Breeding and Gerbil Genetics
reprinted with permission from The ShinDao Dynasty

*There are pictures of Gerbil Mating/Reproduction behavior on this page of my site. If you are under the age of 18, please check with a parent before viewing. I WILL NOT be held responsible. Thank you.*

::Looks BLANK, blinking::- - Kai'yu
::BLINKS::- - Mai'yu
::BLINKS::- - Tai'yu
::Just looks BLANK::- - Rai'yu
::Smiles, blushing softly::- - Katsegura

(::considers:: Oooohh boy, I think I better take over the information on THIS page. ::Chuckles:: It seems shockingly enough that the Yonin Boyz complete with young "kifujin" (lady) are rather.. speechless. After all, it's sort of a well.. rather private subject. I've been breeding now for about a year and I delved into ALOT of information regarding the subject before I started. I will translate it the best that I remember and will of course, give credit where credit is due. I will be updating as I go along. :) - - C.Devoe)


Breeding.. is certainly a labor of LOVE, taking the best consideration and care in regards to your gerbils and their pups.

Why are you breeding?
How will you make sure your pups go to good, caring homes?
What will you do if you can't place them all?

You certainly need to think about these things and formulate a type of plan. Alot of thought needs to go into the decision to breed any animal, and not just for the desire to make money out of it.

Let's face it, we wouldn't appreciate something or someone breeding US and selling our babies, now would we?
Animals deserve the same thought, love, and consideration we give our own families. I do understand the fact that we don't procreate as rapidly as they do, but we have a responsibility that if you can't keep their pups.. that at least good homes are found for them.
If you can't spend the time, money, patience, and love it will take to breed and care for the pups.. then you really should consider staying with SAME-SEX PAIRS and NOT to Breed.

If you feel you ARE ready to attempt breeding your gerbils, then a good idea is to just start with ONE BREEDING PAIR. At least till you can see how your pups will sell in the area you are in, understand the market desire, and be comfortable that they will be going to good homes .

A LOCAL PET STORE for your pups should ALWAYS be considered a LAST RESORT.

If you have to take this method -- CHECK them out first. Talk to them about the care of gerbils, visit them often and on different days of the week and different times. See how they keep their animals.. are they taking proper care of them? Are they healthy and active? Most important -- find out if they would consider selling gerbils as FOOD for reptiles such as snakes or lizards. It would be heart-breaking if you trusted a store with your ""tiny treasures" to find out they ended up becoming something else's dinner.


Reproduction and Mating

Gerbils are considered small "rodents" and as such, they also breed like them. When choosing your pair, it's ALWAYS best to get them from a registered Breeder. That way, you'll be able to see them, ask any questions you may have, and get information on genetics and Family lineage.

Gerbils can breed up to 12 times a year, usually ONCE or a month or EVERY OTHER month.
Litters can be anywhere from One to Eight pups which means..

ONE mating pair can produce 108 pups a YEAR if you calculate the HIGHEST scenario at 9 pups per litter, each month.

Prepared for that?

Female gerbils reach sexual maturity somewhere around the age of 8 to 12 weeks and will go into "season" every 4 to 6 days until she becomes pregnant. The female's "season" usually lasts anywhere from 12 to 24 hours.
When the female goes into "Season" or when the male is sexually excited, he will make a "thumping" noise with his hindlegs usually against whatever he happens to be on top of at the time.
This is perhaps a type of courtship to attract the females interest or like an advertisment to announce that he's seeking to mate.

The male and female will mate several times, usually in the evening, for as long as the female is in "season" and trust me, unless she's ready to mate, she won't tolerate or accept his advances.
The male releases perhaps once out of every few matings. The male usually cleans himself after every mating attempt, but I've heard that a good way to tell if he's released is if both the male and female clean themselves after a mating.

If she takes, a female gerbil's pregnancy lasts anywhere tween 21 and 25 days, usually giving birth the night of the 24th day or at the wee early morning hours of the 25th. Usually they do not show until late into the pregnancy, ( 18 to 20 days ). The female will need a diet of at least 15% crude protein and access to lots of water at all times.

*NOTE* A female gerbil goes back into heat the VERY SAME night she gives birth! So if you are trying to keep your litters short, sweet, and infrequent, you will need to either REMOVE the Male or SPLIT CAGE him with the female at least till her 2nd "season" passes, (about 24 hours).
SPLIT CAGING him with the female is your best option as it keeps them familiar with eachother and reduces the chance of a difficult re-introduction once her season passes.

