LOS ANGELES — The Los Angeles Zoo has received a real treat for Halloween — the birth of its first hippopotamus in 26 years. It was a bit of trick, too, because the mother was on birth control.

The zoo says the baby was born Friday. It was somewhat of a surprise, but staffers had noticed the mother hippo gained weight, which made them suspect she was pregnant.

Mara and her calf get acquainted at the Los Angeles Zoo.

Females give birth while submerged underwater.  A single calf is born, rump first, which immediately paddles to the surface for breath then submerges again to nurse. Babies can often be seen resting on their mothers’ backs.

Vets haven’t determined the sex of the new hippo. But they say the baby appears to be doing well and is bonding with mom.

The mother, 10-year-old Mara, came to the zoo in December from Topeka, Kansas. The father is a 3-year-old named Adhama, who arrived from the San Diego Zoo last year.

For more hippo info, click here.