Social structure: Communication: Feeding and digestion
By Dr Clive Dalton
- The horse is a herd animal with a clearly defined hierarchy.
- Some horses may roam on their own, but horses in the wild are found in "bands" ranging from 4 to 10 individuals. Bigger groups of up to 20 may occur.
- Usually a group is based on a family with one or two mares and their offspring from the last 2-3 years. Maybe there’s an extra young male hanger-on.
- The females in the group are the decision makers and the male or males that accompany them act as guardians rather than leaders.
- There seems to be a shifting system of dominance relationships among members of the band. At different times, the dominance order will be different depending on the circumstances and is not a rigid and formal dominance setup.
- Horses develop tight relationships with other individuals, especially close relatives, and these can complicate the overall social order.
- This special relationship between individuals can be seen with horses kept in housed groups or n small paddocks. You'll see all sorts of idiosyncratic preferences for particular companions and dislike of others.
- Bachelor males usually form small groups of 4 to 8 individuals. They stay alone until mating time, when some start to try and break into an established harem to steal a mating when the stallion is otherwise engaged.
- You can also find solitary males and solitary females, and bands of non-breeding juveniles.
- A stallion as the alpha male may appear to be the herd leader at mating time when they form a harem of mares, but the mares are still important decision makers as to where the herd grazes.
- A stallion may gather some new mares to his harem depending on his dominance in the territory.
- The alpha female shows her real power in doling out discipline to the adolescent males. Subordinate males may also act as security guards in the harem.
- As survival is based on flight rather then fight, vigilance by all animals in the group is important.
- The social order is sorted out by gestures - ears laid back and teeth bared, and individuals may resort to nipping others with their teeth.
- Severe biting and kicking with hind legs in unison is used for more serious sorting out of social problems.
- Stallions fight by rising up, using their front feet to paw the opponent, using the neck to knock an opponent down together with severe biting. They also use their back feet either singly or together for kicking.
- Mutual nibbling or grooming is the way horses reinforce social ranking. They do this to their handlers too.
- Juvenile horses move out or are forced out of the main band and disperse. Females may return to join their old band when they are mature. The chances are by then the alpha male (their father) has changed, so inbreeding is kept to a minimum. The herd leader may still be one of their relatives however.
- Stallions tend to ignore their own fillies when in heat and concentrate on the mares, this being nature's way to reduce inbreeding.
- A male may join a solitary female and start a new band, so there will be no genetic association between them.
Kaimanawa Wild Horses. Photo copyright Wendy Brewer.
Feral herds are the best place to study basic horse behaviour, because there are sufficient numbers of animals and a big enough territory to appreciate the role an individual horse has in the herd hierarchy. So many problems of individual horses isolated from their kind is because owners forget horses are social animals.
The importance of social behaviour can be seen in New Zealand in the Kaimanawa herd of feral horses which roams an area of the North Island high central plateau (tussock country), which is mainly out of bounds to the public as it's used for military training.
These horses originated from escaped animals and deliberate releases from sheep stations in the area in the 1860s, supplemented by miliary horses from the local military camp in 1941 to reduce the risk of disease spread (strangles). An Arab stallion was released into the herd in the 1960s to add his contribution to the mixed genepool.
Numbers increased rapidly over the years and in the 1990s the Department of Conservation required the herd to be reduced and maintained around 500 animals to protect the fragile high country environment.
Culled horses are now offered for sale to the public and the "Kaimanawa Wild Horse Welfare Trust Inc" has been established to provide information on the 'breed', especially on care and welfare of purchased animals.
Visit the Trust's website for full information at (http://www.kaimanawa.homestead.com)
The following photos were taken by Kaimanawa Wild Horse Trust member Wendy Brewer (firstname.lastname@example.org) on an annual visit to study the herd in their native territory arranged by the Trust in February/March.
The pictures are provided here with her kind permission and are copyright, so her permission is required before they can be used for any reason.
The pictures show the well-defined stages in a confrontation between young stallions to determine social order, rather than a fight to the death for the position of alpha herd leader.
1. Meeting and greeting
2. Moving closer
3. Starting to rear and move in for the first contact
4. The full on fight
5. Fight over - agreement reached
Female discipline of teenagers
- Studies by Monty Roberts and others have shown the way mares discipline young males They chase them out of the band and won't let them back in until the females think they are ready.
