change ◽  
Potential Benefits ◽  
Blue Tits

Recent studies have proposed that conditional cooperation may resolve sexual conflict over the amount of care provided by each parent. Such conditional cooperation may allow parents to equalize their investment by alternating their provisioning visits. This alternated pattern of male and female visits, that is, alternation, is thought to stimulate each other’s investment leading to higher levels of provisioning and potential benefits for offspring development. However, experimental studies testing the role of alternation as an adaptive parental strategy to negotiate the level of investment are still absent. Therefore, we manipulated blue tit (Cyanistes caeruleus) parents by temporarily changing their brood sizes to induce changes in demand and thus visit rates. Parents were expected to visit more—assuming that prey sizes were constant—and alternate at higher levels when confronted with an enlarged brood given the greater potential for sexual conflict. In contrast, in reduced broods visit rates and alternation may become lower due to the smaller investment that is needed for reduced broods. We show that the level of alternation did not differ in response to the manipulated brood sizes, despite a directional change in visit rates for enlarged and reduced broods as expected. Nestlings did not benefit from high levels of alternation as no effects on nestling mass gain were present in either of the different manipulations. These findings indicate that alternation does not serve as a mechanism to motivate each other to feed at higher rates. Parents hence appeared to be inflexible in their level of alternation. We therefore suggest that the level of alternation might reflect a fixed agreement about the relative investment by each of the caring parents.

scholarly journals Turn taking is not restricted by task specialisation but does not facilitate equality in offspring provisioning

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maaike Griffioen ◽  
Arne Iserbyt ◽  
Wendt Müller
Keyword(s):  
Sexual Conflict ◽  
Cold Treatment ◽  
Theoretical Concept ◽  
Specific Task ◽  
Conditional Cooperation ◽  
Cyanistes Caeruleus ◽  
Nest Box ◽  
Turn Taking ◽  
Cold Condition ◽  
Blue Tits

AbstractSexual conflict arises when two individuals invest in their common offspring because both individuals benefit when their partner invests more. Conditional cooperation is a theoretical concept that could resolve this conflict. Here, parents are thought to motivate each other to contribute to provisioning visits by following the rules of turn taking, which results in equal and efficient investment. However, parents have other tasks besides provisioning, which might hinder taking turns. To investigate restrictions by other care tasks and whether turn taking can be used to match investment, we manipulated brooding duration in female blue tits (Cyanistes caeruleus) during the early nestling phase by changing nest box temperature. As expected, females subjected to cold conditions brooded longer than females under warm conditions. Yet, contrary to our prediction, females had similar visit rates in both treatments, which suggests that females in the cold treatment invested more overall. In addition, the females’ turn taking level was higher in the more demanding cold condition (and the calculated randomised turn taking levels of females did not differ), hence females don’t seem to be restricted in their turn taking strategy by other care tasks. However, males did not seem to match the females’ turn taking levels because they did not adjust their visit rates. Thus, level of turn taking was not restricted by an other sex-specific task in females and did not facilitate a greater investment by their male partners.

scholarly journals Individual variation in corticosterone and personality traits in the blue tit Cyanistes caeruleus

Behaviour ◽  
2016 ◽  
Vol 153 (13-14) ◽  
pp. 1611-1637 ◽  
Author(s):  
Kathryn E. Arnold ◽  
Katherine A. Herborn ◽  
Lindsay J. Henderson ◽  
Aileen Adam ◽  
Lucille Alexander ◽  
...  
Keyword(s):  
Personality Traits ◽  
Stress Hormones ◽  
Mass Gain ◽  
Blue Tit ◽  
Cyanistes Caeruleus ◽  
State Dependent ◽  
Lower Baseline ◽  
Dependent Variables ◽  
In Captivity ◽  
Blue Tits

Variation in personality traits is predicted to reflect physiology, but the extent to which variations in stress hormones derive from differences in personality and/or state-dependent factors remains unclear. To investigate this, wild blue tits (Cyanistes caeruleus) were briefly brought into captivity and scored for personality and corticosterone (Cort) concentrations. More active females had lower baseline Cort than less active individuals. Exploratory tendency and neophobia did not co-vary with baseline Cort. Stress-induced Cort concentrations were correlated negatively with exploratory tendency and haematocrit, but positively with mass gain in captivity. Therefore, baseline and stress-induced Cort concentrations in wintering blue tits were associated with state-dependent variables, sex, age and personality traits. Key to interpreting the physiology of personality traits seems to be their interactions with other traits that mediate ability to utilise resources, and thus influence an individual’s perception of its current and future energy balance.

