
The following cryptic notes appear in the Animal Care log:
• Purple front was found outside of the chambers this morning. Everyone else was safe inside.
• Black back is definitely looking pregnant.
• Please observe blue/green front’s weight closely, he is looking thin.
• The new pups have caught up in size with brown front.
Who are these colorful characters?
A careful look at the naked mole-rat colony answers the question. The colors are markings the animal care staff uses to identify the colony members. Each animal is given a unique marking – a single color or combination of two colors, either on the shoulders (front) or the lower back.
By marking each animal, we are able to log their weight changes and behavior over time.

Gradually, this information helps us piece together important roles within the colony, and understand why individual animals behave in certain ways.
Some of the animals have distinct physical characteristics or behaviors that have helped earn them titles or descriptors beyond their color markings. Over time, it becomes possible for Animal Care staff to recognize some of the animals at a glance. But without the color markings, it would be harder to monitor their daily behavior or learn their unique physical traits.
We’d like to introduce you to some of our more standout naked mole-rats by sharing their color markings and nicknames.
Black back is one of the two queens. Her nickname is “Elphaba”. Elphaba’s weight ranges from 52 grams non-pregnant to 72 grams pregnant.

Purple/orange front, “Galinda”, is the other queen, who has produced the last successful litter. Galinda currently weighs about 60 grams, she can be much heavier during pregnancy.
Blue/green front is nicknamed “Skinny Guy”, due to his unusual body shape. His appearance makes him a likely candidate for the breeder male, who usually fits this physical description. Skinny Guy weighs 48 grams.
Purple front, on the other hand, is our plumpest animal, and is the dispersing morph. His nickname, due to frequent attempts to escape, is “Hairless Houdini”. He weighs in at an impressive 81 grams.

Brown front is nicknamed “Toothless” for probably obvious reasons. He was part of a litter born just before the colony experienced health problems in 2006/7. At 19 grams, Toothless and his two surviving littermates are smaller than other workers, and are now smaller than some of the pups born in 2009. Their development may have been slowed down by the same circumstances that caused other problems in the colony. Despite the absence of teeth, he still loves to gum on soggy apples and dough balls. However, it is possible that Toothless will always be small.
The next time you're visiting Pacific Science Center, see if you can locate these or any of the other colorful characters at living in our colony.
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