Lecture 31 Flashcards
What is the structure and composition of social groups of horses?
- Most studies on the Przewalski horses
- Single male harem bands most common
- stable hierarchies, particularly females
- Bachelor bands - group of males
What is the spacial use of wild horses?
- Bands occupy “home ranges”
- Range of sizes - 0.9 to 48 km^2
- Sometimes home ranges overlap
- They need food, water, and shelter
- The size of the group varies depending on where they are and climate - the bigger the group the more controlling over resources
- mountain groups: very small bands, bandsoverlap so mares go from group to group
- desert groups: bands remain separate and don’t overlap as much, large range, less food and water
- Island groups: limited resources
- Island groups with high insect population: group together size is larger, less likely to get bitten
What is cohesion and dispersal in feral/wild horses?
- A herd is made up of groups of horses (harem or bands)
- Death or birth are main reasons for change in the herd
- Groups might change through young moving from one band to another
- Young mares - driven out by older mares or taken by other stallions: competition, decrease inbreeding
- Young stallions - leave volunterily or driven out by herd stallion: only the dominant male is allowed to breed
What are some inter-group interactions with horses?
- Harem stallions defends his females
- hapens more when ranges overlap
- Stallions fighting - usually mock fighting
- In confinement where males cannot escape, leads to real fighting and injury
What are some intra-group interactions in horses?
- Horses form strong social bonds
- Form stable hierarchies
- Feral - stallions dominant over females
- Commercial - sometimes geldings dominant
- Rank affected by
- Prior fighting experience, skill, strength, stamina
- Females especially - rank appears to be inherited
- Also maintain social order through tolerance and attachment relationships
- Based on preferences
- Male-male interactions
- Dominant stallions does most of the breeding, but some younger mares might be allowed to breed with younger stallions
- Dominant stallions patrols his harem by defending the edges
- Male-female interactions
- More interest by the male preceding oestrus
- Approaches the mare (high posture, exaggerated gait, whinnies and nickers)
- If no - she kicks at him and clamps her tail
- If she is in full oestrus, she looks for the stallion
- Female-female interactions
- Pair bonds - grooming
- Big part of group cohesion
What is the horse’s vision like?
- Large eyes at either side of their head - wide visual field
- 2 blind spots
- Right behind - where rider would sit
- Right in front - what they are eating
- Monocular vision
- Wide field of vision (good)
- Prey species
- Maintaining visual contact of the herd
- Cannot see well close up (bad)
- Depends where the head is
- Head down, near vision is good
- Head up means horse can see long distances
How is the horse’s vision important for communication?
- When the object is in the corect field of vission, horse is very able to detect even small movements
- Cones vs Rods
- Good night vision (rods)
- Likely important for predator control and for maintaing group cohesion during the night period
- Cones located in eyes also, but disagreement as to what colors are seen
- Facial movements
- Relaxing or tensing of muscles around nostril, mouth and chin
- Clenched jaw
- Dilated nostrils
- Fixed stares
What are the escalating levels of aggression in horses?
- Mild - laying back both ears and moving mouth towards stimulus
- If this doesn’t work, horse might bite (74% of aggression)
- Tail swish - irritation (flies)
- If this doesn’t work, might lead to kicks with back leg
- High arousal state - head and tail held high, elevated paces
- Horse appears bigger - stallions
What are other facial expression shown in horses?
- Drooping head/tail - depression or pain or distress
- Wrinkled nose - prior to bite
- Drooping lower lip - relaxed
- Shape of mouth, eyelids and nostrils can change during certain encounters
How are horses ears important?
- Likely hear more than humans - we think
- Low frequencies?
- Ultrasonic range?
- Ears are large and can rotate
- Can determine the location of sound
- Language is subtle
- Not as important as body language
What are the four types of vocalization in horses?
Nicker (100hz)
- Low pitched pulsating, made with closed mouth
- Greeting, maintaining contact, prior to feeding
Whinny (neigh) (2000hz)
- Loud
- Social isolation to aggression - maintaing contact
Squeal
- Aggressive contacts
- Mating
Groan
- Often in distress or discomfort
What are other sounds that horses make that are not from the larynx?
Snort
- Conflict, clearing airways, alert situations, interesting odor
Blow
- High anxiety situations
How do horses use smell and taste to communicate?
- Scent mark
- Use scent to identify their young
- Group scents
- Mating - mares indicate receptivity through pheromones in urine
- Horse can “sniff” through their long nasal passages - serves to intensify the smells
- Horse has a vomeronasal organ on the floor of the nasal cavity which detectspheromones
- Horse curls its top lip which allows the air to drop onto the organ
What are the social groupings under commercial conditions like for horses?
Managing sports horses
* Usually involve controlled exercise, restricted feeding regimes, restricted housing for part of day
Housing ranges from tethered stalls to range
* Depends on purpose, cultural conditions, availability of space
What are the different types of housing systems for horses?
Tie stalls
* Horses cannot see, touch or smell each other
* Tied to wall
* Can hear each other
Box stalls
* Horses can see, smell and hear each other
* Cannot touch each other
* Individual stalls, not usually tied up
Loose housing
* Horses loose in area together
* see, smell, hear, touch each other