scholarly journals Do glucocorticoids predict fitness? Linking environmental conditions, corticosterone and reproductive success in the blue tit, Cyanistes caeruleus

2017 ◽  
Vol 4 (10) ◽  
pp. 170875 ◽  
Author(s):  
L. J. Henderson ◽  
N. P. Evans ◽  
B. J. Heidinger ◽  
K. A. Herborn ◽  
K. E. Arnold
Keyword(s):  
Reproductive Success ◽  
Environmental Conditions ◽  
Empirical Studies ◽  
Blue Tit ◽  
Cyanistes Caeruleus ◽  
Free Living ◽  
Brood Rearing ◽  
Fledging Success ◽  
Harsh Conditions ◽  
Blue Tits

Glucocorticoids, including corticosterone (CORT), have been suggested to provide a physiological link between ecological conditions and fitness. Specifically, CORT, which is elevated in response to harsh conditions, is predicted to be correlated with reduced fitness. Yet, empirical studies show that CORT can be non-significantly, positively and negatively linked with fitness. Divergent environmental conditions between years or study systems may influence whether CORT is linked to fitness. To test this, we monitored free-living blue tits ( Cyanistes caeruleus ) during breeding over 3 years. We quantified foraging conditions during brood rearing, and examined whether they were correlated with parental baseline CORT and reproductive success. We then tested whether CORT predicted fitness. Elevated parental CORT was associated with lower temperatures, greater rainfall and lower territory-scale oak density. Whereas asynchrony with the caterpillar food peak was correlated with reduced nestling mass and fledging success, but not parental CORT. Only low temperatures were associated with both reduced nestling mass and elevated parental CORT. Despite this, parents with elevated CORT had lighter offspring in all years. Contrarily, in 2009 parental CORT was positively correlated with the number fledged. The absence of a direct link between the foraging conditions that reduce nestling quality and elevate parental CORT suggests that parental CORT may provide a holistic measure of conditions where parents are working harder to meet the demands of developing young. As the positive correlation between parental CORT and fledging success differed between years, this suggests that contrasting conditions between years can influence correlations between parental CORT and fitness. Ultimately, as CORT concentrations are intrinsically variable and linked to the prevalent conditions, studies that incorporate environmental harshness will improve our understanding of evolutionary endocrinology.

scholarly journals Does mist-netting provide reliable data to determine the sex and age ratios of migrating birds? A case study involving the Great Tit (Parus major) and the Blue Tit (Cyanistes caeruleus)

2013 ◽  
Vol 32 (2) ◽  
Author(s):  
Jarosław K. Nowakowski ◽  
Jacek Chruściel ◽  
Krzysztof Muś
Keyword(s):  
Parus Major ◽  
Great Tit ◽  
Reliable Data ◽  
Blue Tit ◽  
Cyanistes Caeruleus ◽  
Baltic Coast ◽  
Migrating Birds ◽  
Blue Tits ◽  
Age And Sex

AbstractNowakowski J.K., Chruściel J., Muś K.: Does mist-netting provide reliable data to determine the sex and age ratios of migrating birds? A case study involving the Great Tit (Parus major) and the Blue Tit (Cyanistes caeruleus). Ekologia (Bratislava), Vol. 32, No. 2, p. 173-185 , 2013.Ringing results of tits caught at two stations on the Polish Baltic coast were used to check if mistnetting could be successfully used to analyse the composition of sex and age classes of migrating birds. Four hypotheses are discussed, describing the distribution of age and sex classes during migration, and the consequences these distributions might have for the catching results. We analysed records of 59 000 Blue Tits and more than 84 000 Great Tits that were caught and we found a similarity in the results of catches at stations 188 km apart, and a higher similarity among catching sites 0.5-16 km apart. These results proved that mist-netting provides reliable data on the sex and age structure of migrating flocks, and that these data can generally be interpreted as representative for at least the area in a radius of more than 10 km. The results also showed a migratory divide through the central part of the Polish Baltic coastline between irruptive Blue Tits in the west and regular partial migrants in the east. Great Tits showed no tendency for irruptions anywhere in the study area. A high correspondence in the age and sex ratio was found for Great Tits and Blue Tits, in particular where both species are regular migrants. We found that the ratios of females and immatures did not differ by more than 1% over many years of study in these areas.

scholarly journals Do Partial and Regular Migrants Differ in Their Responses to Weather?

