Courtship Feeding and Mate Choice in Thynnine Wasps (Hymenoptera, Tiphiidae)

1987 ◽  
Vol 35 (5) ◽  
pp. 451 ◽  
Author(s):  
J Alcock ◽  
DT Gwynne

Females of two species of thynnine wasps, Megalothynnus klugii and Macrothynnus sp., attract mates while perched upright on vegetation close to the ground. When given an experimental choice between two females of different sizes, males of M. klugii carry off and copulate with the larger female significantly more often than they do the smaller one. No such preference was exhibited by males of Macrothynnus sp. Females of both species resist being removed from their calling perches and large males succeed more often than small ones in carrying away very large females. Despite mechanisms allowing a preference for large partners by both males and females in M. klugii, there is no evidence, in nature, of positive assortative mating according to body weight in this species. Various conditions, especially a scarcity of fertilisable females, may severely limit the choice of mates by males of these wasps.

2006 ◽  
Vol 2 (2) ◽  
pp. 250-252 ◽  
Author(s):  
Gudbjörg Á Ólafsdóttir ◽  
Michael G Ritchie ◽  
Sigurdur S Snorrason

Recently, models of sympatric speciation have suggested that assortative mating can develop between sympatric morphs due to divergence in an ecologically important character. For example, in sympatric pairs of threespine stickleback ( Gasterosteus aculeatus L.) size-assortative mating seems to be instrumental in reproductive isolation. Here, we examine courtship behaviour and assortative mating of newly described sympatric stickleback morphs in Lake Thingvallavatn, Iceland. We find that the two morphs show strong positive assortative mating. However, the mechanism involved in mate choice does not seem to be as straightforward as in other similar systems of sympatric stickleback morphs and may involve variation in nest type.


2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Katja Räsänen ◽  
Matthieu Delcourt ◽  
Lauren J. Chapman ◽  
Andrew P. Hendry

In ecological speciation, reproductive isolation evolves as a consequence of adaptation to different selective environments. A frequent contributor to this process is the evolution of positive assortative mate choice between ecotypes. We tested this expectation for lake and inlet stream threespine stickleback (Gasterosteus aculeatus) from the Misty system (Vancouver Island, Canada), which show strong genetically based adaptive divergence and little genetic exchange in nature. This, and work on other stickleback systems, led us to expect positive assortative mating. Yet, our standard “no-choice” laboratory experiment on common-garden fish revealed no evidence for this—despite divergence in traits typically mediating assortative mating in stickleback. These results remind us that divergent natural selection may not inevitably lead to the evolution of positive assortative mate choice. The apparent lack of strong and symmetric reproductive barriers in this system presents a conundrum: why are such barriers not evident despite strong adaptive divergence and low gene flow in nature?


1985 ◽  
Vol 63 (2) ◽  
pp. 334-339 ◽  
Author(s):  
R. Harmsen ◽  
L. R. McKay

Relative mating success of genetically different males of Drosophila pseudoobscura was measured with five female strains using an experimental set-up consisting of a mating chamber containing 20 females of one strain and a total of 20 males of two different strains. No evidence was found indicating negative assortative mating, neither of the direct type, nor of the "rare male" type. Some strains, however, displayed strong positive assortative mating, as males of the same strain as the females were significantly more successful in obtaining copulations than were males of another strain present in the mating chambers. Deviations from random mating can be interpreted as the result of some males possessing higher levels of "vigour," but an alternative explanation is favoured, one involving female choice. Experimental results do indicate that the orange-eyed mutant flies, used as one of the male strains in all experiments, did have a relatively low level of courtship vigour, but not low enough to account for more than a small fraction of the differential mating success observed in some of the experiments.


2019 ◽  
Author(s):  
Iris Jasmin Holzleitner ◽  
Kieran J. O'Shea ◽  
Vanessa Fasolt ◽  
Anthony J Lee ◽  
Lisa Marie DeBruine ◽  
...  

