Human sperm competition
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Sperm competition is a form of post-copulatory sexual selection whereby male sperm simultaneously physically compete to fertilize a single ovum. Sperm competition occurs between sperm from two or more
Stained human sperm
Extra-pair copulation
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Extra-pair copulation is a mating behaviour in socially monogamous species wherein one of the members of the pair breeds with an organism outside the bound pair. EPC in the animal kingdom has mostly b
Human sperm competition
…to fertilize a female within a sufficiently short period of time. This results primarily as a consequence of polyandrous mating systems, or due to extra-pair copulations of females, which increases the chance of cuckoldry, in which the male mate raises a child that is not genetically related to him. Sperm competition…
In tree swallow (Tachycineta bicolor) nests, most broods contain at least one extra-pair egg.
Seychelles warblers (Acrocephalus sechellensis) display effective mate guarding strategies.
Pair of zebra finches: Bird Kingdom, Niagara Falls, Ontario, Canada
Black-capped chickadee nest.