- This signalling is done by an alpha mare that goes out to the edge of the band and turns her hindquarters to the males who are looking for a signal to re-enter.
- When the mare decides the young male has done his penance, she goes to meet him nose-to-nose and he follows her back into the band.
- Mares have very strong natures and this is a reason why they are preferred as poly ponies. They can easily be trained to barge into other horses and be competitive.
Signals used by horses to communicate can be:
- Visual - signals using all parts of the body.
- Acoustic - sound
- Tactile - touch
- Chemical - smells
- All combinations of these used in different circumstances.
- There's a wide range of visual signals in the horse using most parts of the body.
- Because of acute vision, horses can pick up slight changes in these signals.
- They are associated with other body signals - all interacting.
- Opening and shutting the mouth, sometimes making teeth contact.
- Used a lot by foals to denote submission to the mare.
- It's a stylised grooming signal.
- Aggressive mood with clear intention to bite.
- Jaws and teeth held open.
- Teeth fully exposed.
- This is opposed to soft lips which shows relaxation.
- Shows tension but less violent.
- Top lip curled up and head raised high.
- Characteristic of stallions smelling mare's genitals and urine.
- Can be seen in mares smelling other mare's urine.
- Can be wrinkled showing disgust.
- Are flared in excitement or fear.
- Closed in pain or when exhausted.
- Open wide in fear.
- Shows whites of eyes when angry or terrified.
- Half closed in peaceful relaxation or submission.
- Head shake
- Sideways shake suggesting stress.
- Sharp upwards head toss showing annoyance.
- Head jerk - upwards and backwards showing annoyance.
- Ducks head down and back repeatedly.
- Used to increase range of vision.
- Nose moves with top of head still.
- Indicates horse is ready for action
- Pushes head forward in assertive move.
- Threat or indication of aggression.
- The next action will be biting.
- Attention seeking.Warning to take notice of me.
- Head snaking.
- Used by stallion to round up mares.
- Side to side wobble.
- Biting threats often accompany it.
- Common in boxed horses with little mental stimulation.
- Like seen in bored caged birds.
- Same problem in horse - boredom.
- Horse stands making circular neck movements.
- Shows intense stress.
- Found in boxed horses with no mental stimulation.
- Pricked - shows alertness
- Horse is paying attention
- Airplane ears - held out to the side with openings downwards.Horse is psychologically low and has lost interest in things.
- Drooped - horse is dozy or in pain. Showing feelings or inferiority.
- Drooped backwards - seen in ridden horse.Showing submission to rider. Sign of brutal owner. Mare approaches stallion often in this pose.
- Twitching and flicking. Sign of a stressed horse. Sign of confusion.
- Pinned ears - flattened back. Shows aggression. Provides protection when fighting
- Sign of excitement.
- Sign of intention to play among young horses.
- Seen when stallion approaches mare.
- Shown by mare when ready for service - hold tail to the side.
- Sign of submission
- Sign of exhaustion
- Sign of illness
- Seen in very aggressive horse. Stallions ready for battle
- First sideways then up and down.
- Shows horse is ill at ease, anxious or confused.
- Increased power of side flick in real rage.
- Flicked high in air and slapped down hard is warning that kicking will follow.
- Sign of anxiety
- Horse sensing danger
- Defensive signal.
- Don't push me signal.
- Varies in intensity denoting degree of concern.
- Often when horse craves company or has lost a companion.
- Low pitched and guttural.
- A salutation.
- Long low pitched nicker.
- Mares do this when stallion approaches.
- Stallions have personalised courtship nickers.
- Soft and barely audible to humans.
- Mare's message to foal
- Starts as a squeal and ends as a nicker.
- The loudest and longest call.
- Isolated horse uses it for security like wolf howl.
- It's a request for information rather than alarm.
- Shows intense rage of a fighting stallion.
- Contains a fair element of fear too.
- Sign of well-being.
- An enquiry sound - what's this?
- Remove dust from nose when feeding.
- Sign of exhaustion - when overloading pack horse.
- Sign of excess exertion.
