There are two main herds of horses living on Assateague Island. The Maryland herd is managed by the National Park Service and kept to population of 80-100 horses by using a contraceptive vaccine on mares who are allowed to have at least one foal. The herds are separated by a fence at the Virginia/Maryland State line. The Maryland herd does NOT receive feed in the winter nor do they receive any type of veterinarian treatment. Please note that taking it upon yourself to feed the Maryland horses with carrots, apples or other food disrupts their digest systems and can cause them to colic, at times leading to death.

The Virginia herd is owned a managed by the Chincoteague Volunteer Fire Company which is allowed to graze the horses on Chincoteague National Wildlife Refuge, through a special use permit issued by the U.S. Fish and Wildlife Service. The permit restricts the size of the herd to approximately 150 adult animals in order to protect the other natural resources of the wildlife refuge. It is the Virginia herd which is referred to as the "Chincoteague" ponies. Typically, each summer, the Chincoteague Volunteer Fire Company rounds up the horses using “Saltwater Cowboys” and cross them from Assateague Island to Chincoteague during slack tide to be auctioned off. At the end of each rising and falling tide, there is a period called 'slack tide', when there is little or no current, or movement of water, in or out of the bays, harbors, and estuaries. Slack tide usually lasts 2.75 to 3 hours, although it varies with location. To learn more about the Chincoteague herd, please google Chincoteague Ponies and you will learn quite a bit more. 

How do horses get their names?
Each horse is identified by the park service with their Keiper number (read below for more information about Keiper Numbers). However, periodically, after a foal is born, the Assateague Island Alliance (AIA) will have an auction ("Name that Horse") or raffle which allows individuals or families to name a horse. The young Assateague foal auction on eBay starts with a bidding of $500.00. This is a major fundraiser for AIA and the money typically goes to the wild horse management program of the National Seashore.

Where do the wild horses find water on the island?
There are approximately 42 ponds on the Maryland portion of Assateague Island, and during a rainy period there are countless ephemeral pools. That is where the wild horses find their water year-round, as well as every other type of wildlife. During the summer, well-meaning visitors often turn on a spigot to give the horses water. Please call a ranger if you see this happening. Again, while one thinks they are doing the horse a favor, it contributes to changing their behavior in a negative way. Often, horses trying to get access to the "free drink" become aggressive, kicking and biting each other and, quite possibly, a human trying to “help them out.” The wild horses do quite well on the island without human intervention, surviving for well over 300 years. Help us keep them wild, will you?

How Horses Adapt to Weather
Left to adapt to their environment, Assateague horses must create their own protection, and a horse’s winter coat is a remarkably protective feature. The coat starts to grow long before the cold days of winter. As the days began to shorten and the retinas receive fewer hours of sunlight each day, the brain is stimulated to release extra melatonin, a hormone that prompts the hair follicles to produce more hair. You may notice that the horses’ winter coats appear to be fluffy. This is because the hairs lift up to trap warm air, creating insulation, much like a bird creates insulation by fluffing its feathers. Even more incredible…the long outer hairs form channels that help repel water. And if you separate those hairs, underneath there is a layer of dry hair and skin. Pretty Amazing!

How Do the Horses Survive Storms (e.g., Hurricanes, etc.) 

Whenever severe weather threatens Assateague Island National Seashore, we inevitably get asked the question "how will the horses survive the storm?". Horses have a natural instinct to flee from adverse weather. Experts state that horses are smart and know when storms are coming, have their “special spots” on the island to weather the storms and will move to higher ground. The herd has been around since the mid-1600s and they know where to go and what to do. Attempting to herd them or do other, would cause additional stress as well. Plus, we really don’t have any life preservers that will fit them.

Generally, the Assateague horses retreat from the developed areas of the park to spend the cooler months in the bayside marshes where their preferred forage, Spartina alterniflora (Saltmarsh Cordgrass), grows abundantly. And what in the world do they do when a hurricane or nor'easter strikes? During extreme weather conditions they find shelter from high winds and storms by temporarily retreating from the marshes to forested or densely vegetated areas and turning their tails to the wind. 


Have you ever wondered why the new foals have a funny looking coat? People often ask if there is something wrong with the foals wondering if they have a skin condition based on their appearance. So why do they have those rings around their eyes and muzzle? Rest assured, no skin condition. They are shedding the soft and fluffy foal coat, and the new, sleek adult coat is darker and smoother. Rest assured, they shed around the eyes and muzzle first, and gradually the rest of it will be replaced. You will see some newborns that actually look as if they have a mask or are “Batman.”


