Final - Horse Behaviour Flashcards
What do ethogram tables include?
- Name of behaviour (label)
- Description of behaviour (in pics or words)
What is generally understood about behaviour names?
- Can have same name, but different description
- Can have same descriptions, but different names
What affects the names of behaviours?
- Use of unique jargon by those involved with each species
- Regional differences in terms
*Thus, behaviour literature uses a variety of terms and it’s important to focus on the behaviour itself and what it is
What is the evolutionary background of horses?
- Horse ancestor is a pony-shaped mongolian wild horse (Przewalski’s horse)
- True horses occupied the Eurasian lowlands north of the great mountain ranges
- Despite their morphological differences, all the breeds, groups and types of domestic horses belong to one species
What are used for behavioural comparisons?
For behavioural comparison, many use feral horses rather than the Przewalski horse
- Przewalski’s still exist in captivity, but came from a nucleus of 11 foundation animals THUS, they have emerged from a shallow gene pool over the past 20 generations of captivity
- Mustangs found roaming North America are feral representations of these species
Behavioural biology of horses
- Long nose
- allow it to graze while maintaining surveillance above the grass - Relies on caution, speed, and agility
- w/o horns or antlers, these are its chief means of self-preservation - Social herbivores
- seek companions for added safety, mutual comfort and enhanced detection of food
- feels insecure when isolated - Ability to use minimal physical effort to rest while standing
- Trickle-feeder obliged to forage frequently (generalist herbivore)
Behavioural biology: trickle feeder
A horse is a trickle-feeder obliged to forage frequently (generalist herbivore)
- Has NOT evolved to eat and then ruminate in one spot
- It eats and moves and eats and moves
- Restriction of movement and imposing periods of fasting are likely to be more problematic to equids than to members of many other species
Horses: Feeding and Foraging
- As temp increases, foraging behaviour decreases
- Time of day affects foraging bout length
- longer feeding bouts at dawn and in the late afternoon - Breaks btw feeding bouts are short
- tend to occur to perform other activities such as maintenance, social and repro behaviours
Horses: Vision
- Horses can see objects clearly but also maintain distant watchfulness
- Panoramic vision: 330-350
- Binocular vision: 60-70 - The blind zone accounts for a proportion of startle responses, including shying
- Image magnification is 50% greater than humans
- Good distance vision
- Night vision
- Dichromatic vision
- yellow is identified most easily, followed by greens, then blues with reds the least easily identified
- better than humans at discriminating btw shades of grey but trouble w discriminating btw greens and greys of similar brightness
What is the horse’s visual field affected by?
Visual field is affected by the level at which the head is carried
Horses: Hearing
- Similar to humans, but may hear at higher pitches
- Funnel-shaped ears can move in unison or independently
- 10 muscles, the ears can be moved in lateral arcs of 180
- direction the ear is pointing helps to indicate where the horse’s attention is focused - Can protect their hearing from very loud noises by laying ears flat
What may horses with impaired hearing show more of?
Drooping of the ears
Horses: Smell and Taste
- Olfactory sense is well developed
- Have a vomernasal organ and show the flehmen response
- Sense of taste that can discriminate btw safe and toxic plants with variable accuracy
- may be able to detect trace minerals
Horses: Touch
- Very sensitive to tactile stimulation
- especially around the muzzle and ears
- some horses dislike their ears, eyes, groin and bulbs of the heels being touched - Sensitive to the presence of others at their side
- Allogrooming areas
- common along mane
- less common over back and rump
- rare along shoulders and underside of the neck
Allogrooming areas
- common along mane
- less common over back and rump
- rare along shoulders and underside of the neck
What grooming styles are used by horses?
rolling, shaking, rubbing, scratching, and nibbling
In feral horses what do social groups consist of?
Harem groups: typically 1 male, a variable number of females and young horses
Bachelor groups: excess males
- leave their natal band around 0.7-3.9 yrs of age
Under the permanent harem-type of social organization, females are in constant association with a male. What does this result in?
- Detection of heat is assured
- Harem males do most of the breeding
What does stability of the harem group depend on?
- The herding instinct of the stallion
- Strong social attachment btw harem members
- Rejection of intruders
Horses: Dominance Hierarchy in feral vs domesticated horses
In feral or domesticated horses:
- a dominance hierarchy develops, and once developed remains stable; serves to reduce aggression and agonistic encounters
In feral groups, males tend to rank at the top
- dominance expressed as threats to bite or kick, or actual biting and kicking
In domesticated groups, dominance is expressed in competitive situations
- ex. a restricted food source
Horses: Dominance Hierarchy in small vs large herd
In small herds
- dominance hierarchies are linear
In large herds
- triangular relationships have been observed; most social triangles occur in the middle of a band’s organization
What factors appear to affect rank in a dominance hierarchy?
- Height or body wt, but not necessarily age, appear to affect rank
- Length of time in band appears to affect rank
- The daughters of a dominant mare tend to be dominant within their own herds
In terms of sexual receptivity, horses are…
Seasonally polyestrous
- long day breeders
- duration of estrus decreases at ht of the breeding season
