ISSN:
1432-0762
Schlagwort(e):
Mating tactics
;
Paternity analysis
;
Reproductive success
;
Sperm competition
;
Sorex araneus
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Biologie
Notizen:
Abstract The common shrew (Sorex araneus) is a solitary small mammal with a promiscuous mating system. Previous studies of this species suggest that females typically mate multiply, and that males may adopt alternative mate-searching tactics. We studied two generations of common shrews in a population near Oxford, England. Males were found to adopt two different mate-searching tactics. Those classed as type A occupied relatively small exclusive ranges during March, and made repeated long-distance movements to visit female ranges around the time of first oestrus in April. Males classed as type B established large overlapping ranges in areas of relatively high female density during March, and maintained these ranges throughout April. Type B males were larger than type A males at an early stage of sexual maturation, but there was no difference in the adult body size of the two types of male. Type A males had significantly higher epididymal sperm counts than type B males. Paternity analyses of litters born during the first year of the study reveal that the mean number of offspring fathered by type B males was greater than the mean number fathered by type A males. It is concluded that different mate-searching tactics may be conditional upon the timing of sexual maturation. Differences in sperm production are discussed in relation to sperm competition theory.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00175460
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