Breeding The Black Milk Snake

The black milk snake (Lampropeltis triangulum gaigeae) is gaining in popularity among the colubrid crowd and converting more than a few non-colubrid fans. It possesses nearly all of the traits reptile lovers want in a pet: easy to care for, easygoing personality and easy on the eyes.

Though some may scoff at the beauty of an all-black snake, they probably have not seen a black milk in the flesh. The iridescence and muscular body of these calm snakes are something to be appreciated up close. There's a reason why indigo snakes (Drymarchon couperi) are so revered, and the black milk has some of that beauty without needing a federal permit or the $1,000 price tag. Though black milks used to fetch at least $500 for hatchlings in the mid-1990s, the price has steadily fallen as more breeders have caught on to this mild-mannered monster. As of this writing, hatchlings can be found on the Internet directly from breeders for as low as $75. Most decent-sized reptile shows have vendors with some black milks priced between $75 and $200. Along with their natural allure, black milk snakes have something that few other common captive-bred reptiles have: mystery.

Black Milk Snake Range

Black milks are a Central American milk snake found mainly in the high-altitude cloud forests of Panama and Costa Rica. How high? Try 5,000 to 7,400 feet in Costa Rica and 4,300 to 6,500 feet in Panama. Although not an aquatic species, in the wild they live in cloudy, wet microhabitats, of which the forest floors of Panama and Costa Rica have plenty.

Black milks start off as big, tricolored hatchlings (red base color with some black tipping on scales, and bands of white and black) around 12 inches in length or more. Some of my hatchlings have been 16 inches out of the egg. Able to take baby rodents from the start, black milks grow steadily, eventually reaching as long as 7 feet by 4 to 5 years of age (though lengths of 5 to 6 feet are more common). These are beefy snakes. My trio of adults are all about 6 feet and weigh approximately 3 to 3 1/2 pounds. In the wild, it's believed these snakes eat pretty much anything they can overpower, including rodents, lizards, perhaps other snakes and probably small birds.

Alan Kardon, curator of reptiles and amphibians at the San Antonio Zoo, has high praise for the snake he helped introduce to reptile keepers. The San Antonio Zoo started one of the early lines of black milks, and the zoo's progeny is one of several lines circulating in the herpetocultural world. According to Kardon, the zoo acquired some of its founder stock in 1985. One of the founder males, currently just over 7 feet long, is still alive, "and this was not a baby. He was probably 3 years old," Kardon says. The zoo does not have the animals on display anymore but still uses them for docent programs.

Easy to Keep

The closest milk snakes to rival the size of a black milk would be Ecuadorians (Lampropeltis triangulum micropholis), Andeans (L. t. andesiana), Guatemalans (L. t. abnorma) and Hondurans (L. t. hondurensis), but I think the black milks take the prize because they are a bit more bulky and are consistently huge. For the record, in his book Kingsnakes and Milk Snakes (T.F.H. Publications, Inc., 1990), Ronald G. Markel lists L. t. micropholis as the largest milk snake, with a size "reaching 60 inches."

Because of their size, black milks need large cages. Racks won't work. These are not overly active snakes, but I believe it is unhealthy to keep them in anything smaller than a cage with less than 6 square feet of floor space – this would be equal to a cage measuring 3 feet long, 2 feet wide and 1 to 2 feet tall. Bigger is better. Any of the commercially available plastic cages work fine, so long as they have a locking device to secure the sliding or hinged doors.

Black milks are a montane species and therefore have some special requirements regarding temperature. But these requirements actually make them easier to keep. Black milks like it cool. Ambient cage temperatures in the low to mid 70s Fahrenheit are fine. Black milks benefit from a warm basking spot when the ambient high temperature in the cage is 70 or lower. My basking spot, which uses a 50-watt infrared bulb, gets about 85 degrees. I only have the light on for about four to six hours in the morning if needed.

My schedule for heating a black milk cage varies by season and is as follows:

Winter: No heat for adults, room temperature set to 58 degrees.

Spring: Basking bulb on for four to six hours when the room temperature is below 70 degrees.

Summer: Ambient temperature about 72 to 78 degrees. No basking light needed.

Fall: Basking bulb on for four to six hours when the room temperature is below 70 degrees.

Avoid temperatures above 80 degrees. Always provide a cool retreat area. Kardon said the display at the San Antonio Zoo kept its black milks in the "cool room" with daytime highs of 72 to 73 degrees and nighttime lows as cool as 56 degrees. The basking lights were kept on for no longer than seven hours.

Substrates

Black milks do well on a variety of substrates so long as you provide a cool, moist hidebox. Cypress mulch is probably the best substrate, as it does well in high-humidity setups and resists mold growth. You can also use shredded aspen, soft paper pulp products such as Carefresh, or even newspaper. The key, especially when using these drier substrates, is to provide a moist hidebox. I use a 12-quart plastic box with a hole cut in the lid. I stuff the box with moistened – not wet – sphagnum moss. This also doubles as an egg-laying chamber for females during breeding season. Without the moist hidebox, black milks can develop shedding problems. Obviously, avoid cedar, as the oils are toxic to all snakes.

Eager to Eat

Feeding black milks is about as trouble-free as you can get. Nine times out of 10, hatchlings will take a large frozen/thawed pink after their first shed. As adults, black milks will take small- to medium-sized frozen/thawed rats. It's best to offer two smaller rats rather than one larger one. Feed hatchlings once a week. Adults do well feeding every seven to 10 days, but feed females a bit heavier during breeding season, especially if you plan to double-clutch them. Sometimes, black milks take frozen/thawed rodents aggressively, meaning they will pounce. Feeding time is about the only time you don't want your hand near a black milk's mouth. They like to eat! Always provide a source of clean, fresh water. The water bowl does not need to be big enough for a soak.

