Lavender Birchen Marans Genetics: A Beginner's Guide to Understanding the Colors in Your Flock

There is genuine confusion in the Marans breeding community about what Lavender Birchen Marans are and what genetics they carry. These are fair questions, and they deserve clear answers. The genetics behind this variety involve several genes working together — each doing a different job, each capable of being misread without the right context. When those genes are understood correctly, the picture becomes clear. When they aren't, well-intentioned conclusions can lead breeders and buyers in the wrong direction.

This post is written for anyone who is new to poultry color genetics — or who has heard terms like "birchen," "silver," and "lavender" used in the same breath and wasn't sure what any of them actually meant. We'll build the concepts up from the beginning, explain each gene in plain language, and show you what all of it looks like in a real working flock.

First, a Simple Way to Think About Color Genetics

Before we get into the specific genes, it helps to understand that a chicken's color is never controlled by just one thing. Think of it like a recipe with several ingredients. Each ingredient does something different — one determines the base flavor, one changes the color, one adjusts the intensity. When you take one ingredient out or add a new one, the result looks very different, but the underlying recipe is still there.

Chicken color genetics work in the same way. Multiple genes layer on top of each other, each one doing a specific job. The bird you see standing in the pen is the result of all of those genes working together at once. To understand what a bird is carrying and what it will pass to its offspring, you need to understand what each gene does separately. In the Lavender Birchen Marans, four genes are most important: the birchen pattern gene, the silver gene, the lavender gene, and the Melanotic gene. Let's go through each one to better understand what they do.

Where the Birchen Pattern Came From

Domestic chickens descend primarily from the Red Junglefowl, which carries the ancestral wild-type color pattern. As chickens were domesticated and selectively bred, mutations appeared at the E-locus—the group of genes that strongly influences how black pigment is distributed across the plumage.

One of those mutations became known as the Birchen allele, written by geneticists as ER.

Birchen creates a predominantly dark-bodied bird while allowing contrasting gold or silver color to appear in specific areas. These commonly include the hackles around the neck, the saddle feathers of males, and varying amounts of marking on the throat and upper breast. The exact amount of visible pattern can differ considerably between males and females and can also be altered by other pattern and melanizing genes.

It can be helpful to think of ER as part of the bird’s underlying pattern map. It influences where black eumelanin is concentrated and where gold or silver expression may remain visible. However, ER does not act alone. Other genes affect the width, clarity, and intensity of the markings, which is why one Birchen bird may have clear breast lacing while another may appear much darker with only subtle hackle or throat markings.

The name “Birchen” has long been used by poultry breeders to describe the characteristic dark body with contrasting hackle and patterned breast expression. Some Birchen-based birds may also show dark facial skin, dark shanks, or strong overall pigmentation.

Photo credit: (c) Sam Ham, some rights reserved (CC BY-NC)

Extended Black and Birchen: Why They Can Be Difficult to Tell Apart

This is where much of the confusion surrounding Lavender Birchen Marans begins.

Chickens have another E-locus allele called Extended Black, written as E. Like Birchen, Extended Black can produce a very dark bird. When additional pigment-modifying genes are present, an Extended Black bird and a heavily darkened Birchen bird may look surprisingly similar.

However, Extended Black and Birchen are not the same genetic background.

Extended Black (EE) encourages black eumelanin to spread across most of the plumage. A bird carrying Extended Black may appear nearly solid black, although some lighter gold, silver, or red color can still appear—often in areas such as the neck hackles, shoulders, saddle, or wings. Breeders commonly call this unwanted color “leakage”.

Birchen, written as ER, produces a different dark-plumage pattern background. Contrasting gold or silver may appear in the neck hackles, the saddle of males, and sometimes the throat or upper breast. In strongly expressed birds, these markings may look organized and clearly placed. In heavily darkened birds, however, the pattern may be narrow, faint, or almost completely hidden.

Pattern placement can therefore provide useful clues. Repeated, organized hackle and breast markings within a documented family may support a Birchen interpretation, while irregular color breaking through an otherwise dark bird may be more consistent with leakage.

But appearance alone is not a perfect genetic test. Extended Black can sometimes show color in predictable body regions, and Birchen can be altered or hidden by other genes. The most reliable assessment comes from considering mature plumage, pedigree, related birds, and the results of planned crossings.

(AI rendered image)

An Extended Black bird with unstructured silver leakage — silver appearing in no consistent location or pattern.

A Silver Birchen rooster showing organized silver expression through the hackle and saddle, with fine black striping carried within the silver feathers. The structure and placement of this silver expression are important diagnostic clues when distinguishing Birchen-based patterning from other forms of leakage or random color expression.