Have you ever wondered why you sometimes see little horse droppings here and there and, suddenly, you happen upon a massive pile of poo? Well, that’s called a “stud pile.” As the horses roam the island in bands (groups), they, of course, go to the bathroom when and where they need to do so. It may happen anywhere, such as the parking lot, beach, marsh, or woods. If a stallion encounters a pile of waste left by another group, he will immediately mark the pile with his own special brand of poo. He’s letting another stallion know that this is his turf and these are his mares.

At Assateague Island, Rangers also gather fecal samples (poo) for genetic purposes. Using the DNA found in the poo, the rangers are able to determine which horses are related and are able to fill out a “horse family tree.” It also helps them determine if any of the mares are pregnant.

So, while the poo may be a tad unsightly and have a bit of an odor, it’s also helping the rangers know “who’s who on the island;” who may be pregnant and, it helps the stallions know what competition he may have in the future. These droppings are the “golden nuggets” of the island, all a part of the island mysteries.


Did you know that when two horses meet for the first time they will breathe into each other’s nostrils? They will also do this if they haven’t seen each other for a while. This is their way of saying “hello” and remembering the smell of the others breath, similar to how we bring to mind someone’s name (Aren’t you glad we have the power of speech?). At times the breathing becomes a little harder between horses meaning that they may be on their way to working out dominance issues, sometimes leading to biting, squealing, or a quick turn with a swift kick. All good reasons to keep your distance (40 feet or more) when watching or photographing the horses. You never, ever know what may happen.


Have you ever seen a horse making a funny facial expression, as if he or she was laughing, and wondering what they were doing? When the horse curls back its upper lip exposing the front teeth and gums, then inhaling and holding the pose for several seconds, it’s called the “flehmen” response. This is done when the horse senses a smell worthy of exploring. The main purpose of the flehmen response is to find out where there’s a female, whether she’s reproductively ripe, and if not, when she will be. Females typically show this response after birth. Young colts flehmen up to five times more frequently than fillies, and fillies more frequently than mature mares. That’s the science, but, perhaps, it’s just them all having a good laugh at how we “humans” behave.
ELF SHOES OR LAMINITIS (Unusual shape of hooves)

N10T “Ninka” is an older mare who has gotten quite a lot of attention over the years, mostly by concerned campers or beach goers who have witnessed her rather unusual hooves. Dave Smith, veteran member of the Pony Patrol, the organization that helps to educate people on the wild horses, encouraging them to stay a safe distance away, says that people have gotten upset regarding Ninka over the years. (Picture is of N10T's dam, Charmed)

“Lots of people have asked about that mare. She’s been around for quite a while. People get all up in arms about her, but the park’s policy is to not interfere with the herd,” said Smith.

The reason for the numerous inquiries is that Ninka has what is often referred to as “elfin shoes” or “Alladin’s slippers,” so named because the hooves curl up in the front portion. The appearance is quite unusual to see firsthand. Ninka thusly walks a little differently than other horses in her herd, but is nonetheless a fully functioning member of that herd.

These “elf shoes” are often caused by laminitis, also known as founder, a condition wherein the sensitive laminae within the hoof becomes inflamed. According to Bill Hulsander, Chief of Resources Management for Assateague Island National Seashore, laminitis in a wild horse can be caused by a number of reasons.

“One cause is a retained placenta. In horses, retention of the placenta for only a few extra hours is enough to trigger laminitis. In addition, the N10 maternal line of horses, of which Ninka is a product, has produced a number of varying grades of clubfoot and other hoof abnormalities with differing amounts of overgrowth, which periodically breaks back. Ninka’s two brothers each had an extreme hoof abnormality of a front foot, yet both lived their maximum life spans in good health as very successful harem stallions.”

Laminitis is not curable, but is often treated in domestic horses with drug therapy, diet, and a number of other ways, depending upon the initial cause. Treatment for a horse like Ninka could be difficult considering that the cause is most likely genetic. Additionally, the policy of the National Park Service is to not interfere with the horse herd, or any of the other wild animals that call Assateague home.

“Just as with deer, raccoons and other Assateague wildlife, the horses do not receive vet or farrier care, or supplemental feeding.  They are not domestic animals.  Our responsibility to the horses, just as with all other wildlife species on the island, is to ensure that there will always be a thriving population,” explained Hulsander.

Curious about Swamp Cancer or Pythiosis? 

