Initially I didn't like the genetic bottleneck created by just having one pair (i.e. that they should go back and get more now that they know how to care for them, perhaps as a swap) - but then I realized the original source on the island was probably a single individual, so they are all probably virtually clones anyway.
Once they have enough they should sell some - tons of people would be delighted to keep them as pets, and it would remove the risk of having them in just one location.