Although this rooster does not show heavy Birchen lacing across the chest, he is genetically Birchen at the E-locus, as confirmed through test matings and multiple offspring that phenotypically express ER. This is the underlying pattern structure that Lavender Birchen birds carry beneath their softened lavender coloration.

What the Silver Gene Does

Now that we understand what Birchen is, we can separate it from another piece of the puzzle: silver. These two are often talked about together, but they are not the same thing. Birchen is the pattern; silver is the color placed into that pattern.

The Birchen pattern determines where the lighter areas appear on the bird, such as the hackles, saddle, and breast lacing. The silver gene determines what color those lighter areas will be.

On a Birchen bird without silver, those areas show as warmer tones: gold, copper, straw, or red-brown. This is often described as Gold Birchen, or Birchen Brown/Red. When the silver gene is present, those warm tones are replaced with cooler white, silver, or icy gray tones. That is what creates a Silver Birchen bird.

The pattern structure is the same in both birds. What changes is the color being expressed within that pattern. Silver and Birchen are separate genetic factors doing separate jobs, which means a bird can absolutely be both Silver and Birchen at the same time.

Black Copper Marans — shown here to illustrate warm copper expression within the birchen-family pattern. In a Silver Birchen bird, these copper tones are replaced by silver-white while the underlying pattern framework remains similar. Photo is for color comparison only; no copper- or gold-based birds were used in the development of our Lavender Birchen line.

What Lavender Does — and Why It Is Not the Same as Blue

Lavender is a dilution gene. Its job is to soften the intensity of pigments that are already present on the bird — it does not create a pattern, and it does not decide where colors are placed. When a chicken inherits two copies of the lavender gene, black pigment is diluted into a soft gray-lavender shade, and warm tones like red or gold can lighten into cream or straw.

You may also hear lavender referred to as Self Blue. In poultry genetics, these two names describe the exact same recessive gene — and this is actually where a lot of confusion begins, because Self Blue sounds like it should be related to ordinary Blue. It isn't, and the two work in genuinely different ways.

Lavender is recessive, meaning a bird needs to inherit one copy from each parent to visibly show the color. A bird with only a single copy will typically look normally colored but can still pass lavender on to its offspring — breeders call these birds lavender splits.

Ordinary Blue, by contrast, is incompletely dominant, which means the number of copies a bird carries directly changes its appearance: no copies produces black, one copy produces blue, and two copies produce splash. This is why breeding two blue birds together commonly produces a mix of black, blue, and splash chicks in the same hatch.

Lavender doesn't behave that way. When two lavender birds — each carrying two copies of the gene — are bred together, every chick inherits a lavender gene from each parent and is expected to be lavender as well. There's no equivalent to the black/blue/splash split you'd see with ordinary Blue.

The simplest way to keep the two straight: Self Blue is lavender. Blue is a completely separate gene. They can sometimes look similar at a glance, but they're inherited differently and behave very differently in a breeding program.

There's also a real difference in what each gene actually dilutes — and this is the detail that matters most for telling them apart visually. The Blue gene only dilutes black pigment (eumelanin). It does not touch red or gold pigment at all. That's why a Blue Copper bird can have a soft blue-gray body while still carrying a bold, untouched copper hackle and saddle — the blue dilution and the copper color exist side by side without affecting each other. Lavender works differently: it dilutes both black pigment and red/gold pigment together, across the whole bird. That's why a Lavender Birchen bird tends to look evenly softened all over, without the sharp two-tone contrast you see in a Blue Copper bird.

Left: A Lavender Birchen Marans rooster — the lavender (Self Blue) gene dilutes both black and red/gold pigment together, producing an even, uniformly softened body color. Right: A Blue Copper Marans rooster — the Blue gene dilutes only black pigment, which is why his blue-gray body sits in sharp contrast with his copper hackle and saddle, left untouched by the dilution. This is the real distinction between the two genes: Blue dilutes black alone, while lavender dilutes black and red/gold pigment together.

When lavender is added to a Silver Birchen bird, it softens the black portions of the pattern into gray-lavender while the silver areas stay silver-based — though the overall contrast often looks gentler, since the black surrounding the silver has been diluted. Lavender isn't responsible for the birchen pattern itself, and it isn't responsible for the silver coloring either. It simply turns down the intensity of pigments that the other genes have already placed.

The most complete name for these birds is Lavender Silver Birchen. In everyday conversation, breeders often shorten that to Lavender Birchen — which is perfectly fine, as long as it's understood that lavender, silver, and birchen are three separate genetic pieces working together, not one single trait. Our Lavender Birchen line is built on the lavender gene.