Many of our Assateague Friends have raised the question about the fungal infection, Pythiosis or "swamp cancer” (not really cancer) with respect to the Maryland herd. There have been no signs of the disease in the Maryland herd and Resource Management staff consistently monitors the horses for any signs and symptoms. Pythiosis thrives in stagnant pools of fresh water and is a naturally occurring pathogen. You may be aware that the two herds of horses are managed very differently on Assateague Island. The Maryland herd is free to roam the entire Maryland section of Assateague and they are able to access many varied sources of fresh water in the back country. Of note is that many of the freshwater ponds in MD often get surrounded by salt water, thereby potentially minimizing the overall risk of phythiosis. There are approximately 42 ponds on the Maryland portion of Assateague Island, and during a rainy period there are countless ephemeral pools. That is where the feral horses find their water year-round, as well as every other type of wildlife. That plus the smaller size of the MD herd both attribute to a much less hospitable environment for swamp cancer. The Chincoteague ponies are kept in grazing compartments on the Virginia portion of Assateague and there is a physical fence at the state line to prevent the two herds from coming in contact.   The National Park service is constantly monitoring the horse population and the horses are managed as a wild herd. If you have questions about this or other items, we encourage you to reach out directly to the Assateague Island National Seashore team. For more information, click here to contact the National Park Service.


You see, innocently, we teach them to approach us, the island visitors, looking for free handouts. They will try to put their head in your car, raid your campsite or beach party. People “teach them to do this,” unfortunately, and accidentally are reinforcing the bad behaviors of the pony. Think about it: A wild pony has a diet mostly by eating grass. They can get very ill by eating food that is not plentiful on the island and that includes things that you think may not hurt them, like carrots and apples. Heaven forbid, if they eat a Cheeto or Dorito. It gives them a stomach ache called colic, because their tummy is not used to digesting those foods.  Stomach aches, as you know are NOT fun, so the ponies try to eliminate the pain by rolling which can ultimately lead to twisting their intestines. Ouch. It’s just NOT a good thing as this can ultimately lead to their death, sadly.

BTW, one wild horse in Corolla, North Carolina choked on an apple and died. He wasn’t used to eating apples like domestic horses, unfortunately.

Do NOT turn on the water spigots, even though it’s fun to watch and they look thirsty. There is plenty of fresh water on the island and they know where to find this. By turning on the spigots, again, you are teaching them bad behavior and they will get into fights trying to get to the water. Bones have been broken (human) and people have been bitten. By the way, the Assateague horses drink over twice the amount of water that domesticated horses will due to their salty food supply. All of that drinking, combined with a high salt diet contributes to their bloated appearance

So, we encourage you to keep ALL food in the car, even pet food! (Yes, they are masters of opening up Tupperware containers, coolers or even stealing a hot dog off of a hot grill).

A Wink and a Nod (Courtship & Mating)
Horses are referred to as "long-day breeders" because they come into heat (season) as the days increase in length in the spring. The natural breeding season for horses in the Northern Hemisphere is the spring or summer. Light is the controlling factor in causing mares to come into season in the early spring. Some mares, can breed during the winter months, however. The cycle occurs roughly every 19 - 22 days. Mares carry their young (called foals) for approximately 11 months from conception to birth (average range is 320 - 370 days). Horses will curl their upper lip and press it to the back of their nose, which is called the Flehman response (almost as if they are laughing). A stallion will make this face when he examines a mares urine to find out if she is in heat or season. The Flehman response increases the flow of air through the nostrils, which brings the scent openings behind the incisors on the upper palette to the vomeronasal organ. Click here for more information on horse breeding.

Horses or Ponies (Here’s What the National Seashore Believes)
You may notice that the wild horses on Assateague Island National Seashore are often referred to as “ponies” by some. There is even some signage at the State Park that says “ponies.” That being said, the National Seashore refers to them as horses. Here’s why: The short answer is that they are most closely related to horse breeds than pony breeds. Anything less than 14.2 hands (a "hand" is 4", and equines are measured to the top of the shoulder) is generally considered a pony (and the Assateague horses are 12-13 hands); yet there are many, many exceptions. Here are a few examples: Arabians are often less than 14.2, miniature horses are very tiny, and Caspian horses are 12-13 hands, similar to Assateague horses, but they are all still horse breeds. And on the other side, Connemara ponies are often more than 14.2 hands, but are still a pony breed. Many breeds of horses and ponies have been turned out on the island for hundreds of years, and over time, many were left to go feral. The smaller type we see now is what has adapted best to the conditions on the island and to the available forage, surviving and thriving over the years. Genetically they are a smaller animal. Call them horses or ponies, but remember that they are wild and we need your help in keeping them that way by not feeding them, not petting them, moving away from them if they approach you and keeping a distance of at least 40 feet. Every interaction makes a difference! If you see someone breaking the law or doing things that prevent these horses from remaining wild, please contact the ranger station at 757.898.0058

Is a horse pregnant or not?
Each November, Assateague Island National Seashore biologists conduct pregnancy tests on the mares among the population of wild horses on the barrier island in an attempt to predict how many, if any, new foals are expected to join the herd in the coming year. Essentially, staffers follow the mares and wait for them to defecate. Samples are collected, frozen and sent to a lab to be analyzed to determine if any of the mares will be expecting next spring. Of course, there could be a surprise or two. For example, in 2019, Susi Solé (N2BHS-M) gave birth to N2BHS-MR (Seases Bay Breeze or "Breezy") in January and it was a complete surprise (albeit, her tummy was very, very round).

