scholarly journals The Cost of Mating: Influences of Life History Traits and Mating Strategies on Lifespan in Two Closely RelatedYponomeutaSpecies

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
A. C. Bakker ◽  
J. Campos Louçã ◽  
P. Roessingh ◽  
S. B. J. Menken

Theory predicts that in monandrous butterfly species males should not invest in a long lifespan because receptive females quickly disappear from the mating population. In polyandrous species, however, it pays for males to invest in longevity, which increases the number of mating opportunities and thus reproductive fitness. We tested an extension of this idea and compared male and female lifespan of two closely relatedYponomeutaspecies with different degree of polyandry. Our results confirmed the theoretical prediction that male lifespan is fine-tuned to female receptive lifespan; once-mated males and females of both polyandrous species had an equal lifespan. However, the degree of polyandry was not reflected in male relative to female lifespan. The observed similar female and male lifespan could largely be attributed to a dramatic reduction of female lifespan after mating.

Behaviour ◽  
2019 ◽  
Vol 156 (10) ◽  
pp. 1017-1037 ◽  
Author(s):  
Colton S. Lynn ◽  
Benjamin Dalton ◽  
Alicia Mathis

Abstract When both males and females are territorial, spatial and aggressive behaviour can vary between the sexes. We examined differences in exploratory and competitive behaviour between males and females and residents and intruders of two species, the Ozark zigzag (P. angusticlavius) and southern red-backed (P. serratus) salamanders. For exploratory behaviour, males and females differed in distance traveled based on species, but females of both species were significantly more cautious than males about leaving territories. In competition trials, male and female territory residents (owners) did not differ in defensive behaviour, but female intruders were more aggressive than male intruders. Overall, P. angusticlavius showed more aggressive behaviour, explored more, and were less cautious about leaving territories than P. serratus. Female intruders of both species fight harder, potentially to gain territories, and are more cautious about leaving territories, which may indicate that the cost of not having a territory is greater for females.


2017 ◽  
Vol 284 (1851) ◽  
pp. 20162174 ◽  
Author(s):  
Mikael Puurtinen ◽  
Lutz Fromhage

We study the evolution of male and female mating strategies and mate choice for female fecundity and male fertilization ability in a system where both sexes can mate with multiple partners, and where there is variation in individual quality (i.e. in the availability of resources individuals can allocate to matings, mate choice and production of gametes). We find that when the cost of mating differs between sexes, the sex with higher cost of mating is reluctant to accept matings and is often also choosy, while the other sex accepts all matings. With equal mating costs, the evolution of mating strategies depends on the strength of female sperm limitation, so that when sperm limitation is strong, males are often reluctant and choosy, whereas females tend to accept available matings. Male reluctance evolves because a male's benefit per mating diminishes rapidly as he mates too often, hence losing out in the process of sperm competition as he spends much of his resources on mating costs rather than ejaculate production. When sperm limitation is weaker, females become more reluctant and males are more eager to mate. The model thus suggests that reversed sex roles are plausible outcomes of polyandry and limited sperm production. Implications for empirical studies of mate choice are discussed.


2017 ◽  
Vol 38 (2) ◽  
pp. 943
Author(s):  
Luiz Carlos Pereira ◽  
Luís Carlos Vinhas Itavo ◽  
Rodrigo Gonçalves Mateus ◽  
Eduardo Souza Leal ◽  
Urbano Gomes Pinto Abreu ◽  
...  

This study aimed to evaluate the performance and economic viability of including the aerial parts of cassava (PAM) in the feed of semi-confined lambs for partial reduction of food concentrates. Fifty-six sheep, including males and females of the Pantaneira genetic group weighing 18.84 ± 2.02 kg on an average were used. The experiment was conducted in a factorial randomized complete block design with four treatments, each with seven females and seven males. Each group of 14 animals received one of four treatments: control, 10% of food concentrate in diet replaced with PAM, 20% replaced with PAM, and 30% replaced with PAM. The average total gain in weight (GWT) of the male lambs was 26.89% higher than the gains observed in females. Based on the cost analysis, we observed a linear effect (P < 0.01), i.e., a decrease in the feed cost for male and female groups with increase in PAM content. For the study period, the expenditure for the control male group was the highest at $ 17.60 per animal. Expenditure for the PAM 30 male group was the lowest at $ 12.74 per animal. These figures reflect the actual operating costs (COE), i.e., the power is 75.78% and 74.77%, for male and female groups respectively. The total cost, decreased linearly (P < 0.05) with PAM 30 treatment costing the least at $ 47.90, which was $ 7.02 lower than the control. When assessing the net margin per kilogram among the female groups, we observed a quadratic effect (P < 0.01) with a maximum gain of 23.98% when adding PAM and $ 0.50 kg-1. Our results show that the raising of lambs in semi-confinement was economically viable, and the addition of the aerial part of processed cassava in the feed presented a higher economic return. Further, the addition of aerial parts of cassava did not affect the performance of the lambs.


