Presumably whatever their nutrition and health requires, for instance, if a tree frog requires fruit flies to maintain a healthy and balanced diet, then the conservation center probably feeds their tree frogs fruit flies.
Uracil is found in RNA and not DNA. DNA instead has thymine
Some species we see in Alaska and nowhere else in the Wolrd are:
Bats
Shrews
Bears
Seals
White Wolfs
Sea lions
Racoons
Walrus.
Bears, Seals, White Wolfs and Sea lions survive the cold weather much more than those other animals.