scholarly journals Song as a signal to negotiate a sexual conflict?

2003 ◽  
Vol 53 (2) ◽  
pp. 159-171 ◽  
Author(s):  
Simon Verhulst
Keyword(s):  
Sexual Conflict ◽  
Brood Size ◽  
Optimal Solution ◽  
Parus Major ◽  
Positive Association ◽  
Production Costs ◽  
Life History Trait ◽  
Male Song ◽  
Song Rate ◽  
Second Clutch

AbstractSexual conflict occurs when the optimal solution regarding e.g. a life history trait differs between co-operating individuals of different sex. When deciding a conflict is not instantaneous, some form of negotiation can be expected to evolve. In great tits, Parus major, a sexual conflict exists over the number of clutches that are reared, because the fitness costs of a second clutch are greater for females. A conflict is also likely to exist over investment in the first brood - each parent benefiting from a greater investment by the partner. Male great tits sing when rearing the first brood, and if acoustic signals play a role in the negotiation of a sexual conflict, a positive association between male song rate and maternal investment is predicted. In agreement with this hypothesis, maternal effort (in kJ/day) relative to paternal effort was positively correlated with male song rate. Furthermore, females were more likely to start a second clutch when their male had a high song rate, and high song rate was associated with shorter inter-clutch intervals. Song rate was higher when brood size was experimentally reduced and, independent of brood size manipulation, males with high song rate produced higher quality fledglings. These results indicate that song rate reflects the males' state, suggesting it may function as a handicap signal. Although song rate seems too low (<4% of time) for honesty to be maintained by production costs alone, signalling costs may be amplified by the fact that song appears restricted to the time when the male and female are both near the nest. To achieve a high song rate, the male may have to spend a large amount of time near the nest, thereby seriously restricting time available for other activities.

Effect of Experimentally Altered Brood Size on Frequency and Timing of Second Clutches in the Great Tit

The Auk ◽  
1987 ◽  
Vol 104 (4) ◽  
pp. 700-706 ◽  
Author(s):  
Henrik G. Smith ◽  
Hans Källander ◽  
Jan-Åke Nilsson
Keyword(s):  
Brood Size ◽  
Parus Major ◽  
Reproductive Development ◽  
Great Tit ◽  
Lower Probability ◽  
Hatching Date ◽  
Fledgling Survival ◽  
First Clutch ◽  
Second Clutch ◽  
Food Depletion

Abstract Brood size in the Great Tit (Parus major) was manipulated (increased, decreased, or unchanged) when nestlings were 5 days old. Both the frequency of second clutches and the interbrood interval were affected. The number of nestlings and hatching date, but not nestling and female mass, differed between first broods followed and not followed by second clutches. Hatching date and the number of nestlings in the first brood explained most of the variation in interbrood interval, whereas female mass did not contribute. Feeding first-brood nestlings and fledglings is an energy-demanding process, and the female may have to allocate resources to brood-feeding at the expense of reproductive development. Furthermore, a larger brood requires a longer period of feeding than a smaller brood. These circumstances probably explain why the size of the first brood affects the timing of the second clutch. Female condition and food depletion of the territory do not seem to be important. Because late second clutches have a lower probability of fledgling survival than do earlier ones-and consequently are of lower value from the female's standpoint-a large first clutch may delay laying to the point that a second clutch is not worthwhile. We conclude that a female's decision whether to lay a second clutch is a strategic one based on the value of the second clutch; a female that "decides" to lay a second clutch starts as quickly as possible.

scholarly journals Decline in the frequency and benefits of multiple brooding in great tits as a consequence of a changing environment

2009 ◽  
Vol 276 (1663) ◽  
pp. 1845-1854 ◽  
Author(s):  
Arild Husby ◽  
Loeske E.B. Kruuk ◽  
Marcel E. Visser
Keyword(s):  
Life History Traits ◽  
Parus Major ◽  
Population Level ◽  
Climatic Conditions ◽  
Long Term Study ◽  
Double Brooding ◽  
First Clutch ◽  
Second Clutch ◽  
Reproductive Events

For multiple-brooded species, the number of reproductive events per year is a major determinant of an individual's fitness. Where multiple brooding is facultative, its occurrence is likely to change with environmental conditions, and, as a consequence, the current rates of environmental change could have substantial impacts on breeding patterns. Here we examine temporal population-level trends in the proportion of female great tits ( Parus major ) producing two clutches per year (‘double brooding’) in four long-term study populations in The Netherlands, and show that the proportion of females that double brood has declined in all populations, with the strongest decline taking place in the last 30 years of the study. For one of the populations, for which we have data on caterpillar abundance, we show that the probability that a female produces a second clutch was related to the timing of her first clutch relative to the peak in caterpillar abundance, and that the probability of double brooding declined over the study period. We further show that the number of recruits from the second clutch decreased significantly over the period 1973–2004 in all populations. Our results indicate that adjustment to changing climatic conditions may involve shifts in life-history traits other than simply the timing of breeding.

