hmm... we're studying birds in biology.
wat about bugs? wat about fish? wat about other mammals? is it if they go into cycles of heat and non heat than they have menstrual cycle?
is menstrual cycle defined having blood come out... or just that there is an ovulation cycle? or if you have an ovulation cycle blood has has to come out as some point?
need a bio expert here
The Wise Wolf
Favorite Answer
Animals do not have periods in the same way humans do. In humans, an egg is released from the ovaries once a month - this is the woman's fertile time. At this point in the cycle, the lining of the womb is thickened in preparation for an embryo to embed in it should pregnancy occur. If the woman does not become pregnant, the womb lining and the unfertilised egg are discarded - this is what the 'blood' shed during a period is. This is menstruation. Obviously, since birds reproduce by laying eggs, they do not need to develop a thickened womb lining in the first place, much less shed it.
In other mammals, if they do not become pregnant during their fertile time (which may occur much more often or much less often than in humans, depending on the species), they reabsorb the womb lining and egg into the body rather than shedding it - they don't 'bleed' the way we do. Quite why we expel it from our bodies rather than reabsorbing it is not known, but it must have had some evolutionary advantage at some point in our history or it would not have evolved.
Note that the bloody discharge seen in some animals, such as dogs and cats, when they are in oestrus (commonly called 'heat' or 'season'), is NOT a period. The animal is NOT shedding its womb lining - the discharge is to produce scent to let any nearby males know they are receptive, and to provide lubricant for intercourse. Oestrus is the animal's fertile time, the time she is ready to conceive - the womb lining is thickened and eggs have been released or are about to be released with the stimulus of mating. In most animals, this is the only time the animal feels sexual desire, since it is the only time pregnancy can occur and it would be pointless to mate at any other time. This is the point in the cycle that comes BEFORE a period in humans, since we only have periods to get rid of the unused womb lining and egg if we don't become pregnant.
cartlidge
Yeah, you basically responded your question & perchance you need to take a nearer seem on the idiots who tell human beings the incorrect counsel extremely than the human beings who've been counseled of the incorrect counsel. once you're in simple terms getting to know & naive you're taking something on board. training is the main important! As for the roos. they have a furnish of embryos that lay dormant. One embryo swings into production at a time. as quickly as the joey has left the pouch, died, or regardless of the subsequent embryo is introduced directly to swing into replica. while the joey is suckling it sends off alerts that quickly give up replica. they are able to have 3 embryo's & joeys in a million 365 days. So there's slightly extra to it than in simple terms storing & constructive situations. Sorry...you introduced it up first :)))
Anonymous
NO!!!!!!!!!!!!!!!!!!!!!!
Only human females menstruate!
ESTRUS is the exact opposite of menstruation!
"Having blood come out" is ***NOT*** the definition of menstruation.