Previous research suggests that humans show positive assortative mating, i.e. tend to pair up with partners that are similar to themselves in a range of traits, including facial appearance. Facial appearance can function as a cue to genetic similarity and plays a critical role in human mate choice. Evidence for positive assortative mating for facial appearance has largely come from studies showing people can match pictures of couples’ faces at levels greater than chance and that facial photographs of couples are rated to look more similar than those of non-couples. However, interpreting results from matching studies as evidence of positive assortative mating for facial appearance is problematic, since this measure of perceived compatibility does not necessarily reflect actual physical similarity, and may be orthogonal to, or even negatively correlated with, physical similarity. Even if participants are asked to rate facial similarity directly, it remains unclear which, if any, face shape cues contribute to an increased perception of similarity in romantic couples. Here we use a shape-based assessment of facial similarity to show that the median similarity of long-term couples’ face shapes is only slightly greater than that of an age-matched control sample. Moreover, this was driven by the most similar 40% of couples, while the most dissimilar 20% of couples actually showed disassortative mating for face shape when compared to the control sample. These data show that a simple measure of central tendency obscures variability in the extent to which couples display assortative or disassortative mating for face shape. By contrast, a more fine-grained analysis that considers the distribution of variation across couples in the extent to which they resemble each other suggests that both positive and negative assortative processes influence human mate choice.


2017 ◽  
Vol 60 (No. 12) ◽  
pp. 682-690
Author(s):  
A. Charuta ◽  
MR Tatara ◽  
M. Dzierzecka ◽  
E. Polawska ◽  
I. Ptaszynska-Sarosiek

The aim of this study was to evaluate interrelationships of body weight and bone weight and densitometric properties of the tibiotarsus in White Koluda Geese (W31) in the post-hatching period. The study was performed using dual-energy X-ray absorptiometry (DEXA) and peripheral quantitative computed tomography (pQCT) at two different parts of tibia: proximal metaphysis and mid-diaphysis. The investigation was performed on 100 bones obtained from males and females at the age of 1, 14, 28, 42 and 56 days of life. All the calculations were performed using the Statistica 9.0 software (StatSoft, Inc. Tulsa, USA). Pearson’s correlation coefficient of body weight and bone weight with all the investigated variables of bone was determined. Depending on the method used for densitometric measurements – DEXA or pQCT, the current study has revealed significant differences in the number of correlations of bone weight and body weight with the evaluated densitometric parameters. Sex-related differences in the investigated interrelationships were also found. In the case of proximal epiphysis, negative correlations of vBMD, tBMC, CTR_DEN and CRT_CNT with body weight and bone weight dominated in one-day-old males. Based on the current observations and the negative correlations of body weight and vBMD, CRT_DEN and TRAB_DEN obtained in the mid-diaphysis of tibiotarsus at the age of 14 days of life, it was concluded that this bone is much more prone to deformations and fractures in males than in females.


2016 ◽  
Vol 68 (4) ◽  
pp. 1077-1084
Author(s):  
I. del C. García-Osorio ◽  
J. Oliva-Hernández ◽  
M.M. Osorio-Arce ◽  
G. Torres-Hernández ◽  
J. A. Hinojosa-Cuéllar ◽  
...  

ABSTRACT The aim of this study was to determine the influence of gender on pre-weaning growth, yield and weight of primal cuts of the carcass of Blackbelly x Pelibuey lambs. 16 twin lambs were used. The lamb gender was the fixed factor. The variables evaluated were: body weight at birth and at weaning, average daily weight gain, weight and yield of carcass and primal cuts: neck, arm, thorax, abdomen and leg. Gender did not affect (P>0.05) body weight at birth. However, the pre-weaning average daily weight gain and body weight at weaning were affected (P<0.05) by the gender. Hot carcass yield and weight and primal cuts were not affected (P>0.05) by the gender of the lamb. Nevertheless, the area of the Longissimus dorsi muscle and cavity fat were different between males and females (P<0.05) 11.5±0.73cm2 and 198±0.05 g vs 9.3±0.73cm2 and 282±0.05g, respectively. In conclusion, in twin lambs Blackbelly x Pelibuey males had greater average daily weight gain and body weight at weaning than females. Carcass yield and weight and primal cuts were not affected by the gender of the lamb. However, males had greater area of the L. dorsi muscle than females and these in turn had a greater amount of cavity fat than males.


