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An Alphabet of Hamster Facts (B)

Banding, symbol BaBa or Baba

Syrians have the white banded which is dominant and because it is not a lethal gene, it can occur in the homozygous i.e. pure form. Homozygous (or pure) bandeds will produce 100% banded offspring regardless of what they are mated to. Heterozygous bandeds (i.e. those carrying only one gene) will produce 50% bandeds if mated to a non-banded, and 75% banded (of which 25% will be pure banded) if mated to another heterozygous banded. Bandeds will often have flesh and normal coloured ears and may have one or both eyes ruby in colour.

Banding in the campbells russian has been documented, mainly expressed as a white collared phenotype.

Black, symbol aa

A recently introduced long-awaited recessive mutation of the Syrian hamster with a phenotype (appearance) of a black animal with black eyes and dark grey/black ears. On closer inspection you will notice upon blowing the coat that the black colour is confined to the top approximately one-third of the coat with a paler grey base coat. All specimens have white socks and clear nails (ring me if yours hasn't!) and many have white patches on the chin and belly. Odd white hairs can often be seen on the top coat of the animal and as they age they can become bronzed. Breeders should aim for as black an animal as possible, trying to breed out the white hairs/patches. Black can appear as tortoiseshell, banded and dominant spotted and the contrast in colours is quite striking.


Water bottles are convenient and keep food out of water bowls. Ensure as best you can that hamsters cannot get to gnaw at unprotected plastic parts of the bottle and lid. The best bottles have completely stainless steel tubes and ball bearings to prevent dripping, but watch out for ball bearings sticking and preventing water flow. Give bottles a gentle squeeze from time to time to check that water can come out. If none does, shake them very hard to dislodge whatever has jammed the ball bearing. If your hamster appears not to be drinking, check this possibility first.


Syrian hamsters have a 4 day cycle (females) and a 16 day pregnancy. Females need sufficient daylight to believe it is the breeding season (extend the day length artificially in the winter using a timer with 16 hours light per day). Males need warmth or they retract their testes and the sperm die, which renders the males temporarily infertile. As males and females have to be kept separate, females will accept the male for about 30 minutes on the day out of her 4 day cycle when she is on heat.

Dwarf Russians and Chinese will live together, therefore in some ways they breed more easily. Again, light and heat are factors in breeding success. It is also believed that levels of overcrowding have an impact. Pregnancy lasts 18 to 21 days, with the females being impregnated immediately after the birth, and the next litter appearing as the previous litter is weaned.

Brown, symbol bb

The guinea gold or rust hamster is actually the brown mutation, and for many years was misnamed the rust (rr) whilst the cinnamon was misnamed the brown (bb). When rust was reclassified as bb, cinnamon had to move along too, and became pp or the pink-eyed dilution.

bbdgddg = Beige

bbee = red-eyed cream (not the normal standard ppee which is cinnamon and BE Cream)


Syrians particularly like to burrow and if placed in a bin of sawdust will disappear for ages! The Dwarf species like to burrow around too. Consider providing a play zone with a burrowing area.