Search results
Results from the WOW.Com Content Network
English: Complete demonstration of the orgasm process of an adult male. The subject is a 27-year-old healthy circumcised Caucasian male. The video begins with the subject's genitals in a non-aroused flaccid state (0:00). As arousal progresses(0:30), the subject's penis becomes erect, the scrotum tightens and the testicles elevate.
Polygynandry is a mating system in which both males and females have multiple mating partners during a breeding season. [1] In sexually reproducing diploid animals, different mating strategies are employed by males and females, because the cost of gamete production is lower for males than it is for females. [2]
Polygyny threshold model graph. The polygyny threshold model is an evolutionary explanation of polygyny, the mating of one male of a species with more than one female. The model shows how females may gain a higher level of biological fitness by mating with a male who already has a mate. The female makes this choice despite other surrounding ...
Polygyny is more widespread in Africa than in any other continent. [2] Some scholars theorize that the slave trade's impact on the male-to-female sex ratio was a key factor in the emergence and fortification of polygynous practices in regions of Africa.
Polygyny (the most common polygamous mating system in vertebrates so far studied): One male has an exclusive relationship with two or more females. This is associated with one-male, multi-female group compositions. Many perennial Vespula squamosa (southern yellowjacket) colonies are polygynous. [3]
The polygyny threshold model also shows the effects of female reproductive success when multiple females in the same territory mate with one male. In this situation, the female has the option of breeding with an unmated male in a poor-quality territory or with an already-mated male in a high-quality territory.
After hatching of embryos, the female crosshatch triggerfish leaves the male's territory. This mating system is an example of male-territory-visiting polygamy. Triggerfishes exhibit other types of mating systems, as well, such as a nonterritorial-female (NTF) polygyny and territorial-female (TF) polygyny.
In animal behavior, resource defense polygyny is a mating strategy where a male is able to support multiple female mates by competing with other males for access to a resource. [1] [2] In such a system, males are territorial. Because male movement is restricted, female-female competition for a male also results.