- These sound can be heard over long distances.
- Seen in stressed or bored horses in stables.
- Some horses kick the walls in boredom.
- Can be slow release of gas from anus when horse is relaxed.
- Or a short sharp burst of wind when the horse is under tension when pulling load or in fear or stress.
- These are a very common means of communication.
- Seen when horses meet - nose to nose.
- Mares use nudges to direct foals to udder and away from it.
- Foals use it to warn the mare they are going to suckle the udder.
- Handlers use it, along with the voice to warn a horse of where they are.
- Aggression is all about tactile communication - pushing and biting.
- Touch is used by riders to direct the horse.
- Horses prefer to travel in floats facing the rear, although they are seldom moved this way. It seems that when the vehicle slows they prefer to take pressure on their rears rather than with their chests.
- Horses have an excellent sense of smell.
- It's important in meeting and greeting, they smell noses, breath, flanks and genital area.
- Smelling continues to dung and urine.
- Smell is used in foal recognition by the mare as well as visual clues.
- The foal to locate the udder using smell.
- Horses need to sleep, and most is done standing but they do sleep lying down.
- They drowse during the day but truly sleep at night.
- Their sleep cycle is short - 15 mins sleep then 45 mins awake.
- A horse that is forced to stand continuously, e.g. on long air flights, will be sleep deprived so must be rested on arrival.
- Group behaviour affects sleep. Dominant animals lie down first and set the pattern.
- Young horses need more sleep than the old.
- Horses prefer to lie on dry earth or sand and not cold wet areas.
Grooming and body care
- Horses like to roll in soft earth or sand, especially after exercise and when hot and sweaty.
- They scratch their own bodies with their hooves, teeth and lips.
- There is always concern over the welfare of horses covered in summer. Covered horses are very visual for the public and people assume the horse will be stressed in the heat.
- Covered horses need regular checking as external parasites can build up under the cover.
- Horses sweat over their bodies, so hosing down and grooming after exercise is much appreciated by the horse.
- Grazing behaviour and elimination.
- Horses ruin pastures faster than any other animal.
- The can graze much closer than ruminants as they have both top and bottom teeth.
- They overgraze areas that end up like lawns, and dung in other areas which they will not graze because of the smell.
- Pastures under continual grazing become "horse sick" - i.e. heavily contaminated with internal parasites and the dunging areas grow weeds.
- Horses tend to dung and urinate on areas where other horses have done the same as it's an important means of communication. Stallions regularly dung and urinate where mares have done so.
- Horses (especially feral horses) get a lot of information from dung and urine heaps about what is going on in the territory.
- Horses eat for long periods averaging about 12 hours a day and when feed is short they'll graze for up to 18 hours.
- Overfeeding is a major problem leading to "founder of the foot" causing lameness and general obesity.
- But with horses kept on bare paddocks all day and yarded at night to control their feed intake, boredom can become a problem leading to other behavioural issues.
- Horses dung every 3-4 hours and can defaecate while moving but have to stop to urinate as this requires muscle relaxation of the pelvis and hind legs.
- Horses can be trained to urinate by whistling (a conditioned response). When you see the horse urinating naturally, start to whistle so it will build an association between the whistle and the behaviour. With continual reinforcement the horse will learn to urinate on the signal.
Feeding and Digestion
- Horses are herbivores like cattle but are not ruminants.
- They cannot eat as quickly as ruminants that regurgitate their feed for further processing, so horses spend most of their day grazing.
- They eat a wide range of pasture plants and weeds. They don't like large quantities of lush legumes and need regular roughage to avoid digestive upsets.
- They digest their fibre in the colon, hence methane and carbon dioxide are passed out through the anus.
- Horses have a very mobile top lip that allows close cropping of pasture whereas the cow uses its long prehensile tongue.
- Unlike ruminants, horses have upper and lower incisors so they can nip off grass very short like a well-mown lawn.
- When starved horses will eat mud and old dung and will ring-bark trees.
- Don't let them have access to silage bales as they'll chew the plastic wrap.
- The main digestive disorder is colic and it can be very hazardous for the horse and handler, especially if the horse gets down in a box. Get it outside and keep it walking hoping it will clear some wind. Get urgent veterinary help.