How are the Reapers numbers sustainable?

Question

Throughout the ME series we see Reapers being destroyed. Notable examples of this are:

• Sovereign in ME1 after it was disabled
• The Reaper on Rannoch
• The Reaper on Tuchanka
• During the Final battle for Earth by some species' dreadnought (with good war assets)
• Possibly during the Battle for Palaven (I seem to remember the Turians damaging/destroying at least 1)

We also know of at least 2 other confirmed Reaper deaths:

• The derelict Reaper orbiting Mnemosyne in the Thorne system of the Hawking Eta.
• The Leviathan of Dis which was hidden by the evil evil Batarians, long may the racist bastards suffer in the depths of batarian hell.

According to the game however the Reapers only produce one additonal Reaper per cycle and this is confirmed by the wiki (which is not really a good source)

"Available information suggests that a single race is harvested during each cycle to produce Reaper Capital Ships"

So I see a problem with the math here. Our cycle alone has killed at least 3 Reapers and other cycles have managed to kill two at least as well. I imagine that, though our cycle has been the only one that we know of to mount a large, unified full scale war on the Reapers, other cycles would have had an approximately equally strong military. If we were able to kill so many Reapers I predict that other cycles should have been able to kill at least one per cycle through whatever means. I am aware by the way that other cycles had their government and communications immediately destroyed by the Reapers, but they still should have been able to mount at least 1 solid stand despite this.

So the problem is that the Reapers reproduce at the rate of 1 per cycle, but could be being killed at a rate equal to or greater than 1 per cycle. This is not sustainable if my assumptions are correct.

Am I incorrect in assuming other cycles had weapons as strong as ours?

Answer 1

I think you possibly misinterpreted the text:

Available information suggests that a single race is harvested during each cycle to produce Reaper Capital Ships; it appears that other space-faring races harvested during the cycle are used to produce Destroyer-class Reapers. Exactly how or why this distinction is made is unknown.

This means that only a single race during a harvest is chosen to create new capital ships - note the plural. Which means that they pick a race (like Proteans in previous cycle and it seems that Humans in current) and process it into a Sovereign-class capital ships, each containing billions of processed minds. It never says that single race=single ship and in case of Protheans who were indeed ruling over multitude of planets such assumption would be highly unlikely (after all even they wouldn't fit into a single ship).

Also probably a few of mentioned above reapers were only Destroyer class ones, which are in fact the bulk of the Reaper's fleet.

While I can't find anywhere official statement saying that "during a harvest Reapers create X new capital ships using Y beings per ship", it is safer to assume that more than one (but probably no more than few) is made during harvest simply using Occam's razor:

• The Reapers already made partially functional Human Reapaer using barely hundreds or thousands of humans ergo not as many minds are required to create working ship.

• Their capital ships are not indestructible so...

• As you mentioned in the original post, if only one capital ship was created, their fleet would be unsustainable, since single lucky shot (although very powerful one) would made whole previous harvest invalid (and they don't kill for the killing sake but to preserve the harvested specie)

Now on the other hand the derelict Reaper is 37,000,000 years old, which means that there should be at least 740 Sovereign-class ships have been created since then (assuming indeed there was new harvest every 50k years) and yet we somehow don't see so many capital ships. This might be due to the fact that they just barely started to appear in the Milky Way and their bulk forces are still on their way or that so many of those ships have been destroyed.

Answer 2

Consider the reaper the collectors were trying to build, apparently to use for opening the Citadel relay to deep space. That would only have worked if the collectors were actually able to collect a number large enough; we can probably disregard what the crew said about "targeting Earth" as exaggeration - they could possible hope to take out a poorly defended colony, but not anything protected by a full fleet. The baby-reaper is nevertheless well along the path to independent status after being fuelled by a number of humans in the low millions (Horizon and Freeedom's progress had a combined population of about 1.5 million, as per the Incursion comic). The total human population of a few billion should thus be more than enough for a few capital ships. On top of this are all the smaller ships made from other races.

We should also remember that this cycle is very special; had Sovereign's Saren gambit succeeded, the galaxy would not have been able to put up such a stiff, coordinated resistance, and would not have had two and a half years to study reaper technology. An ordinary cycle might see a few Reapers taken out, but not enough to deplete their numbers.