Usually, when the female goes into labor and starts birthing her pups, the male will go off and nest down in another part of the cage during/after the female gives birth. But because gebils are a social society, he may sneak a son or daughter with him when he does. If that happens, you'll want to return the pup he takes to the mother as soon as possible.

Don't worry.. the male will return to the family usually within 24 to 48 hours.

Believe it or not, the male is usually an EXCELLENT father, sometimes better than some female gerbils are at mothering! He will help care for the pups so the female can take a break, go eat something, or take a well deserved nap.

Removing the male is usually not necessary unless you want to avoid further litters, or the male is harming the newborn pups. The male helps the female take care of the litter and that helps reduce the stress on the female.
Female gerbils are very good mothers and can raise a litter of pups on her own if you feel the male needs to be removed, but this causes alot of stress on the female to raise a litter by herself. Especially if the female is a first-time mother. It's a 50/50% chance that you could lose the litter of a lone first-time female mother. If the litter tho lives to at least opening their eyes ( 15 to 20 days old ) and past the 22nd day, then usually 95% of the time they will survive unless something happens like they get sick, etc. etc.

However, if you DO chose to remove the male, unless you RE-intro him back into the tank with her within 24 hours, you will have to Split cage him to her once her pups are weaned and out of the tank. If you wait longer than 24 hours to put him back with the female.. you cannot intro him while she has young pups. She WILL attack him in defense of her pups as she will not remember him the father of her litter and will consider him a threat to her young.


Your New Pups!

First born pups are completely helpless and are born hairless and blind. They will rely on their mother for EVERYTHING.
For the first 7 days or so, you'll want to check on the new litter EVERYDAY just to make sure things are going well and no one has gotten seperated. The 1st-3rd days, you'll also want to look at their middle for a small whiteness, about the size of a pinto bean. Believe it or not, this is their mother's milk settling in their tiny tummies and will let you know if she is feeding them.
If a pup gets seperated from the others or is out of the nest, be sure to GENTLY return him.


Usually if your gerbils are tame enough, they won't mind your smell on their pups..but if they smell like anything else, such as you pet the family feline before handling a pup, this could greatly disturb the parents and could cause the pup to be harmed.

It's EXTREMELY important that you keep the contents of the tank VERY simple when breeding so that the pups don't get hurt.

The Tank should have in it:

Bedding -- Aspen or Corn-Cob ( NO CEDAR, PINE, or CAREFRESH!)

Why not Carefresh? My experience has been that Carefresh is MUCH too dusty and the dust gets into the little ones lungs when they breathe and causes Respiratory Infections which can be VERY lethal at such a tiny age.

NO wheels, toys, large wood peices, or unsecured items like wooden bridges or cubes.

One of the things I have done is secured wooden bird nesting boxes to the bottom of the glass aquariums with velcro. That way it can be removed for cleaning but the gerbils cannot dig under it or move it and young pups cant get trapped under it.

and.. a Water Bottle

Its fine to throw in some toilet paper rolls for the parents to chew on, after all, the soon-to-be parents need some distractions as well.

ALSO.. for the first week or so of the pups lives (about 10 days) you should'nt introduce anything large and new, like New Kleenex boxes, cereal boxes, etc, into the Cage. This may disturb the mother and cause her to neglect her pups for several hours while she handles the "intrusion".

Clean the cage once BEFORE the female gives birth and then do not clean the cage again till the pups are at LEAST 10 to 15 days old. After that, you can clean the cage as you normally would.


Pup Handling/Sexing

Its controversial when exactly you should handle the pups. Some breeders handle them right away as early as a day old, and others handle them when they reach about 10 days old.

If you have what seems a VERY nervous mother, or the female is a FIRST time mother, it might be best to handle the pups when they are about 10 days old.
I had a very nervous first time mother and when I checked the pups the day after they were born.. it caused some complications with her neglecting them for several hours.

It is important to try not to be an annoyance and bother the mother too much in these first few days.. peek in and check on them everyday but don't do more than that till they are older. Don't worry..left to their own devices, gerbil mothers WILL care for their babies even if it seems they are not feeding them or are too rough with them. Gerbil pups are certainly ONE thing.. VERY hardy!

