scholarly journals Food availability limits avian reproduction in the city: An experimental study on great tits Parus major

2020 ◽  
Vol 89 (7) ◽  
pp. 1570-1580 ◽  
Author(s):  
Gábor Seress ◽  
Krisztina Sándor ◽  
Karl L. Evans ◽  
András Liker
Keyword(s):  
Experimental Study ◽  
Food Availability ◽  
Parus Major ◽  
Avian Reproduction ◽  
The City

scholarly journals Epigenetic mediation of the onset of reproduction in a songbird

2020 ◽  
Author(s):  
Melanie Lindner ◽  
Veronika N. Laine ◽  
Irene Verhagen ◽  
Heidi M. Viitaniemi ◽  
Marcel E. Visser ◽  
...  
Keyword(s):  
Climate Change ◽  
Dna Methylation ◽  
Phenotypic Plasticity ◽  
Regulatory Region ◽  
Natural Populations ◽  
Parus Major ◽  
Great Tit ◽  
Egg Laying ◽  
Avian Reproduction ◽  
Directional Variation

ABSTRACTClimate change significantly impacts natural populations, particularly phenology traits, like the seasonal onset of reproduction in birds. This impact is mainly via plastic responses in phenology traits to changes in the environment, but the molecular mechanism mediating this plasticity remains elusive. Epigenetic modifications can mediate plasticity and consequently constitute promising candidates for mediating phenology traits. Here, we used genome-wide DNA methylation profiles of individual great tit (Parus major) females that we blood sampled repeatedly throughout the breeding season. We demonstrate rapid and directional variation in DNA methylation within the regulatory region of genes known to play key roles in avian reproduction that are in line with observed changes in gene expression in chickens. Our findings provide an important step towards unraveling the molecular mechanism mediating a key life history trait, an essential knowledge-gap for understanding how natural populations may cope with future climate change.IMPACT SUMMARYNatural populations are increasingly challenged by changing environmental conditions like global increases in temperature. A key way for species to adapt to global warming is via phenotypic plasticity, i.e. the ability to adjust the expression of traits to the environment. We, however, know little about how the environment can interact with an organism’s genetic make-up to shape its trait value. Epigenetic marks are known to vary with the environment and can modulate the expression of traits without any change in the genetic make-up and therefore have the potential to mediate phenotypic plasticity.To study the role of epigenetics for phenotypic plasticity, we here focus on the great tit (Parus major), a species that is strongly affected by global warming and plastic for temperature in an essential phenology trait, the seasonal onset of egg laying. As a first step, we investigated whether great tit females show within-individual and short-term variation in DNA methylation that corresponds to changes in the reproductive state of females. We therefore housed breeding pairs in climate-controlled aviaries to blood sample each female repeatedly throughout the breeding season and used these repeated samples for methylation profiling.We found rapid and directional variation in DNA methylation at the time females prepared to initiate egg laying that is located within the regulatory region of genes that have previously described functions for avian reproduction. Although future work is needed to establish a causal link between the observed temporal variation in DNA methylation and the onset of reproduction in female great tits, our work highlights the potential role for epigenetic modifications in mediating an essential phenology trait that is sensitive to temperatures.

scholarly journals An experimental study on premixed CNG/H2/CO2 mixture flames

2018 ◽  
Vol 8 (1) ◽  
pp. 32-40 ◽  
Author(s):  
Ilker Yilmaz ◽  
Harun Yilmaz ◽  
Omer Cam
Keyword(s):  
Experimental Study ◽  
Thermal Power ◽  
The Other ◽  
Gas Composition ◽  
Atmospheric Conditions ◽  
Swirl Number ◽  
Combustion Performance ◽  
Temperature Distributions ◽  
The City ◽  
Flame Behaviour

Abstract In this study, the effect of swirl number, gas composition and CO2 dilution on combustion and emission behaviour of CNG/H2/CO2 gas mixtures was experimentally investigated in a laboratory scale combustor. Irrespective of the gas composition, thermal power of the combustor was kept constant (5 kW). All experiments were conducted at or near stoichiometric and the local atmospheric conditions of the city of Kayseri, Turkey. During experiments, swirl number was varied and the combustion performance of this combustor was analysed by means of centreline temperature distributions. On the other hand, emission behaviour was examined with respect to emitted CO, CO2 and NOx levels. Dynamic flame behaviour was also evaluated by analysing instantaneous flame images. Results of this study revealed the great impact of swirl number and gas composition on combustion and emission behaviour of studied flames.

