Wild Valentines: Zoo Animals Enjoy Sweet (and Kinda Gross) Treats

aldabra tortoise, animal valentine's day, zoo valentine's day, wild valentines, valentine's day at the zoo, sweet animals on valentines day, gross valentines, animal valentines, zoo valentines, animals — A massive Aldabra tortoise eyes a sweet Valentine's Day treat at the National Zoo. (Image credit: Jennifer Zoon, Smithsonian's National Zoo.)

On Valentine's Day, humans often struggle to find the perfect gift for their beloved. Thankfully, if all else fails, flowers and chocolates will likely do the trick. But how do you express your affection for a crocodile?

Say it with cow blood and rats, of course.

Zoos around the United States and the United Kingdom marked Valentine's Day this year by giving their resident loved ones a host of gifts. Some of the valentines were sweet, some were (to a human eye) vaguely disgusting, and all were received with varying degrees of glee.

How do you say, "I love you," to the massive predatory reptile in your life? A Cuban crocodile at the National Zoo. (Image credit: Jennifer Zoon, Smithsonian's National Zoo.)

At the National Zoo in Washington, D.C., Cuban crocodiles feasted on heart-shaped treats made from water, beef blood, beet juice, gelatin, white rats and black mice.

In the wild, the highly endangered reptiles are known to leap from the water and snatch prey from overhanging branches, yet no such acrobatics were required at the zoo. Zoo nutrition staff tossed the Valentine's Day treats into the crocodiles' enclosure, and the reptiles made short work of the snacks.

Other giant reptiles at the National Zoo received some Valentine's Day love. Zoo staff whipped up heart-shaped snacks made out of water, beet juice, beets, carrots, sweet potatoes and gelatin for the Aldabra tortoises.

The massive herbivores, native to the Seychelles Islands off the east coast of Africa, can weigh up to 350 pounds (159 kilograms) and live more than 100 years.

They ate the snacks, but with less abandon than the crocodiles. [See photos of animals and their valentines.]

Somebody loves you, Walker. The polar bear investigated his fish-scented valentine. (Image credit: Highland Wildlife Park.)

At Highland Wildlife Park in Scotland, Walker the polar bear received a giant, heart-shaped valentine drizzled with cod-liver oil, a scent that proved irresistible to the young bachelor, who is spending Valentine's Day alone this year.

The zoo is currently searching for a mate for the 3-year-old bear, who is large even for a polar bear — the largest bear species on Earth, and a species that is facing serious threats.

At the end of 2011, the wildlife park staff had found a match for Walker — but it turned out the female bear was already pregnant.

Walker is still single.

Reach Andrea Mustain at amustain@techmedianetwork.com. Follow her on Twitter @AndreaMustain. Follow OurAmazingPlanet for the latest in Earth science and exploration news on Twitter @OAPlanet and on Facebook.

Andrea Mustain was a staff writer for Live Science from 2010 to 2012. She holds a B.S. degree from Northwestern University and an M.S. degree in broadcast journalism from Columbia University.