ANS 104-Maternal Behavior

9-11

altricial

less developed

• sensory systems not developed

• dependent on mother for warmth, food

• limited locomotion

precocial

more developed

• sensory systems developed

• can get around on own

• may be able to forage on their own

parity

have borne offspring

nulliparous

never having offspring

primiparous

1st time having offspring

multiparous

having  born offspring before

nesting

often characterized by 

• separation from other adolescents and adults 

• seeking protection 

• provision of warmth, depending on need

domestic sows nesting ex.

• 2-3 days before parturition begins, leaves group and seeks nesting site

• 15-24 hours before select nest site

cows in natural environment nesting ex.

• mother chooses secluded spot

  • reduced vision for predators

cows on farm nesting ex.

choose to give birth in a corner and away from the group

responsiveness

• heightened behavioral response to young 

• willingness to interact with stimuli that otherwise might not be attractive

  • stimuli have biological importance

sensitive period: reponsiveness

• window of time during which a specific behavior is acquired

  • bond formation 

  • begins increased responsiveness to all young and ends with individual recognition and discrimination of offspring by mother

• varies in length by species

sensitive period: responsiveness to amniotic fluid/placenta

1. amniotic fluid and placenta highly attractive

• amniotic fluid stimulates grooming 

• consuming placenta may provide nutrients and limit cues for predators 

2. becomes repulsive when sensitive period ends 

licking is highest

immediately after birth and declines

• cows that have had a calf before lick more immediately

sensitive period: responsiveness to neonate

• association of amniotic fluid+ neotnate=bond

in cows, will she accept her offspring if they are taken away and given back?

• with no contact: accept 1-3 hours later

• with 5 min of contact: accept 12 hours later

in goats, will she accept her offspring if they are taken away and given back?

• only 5 min of contact, 13/15 does accept their young 3 hours later 

• AND know to reject kids that are not theirs

connection between ‘nesting’ and sensitive period

• nesting: involves moving away from others

• sensitive period: discrete window of time during which a specific behavior is acquired

discrimination

using sensory information to recognize own young and tell them apart from others

discrimination-smell

• in response to smell of lamb and amniotic fluid more cells are firing after giving birth

• in response to smell of food, more cells are firing before giving birth

for anosmic sheep

she accepts kids that don’t even look like hers

• proves that smell is important for discrimination

discrimination: sound

ewes look at both speaker, but move toward speaker playing their own lamb’s call

experiment of piglet vocalizations: needy

• smallest

• just missed nursing

• cool env away from sow

experiment of piglet vocalizations: un needy

• largest

• just had nursed

• warm env away from sow

what did the ‘needy’ piglet vocalizations prove

piglet vocalizations contain biologically important information that the sow uses to discriminate

care=costs

having offspring is expensive

• in animals, in terms of energy and time

direct maternal costs

• immediately helps offspring

• provisioning

  • lactation/nursing

  • feeding

  • huddling

indirect maternal costs

• helps offspring survive in the long run

• protection

  • defending nest sites, food

  • keeping predators away

over a lifetime, parents want…

to have as many kids as possible

• fitness is measures over a lifetime, not just how well a single kid or brood turns out

optimal parental/maternal investment

maximize individual’s adult LIFETIME reproductive success and not necessarily each offspring or reproductive event

mother’s interests

maximize lifetime reproductive success

• more than 1 kid

offspring’s interests

maximize fitness

• survive 

• use maternal resources 

• take as much as they can for as long as they can

how do mothers know when to terminate care

1. experience, age

2. nutritional, health, metabolic status

3. reproductive status

4. life history of the species

weaning in cattle

in nature, cows wean their calves at 7-14 months

on ranches, beef calves are weaned ~6 months

what happens after cows and calves are separated

• vocalize 

• take more steps/ walk more

2 step weaning

fewer vocalizations and steps taken from cows and calves

social isolation affects..

cognitive development 

discrimination learning ex.

• no diff in social vs individually housed calves

• for reversal, individual housed calves could not learn