Melanizing Modifiers: Why Birchen Pattern Can Be Difficult To See

One reason Birchen birds can be difficult to identify by appearance is that other genes may increase the amount of black pigment in their feathers. These are often described collectively as melanizing modifiers.

One known example is the Melanotic gene, abbreviated Ml. In certain genetic combinations, Ml can increase or redistribute black eumelanin and make a Birchen-based bird appear much darker than expected. Research involving Birchen chickens has shown that the interaction between ER and Ml can produce an almost self-black adult bird (see below).

This does not mean that every unusually dark Birchen bird necessarily carries Ml. Several genes can influence how much dark pigment appears and how clearly the pattern is expressed. Without genetic testing or carefully planned breeding trials, the exact modifier usually cannot be identified from appearance alone.

A heavily melanized Birchen bird may retain only subtle visible clues, such as silver or gold in the hackles, faint throat markings, or a limited upper-breast pattern. In some birds—particularly females—the pattern may be so restricted that the bird appears nearly solid black (or solid lavender). The Birchen allele may still be present, but its visible expression in the birds' hackles, neck, etc., is being reduced by the bird’s overall genetic background.

This is why a very dark Birchen bird and an Extended Black bird can sometimes look similar. Their E-locus genetics are different, but how they present visually alone (phenotype) may not be enough to separate them reliably. Chick down may offer clues within a well-documented family, but it is not a definitive test because both Birchen and Extended Black chicks can hatch predominantly dark. Pedigree, mature plumage, controlled test breeding, and, where available, molecular testing provide stronger evidence.

Dark facial skin or dark shanks should be evaluated separately from feather color as skin and shank pigmentation are influenced by genes outside the E-locus, so they do not prove that a bird carries Birchen or Melanotic. They may be consistent traits within a particular line, but they should not be used as a genetic test for plumage pattern. However, in my line, we do see this consistently running with the birchen pattern.

This distinction is especially important when breeding Lavender Birchen birds. Lavender dilutes black eumelanin into gray-lavender, but it does not remove the underlying pattern or the effects of other pigment modifiers. A strongly melanized Lavender Birchen bird may therefore appear dark charcoal-lavender with little visible breast marking, while a less melanized relative may show much clearer hackle or breast pattern.

We carefully select our breeding flocks to not incorporate birds that are overly melanized, and prefer distinct and clear silver expression and Birchen patterning. However, when selecting breeding birds, it is wise not to cull young or very dark birds solely because their Birchen pattern is difficult to see. Grow them to mature plumage, compare them with related birds, and evaluate what they produce. At the same time, a bird should not automatically be assumed to be Birchen simply because it comes from a Birchen breeding project. The most reliable conclusions come from combining phenotype, pedigree, maturity, and offspring results.

Lavender Birchen Marans growouts. showing the Melanotic gene expressing in both feather color and skin pigmentation. We have found that although these birds are lighter in hackles and typical birchen characteristics, they can and do produce birchen-patterned offspring.

Dark offspring from a Lavender Birchen split pairing. These birds are NOT Extended Black — even though they appear to be completely black, they are actually birchen birds whose pattern expression has been suppressed by Ml contributed by the Silver Birchen parent. Evaluating them as they mature and breeding them forward will reveal their true genetics.

How to Read the Evidence in Your Flock

So how can you tell whether a very dark bird may be Birchen-based rather than Extended Black?

Because plumage genes interact with modifiers, the most reliable interpretation comes from evaluating the entire breeding line rather than relying on a single bird or photograph. That is why responsible color evaluation looks at the flock as a whole and considers how the traits behave consistently across generations.

Chick Down at Hatch

Chick down can provide an early clue, especially when you photograph and compare many chicks from the same family over several hatches.

Birchen chicks are often predominantly dark at hatch, sometimes appearing nearly black or very dark brown. Extended Black chicks can also hatch mostly black, however, and may show varying amounts of pale down on the belly, face, throat, or wing tips.

Because both E-locus backgrounds can produce dark chicks, the presence or absence of a pale belly should not be treated as a reliable genetic test by itself. However, if you see consistent patterns over time, it may be a valuable clue and is consistent with Birchen patterning.

Chick down becomes most useful when you use it as a flock-recording tool:

• Photograph chicks at hatch under the same lighting.

• Record the parents of each hatch.

• Note the amount and placement of pale down.

• Compare those observations with the birds’ adult plumage.

• Look for patterns that repeat across multiple matings and generations.

Over time, a consistent chick-down appearance may become a useful clue within your own established line.