When you handle them.. BE EXTREMELY CAREFUL.. and use both hands to hold them as they will leap right out of your hands till they get used to you. Hold them only an inch or 2 above either a pillow or the floor or a bed as a far fall can be fatal.

Usually you can sex the gerbil pups at about this age, (10 days old).
On their undersides, a female will have small indentions around their upper thighs and near their armpits, these are nipple dents. Males won't have these and their bellies will be completely smooth.

BUT.. about 4 to 7 weeks old is the best time to tell sexes if you want to be exactly sure. In females, the space between the anus and the urethra is usually very short. In Males, the anus and urethra is further apart and they will have a bulge at the base of their tails which will be their scrotom.

Another cautious time to handle the pups carefully is about when their eyes open sometime tween 15 and 20 days. Their new sight is unknown to them and usually makes them a bit paranoid, jittery, and nervous where once they were calm before. It will take them a bit to recognize you once more, this time adding sight to smell.
Also about this time they will be sampling the food in the food bowl but they won't wean from milk till about 3 or 4 weeks old. Oatmeal, natural apple sauce, crushed cheerios, and canary seed are softer foods and good choices to help wean them from milk.

WATCH carefully because at this age they are prone to respiratory infections. You can recognize that by a soft "clicking" sound when they breathe. Ornyacycline ( Listed as Tetracycline for birds ) in their water for about 10 days treatment should handle that.

ABC Gerbils lists a GREAT ""Breeding Emergency Kit"" consisting of 3 things:
Kitten Replacement Milk and an EYE Dropper -- in case you might have to self feed pups.
A clamp Lamp with a 40 watt bulb -- In case the mother isn't keeping them warm and you might have to do that for her.
Ornyacycline -- For those nasty respiratory infections I mentioned that pups can get.

Pups are usually ready to leave to a new home when they are about 6 weeks old or when mother has her next litter. If you have removed the father so that mating does not re-occur, you will need to leave a daughter with the mother to help her raise her next litter and place a son with the father for company.

Gerbil Genetics

Okay, this is the confusing part.. but it's actually not too hard once you get the hang of it. I will explain this as simple as possible.

Parent gerbils ( and all gerbils for that matter ) have 6 "Gene Loci". A "CAPITAL" letter is the "dominate" gene and if your gerbil has that dominate gene, your going to see it in how the gerbil looks. For example: (AA, or Aa, or Gg, or Pp)

Small letters are considered "recessive" and the only way you'll ever see that effect is if a small letter is paired with another small letter, meaning "recessive/recessive" (such as aa, or gg, or ee).

A Dominate ( Capital ) letter masks the effect of a recessive gene BUT if the parent has a "recessive" in their gene loci, it can be passed on to their pups.
(Example: Mother - Aa, Father - Aa. Pup could get both recessives - aa )

Here are the 6 Loci in Gerbil Genetics:

A -- this controls the belly color of a gerbil:
Aa or AA -- gerbil will have a WHITE belly
-- gerbil will be "self-colored" ( belly same color as backside) unless the gerbil carries the "spotting" gene which we will explain further down.

E -- this controls the amount of GOLD color effect in the fur:
Ee or EE -- gerbil will have NO gold fur coloring
-- gerbil will have a gold color effect in the fur. This introduces gold.

C -- this controls color lightening of the fur or Color-pointing ( darker extremities, ear tips, and tail):
Cc or CC -- no color-lightening or color-pointing
-- fur color lightening or color-pointing.
There are other gene combinations here, for example:
cbcb - means Colorpointing
chcb - means Colorpointing but lighter than normal.
Cch - this usually fades out a color if other genes are present.
chch - this is a Pink eyed White gerbil no matter what the other gene combinations are.

P -- this controls a gerbils eye color:
PP or Pp -- gerbil will have Black eyes
-- gerbil will have ruby eyes.

G -- this controls the introduction of GREY color into the Fur:
GG or Gg -- gerbil will have NO grey coloring
-- gerbil will have grey in the fur color.

Sp -- this controls Spotting or Pied:
Spsp -- gerbil will be spotted, pied, or mottled.
-- gerbil will not be spotted.

Now.. the differences?
Spotted - White star on the forehead and some spots on tail tip or other places on the body,( Any white -bellied color + Spsp )
Pied -- White star on forehead with a small white trail down back of neck connecting to a white "collar" around the neck, (Any Color + Spsp )
Mottled/Patched -- Big splotches of white all over with small hints of gerbil's color, ( Any self-color + Spsp )

*NOTE*: There is no such thing as a "SpSp" spotting gene as this is considered a LETHAL combination and pups with this gene are usually reabsorbed in the mother's womb, never to be delivered.