Keiper Numbers
Every horse in the Maryland herd is given an alphanumeric code, such as those of the horse pictures here from left N6BM, N6BMT (Sonja), N10O (Tipperary), N6BMT-F (Jojo) and N6BMT-FO (Margaret’s Thunder Heart). This image was taken in 2017 and includes four generations! Notice anything about their codes? Maternal lineage is just one thing you can discover by looking closely at the horses alphanumeric code. When researcher Dr. Ronald Keiper began studying the Assateague horses in 1975, he developed a system that could identify, and trace the maternal ancestry of, each individual horse. The system of alpha-numeric identification numbers he came up with are now known as "Keiper numbers" In 1975, there were only 44 horses in three harem bands living on the Maryland portion of Assateague Island. A harem band consists of a dominant stallion and his mares and immature offspring. Each of these bands was designated by the letter M, N or T. The dominant stallion of each band was given the number 1, resulting in Keiper Numbers. M1, N1 and T1 for the stallions. The other horses in each band were numbered consecutively beginning with 2 (M2, M3, T2, etc.). The letters at the end of each horse’s number indicate that particular individual's maternal lineage and their birth years back to the original 1975 study of the horses. At birth, each horse is assigned a Keiper number created by adding the letter for its birth year to its mother's Keiper number. Birth years began in 1976 with A, B for foals born in 1977, C for 1978, up through Z in 2001. At that point the alphabet was started over with a dash in front of the letter, resulting in -A for foals born in 2002. Accordingly, N6BMT-FN was born in 2015 to N6BMT-F; N6BMT-F was born in 2007 to N6BMT; N6BMT was born in 1995 to N6BM; N6BM was born in 1988 to N6B; N6B was born in 1977 to N6. N6 was present in the herd during the initial 1975 survey and so does not have a birth year letter. She was the sixth horse identified in "N" herd. And the "X" horses? During the 1980s, birth records for the herd were not as closely maintained as they are today. By 1990, there were about 25 unidentified, mostly solid-colored horses living on the island that had been born in the mid-1980s. These horses were designated with an "X" and numbered consecutively. Following a complete genetic study of the horses in 2005, correct identification and parentage for most of these “X” horses were determined based on their genotypes. An example is the mare X13, who was confirmed as being N2BH. Five of these “X” horses could not be positively identified, and so they retained their “X” IDs. However, presumed offspring of the “X” mares living at the time of the genetic study were confirmed as descending from these “X” mares, and so were named according to the same protocol as all of the positively identified horses. The stallion X15NY, for example, was born to X15N in 2000; X15N was born in 1989 to X15, who was one of the five “X” individuals living in 2005 who could not be positively identified. A 1976 B 1977 C 1978 D 1979 E 1980 F 1981 G 1982 H 1983 I 1984 J 1985 K 1986 L 1987 M 1988 N 1989 O 1990 P 1991 Q 1992 R 1993 S 1994 T 1995 U 1996 V 1997 W 1998 X 1999 Y 2000 Z 2001 -A 2002 -B 2003 -C 2004 -D 2005 -E 2006 -F 2007 -G 2008 -H 2009 -I 2010 -J 2011 -K 2012 -L 2013 -M 2014 -N 2015 -O 2016 -P 2017 -Q 2018 -R 2019 -S 2020


Assateague Island National Seashore typically does not intervene when a horse becomes ill, unless it is a traumatic injury or situation. An exception was made in an incident with N2BHS-CKPT in July 2021.

After losing her mother to a low speed traffic accident, a three-month old orphaned foal "Moonbeam" (N2BHS-CKPT) was relocated to the Virginia portion of Assateague island on July 12, 2021. The foal was likely involved in the same motor vehicle accident and appeared slightly lame. While she seemed in good health and was grazing, the National Park Service wildlife veterinarians determined that given her young age, she was at a disadvantage without her mother. Foals generally nurse more than three months and are still learning to graze as well as how to integrate socially into a herd.

As part of the Virginia herd, managed by the Chincoteague Volunteer Fire Company, the foal received immediate supplemental care. The plan was to introduce her into the herd at Chincoteague National Wildlife Refuge and she would not be sold and leave Assateague, VA except for medical care. However, in February 2022 it became apparent that N2BHS-CKPT, "Moonbeam", would not survive out in the wild on Assateague  The decision was made to transfer her to Stoney Creek Chincoteagues in Hughesville, PA under the careful, nurturing, watchful eyes of Tipson Myers.

This is now her forever home, and she is thriving.  You can follow Moonbeam on the Journey of Moonbeam Facebook page.

We wish her well!