Predominantly dark chick down consistent with a Birchen background; this clue, coupled with careful record keeping and evaluation, may help you identify consistent patterns in your flock. We do see this dark chick pattern consistently in our flocks.

Breast Patterning in Mature Birds

One of the easiest places to look for visible Birchen patterning is the upper breast.

In some birds, the breast feathers may have clear silver or gold edges that create a scalloped or laced appearance. In others, the pattern may be much lighter and show only as a few marked feathers near the throat or at the top of the chest. Organized breast markings can also support visible Birchen expression, especially when they appear repeatedly in related birds. However, their absence does not rule Birchen out. Some females may show only subtle hackle markings or a small amount of color near the throat, while related males may display much more pattern. Other genes can make the pattern wider, narrower, darker, or harder to see. A heavily dark-pigmented Birchen bird may show very little to no chest pattern, while a close relative may show much more.

The important point is:

Visible, organized breast markings can support Birchen expression, but a bird can still be Birchen even if those markings are weak or absent. The “correct” amount of breast pattern may also depend on the breed standard and the country where the birds are being shown.

The current French Standard of Perfection (Marans Club Europe) calls for a patterned breast, and calls Birchen, "Silver Black" (ER)- note the "ER" gene even though they are called "Silver Black". https://www.marans.eu/varieang.htm#varietes

However, in Australia, where they are working on getting the Birchen Marans standardized, they require a solid breast with little to no patterning.

For breeders, the most useful things to watch are where the markings appear, how neat they are, and whether the same pattern shows up consistently in the next generation.

A Lavender Birchen Marans split cockerel showing visible breast lacing, consistent with Birchen. Width and placement will likely change slightly in appearance as his adult plumage comes in.

A young Lavender Silver Birchen grow out showing promising Birchen expression, with pale silver contrast developing through the hackle area against a softened lavender body. Birds like this are important to evaluate as they mature, especially in a flock where melanization can influence how clearly the pattern is expressed.

This is the adult photo of the cockerel pictured above. The structured, consistent placement of the lacing is characteristic of birchen expression and is distinct from random silver leakage. The standard birchen pattern (especially in males) naturally features stippling with lacing extending down into the breast. Also note the solid wing color from the shoulder down: the Birchen allele creates a "crow wing" by restricting the pigment (pheomelanin) in the wing triangle in males, turning it completely solid lavender (or all black in black Birchen or Birchen Splits).

Organized lacing and penciling in hens. In hens, the birchen pattern typically shows up as organized lacing or penciling on the breast and chest feathers. Under lavender dilution, the contrast is softer and can be easy to miss at first glance — but look carefully at the structure. The edges on those feathers follow a consistent, organized placement. That organization is the birchen pattern at work, even when dilution has softened the contrast.

Lavender Birchen hens showing clear lacing in the breast and expression in the hackles. These hens are also heavily melanized, potentially masking even greater expression. The breast feathers in Birchen birds often have a narrow trim that can read as partial or single lacing when modified by dilution genes.

Black lavender-split hen with limited visible Birchen expression. This hen shows only a small amount of patterning in the neck and no obvious breast markings. Her dark phenotype reflects strongly suppressed Birchen expression influenced by melanization and other pattern modifiers. Her offspring, including the heavily patterned young black birchen cockerel pictured above, demonstrate that strong Birchen-type expression is present within this family, even though she shows little patterning.

Isabel-Like Offspring as a Supporting Clue

Sometimes Isabel-like chicks or young birds appear in later generations of a Lavender Birchen breeding project. These birds usually show a soft mix of lavender-gray and warm cream or beige. That coloring can happen when the lavender gene softens both black pigment and hidden gold or red pigment. If the cream color appears in the same places where Birchen patterning would normally show—such as the neck, saddle, or upper breast—it may support the idea that Birchen is present in the family.

However, Isabel is not one exact genetic formula, and similar coloring can appear on other genetic backgrounds. An Isabel-like bird does not prove that it is Birchen, and it does not rule out Extended Black.

The best way to use this clue is to look at the whole family. If Isabel-like patterning appears repeatedly in birds from known Birchen matings and matches the pattern seen in their relatives, it can be helpful supporting evidence.

An Isabel-patterned cockerel from this season's hatch. Its appearance may be additional confirmation that the birchen pattern is active in the flock. We see this occasionally in our growouts.

How to Confirm Your Birds' Genetics More Definitively

Visual evaluation is useful but has limits — especially in lines where the Melanotic gene is suppressing pattern expression in the darkest birds. Two practical methods can give you more certainty.

1. Revisit Chick Down Records

As discussed above, chick down can be a useful early clue when tracked consistently across multiple hatches — though it should never be treated as a standalone test, since both Birchen and Extended Black chicks can hatch dark.