The Auk ◽  
2006 ◽  
Vol 123 (2) ◽  
pp. 537-547
Author(s):  
Anna L. K. Nilsson ◽  
Thomas Alerstam ◽  
Jan-Åke Nilsson
Keyword(s):  
Explanatory Power ◽  
Weather Conditions ◽  
Blue Tit ◽  
Cyanistes Caeruleus ◽  
Migratory Activity ◽  
Partial Migrant ◽  
Orientation Cues ◽  
Calm Weather ◽  
Blue Tits ◽  
Good Visibility

AbstractPartial migration is often considered a transitory stage between migration and residency, and whether partial migrants take weather conditions into account during migration is largely unknown. To assess whether partial migrants differ from regular migrants in their responses to weather, we compared the migratory intensity of a partial migrant, the Blue Tit (Cyanistes caeruleus), with more regular migrants in relation to weather at a migratory passage site in southern Sweden (Falsterbo) during the years 1993–2002. The regular migrants in the study were Linnet (Carduelis cannabina), Common Chaffinch (Fringilla coelebs), Brambling (F. montifringilla), and European Robin (Erithacus rubecula). The Blue Tit differed from the regular migrants mainly in showing a striking negative correlation between migratory activity and cloud cover. Also, weather had the highest explanatory power for migratory intensity in the Blue Tit. This suggests that the Blue Tit is more sensitive to weather conditions on migration than the regular migrants and that it preferably awaits days with wholly or partly clear skies before migrating past Falsterbo. As a consequence, Blue Tits usually restrict their migratory flights to the safest occasions, with relatively calm weather, good visibility, and all orientation cues (solar as well as magnetic) available.¿Difieren los Migrantes Parciales y Regulares en sus Respuestas al Clima?

scholarly journals Experimental evidence for the role of calcium in eggshell pigmentation pattern and breeding performance in Blue Tits Cyanistes caeruleus

2010 ◽  
Vol 152 (1) ◽  
pp. 71-82 ◽  
Author(s):  
Vicente García-Navas ◽  
Juan José Sanz ◽  
Santiago Merino ◽  
Josué Martínez–de la Puente ◽  
Elisa Lobato ◽  
...  
Keyword(s):  
Experimental Evidence ◽  
Breeding Performance ◽  
Cyanistes Caeruleus ◽  
Pigmentation Pattern ◽  
Eggshell Pigmentation ◽  
Blue Tits

scholarly journals The effect of social information from live demonstrators compared to video playback on blue tit foraging decisions

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7998 ◽  
Author(s):  
Liisa Hämäläinen ◽  
Hannah M. Rowland ◽  
Johanna Mappes ◽  
Rose Thorogood
Keyword(s):  
Social Interactions ◽  
Social Information ◽  
Video Playback ◽  
Control Groups ◽  
Blue Tit ◽  
Cyanistes Caeruleus ◽  
Foraging Decisions ◽  
Foraging Task ◽  
Blue Tits ◽  
Live Bird

Video playback provides a promising method to study social interactions, and the number of video playback experiments has been growing in recent years. Using videos has advantages over live individuals as it increases the repeatability of demonstrations, and enables researchers to manipulate the features of the presented stimulus. How observers respond to video playback might, however, differ among species, and the efficacy of video playback should be validated by investigating if individuals’ responses to videos are comparable to their responses to live demonstrators. Here, we use a novel foraging task to compare blue tits’ (Cyanistes caeruleus) responses to social information from a live conspecific vs video playback. Birds first received social information about the location of food, and were then presented with a three-choice foraging task where they could search for food from locations marked with different symbols (cross, square, plain white). Two control groups saw only a foraging tray with similar symbols but no information about the location of food. We predicted that socially educated birds would prefer the same location where a demonstrator had foraged, but we found no evidence that birds copied a demonstrator’s choice, regardless of how social information was presented. Social information, however, had an influence on blue tits’ foraging choices, as socially educated birds seemed to form a stronger preference for a square symbol (against two other options, cross and plain white) than the control birds. Our results suggest that blue tits respond to video playback of a conspecific similarly as to a live bird, but how they use this social information in their foraging decisions, remains unclear.

