Parental Behaviour 7

Question 1

What is the parental investment theory proposed by Trivers defined as?

Answer 1

Any investment by the parent in an individual offspring that increases the offsprings chance of surviving at the cost of the parents ability to invest in other offspring

Question 2

What are the three conflicts that can influence the amount a parent invests in its offspring?

Answer 2

1. Between parents on how much care each should provide
2. Between siblings on how much care each should demand
3. Between parents and offspring on supply and demand for care

Question 3

What are precocial young?

Answer 3

Born able to be independent of the parents- born able to see and walk etc.

Question 4

What are altricial young?

Answer 4

Reliant on parents to care and feed them

Question 5

What changed are associated with incubation in chickens?

Answer 5

Large amount of time sitting on egg 
Formation of brood patch 
Stop laying and ovaries regress 
Clucking 
Aggressive pecking when approached 
Voluntary reduction of food intake and body mass

Question 6

What hormone even if injected alone can sustain nesting?

Answer 6

Prolactin

Question 7

What is also needed in order to stimulate prolactin leading to nesting behaviour?

Answer 7

Tactile stimulation of the brood patch

Question 8

What releasing factor controls the release of prolactin from the pituitary in birds?

Answer 8

Vasoactive intestinal peptide (VIP)

Question 9

What happens if immunisation against VIP or prolactin in chickens and turkeys occurs?

Answer 9

It inhibits incubation behaviour

Question 10

What regions of the brain were found to be important for incubation and parental behaviour?

Answer 10

POA and basal hypothalamus

Both are also binding sites for prolactin

Question 11

What is the difference in prolactin levels in precocial and altricial species?

Answer 11

In precocial species prolactin levels decrease after hatching, but it is extended in altricial species

Question 12

What was found in the long term study on scrub jays?

Answer 12

The young remain in the parents territory for several years as helpers- alloparenting

Prolactin increases in the helpers but it’s lower than the parents

Question 13

What are the three major maternal behaviours common to mammals?

Answer 13

1. Lick pups after birth
2. Adopt nursing posture
3. Bring escaped pups back to the nest

Question 14

What did Moltz et al. find in his hormone replacement study?

Answer 14

A sequence of oestradiol-progesterone-prolactin reduced the onset of maternal behaviour from 6 days to 35hrs

But still not as rapid as after normal birth

Question 15

How is prolactin released in mammals?

Answer 15

By the brain via dopamine rather than VIP as in birds

Question 16

What do mPOA lesions do to maternal behaviour?

Answer 16

Reduce both appetitive and consummatory behaviours

Question 17

What is the lateral POA important for in maternal behaviour?

Answer 17

Pup retrieval, nest building and nursing behaviour

Question 18

What is the fish equivalent of oxytocin?

Answer 18

Isotocin