The Optimization of Precision Milling Parameters for Titanium Based on Genetic Algorithm

2012 ◽  
Vol 472-475 ◽  
pp. 1078-1081
Author(s):  
Wen Sheng Zhang ◽  
Hong Xiang Wang ◽  
Hong Du ◽  
Tao Xu
Keyword(s):  
Genetic Algorithm ◽  
Production Efficiency ◽  
Optimal Solution ◽  
Minimum Cost ◽  
Cutting Parameters ◽  
Function Optimization ◽  
Cnc Machining ◽  
Production Costs ◽  
Milling Parameters ◽  
Low Efficiency

The genetic algorithm converges faster compared with the traditional optimization algorithm, the global optimal solution can be quickly obtained and it is very effective for multi-peak function optimization. A milling process parameter optimization model is established for titanium based on genetic algorithm in this paper, the relevant constraints is considered and the optional titanium milling parameters is achieved based on the targets of maximum production efficiency and minimum cost, utilizing MATLAB optimization software to program, the best combination of cutting parameters is got finally. Experimental results show that the cutting efficiency and production costs are significantly improved with the optimized cutting parameters, so that the defects of low efficiency in CNC machining resulting in relying on experienced cutting parameters is overcome.

scholarly journals Female in-nest chatter song increases predation

2016 ◽  
Vol 12 (1) ◽  
pp. 20150513 ◽  
Author(s):  
Sonia Kleindorfer ◽  
Christine Evans ◽  
Katharina Mahr
Keyword(s):  
Gender Differences ◽  
Sex Differences ◽  
Parental Care ◽  
Southern Hemisphere ◽  
Fitness Cost ◽  
Fertile Period ◽  
Male Song ◽  
Song Rate ◽  
Males And Females ◽  
Malurus Cyaneus

Female song is an ancestral trait in songbirds, yet extant females generally sing less than males. Here, we examine sex differences in the predation cost of singing behaviour. The superb fairy-wren ( Malurus cyaneus ) is a Southern Hemisphere songbird; males and females provision the brood and produce solo song year-round. Both sexes had higher song rate during the fertile period and lower song rate during incubation and chick feeding. Females were more likely than males to sing close to or inside the nest. For this reason, female but not male song rate predicted egg and nestling predation. This study identifies a high fitness cost of song when a parent bird attends offspring inside a nest and explains gender differences in singing when there are gender differences in parental care.

scholarly journals Optimasi Jumlah Produksi dan Biaya Distribusi UMKM Semprong Amoundy Menggunakan Metode Simpleks dan Algoritma Greedy

2021 ◽  
Vol 5 (1) ◽  
pp. 9
Author(s):  
Resa Nofatiyassari ◽  
Rianita Puspa Sari
Keyword(s):  
Travelling Salesman Problem ◽  
Optimal Solution ◽  
Production Optimization ◽  
Production Costs ◽  
Travelling Salesman ◽  
Optimal Amount ◽  
Distribution Costs ◽  
House Production ◽  
Distribution Cost ◽  
The Greedy Algorithm

Production optimization must be considered in order to get the optimal amount of production, which is related to company profit. In addition, the distribution route that is not optimal will also cause production costs to expand. These two things are the main problems faced by Semprong Amoundy MSMEs that have not paid attention to optimization of production and optimization of distribution routes. The purpose of this research is to find the optimal solution of the number and type of semprong production to maximize the income of Amoundy MSMEs, and to find a solution for the shortest distribution route to minimize distribution costs of semprong products. The method used to solve this problem is Simplex Method and Travelling Salesman Problem with the Greedy Algorithm approach. The research resulted the decision that Amoundy MSMEs had to produce 18 boxes of large packaged semprong every day to generate maximum income. The distribution route that must be taken to minimize distribution costs is Amoundy House Production – Bontot Delajaya Shop – Erik Shop – Denpasar Shop – Aneka Shop – Oleh-oleh Karawang Outlet – Amoundy House Production, estimated distribution cost of Rp. 20.120,-.Optimasi produksi perlu diperhatikan agar didapatkan jumlah produksi yang optimal, yang mana hal ini akan berhubungan dengan profit perusahaan. Selain itu rute distribusi yang belum optimal juga akan menyebabkan pembengkakan biaya produksi. Kedua hal ini merupakan masalah utama yang dihadapi oleh UMKM Semprong Amoundy yang belum memperhatikan optimasi produksi dan optimasi rute distribusi. Tujuan dilakukannya penelitian ini yaitu untuk mencari solusi optimal dari jumlah dan jenis produksi semprong untuk memaksimalkan pendapatan UMKM Amoundy, serta mencari solusi rute distribusi terpendek untuk meminimalkan biaya pendistribusian produk semprong. Metode yang digunakan untuk adalah Metode simpleks dan  Travelling Salesman Problem dengan pendekatan algoritma greedy. Penelitian menghasilkan keputusan bahwa UMKM Amoundy harus memproduksi 18 box kue semprong kemasan besar setiap hari untuk menghasilkan pendapatan maksimal. Rute distribusi yang harus ditempuh untuk meminimalkan biaya distribusi yaitu Rumah Produksi Amoundy – Toko Bontot Delajaya – Toko Erik – Toko Denpasar – Toko Aneka – Outlet Oleh-oleh Karawang – Rumah Produksi Amoundy dengan taksiran biaya distribusi sebesar Rp. 20.120,-.

