Sexing Marans chickens

A blue marans chick ready to be sexed

How do you sex Marans?

There are a couple of ways to sex Marans. I will start with the the only ones that are able to be sexed as day old chicks. If you have hatchery stock, you are probably at a disadvantage, as these birds are more likely to show a greater variation in colour, marking and development.

Cuckoo Marans are the only type that are auto-sexing and are easy to sex at and early age. All barred breeds have a head spot thanks to the barring gene. The boys have a larger pale head spot than the girls, who have a smaller well defined head spot.

With Cuckoo varieties the males are lighter and the females are darker and this is true of Marans as well and can be determined within a few days of them starting to feather up. They are very easy to sex at around the three week mark as the boys start to look a little lighter than the girls as they have two copies of the barring gene, whereas the girls only have one.

As chicks grow they develop in different ways. With the males the legs grow thicker and stronger and this can be measured. The best way to use this method of sexing Marans is actually to use a pair of calipers and measure the chicks one at a time.

At 4-6 weeks you're looking at comb development the boys have a bright yellow comb that's a little bigger, the girls a dirty yellow and smaller size.

Feather sexing Marans: Most breeds of chicks are monomorphic which means both sexes of chicks look the same after hatching. Some breeds can be feather sexed at day old by looking at the difference in length of the wing feathers a day after hatching. Marans can not be feather sexed.

Below: This male has a large comb compared to the hen in the next picture.

Below: The matching female with a small comb.

That said there are difference is the feathers of chicks as they grow. In my experience the males have more brown on their wings and neck and this becomes more noticeable as their feathers start growing.

By 6 to 8 weeks when the male and female feather patterns start showing you can see the males will have dark red on the shoulders and wings whereas the females will only get copper on their necks and chest area.

Marans with slow developing tail feathers are usually sign that its a boy. Hens seem to grow a tail and feather more evenly and the males seem to get shoulder feathers first.

Male Marans grow sickle or pointed feathers on their necks from about six weeks of age.

Marans can be sexed by behaviour, with a batch of chicks, play fights and chest bumping start around 1 week old and a strong response back to the aggressor usually means both are boys. If the other chick shies away and doesn't want to participate it is more likely to be a hen.

Vent sexing Marans: All chickens can be vent sexed, including Marans but this method is costly. Vent sexing is a Japanese developed the technique of sexing chicks by looking at the cloacae, the small openings on the underside of birds used for waste, egg laying and mating.

Trained vent sexers look and feel for an arrangement of tiny bumps in the vents of male chicks 24 hours after hatching. Experts show accuracy rates of 95 to 98 percent.

DNA sexing: You can use avian laboratory services to sex chicks using DNA evidence. Results come back within a few days and all you need is a blood sample. DNA testing is 99.9 percent accurate but costly.

Wheaten Marans can be reliably sexed between 2-3 weeks of age, the hens have straw coloured or buttery wing feathers and the males grow in darker.

You may be able to buy sexed Marans from a hatchery but unless they are Cuckoo Marans or have been vent sexed then you may be being defrauded.