Last but not least, you'll see a * in the gene code usually following a Dominate letter. That means the gene is unknown, BUT it usually doesnt matter what the combination is as the dominate letter will always take over.
( Example: G* = GG or Gg which means NO greying on the fur regardless of what the other gene is.)


Known Gerbil Colors & Genetic Loci

Here is a list of the known gerbil colors and the basic Gene Pattern of each. I don't have any pictures to go with them but my other links page might link to some other gerbil sites that DO. :)

Golden Agouti -- A*C*E*G*P*
Argente Golden -- A*CCE*G*pp
Topaz -- A*Cc(b)E*G*pp
Light Dark Eyed Honey -- A*Cc(h)eeG*P*
Lilac -- aaCCE*G*pp
Dark Eyed Honey (DEH) -- A*CCeeG*P*
Dove -- aaCc(h)E*G*pp
Blue -- aaC*ddE*G*P*
Sapphire -- aaCc(b)E*G*pp
Slate -- aaC*E*ggP*
Black -- aaC*E*G*P*
Yellow Fox -- A*CCeeG*pp
Light Yellow Fox -- A*Cc(h)eeg*pp
Apricot ( RE Polar Fox or Cream Fox) -- A*C*eeggpp or A*Cc(hy)eeggpp
Honey Cream -- A*Cc(h)eeG*P*Spsp or A*Cc(b)eeG*P*Spsp
Ruby Eyed Silver Nutmeg (RESN) -- aaC*eeggpp
Nutmeg -- aaC*eeG*P*
Silver Nutmeg ( Blue Fox ) -- aaCCeeggP* or aaCc(h)eeggP* ( lighter version)
Red Fox ( Saffron ) -- aaCCeeG*pp
Light ( or Pale ) Red Fox -- aaCc(h)eeG*pp
Pink Eyed White -- **c(h)c(h)******pp
Polar Fox -- A*C*eeggP*
Dark Tailed White (DTW) -- **c(h)c(h)****P*
Ruby Eyed White (REW) -- aaC*E*ggpp
Burmese -- aac(b)c(b)E*G*P*
Grey Agouti -- A*C*E*ggP*
Schimmel ( Rust Point ) -- **C*e(f)e(f)G*P*
Ivory Cream -- A*CCE*ggpp
Ruby Eyed Schimmel ( Orange POint ) -- **C*e(f)e(f)G*pp
Siamese -- aac(b)c(h)E*G*P*
ColorPoint Nutmeg -- aac(b)c(b)eeG*P*
Lt Colorpoint Nutmeg -- aac(b)c(h)eeG*P*
Champagne ( Spotted Schimmel) -- **C*e(f)e(f)G*P*Spsp
Black Eyed White (BEW)
A few (BEW) combinations here:
Colorpoint Polar Fox -- A*c(b)c(*)eeggP*
Silver Schimmel -- **C*e(f)e(f)ggP*
and Colorpoint Schimmel -- **c(b)c(*)e(f)e(f)**P*
*( Light Colorpoint Nutmegs are also BEW but they molt around 8 weeks or so )*
ColorPoint Agouti ( Cinnamon Pearl ) -- A*c(b)c(b)E*G*P*
Light Colorpoint Agouti -- A*c(b)c(h)E*G*P*
Colorpoint Slate -- aac(b)c(b)E*ggP*
Light Colorpoint Slate -- aac(b)c(h)E*ggP*0
Colorpoint Grey Agouti ( Silver Pearl ) -- A*c(b)c(b)E*ggP*
Lt. Colorpoint Grey Agouti -- A*c(b)c(h)E*ggP*
Colorpoint Silver Nutmeg -- aac(b)c(b)eeggP*
Lt Colorpoint Silver Nutmeg -- aac(b)c(h)eeggP*

( Well.. I hope this information is helpful and gets you well on the way to understanding gerbil breeding and the basics on the Genetics. If I've helped in giving important information and you in making your decision whether to breed or not to breed, then I consider a Job well done. Always feel free to Email me about any questions or concerns you have that I may not have covered. I'm happy to help where and when I can. -- C.Devoe )

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 Created on 03 October 2005