Breeding Black Milk Snakes

Before attempting to breed your snakes, be sure they are old enough and big enough. I wouldn't try to breed a female black milk until she is in her fourth year, and waiting until she is in her fifth year is better. I think they grow and mature just a tad slower than Hondurans and benefit from the extra year. I also believe that waiting until your female is at least 4 years old will result in a better life of breeding, more eggs and bigger hatchlings. Breeding females should be at least 5 feet long, too.

I cycle my black milks similar to how I cycle my Hondurans. They get their last meal of the year during the last week of October. By mid-November, I begin gradually reducing the amount of time the basking light is on. If you have any cage lighting or room lights on a timer, reduce them to an eight-hour day. By December 1, I cut off the basking light, keeping the ambient cage temperature in the mid- to upper-60s. By mid-December, all the lights are off in the room save ambient sunlight from the windows. The room thermostat is set for 58 to 60 degrees.
For all of January and February, the temperature in my reptile room is maintainted in the low 60s during the day and the upper 50s at night. (Alan Kardon states that the San Antonio Zoo would drop temperatures down to 54 degrees at night during January and February, with no basking light during the day.)

Try not to disturb your snakes during the winter. Check water bowls and clean as necessary, and take some temperature readings. Other than that, just leave them alone.

Begin gradually warming your snakes on March 1 by providing a basking spot for two hours each day. Turn on cage lighting for eight hours during the day – if you don't have cage lighting, set the room light on a timer. By mid-March, the ambient temperature should be a few degrees below your summer levels. Start feeding your snakes. I have occasionally warmed my snakes up earlier by several weeks in an effort to get them breeding earlier in the year. Sometimes it works.

Black milks sometimes begin exhibiting breeding activity after their first shed following the winter cool-down. This shed normally happens within a month or so after coming out of winter. More often, breeding takes place after the second shed cycle, and sometimes it takes three shed cycles.

Put your male into the female's cage each time after she sheds during the breeding season and see what happens. If he gives chase and she allows him to lock up – bingo. I'll usually give them a couple of hours together, and sometimes overnight, to attempt breeding. Then remove the male. Wait about three days before attempting another breeding regardless of whether you observe a successful lock up. I'll allow the snakes to breed four or five times during this period. Because of a black milk snake's bulk, it is sometimes difficult to detect when a female is swollen with eggs or when it is ovulating. Usually, you can feel – and maybe even count – the eggs by gently running your fingers along the belly. To be safe, have the moist hidebox in the cage at all times so you don't miss a clutch of eggs. Usually the surefire sign that your black milk is about to lay a clutch of eggs is she will refuse food after a shed. Typically, this would be her third shed in the season and is considered her pre-egg-laying shed.

Clutch size can be from six to as many as 18 big eggs. Eight to 10 eggs is the norm. Usually, they will be laid 10 to 16 days after the pre-egg-laying shed. Try not to disturb the female too much when she is getting ready to lay. It's important that she feel her laying site is secure and safe. Disturbing the female during laying is one thing I believe leads to egg retention, which can harm or even kill the snake.

Once the eggs have been laid – and it will likely take a full day for her to finish – carefully remove the female from the hidebox and place the eggs, in the same position as they were laid, in an incubation box of moistened vermiculite (2-1 ratio by weight of vermiculite to water). Close up the box, making sure it is ventilated with a dozen or so holes along the side that measure about the diameter of a screw. This will prevent excess moisture from building up and dripping onto your eggs. Incubate them at 78 to 82 degrees for 65 to 75 days. Lower incubation temperatures (down to 74 degrees) will increase the incubation time. Higher temperatures can result in deformities or embryo death. Hatchling black milk snakes can be kept in commercial rack setups with shoebox-sized plastic boxes or small (about 5-gallon size) cages. Provide some undertank heating for a warm area of about 78 degrees, and the rest of the cage can be 68 to 72 degrees.

 Black Milk snake Mysterious Color Change

Black milks are the only species of milk snake that exhibits a drastic color change. While many milk snakes will develop black tipping with age, black milk snakes eventually turn solid black. Occasionally you will see an adult that retains some faint banding, but the best will be solid black with maybe just a brownish scale or two under the chin.

Why do they change? No one really knows for sure, but Alan Kardon explained the predominant theory. As hatchlings, black milks mimic venomous coral snakes in appearance. It is a common defense mechanism used by many snakes in the Lampropeltis genus. But as they get older, the environmental conditions and the sheer bulk of the snakes demand a change.
"A big, cold-blooded vertebrate at high altitude will need to heat up quickly," Kardon explained. "Some European vipers also have melanistic tendencies."

Black retains heat and thus allows the big adults to heat up to adequate temperatures for digestion and good health in the cloudy, cool, montane habitats in which they live.

Calm and Tolerant

Black milks tend to be somewhat calm right out of the egg. While hatchling Hondurans can be nippy or excessively squirmy for the first couple months, black milks don't have the same feistiness. As adults they are even mellower, tolerating regular handling, and they make awesome display animals. I have never been bitten by an adult.

It's a good thing they are mellow, because holding a black milk snake is the best proof you can get of how powerful these serpents are. They are densely muscular, heavy-bodied, rat-pounding machines. If you have the space for one of these incredible snakes and want a snake that is naturally beautiful and easy to care for, black milks are the perfect choice.

The author wishes to thank Alan Kardon for his time and wisdom regarding black milk snakes.