Aldabra Giant Tortoises are bred in Mauritius and Rodrigues in their hundreds. Some of these are used for rewilding projects on islands and some are sold to collectors. The original tortoises were imported to Mauritius in the late 19th century at the suggestion of Charles Darwin to set up breeding projects in case the wild population in Aldabra should be exterminated.
Carl - do you know anything of the setup that the breeders have for producing large numbers? Is it space, terrain, multiple males, climate (or even all of the above) which are factors in success?
There are breeding herds on Mauritius and Rodrigues kept in large groups of adults with multiple males. The tortoises are in large natural enclosures or on islands.
I do remember it mentioned that when San Deigo zoo first bred them it was after their were some building work was done in the enclosure which left behind quite a bit of sand which was used by the Tortoises to get a better position when mating also for any egg laying at that time!
Some issues may be under-heating in temperate zoos (their normal temperature is in the 30o's, much above open grassy paddocks and open-fronted indoor exhibits) and lack of strongly seasonal temperature and food regime.
After seeing this group just a couple of weeks ago I am surprised how large they have now become some I believe would be tripled in size if not more. Darling Downs zoo seems to become Tortoise central within the zoos in the country not just for the first import of ten Aldabra but also keeping five from the second importation. Just to add also with keeping five Radiated Tortoises from a group confiscated in Hong Kong a few years ago and now another five from a more resent confiscation brings the zoos collection up to ten for this species which should help in the future when breeding starts to happen. @Kifaru Bwana
Not forgetting separating males and females in captive conditions in order to give the females some rest and allow them to be in mating mode with the males when they do put them out together. @Zorro, when and if no sign of pyramiding in the tortoises ... that is a good thing. Not sure how old as hatchlings the original imports were. So, I cannot comment whether overtly rich diets are a case in point. I would hope not ... though. Under natural conditions these giants reach sexual maturity at 15-20 years of age (and pretty much carapace size based over anything else). Sexing is also done later as their distinguishing sex features become more pronounced later in life.
Over and above some of these breeding facilities are now major suppliers for zoos for younger giant tortoises. I do hope they learn by example and from husbandry experiences gained in near natural conditions on Mauritius and Rodrigues. BTW: Currently, some of the giants have become candidate species for mainland Madagascar too. Madagascar used to have its own giant tortoise species along with the already - in tortoise terms - sizeable ploughshare or angonoka tortoise of Madagascar.
I would assume they have done much research into the best possible diets for them they have quite a good reptile collection there I am sure they would be doing the right thing by them.
