I've not seen/read any female Orcs mentioned in the movies or in the books. In one of the movies, an Uruk-hai is momentarily shown emerging from a giant, grown-Orc sized flesh packet. So are they created with spells, or do they follow the Standard Reproductive Model.
10They are born. In Tolkien's world, no one can create life except Eru.– user8252Dec 18, 2012 at 4:58
39Well, when a mammy orc and a daddy orc are very much in love...– user8719Dec 18, 2012 at 9:01
12"And this in turn has given rise to the belief that there are no orc women, and that orcs just spring out of holes in the ground!"– fire.eagleDec 18, 2012 at 20:18
10IntercORC...I hate myself.– Monty129Dec 25, 2012 at 10:02
8Orc babies are delivered by a storc.– KorvinStarmastFeb 21, 2017 at 21:00
It's clearly stated multiple times in The Silmarillion that only Ilúvatar can create life.
In chapter 2 of "Quenta Silmarillion" ("Of Aulë and Yavanna"), Aulë creates the dwarves, but Ilúvatar chastises him:
Why dost thou attempt a thing which thou knowest is beyond thy power and thy authority?
In chapter 3 ("Of the Coming of the Elves and the Captivity of Melkor") the creation of the Orcs is explained:
...all those of the Quendi who came into the hands of Melkor, ere Utumno was broken, were put there in prison, and by slow arts of cruelty were corrupted and enslaved; and thus did Melkor breed the hideous race of the Orcs in envy and mockery of the Elves...
For the Orcs had life and multiplied after the manner of the Children of Ilúvatar; and naught that had life of its own, nor the semblance of life, could ever Melkor make...
13That is so horrible. F**k you Melkor. Thanks Ward. Dec 18, 2012 at 11:33
5+1 To add to your great answer, I think Aulë wasn't capable to create life either. Wasn't Ilúvatar the one who "breathed" life into the corpses of the newly created Dwarves? Dec 18, 2012 at 16:50
12@adityamenon I actually support Melkor! Here are my reasons: 1- The Silmarillion, Hobbit and LotR would have been utterly boring without him and his actions; 2- He was a rebel who made his own rules, sticking it to The Man, 3- It's likely this was all Ilúvatar's plan anyway, and Melkor never ceased being his instrument :) Dec 18, 2012 at 16:53
5@adityamenon I made it up. Since Tolkien was Catholic, it's likely Eru is somewhat like the Christian god; and the explanation for Evil (Melkor) is that it is a consequence of Free Will (i.e. not directed by Eru). However, this is speculation on my part. I still root for Melkor, because he looks badass in armor! Dec 23, 2012 at 23:48
3@AndresF. - I know it's old, but re: your 3, see Ainulindale: "And thou, Melkor, shalt see that no theme may be played that hath not its uttermost source in me, nor can any alter the music in my despite".– user8719Dec 10, 2013 at 19:28
The Munby Letter includes an authorial statement on this matter:
There must have been orc-women. But in stories that seldom if ever see the Orcs except as soldiers of armies in the service of the evil lords we naturally would not learn much about their lives.
There's also a caution in this statement - if Orcs (or any other being, for that matter) are only ever seen in one context within the story, then you don't need (and shouldn't feel that you need) any kind of explicit statement regarding their activities in other contexts.
Orcs originated from Elves, twisted and tainted by Morgoth. As the elves taken were both male and female, the first Orcs were also male and female. As such, they are able to reproduce.
2The origin of Orcs isn't clear. Tolkien spent decades trying to figure it out. They may have been elves.– isanaeJan 15, 2017 at 9:48
I always imagined that Orcs can reproduce in two ways.
All Orcs either fill a male or female role in the reproductive cycle. All Orcs, however still appear and act masculine. This would also explain why Orcs never seem to hold any desire for women, because they probably have no concept of sexual preference.
Powerful magic-users such as Melkor, Sauron, or Saurman are capable of using some sort of device or substance to manufacture Orcs. Orcs' numbers seem to grow much faster when a powerful magic-user is leading them. The Orcs pretty much stopped breeding, and devolved into Goblins once The One Ring was destroyed and Sauron was defeated. My guess is that these Orcs were breeded, and thus didn't know how to reproduce sexually, or just couldn't supplement their numbers as they relied on Sauron's breeding.
I feel this would explain a lot. It was clearly very surprising when Saruman was able to mass such a large amount of Uruks so quickly, so I imagine magical breeding was involved. It would also explain the relationship between Azog and Bolg, since Bolg is Azog's son, and inherited his rank when Azog died. It's also said that Uruks were bred with Men, so they would need some form of sexual reproduction. So in essence, both of these methods of reproduction could exist at the same.
Another answer on this very page quotes a letter by Tolkien, the author of The Lord of the Rings, saying "There must have been orc-women. But in stories that seldom if ever see the Orcs except as soldiers of armies in the service of the evil lords we naturally would not learn much about their lives." This implies that the orcs that we see in the story are not the orc-women. Saruman's Uruk army wasn't made that quickly, and it's implied that he made them (in the books) via interbreeding Orcs and Men.– wyvernOct 19, 2017 at 2:44