ch 10 self groomig

Chapter Contents

  • Grooming
  • Body Care

Grooming

  • Importance of Grooming:
    • Maintains integument health.
    • Contributes to affirming social bonds among horses.
    • Reinforces affiliations and sharing odors.
    • Evidence suggests horses rely on scent mainly to recognize familiar conspecifics when in proximity.

Mutual Grooming

  • Definition:

    • Mutual grooming allows horses to reach areas difficult for self-grooming and facilitates the exchange of odors.

  • Physiological Effects:

    • Conducting mutual grooming reduces heart rate; specific calming effect seen when grooming certain regions like the mane and withers.
    • Noted that heart rate in foals can decrease by an observed mean of 14% when humans scratch preferred areas.
    • Allows handlers to reward horses without food.

  • Timeline of Behavior:

    • Starts in the first week of life, peaks during the second and third months of life due to foals finding physical contact intensely gratifying.
    • Initially, mutual grooming is performed with the dam, who may reject other partners when her foal seeks attention through allogrooming.

  • Grooming Patterns:

    • Most horses engage in mutual grooming for about three minutes at a time.
    • Females participate more in mutual grooming than males, indicating a social behavior linked to sex.
    • Partners in mutual grooming usually share preference based on social rank and kinship.
    • In context of natal bands, mares and their offspring groom each other rather than unrelated horses.

  • Influence of Social Structure:

    • Absence of stallions enables grooming between same sex-age groups, with stallions in multi-stallion harems grooming each other.
    • Mutual grooming movements typically begin at the cranial neck and move to areas like the withers and the tail-head.

  • Variability of Mutual Grooming:

    • Frequency is subject to daily and seasonal changes.
    • Peaks noted during coat shedding seasons, particularly in April and July in Northern Hemisphere studies.

  • Effects of Social Deprivation:

    • Colts stabled alone for 9 months showed significant increases in social grooming after being released to interact with other horses.
    • This reflects a post-inhibitory rebound effect of grooming motivation.

Self-Grooming

  • Definition:

    • Self-grooming exhibits resourcefulness as horses utilize their hooves, mouths, and environmental objects to relieve irritation.

  • Frequency of Behavior:

    • During weeks 5-8 of a foal's life, self-grooming peaks at an average of 12.3 times per hour.
    • This frequency declines in adults to 1.2-2.2 times per hour.

  • Differences Between Life Stages:

    • Dams focus self-grooming on rolling and rubbing against surfaces, while foals engage in scratching and nibbling behaviors.
    • The cycle of shedding correlates to photoperiod, influencing self-grooming frequency.

  • Horse-Human Bond:

    • Scratching by humans serves as a primary reinforcer and can strengthen the horse-human bond.
    • Misunderstandings about grooming needs for cleanliness can irritate horses and affect handler relationships negatively.

Grooming Techniques

  • Rolling:

    • Horses prefer to roll on bare patches such as sand or mud, with over 80% of rolling occurring on areas previously rolled by others.
    • The act of rolling is also related to depositing scent on their bodies.

  • Mechanics of Rolling:

    • Involves lateral movement supported by neck and head, with a tendency to roll back onto the original side after rolling.
    • Small enclosure sizes can inhibit natural rolling behavior.

  • Shaking:

    • Shaking occurs primarily after untacking or rolling and involves coordinated muscle contractions causing vibrations of the skin to dislodge insects.
    • A perceived belief historically was that if water is squirted into a mare's ears, she would not shake her head if pregnant.

  • Rubbing:

    • Rubbing against fixed objects or using their muzzle is common, with foals often rubbing for extended periods.
    • Some mares exhibit rubbing behavior in what appears to be a pleasurable context.

  • Scratching:

    • Horses can use hindlimbs to scratch, more commonly seen in foals.
    • This action can involve rather peculiar behaviors in ponies, such as putting a pastern in their mouth to bite and scratch.

  • Nibbling and Licking:

    • Teeth are often used rhythmically for scratching or as small bites in grooming.
    • The act of licking is less common during mutual grooming but serves significant roles in mother-infant bonding and hygiene through bot egg removal.