scholarly journals A Blue Tit Cyanistes caeruleus population: its recent increase and breeding data

Ornis Svecica ◽  
2012 ◽  
Vol 22 (1–2) ◽  
pp. 19-24
Author(s):  
Karl Gustav Schölin ◽  
Hans Källander
Keyword(s):  
Population Size ◽  
Negative Relationship ◽  
Breeding Population ◽  
Laying Date ◽  
Strongly Correlated ◽  
Blue Tit ◽  
Cyanistes Caeruleus ◽  
South Central ◽  
The Mean ◽  
Blue Tits

Before 1983, Blue Tits Cyanistes caeruleus never made up more than four pairs of the breeding population in a nestbox study carried out in South Central Sweden. From five breeding pairs in 1983, the population increased to 29 pairs in 2007 and remained high to the end of the study in 2011. Mean laying date was strongly correlated with mean April temperature, which increased during 1983–2011. During the same period mean laying date became nearly ten days earlier. Mean clutch size was 9.90 eggs but varied both within and between years and showed a negative relationship to population size. The mean number of fledglings varied strongly between years, partly because of predation but also due to nestling starvation.

scholarly journals Microclimate, CO2 and CH4 concentration on Blue tits (Cyanistes caeruleus) nests: effects of brood size, nestling age and on ectoparasites

2019 ◽  
Author(s):  
Francisco Castaño-Vázquez ◽  
Santiago Merino ◽  
Soledad Cuezva ◽  
Sergio Sánchez
Keyword(s):  
Brood Size ◽  
Isotopic Signature ◽  
Blue Tit ◽  
Cyanistes Caeruleus ◽  
Nest Boxes ◽  
Nestling Period ◽  
Ch4 Concentration ◽  
The Difference ◽  
Blowfly Pupae ◽  
Blue Tits

ABSTRACTThe presence of nestlings and other nest dwelling living beings in nests built in cavities could alter the composition of gases inside the cavity. In addition, this different concentration of gases could be used by some parasites as a cue to localize their hosts. Here, we explored the temporal variation in the concentration and isotopic signature of carbon dioxide (CO2) and methane (CH4) inside nest boxes of blue tits Cyanistes caeruleus during the nestling period (days 3, 8, 13, 20 and 21 post-hatching). Concentration of gases and isotopic signature were significantly different inside of nests than outside (forest) during the nestling period. CO2 concentration was higher inside nest while CH4 was lower than in forest air. The differences in the concentration of CO2 between nest boxes and forest were higher on days 8th and 20th of nestling age than in other ages while the CH4 was lower on day 20th of nestling age than in other ages. Moreover, CO2 variation was positive and significantly related with brood size and negative and significantly with hatching date. The difference of CO2 between inside of nests and forest on 8th day of nestling age were negative and significantly related to flea larvae abundance as measured at the end of the nestling period. A significant positive relationship was found between the difference of CH4 between nests and forest and the final abundance of flea larvae for the same nestling age. In addition, flea larvae abundance was positive and significantly related with the relative humidity in nests at 8 days of nestling age. Moreover, blowfly pupae abundance was negative and significantly related with the difference of temperature in nests at 3 day of nestling age. The condition of blue tit females was negative and significantly related with the abundance of blowfly pupae.

Grape Seeds Extract as Brain Food: A Review

2017 ◽  
Vol 9 (1) ◽  
Author(s):  
Souad El Gengaihi ◽  
Doha H. Abou Baker
Keyword(s):  
Antioxidant Activities ◽  
Complex Mixture ◽  
Grape Seed Extract ◽  
Grape Seed ◽  
Seed Extract ◽  
Amyloid Peptide ◽  
Grape Seeds ◽  
Potential Benefits ◽  
Reduced Risk

Interest in the biological role of bioactive compounds present in medicinal herbs has increased over the last years. Of particular interest are plants that have an anti-Alzheimer activities. Several plants can be useful for Alzheimer (AD) management. Such as these which have anti-inflammatory activity, acetylcholinesterase (AChE) inhibitory action, antiapoptotic, slow the aggregation of amyloid peptide and antioxidant activities. Grape seed extract (GSE) is a complex mixture of several compounds, mostly represented by polyphenols and flavonoids. Their consumption is safe and is recognized to exert several health benefits. GS flavonoids have been associated with the reduced risk of chronic diseases, we present some findings on the potential benefits of GSE for the treatment of AD.

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