2. Run a Test Cross

A test cross is the most reliable way to confirm what E-locus gene a bird is carrying. To do a test cross, you breed the bird in question to a wild-type or duckwing bird — a bird with the ancestral "normal" coloring. The offspring will reveal the genetic base of the bird you're testing. If the bird carries the birchen gene, the male offspring from that cross will display a specific pattern called crow-wing — a classic birchen-family expression that is easy to recognize. If the bird is Extended Black, the offspring will look different — irregular, incomplete markings without organized birchen pattern expression. One well-documented test cross can tell you more about your birds' genetics than years of visual evaluation alone.

Putting It All Together

Color genetics is genuinely hard to explain in words alone — and lavender birds present an extra challenge because dilution softens contrast throughout, making patterns harder to see than they would be on a fully dark or undiluted bird. No single photo of a single adult bird tells the whole genetic story. The evidence builds across multiple birds, at different ages, and over multiple generations.

If there is one thing to take away from all of this, it is that a bird's color is always the result of multiple genes working together — and you cannot understand what a bird is carrying simply by looking at any one of those genes in isolation.

Here is a plain-language summary of the four genes that matter most in a Lavender Birchen Marans:

• The Birchen gene (ER) is part of the E-locus pattern system. It helps create a dark-bodied bird with contrasting color expressed in areas such as the neck hackles, the saddle of males, and sometimes the throat or upper breast.

• The Silver gene (S) affects the warm red or gold pigment that would otherwise appear in the patterned areas. It suppresses much of that warm pigment, causing those areas to appear white or silver instead. Silver does not create the Birchen pattern. It changes the color expressed within that pattern.

• The Lavender gene (lav) is a recessive dilution gene. A bird must inherit two copies to visibly express lavender. It softens and dilutes the whole picture — turning black into gray-lavender and silver into a muted, smoky pale tone. Two copies are required for a bird to visually express it.

• The Melanizing and Pattern Modifiers- Other genes can increase, reduce, or rearrange the amount of dark pigment visible in the feathers. These are often called melanizing or pattern modifiers. One known example is the Melanotic gene, (MI), but it is important not to assume that every dark bird carries Ml. Several genes may contribute to a heavily darkened appearance, and the exact cause usually cannot be identified by sight alone.

  A Birchen-based bird with strong melanizing influence may show only a small amount of visible pattern while another close relative may show much clearer hackle or breast markings. The Birchen allele may still be present in both birds, even though their outward appearances differ. At the same time, a dark bird should not automatically be labeled Birchen simply because it comes from a Birchen breeding project. Pedigree, mature plumage, related offspring, and controlled breeding results should all be considered together.

  
  

If you are moving forward with your own Lavender Birchen Marans flock, the most important thing you can do is hatch plenty of chicks and evaluate them at multiple stages of development — not just as adults, but at hatch, through the juvenile feathering, and into maturity. Color and pattern continue to develop and clarify over time, and a bird that looks unremarkable at eight weeks may tell a very different story at six months. Look at your flock as a whole rather than fixating on individual birds. Consistency across multiple birds — in chick down color, in pattern placement, in what the splits and subsequent generations produce — is what tells you what your line is actually carrying. There isn't a single trait that provides the entire answer. The most useful evidence comes from patterns that develop across multiple birds and several generations.

Here are a few markers to look for in the Lavender Birchen line:

• birds with bold, visible pattern;

• heavily darkened birds with very little visible pattern;

• lavender birds in a range of lighter and darker shades;

• black offspring carrying one copy of lavender (in splits);

• and occasional unexpected colors as hidden genes recombine (occasional white Marans have been produced in our flocks).

  
  

These variations are not automatically proof that the line is correct or incorrect. They are just information. Careful records and repeated matings will help reveal which birds consistently move the flock closer to your breeding goal.

I suggest photographing your birds, documenting your matings, following them through to maturity, and paying close attention to what each bird produces. Consistency is KEY.

The goal is not to make assumptions based on a single observation or a single trait. It is simply to build a well-documented line through thoughtful selection, honest evaluation, and generations of consistent breeding.

I have been working with this line since 2013, and the process has involved much more than selecting for plumage color. Strong Marans type, egg color, feathered shanks, vigor, temperament, fertility, and consistency all have to be considered alongside the Birchen and lavender traits. I know genetics can feel overwhelming at first, but the patterns become easier to recognize with time and observation. Every hatch provides another piece of information. We are continually learning, and every hatch teaches you something! Trust the process, document what you see, and let the birds show you what they are carrying. Most importantly.... enjoy the journey!