Further to my earlier post, I have checked both the
European Hippopotamus Studbook and the excellent book “
A Survey of the Hippopotamus in Captivity in the British Isles” (John Frost; 1996).
You might be interested that both "Spot" and "Sonia" had two calves each at Longleat, as follows:-
"Spot"
- Male "Invincible" born ?? Sept 1982**
- Male "Harvey" born 13th Oct 1983
"Sonia"
- Male "Nautilus" born 25th Sept 1982
- Male "Walley" born 4th Sept 1984
** There is a slight discrepancy on the date "Invincible" was born. John Frost"s book gives 18th September 1982 whilst, according to the studbook, it was ten days earlier on 8th September 1982. I don't know which is correct. (The two sources agree exactly about the other three dates of birth.)
NB John Frost's book doesn't use the name "Sonia" he refers to this individual as the "Big Female" but it's clearly the same animal.