ZSL (Zoological Society of London) London Zoo keepers weren't privy to a secret between their two-toed sloths Leander and Marilyn. The pair had successfully mated and Marilyn was pregnant, something that the staff learned long after the fact.
Leander had been transferred to ZSL London Zoo from a zoo in Germany in order to be paired with Marilyn. The keepers were making an effort to get Marilyn and Leander to acknowledge each others' presence -- little did they know that they were already sloth sweethearts!
Zoo staff member Tegan McPhail explained,
“To say we were surprised when Marilyn fell pregnant is something of an understatement – we weren’t aware that she’d even been near the male.
When Leander arrived at the Zoo at the end of 2012, he and Marilyn just didn’t appear particularly interested in each other, but we knew that with sloths these things can take some time.
However, with the arrival of the first sloth to be born at ZSL London Zoo, it appears that it was all an act on their behalf and our two very sneaky sloths were getting amorous behind our backs!"
The baby two-toed sloth, whose sex is yet to be determined, is tightly bonded with Marilyn. By all accounts she is proudly showing off her baby. Via Zooborns.