Avian eggshell formation in calcium-rich and calcium-poor habitats: importance of snail shells and anthropogenic calcium sources

1996 ◽  
Vol 74 (6) ◽  
pp. 1035-1044 ◽  
Author(s):  
J. Graveland
Keyword(s):  
The Netherlands ◽  
Parus Major ◽  
Calcium Deficiency ◽  
Avian Reproduction ◽  
Eggshell Formation ◽  
Eggshell Quality ◽  
Calcium Source ◽  
Calcium Sources ◽  
Rich Material ◽  
Normal Food

Most passerines depend on the intake of calcium-rich material in addition to their normal food for proper eggshell formation and skeletal growth. A large proportion of Great Tits (Parus major) in forests on nutrient-poor soils in the Netherlands produce eggs with defective shells as a result of calcium deficiency. Eggshell defects are much scarcer near human settlements and do not occur on nutrient-rich soils. I investigated this variation in eggshell quality by examining the use of calcium-rich material by the birds. The results show that calcium-rich items in nest material and droppings can be used as a measure of calcium consumption. Snail shells were the main calcium source in forests where eggshell defects did not occur. In forests where the tits exhibited calcium deficiency, snail shells were rarely taken and birds used anthropogenic calcium sources such as chicken grit and chicken eggshells. It was demonstrated that the dependence on snail shells and the use of alternatives such as anthropogenic calcium sources in areas where snails are scarce are general features of calcium intake among birds. Thus, calcium limitation may be a common phenomenon in avian reproduction on poor soils in countries less populous than the Netherlands.

AN EXPERIMENTAL STUDY ON THE INFLUENCE OF TICK INFESTATIONS ON NESTLING PERFORMANCE IN GREAT TITS (PARUS MAJOR)

The Auk ◽  
2008 ◽  
Vol 125 (4) ◽  
pp. 915-922 ◽  
Author(s):  
KATHARINA GALLIZZI ◽  
LINDA L. BISCHOFF ◽  
LISE GERN ◽  
HEINZ RICHNER
Keyword(s):  
Experimental Study ◽  
Parus Major

scholarly journals Parental control: ecology drives plasticity in parental response to offspring signals

2021 ◽  
Author(s):  
Shana Caro ◽  
Adara C Velasco ◽  
Tjomme van Mastrigt ◽  
Kees van Oers ◽  
Ashleigh S Griffin ◽  
...  
Keyword(s):  
Food Availability ◽  
Environmental Conditions ◽  
Meta Analysis ◽  
Bird Species ◽  
Parus Major ◽  
Food Distribution ◽  
Offspring Quality ◽  
Information Availability ◽  
Parental Response ◽  
Signalling Systems

Different bird species have completely different parent-offspring interactions. When food is plentiful, the chicks that are begging the loudest are fed the most. When food is scarce, bird species instead feed the largest offspring. While this variation could be due to parents responding to signalling differently based on food availability, it could equally be due to offspring adjusting their behaviour, or to variation in information availability. We tested between these competing explanations experimentally, by manipulating food availability in a population of wild great tits, Parus major, while standardising offspring behaviour and size. We found that when food was more plentiful, parents were: (1) more likely to preferentially feed the chicks that were begging the most; and (2) less likely to preferentially feed larger chicks. In addition, we consistently found these same patterns, in a meta-analysis across 57 bird species. Overall, our results suggest that parents have more control over food distribution than offspring do, and that they flexibly adjust how they respond to both offspring signals and cues of offspring quality in response to food availability. Consequently, depending upon environmental conditions, predictably different signalling systems are favoured.

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