Photo: Jaguars Get Bloody Valentines

For jaguars, a heart-shaped box of chocolates won't suffice on Valentine's Day. But a heart-shaped block of frozen blood will certainly do.

That's exactly the kind of valentine five-year-old jaguar mom Nindiri and her two 10-month-old cubs, Tikal and Maderas, were treated to this week at the San Diego Zoo. The "bloodsicles" are made up of beef blood, beef hearts and pieces of meat, zoo officials said, and they serve as a special source of enrichment for the captive cats.

Jaguars are the largest of the big cats that live in the Western Hemisphere and the third largest any cat in the world, with females that can grow to 70 pounds (32 kg) and males that can hit 120 pounds (54 kg).

Latest Videos From

Watch full video here:

The South American native word for jaguar, yaguara, means "animal that kills in a single bound," but for all their ferocity, the jaguar is listed as an endangered species in the United States. Demand for the cat's beautiful spotted fur and loss of habitat have drastically reduced their populations throughout their range from the southwestern United States through Argentina.

Follow LiveScience on Twitter @livescience. We're also on Facebook & Google+.