Parasitology ◽  
1999 ◽  
Vol 119 (5) ◽  
pp. 447-454 ◽  
Author(s):  
J. BOISSIER ◽  
S. MORAND ◽  
H. MONÉ

The sexual life-history traits of Schistosoma mansoni have been reviewed to compare male and female performance and pathogenicity against Biomphalaria glabrata during the life-cycle. A meta-analysis was used on pooled results from different experiments. In most cases, there was no difference between males and females but male cercariae were significantly more infectious than female cercariae. Conversely, cercarial production and cercarial life-span were significantly greater for females than for males; furthermore, females have a tendency to occur in molluscs of larger size. Each difference is discussed and interpreted when possible in terms of male and female differences in transmission strategies. The female strategy may consist of producing many long-living larvae. The male strategy may consist of producing few short-living larvae and would invest in the quality of these larvae instead of their quantity or their life-span.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7143
Author(s):  
Eric Novelo Galicia ◽  
Moisés Armando Luis Martínez ◽  
Carlos Cordero

In many butterfly species, the posterior end of the hindwings of individuals perching with their wings closed resembles a butterfly head. This “false head” pattern is considered an adaptation to deflect predator attacks to less vulnerable parts of the body. The presence of symmetrical damage in left and right wings is considered evidence of failed predator attacks to perching butterflies. In this research, we tested the prediction derived from the deflection hypothesis that the degree of resemblance of the false head area (FH) to a real head, as measured by the number of FH “components” (eyespots, “false antennae”, modified outline of the FH area and lines converging on the FH area) present in the hindwings, is positively correlated to the frequency of symmetrical damage in the FH area. We studied specimens from two scientific collections of butterflies of the subfamily Theclinae (Lycaenidae) belonging to the Universidad Nacional Autónoma de México (Colección Nacional de Insectos [CNIN] and Museo de Zoología, Facultad de Ciencias [MZFC]). We scored the presence of symmetrical damage in a sample of 20,709 specimens (CNIN: 3,722; MZFC: 16,987) from 126 species (CNIN: 78 species; MZFC: 117 species; 71 species shared by both collections) whose hindwings vary in the number of FH components, and found that, as predicted, the proportion of specimens with symmetrical damage increases as the number of FH components increases. We also tested the hypothesis that behavioural differences between the sexes makes males more prone to receive predator attacks and, thus, we predicted a higher frequency of symmetrical damage in the FH of males than in that of females. We found that the frequency of symmetrical damage was not significantly different between males and females, suggesting that behavioural differences between the sexes produce no differences in the risk of being attacked. Overall, our results provide support to the idea that the FH of butterflies is an adaptation that deflects predator attacks to less vulnerable parts of the body in both sexes.


1968 ◽  
Vol 58 (4) ◽  
pp. 600-612 ◽  
Author(s):  
Robert Boyd ◽  
Donald C. Johnson

ABSTRACT The effects of various doses of testosterone propionate (TP) upon the release of luteinizing hormone (LH or ICSH) from the hypophysis of a gonadectomized male or female rat were compared. Prostate weight in hypophysectomized male parabiotic partners was used to evaluate the quantity of circulating LH. Hypophyseal LH was measured by the ovarian ascorbic acid depletion method. Males castrated when 45 days old secreted significantly more LH and had three times the amount of pituitary LH as ovariectomized females. Administration of 25 μg TP daily reduced the amount of LH in the plasma, and increased the amount in the pituitary gland, in both sexes. Treatment with 50 μg caused a further reduction in plasma LH in males, but not in females, while pituitary levels in both were equal to that of their respective controls. LH fell to the same low level in partners of males or females receiving 100 μg TP. When gonadectomized at 39 days, males and females had the same amount of plasma LH, but males had more stored hormone. Pituitary levels were unchanged from controls following treatment with 12.5, 25 or 50 μg TP daily, but plasma values dropped an equal amount in both sexes with the latter two doses. Androgenized males or females, gonadectomized when 39 days old, were very sensitive to the effects of TP and plasma LH was significantly reduced with 12.5 μg daily. Pituitary LH in androgenized males was higher than that of normal males but was reduced to normal by small amounts of TP. The amount of stored LH in androgenized females was not different from that of normal females and it was unchanged by any dose of TP tested. Results are consistent with the conclusion that the male hypothalamic-hypophyseal axis is at least as sensitive as the female axis to the negative feedback effects of TP. Androgenization increases the sensitivity to TP in both males and females.


