scholarly journals A Comparative Study of Mating Strategies in Two Species of Philanthus (Hymenoptera: Sphecidae)

Author(s):  
Howard Evans ◽  
Kevin O'Neill

Our work on the reproductive biology of Philanthus pulcher and P. zebratus in Jackson Hole in 1980 was a continuation of a study which had three major objectives. The first was to determine the relationship between female and male activity patterns. As in other species with extensive female-contributed and no male-contributed parental investment, females are a resource necessary for reproductive success of males. Thus, the activity of females in time and space should be an important parameter affecting the evolution of male mating strategies. Our work in this area is being combined with data we have gathered elsewhere on other species of Philanthus (O'Neill and Evans, unpublished). The second objective was to determine what characteristic of males was important in determining reproductive success and the form of the mating strategy. Since our preliminary data on Philanthus indicated that body size may be the most important variable affecting male reproductive success, we concentrated on this aspect of male biology. This report will focus on our results in this area. The third objective was to determine the role of male-produced sex pheromones in the mating system. (* Erratum: pp. 56 and 57 should be 51 and 52 )

Author(s):  
Howard Evans

This research is part of a continuing, broad-scale field study of both male and female behavior in solitary, ground-nesting wasps. Emphasis at the present time is on the genus Philanthus (Hymenoptera, Sphecidae). Earlier work in Jackson Hole (Evans, 1970, 1973) had revealed the presence of large nesting aggregations of three species of this genus. Since that time we have come to appreciate that male mating strategies are deserving of detailed, comparative study; we are also aware of details of nest structure that need to be clarified. The ultimate goal of these studies is the preparation of a monograph on the comparative behavior of the species of Philanthus.


1988 ◽  
Vol 36 (5) ◽  
pp. 521 ◽  
Author(s):  
D Cook

One component of the reproductive success (fitness) of Onthophagus binodis Thunberg males was estimated by the number of offspring their mate produced relative to male horn and body size. O. binodis males consist of large horned and small hornless morphs. Female fecundity was significantly increased when reproducing with: (1) large horned males compared with small hornless males; (2) the horned morph compared with the hornless morph of males with similar body size. Horned males cooperating with females invest a considerable effort in providing each egg with dung. Hornless males do not appear to assist females after mating. Alternative male mating strategies are predicted under intense intrasexual competition. As hornless O. binodis males persist in large numbers alongside cooperative, mate guarding horned males, selection should favour alternative tactics by hornless males to gain reproductive opportunities.


2016 ◽  
Vol 78 (12) ◽  
pp. 1316-1325 ◽  
Author(s):  
Joyce A. Parga ◽  
Michelle L. Sauther ◽  
Frank P. Cuozzo ◽  
Ibrahim Antho Youssouf Jacky ◽  
Richard R. Lawler ◽  
...  

Behaviour ◽  
2011 ◽  
Vol 148 (11-13) ◽  
pp. 1372-1392 ◽  
Author(s):  
Alice U. Edler ◽  
Thomas W.P. Friedl

AbstractThe role of bright plumage colouration for female choice has been the focus of research in sexual selection for many years, with several studies showing that females prefer the most elaborately ornamented males, which are often also the highest quality individuals. Here, we analysed the associations between reproductive performance and plumage, body condition and blood parasite load in the red bishop (Euplectes orix), a sexually dimorphic and polygynous weaverbird species, where males in a carotenoid-based orange-to-red breeding plumage defend territories and build many nests to which they try to attract females. Male reproductive success in terms of number of nests accepted was mainly determined by the number of nests built, but was also positively related to blood parasite load, while we found no influence of plumage characteristics. Together with previously obtained data, our results indicate that plumage characteristics in the red bishop do not affect male reproductive success and are generally not suitable to reliably indicate male quality. We suggest that the primary function of the brilliant orange-scarlet breeding plumage might be presence signalling in terms of increasing conspicuousness of breeding males to females searching for mates.


2016 ◽  
Vol 283 (1843) ◽  
pp. 20161883 ◽  
Author(s):  
Viola Pavlova ◽  
Jacob Nabe-Nielsen ◽  
Rune Dietz ◽  
Christian Sonne ◽  
Volker Grimm

Polar bears ( Ursus maritimus ) from East Greenland and Svalbard exhibited very high concentrations of polychlorinated biphenyls (PCBs) in the 1980s and 1990s. In Svalbard, slow population growth during that period was suspected to be linked to PCB contamination. In this case study, we explored how PCBs could have impacted polar bear population growth and/or male reproductive success in Svalbard during the mid-1990s by reducing the fertility of contaminated males. A dose–response relationship linking the effects of PCBs to male polar bear fertility was extrapolated from studies of the effects of PCBs on sperm quality in rodents. Based on this relationship, an individual-based model of bear interactions during the breeding season predicted fertilization success under alternative assumptions regarding male–male competition for females. Contamination reduced pregnancy rates by decreasing the availability of fertile males, thus triggering a mate-finding Allee effect, particularly when male–male competition for females was limited or when infertile males were able to compete with fertile males for females. Comparisons of our model predictions on age-dependent reproductive success of males with published empirical observations revealed that the low representation of 10–14-year-old males among breeding males documented in Svalbard in mid-1990s could have resulted from PCB contamination. We conclude that contamination-related male infertility may lead to a reduction in population growth via an Allee effect. The magnitude of the effect is largely dependent on the population-specific mating system. In eco-toxicological risk assessments, appropriate consideration should therefore be given to negative effects of contaminants on male fertility and male mating behaviour.


Behaviour ◽  
2015 ◽  
Vol 152 (7-8) ◽  
pp. 1113-1144 ◽  
Author(s):  
Karpagam Chelliah ◽  
Raman Sukumar

Elaborate male traits with no apparent adaptive value may have evolved through female mate discrimination. Tusks are an elaborate male-only trait in the Asian elephant that could potentially influence female mate choice. We examined the effect of male body size, tusk possession and musth status on female mate choice in an Asian elephant population. Large/musth males received positive responses from oestrous females towards courtship significantly more often than did small/non-musth males. Young, tusked non-musth males attempted courtship significantly more often than their tuskless peers, and received more positive responses (though statistically insignificant) than did tuskless males. A positive response did not necessarily translate into mating because of mate-guarding by a dominant male. Female elephants appear to choose mates based primarily on traits such as musth that signal direct fertility benefits through increased sperm received than for traits such as tusks that may signal only indirect fitness benefits.


1998 ◽  
Vol 79 (4) ◽  
pp. 1317-1324 ◽  
Author(s):  
J. L. Rachlow ◽  
E. V. Berkeley ◽  
J. Berger

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