scholarly journals Algoritme Particle Swarm Optimization (PSO) untuk Optimasi Perencanaan Produksi Agregat Multi-Site pada Industri Tekstil Rumahan

2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Agung Mustika Rizki ◽  
Afina Lina Nurlaili
Keyword(s):  
Particle Swarm Optimization ◽  
Production Planning ◽  
Particle Swarm ◽  
Optimal Solution ◽  
Pso Algorithm ◽  
Efficient Solutions ◽  
Production Costs ◽  
Aggregate Production Planning ◽  
Swarm Optimization ◽  
Aggregate Production

In the industrial world, companies need to manage their production areas well. One way is to implement aggregate production planning. The goal is that the production costs incurred by the company can be controlled properly. However, production planning cannot be formulated quickly. The problem is more complicated if the company has several production locations. The difference in location also affects the production references and standards applied in each location. Based on these problems, the authors propose to apply the Particle Swarm Optimization (PSO) algorithm to solve the problem of aggregate production planning in order to obtain the optimal solution for each production location. As a result, the algorithm proposed by the author can produce optimal and efficient solutions for 6 production sites. This is evidenced by the relatively short time required compared to the previous planning by the company.

Playback of male song advanced onset of nest building but not initial egg date or breeding synchrony in the Great Tit Parus major

2019 ◽  
Vol 161 (2) ◽  
pp. 585-588 ◽  
Author(s):  
Ye Gong ◽  
Bo Qin ◽  
Yufang Qin ◽  
Wei Sun ◽  
Haitao Wang
Keyword(s):  
Parus Major ◽  
Great Tit ◽  
Nest Building ◽  
Male Song ◽  
Breeding Synchrony

Clutch Size

2012 ◽  
Author(s):  
Tony D. Williams
Keyword(s):  
Life History ◽  
Clutch Size ◽  
Brood Size ◽  
Interspecific Variation ◽  
Life History Trait ◽  
Size Determination ◽  
Physiological Mechanisms ◽  
Lifetime Fitness ◽  
Upper Limit ◽  
Individual Variations

Clutch size is generally considered to be one of the most important determinants of reproductive success and lifetime fitness in birds. It is also perhaps the most well-studied life-history trait in birds, though many reviews have focused on interspecific variation. Clutch size sets an upper limit on brood size, and in single-brooded species, clutch size will therefore determine the maximum annual fledgling productivity. This chapter identifies the physiological mechanisms underlying individual, phenotypic variation in clutch size. Topics discussed include individual variations in clutch size and clutch number; why clutch size varies among individuals; selection on clutch size; and physiological mechanisms of clutch-size determination.

scholarly journals Twofold cost of reproduction: an increase in parental effort leads to higher malarial parasitaemia and to a decrease in resistance to oxidative stress

2011 ◽  
Vol 279 (1731) ◽  
pp. 1142-1149 ◽  
Author(s):  
Philippe Christe ◽  
Olivier Glaizot ◽  
Nicole Strepparava ◽  
Godefroy Devevey ◽  
Luca Fumagalli
Keyword(s):  
Oxidative Stress ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Brood Size ◽  
Parus Major ◽  
Cost Of Reproduction ◽  
Cell Resistance ◽  
Parental Effort ◽  
Brood Size Manipulation ◽  
Measured Resistance

Parental effort is usually associated with high metabolism that could lead to an increase in the production of reactive oxidative species giving rise to oxidative stress. Since many antioxidants involved in the resistance to oxidative stress can also enhance immune function, an increase in parental effort may diminish the level of antioxidants otherwise involved in parasite resistance. In the present study, we performed brood size manipulation in a population of great tits ( Parus major ) to create different levels of parental effort. We measured resistance to oxidative stress and used a newly developed quantitative PCR assay to quantify malarial parasitaemia. We found that males with an enlarged brood had significantly higher level of malarial parasites and lower red blood cell resistance to free radicals than males rearing control and reduced broods. Brood size manipulation did not affect female parasitaemia, although females with an enlarged brood had lower red blood cell resistance than females with control and reduced broods. However, for both sexes, there was no relationship between the level of parasitaemia and resistance to oxidative stress, suggesting a twofold cost of reproduction. Our results thus suggest the presence of two proximate and independent mechanisms for the well-documented trade-off between current reproductive effort and parental survival.

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