Parental Care Christel Moons. What is parental care? Parental care (or parental investment) = Any...
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Transcript of Parental Care Christel Moons. What is parental care? Parental care (or parental investment) = Any...
Parental CareParental Care
Christel Moons
What is parental care?What is parental care?
Parental care (or parental investment)
= Any behavior towards offspring that increases the chances of the offspring’s survival at the cost of the parent’s ability to invest in other offspring
Advantage of parental care?Advantage of parental care?
Offspring: survivalParent: evolutionary advantage
– Contributes to reproductive fitness
– Fitness = The relative ability of an organism to survive and leave offspring that themselves survive and leave offspring
Disadvantage of parental Disadvantage of parental care?care?
Expensive to provide parental care– Staying close to the young ( new mating)– At the expense of own survival rates
Foraging for food that mainly goes to offspring Presence of young attracts predators
Hypothesis by David Lack: (trade-off)
There is a cost of reproduction that forms some sort of limit on how much an animal can do to
provide care to its offspring
The imbalance between the The imbalance between the sexessexes
Animal kingdom: Females provide most or all of parental care Resulting from evolutionary imbalance
– Females invest more in conception, gestation, parturition
– Males provide ‘cheap’ sperm, take no part in gestation, parturition
– Exceptions to the rule: e.g. Stickleback, Sea Horse
Maternal care in mammalsMaternal care in mammals
Altricial mammals– Deaf, blind– Deficient in motor control and temperature regulation– Need:
Nursing Warm nest Retrieved into the nest
– Parental care: Lick offspring for defecation/urination; defensive
Characteristics of newborn Characteristics of newborn mammals (cont.)mammals (cont.)
Precocial mammals (Ungulates)– More motory and sensory mature (large groups,
migrating in search for food)– Need:
Fast drying after birth Nursing
– Parental care: No nest building Encouraging first attempts at standing/walking and nursing Selective, individual bond with foal (recognition in herd)
Maternal care in Maternal care in horseshorses
First mare-foal interactionFirst mare-foal interaction
Gestation: 315-365 days (average=340)Parturition = act of giving birthAfter parturition:
– Mare licks fetal membranes– = Process to become familiar rather than
cleaning– Olfactory cues !!!– Primary socialization established within 2 hrs.– Separation extreme anxiety + disorientation
by the foal
First mare-foal interactionFirst mare-foal interaction(cont.)(cont.)
Foal develops motor/auditory/tactile skills fast– Foal initially follows any large object– Gradually learns ‘correct object’
First nursing attempt after standing:– Standing: within 60, up to 120 minutes after birth
– Fillies vs. Colts
– Nursing: 30 – 120 minutes after birth ‘air sucking’ Nursing position = reverse parallel Bunting
Indicators of maternal careIndicators of maternal care1. Proximity
– Distance between mare and foal– On pasture < 5 m on day 1– Due to foal behavior, even when lying down– Very little physical contact– Recumbency response:
“when her foal lies down, the mare stops engaging in any other activity and stays near her young, by instinct on alert for predators, even though there may be no such dangers anywhere near”
– Trends with age
Indicators of maternal careIndicators of maternal care(cont.)(cont.)
2. Nursing – Definitions (research-based):
1979: The time a foal first nuzzled the mare’s udder for 3 seconds until the final time the foal removed its head from the medial side of the mare’s hind limb
1980-81: Start of a nursing bout was recorded when the foal actually sucked for the first time
1983: A period of nursing activity delimited by intervals of non-nursing activity lasting for 27 secs
Indicators of maternal careIndicators of maternal care(cont.)(cont.)
– Definitions (cont.): 1992: Including pre-nurse nuzzling, sucking, intra-
bout pauses and intra-bout nuzzling
1994: Including pre-suck nuzzle, pre-suck pause, suck, intra-suck nuzzle and intra-suck pause
Indicators of maternal careIndicators of maternal care(cont.)(cont.)
Functions of nursing:
Nourishment
Initial passive transfer of immunity (Colostrum)
Comfort Behavior
Indicators of maternal careIndicators of maternal care(cont.)(cont.)
Nursing Behavior
– Initiation of nursing:By mareBy foal
– Crossing the bow
Indicators of maternal careIndicators of maternal care(cont.)(cont.)
Nursing Behavior– Nursing bout frequency and duration
Frequency(per hour)
Belgian draft horses
9
Draft + mule foals
14
Welsh ponies
4
Duration: 78 – 84 seconds
Indicators of maternal careIndicators of maternal care(cont.)(cont.)
Nursing bout termination– Constant individual differences between foals– Mares < Foal– Termination by foal:
Remove head from udder Walk away
– Termination by mare (Welsh ponies): Walk away Kick at abdomen Lift hind limb to obstruct nursing Direct aggression against foal
Indicators of maternal careIndicators of maternal care(cont.)(cont.)
3. Aggression– Rare during first month; nursing related– Different forms:
Laying back of ears Bite threat Bite Kick threat Kick Squeal Bunt Tail swish
Indicators of maternal careIndicators of maternal care(cont.)(cont.)
– Response from foal No discernable response Short pause in nursing Aggressing back at the mare
Indicators of maternal careIndicators of maternal care (cont.) (cont.)4. Other interactions
• Mutual grooming = Reciprocal coat care in which the partners
nuzzle and chew on one another’s coatFillies () groom about twice as much as
colts () do
Indicators of maternal careIndicators of maternal care(cont.)(cont.)
4. Other interactions
• Play3 major types of play: general motor,
interactive, and object manipulationIn stall: foal explores environment by mouthing
parts of stall, mare’s tail/ear/halterOn pasture: Galloping away from the mare in
what appears to be thrill-seaking behavior