ZooBorns recently offered readers a glimpse of the beautiful twin Sumatran Tigers born at ZSL London Zoo. (Please see the lovely pics from our article: “Zoo Releases Video of Cubs for International Tiger Day”)
The cubs were born June 27 to mom, Melati, and dad, Jae Jae. Keepers eventually discovered they were dealing with a male and a female cub.
In relation to “twins”, there is always the question of how to tell which-from-which. A recent blog post from the Zoo offered some insight into how they are able identify which one is the relaxed male, Achilles, and which one is confident female, Karis.
Photo Credits: ZSL London Zoo / Images 1 & 2: Karis (left), Achilles (right) ; Images 3 & 4: Achilles (two distinct curves come out of the outer corners of his eyes); Image 5: Karis (small heart-shape, or upside down V, on top of head)
Keepers note that Achilles is darker in comparison to his sister Karis, and he also has thicker markings. According to the Zoo, Achilles very much takes after dad Jae Jae, with a chilled-out personality and wide face, and young Karis is defined as her mother’s daughter, with narrow features and feisty character.
Achilles also has two distinct curves that come out of the outer corners of his eyes. These thick, dark lines are prominent in comparison to markings around sister Karis’s eyes.
If looking at Karis from above, she has a small heart shape (or upside down 'V') on the top of her head, in addition to some solid strips of ginger on her back. Tigers ordinarily have a solid black line running down their spine, but Karis has a few breaks, resulting in two distinct stripes running horizontally across the length of her back.
The mischievous pair has had meat introduced into their diet. According to the Zoo’s blog post, “When they’re not having play fights with each other you’ll most likely find them enjoying a nap somewhere in Tiger Territory, sleeping for up to 20 hours a day.”
The Sumatran Tiger (Panthera tigris sumatrae) is the smallest of the six subspecies in existence today and are only found on the island of Sumatra in Indonesia.
Originally, nine Tiger subspecies were found in parts of Asia but three have become extinct in the 20th century. Less than 400 Sumatran Tigers remain the wild. They are classified as “Critically Endangered” on the IUCN Red List of Threatened Species.