2020 ◽  
Vol 27 (4) ◽  
pp. 195-200
Author(s):  
Ufuk Bülbül ◽  
Halime Koç ◽  
Yasemin Odabaş ◽  
Ali İhsan Eroğlu ◽  
Muammer Kurnaz ◽  
...  

Age structure of the eastern spadefoot toad, Pelobates syriacus from the Kızılırmak Delta (Turkey) were assessed using phalangeal skeletochronology. Snout-vent length (SVL) ranged from 42.05 to 86.63 mm in males and 34.03 to 53.27 mm in females. Age of adults ranged from 2 to 8 years in males and 3 to 5 years in females. For both sexes, SVL was significantly correlated with age. Males and females of the toads reached maturity at 2 years of age.


2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Kyle Landon Jossy

This study looked at how males and females were portrayed, based on the amount of skin shown in the clothing worn.  A Content analysis was performed on a sample of 20 randomly selected popular comics from the last 3 years.  Both male and female characters were rated on how much skin they showed in three clothing categories; neck line, sleeve length, and lower body.  Results showed that in all 3 categories, women consistently wore more revealing clothing.  The findings demonstraetd that the comic book industry is comparable to other forms of media, in the sexualization of female characters, by having them wear more revealing clothing.


Metabolites ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 206
Author(s):  
Leon Deutsch ◽  
Damjan Osredkar ◽  
Janez Plavec ◽  
Blaž Stres

Spinal muscular atrophy (SMA) is a genetically heterogeneous group of rare neuromuscular diseases and was until recently the most common genetic cause of death in children. The effects of 2-month nusinersen therapy on urine, serum, and liquor 1H-NMR metabolomes in SMA males and females were not explored yet, especially not in comparison to the urine 1H-NMR metabolomes of matching male and female cohorts. In this prospective, single-centered study, urine, serum, and liquor samples were collected from 25 male and female pediatric patients with SMA before and after 2 months of nusinersen therapy and urine samples from a matching healthy cohort (n = 125). Nusinersen intrathecal application was the first therapy for the treatment of SMA by the Food and Drug Administration (FDA) and the European Medicines Agency (EMA). Metabolomes were analyzed using targeted metabolomics utilizing 600 MHz 1H-NMR, parametric and nonparametric multivariate statistical analyses, machine learning, and modeling. Medical assessment before and after nusinersen therapy showed significant improvements of movement, posture, and strength according to various medical tests. No significant differences were found in metabolomes before and after nusinersen therapy in urine, serum, and liquor samples using an ensemble of statistical and machine learning approaches. In comparison to a healthy cohort, 1H-NMR metabolomes of SMA patients contained a reduced number and concentration of urine metabolites and differed significantly between males and females as well. Significantly larger data scatter was observed for SMA patients in comparison to matched healthy controls. Machine learning confirmed urinary creatinine as the most significant, distinguishing SMA patients from the healthy cohort. The positive effects of nusinersen therapy clearly preceded or took place devoid of significant rearrangements in the 1H-NMR metabolomic makeup of serum, urine, and liquor. Urine creatinine was successful at distinguishing SMA patients from the matched healthy cohort, which is a simple systemic novelty linking creatinine and SMA to the physiology of inactivity and diabetes, and it facilitates the monitoring of SMA disease in pediatric patients through non-invasive urine collection.


Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 392
Author(s):  
Antonio Pulido-Pastor ◽  
Ana Luz Márquez ◽  
José Carlos Guerrero ◽  
Enrique García-Barros ◽  
Raimundo Real

Metapopulation theory considers that the populations of many species are fragmented into patches connected by the migration of individuals through an interterritorial matrix. We applied fuzzy set theory and environmental favorability (F) functions to reveal the metapopulational structure of the 222 butterfly species in the Iberian Peninsula. We used the sets of contiguous grid cells with high favorability (F ≥ 0.8), to identify the favorable patches for each species. We superimposed the known occurrence data to reveal the occupied and empty favorable patches, as unoccupied patches are functional in a metapopulation dynamics analysis. We analyzed the connectivity between patches of each metapopulation by focusing on the territory of intermediate and low favorability for the species (F < 0.8). The friction that each cell opposes to the passage of individuals was computed as 1-F. We used the r.cost function of QGIS to calculate the cost of reaching each cell from a favorable patch. The inverse of the cost was computed as connectivity. Only 126 species can be considered to have a metapopulation structure. These metapopulation structures are part of the dark biodiversity of butterflies because their identification is not evident from the observation of the occurrence data but was revealed using favorability functions.


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