2021 ◽  
Author(s):  
Thomas E White ◽  
Amy Locke ◽  
Tanya Latty

Abstract Structurally coloured sexual signals are a conspicuous and widespread class of ornament used in mate choice, though the extent to which they encode information on the quality of their bearers is not fully resolved. Theory predicts that signalling traits under strong sexual selection as honest indicators should evolve to be more developmentally integrated and exaggerated than nonsexual traits, thereby leading to heightened condition dependence. Here we test this prediction through examination of the sexually dimorphic faces and wings of the cursorial fly Lispe cana. Males and females possess structural UV-white and golden faces, respectively, and males present their faces and wings to females during close-range, ground-based courtship displays, thereby creating the opportunity for mutual inspection. Across a field-collected sample of individuals, we found that the appearance of the faces of both sexes scaled positively with individual condition, though along separate axes. Males in better condition expressed brighter faces as modelled according to conspecific flies, whereas condition scaled with facial saturation in females. We found no such relationships for their wing interference pattern nor abdomens, with the latter included as a nonsexual control. Our results suggest that the structurally coloured faces, but not the iridescent wings, of male and female Lispe cana are reliable guides to individual quality and support the broader potential for structural colours as honest signals. They also highlight the potential for mutual mate choice in this system, while arguing for one of several alternate signalling roles for wing interferences patterns among the myriad taxa which bear them.


Author(s):  
P. M. Parés- Casanova ◽  
A. Kabir

Sexual dimorphism, defined as phenotypic differences between males and females, is a common phenomenon in animals. In this line, Rensch’s rule states that sexual size dimorphism increases with increasing body size when the male is the larger sex and decreases with increasing average body size when the female is the larger sex. Domesticated animals offer excellent opportunities for testing predictions of functional explanations of Rensch’s theory. Pigeon breeds encounters many different functional purposes and selective constraints, which could influence strongly their morphology. The aim of this paper is to examine, for first time, Rensch’s rule among domestic pigeons. It was compiled a database of 12 quantitative traits (body weight, body height, beak thickness, beak length, neck length, neck thickness, wing length, rump width, tail length, tarsus length, tarsus thickness and middle toe length) for males and females of 11 different domestic pigeon breeds: Bangladesh Indigenous, Racing Homer, Turkish Tumbler, Indian Lotan, Kokah, Mookee, Indian Fantail, Bokhara Trumpeter, Bombai, Lahore and Hungarian Giant House; Rock Pigeon (Columba livia) was also considered as wild relative for comparative purposes. Comparative results between males and females showed that only body weight, wing length and neck thickness were consistent with Rensch’s rule. The rest of trait did not present correlations. Among domestic pigeons, there can appear different expressions of dimorphism according to each trait, so it must be considered that Rensch’s rule vary when considering other traits than body weight.


Author(s):  
V. S. Zaplatynsky

This article presents data on dynamics of linear growth and weight rates of obroshynska gray and obroshynska gray natural groups geese, factional fluff content, correlation coefficients between body weight and body sizes and amount of feathers. It has been found that male and female individuals of obroshynska gray natural group geese dominated by live weight of obroshynska white natural group geese. Particularly, this advantage in 90 days aged males was 549.4 (P < 0.05), in 120 days aged males – 635.6 (P < 0.01) and in 180 days aged males – 422.6 (P < 0.05) g, in females – 177.0, 461.8 (P < 0.01) and 401.8 g respectively. It has been also revealed the obroshynska gray natural group geese domination by researched body sizes in all geese ages, but it was only reliable in some cases. Geese of both sexes in both natural groups were characterized by high fluff and feather level. We investigated age, sex and interbreed differentiation on fluff and feather levels in studied geese groups. It should be noted that fluff and feather level was better in white geese indicating a better fluff and feather quality. The correlation coefficients between body weight and overall fluff and feather levels in females of obroshynska gray natural group geese dependent on ages and fluff and feather levels were between -0.30 – +0.63, in males – between -0.51 – +0.68 and in obroshynska white natural groups geese coefficients were between -0.29 – +0.70 and -0.30 до +0.82 respectively. It has been found the correlations between geese body sizes and fluff and feather levels. In males and females geese from abroshynska gray natural group depenent on ages, body sizes and fluff and feather levels coefficients were -0.49 – +0.81 and -0.76 – +0.88, and for obroshynska white natural group geese – -0.49 – +0.90 and -0.65 – +0.65.


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