Parental Behaviour Flashcards
Parental behaviour evolved to improve what?
Parental behaviour evolved to improve survival of offspring and species fitness
Which of Tinbergen’s questions does parental behaviour fit in?
Adaptive value
In general species that provide intense parental care have what in terms of offspring and why?
Fewer offspring
In general species that provide intense parental care have fewer offspring
This is due to trade offs between the benefits and costs of parental behaviour
What types of parental care are there?
No parental care
Single parent
Both parents
Cooperative breeding
This is where members of the parents extended family or group help rear the youngThe degree of care involvement also varies between species in terms of what 2 things:
Protection
Teaching important survival lessons
Parental behaviour can also vary dependent on the type of offspring that species has
Give examples of types of offspring
Altricial
Hatched or born in an undeveloped state and requiring care and feeding by the parents
Precocial
Hatched or born in an advanced state and able to feed itself almost immediately
What type of parental behaviour would you expect to see with altricial young?
Both parents contributing to the rearing of the young
What kind of parenting would you expect to see with precocial young?
Single mother parenting
If the offspring are precocial then it’s unlikely to see males contributing to parental care
We also see different forms of parental care depending on the social systems the parent live in
Give examples of this
Polygynous species
Polygynous species are where 1 male mates with multiple females
With polygynous species paternal care is reduced for both altricial and precocial young
Promiscuous
Promiscuous species are where an individual mates with any other individual
In promiscuous species the rearing of young is either exclusively done by the female or shared between both parents
Promiscuous species have:
More intensive care for altricial young usually
Less intensive care for precocial young
What 3 things determine parental behaviour?
Types of offspring
Social systems the parents live in
Milk
What about milk determines how much time the female spends with her offspring?
The composition and physiology of the species milk will determine how much time the female spends with her offspring
What happens in species where females produce high milk contents?
In species where females produce high milk contents then nursing bouts are likely to be shorter
This is because they’re providing more energy in 1 go
Animals with less nutritional content in their milk will have more constant maternal behaviour directed to their infant
What is the cause of conflict between sexes?
For males:
Gametogenesis is cheap in terms of energy and happens frequently
Investment in offspring is typically none to little
For females:
Gametogenesis is:
costly in terms of energy costs
happens rarely in females
Sometimes there can be an:
Induced ovulation
Delayed implantation
Investment in offspring care is often heavy
What are the conflict between the sexes due to?
The differences are due to differences in their reproductive biology
True or false
Although it is typically the females that rear the offspring there are exceptions to this in the animal kingdom
True
Give examples of single father parenting behaviour in animals
In some species of fish the female lays the eggs and leaves the male to look at after them
The male will aerate the eggs which signals to other females that they’re a good parent and so the female will go and lay their eggs in his clutch as well
In jaw fish and amphibians the male will keep all the eggs in their mouth to keep them safe
In these species the males reproductive output is limited by their mouth size
In these species the fertilisation process is usually external to the mating individuals
What 3 reasons are why females often provide more paternal care?
When fertilisation is internal the female will 100% know that the offspring is theirs since the offspring will develop and then leave the body to be born
Females usually raise offspring since the long term cost of raising offspring or providing more maternal care is reduced since it’s actually their offspring
Males don’t usually rear offspring because there’s a potential that it isn’t their offspring, so they would be spending energy ensuring that another males genes are passed to the next generation
True or false
There is a conflict between the needs and the energetic demands of both parents and offspring
True
For parents there is a point at which caring for current offspring compromises the potential investment they can give to future offspring
Due to this what is the difference in optimal care giving for parents and the optimal care receiving offspring?
The optimal care giving time for parents is shorter than optimal care receiving time in offspring
True or false
Some actions that we observe from parents in captivity may be due to the conflicts between parental and offspring needs
True
True or false
Some actions can advance the fitness of an offspring while reducing the the reproductive success of its parents and vice versa
Results in trade-offs between offspring quantity and quality within a brood/clutch/litter can vary
True
True or false
Some actions can advance the fitness of an offspring while reducing the the reproductive success of its parents and vice versa
Results in trade-offs between offspring quantity and quality within a brood/clutch/litter can vary
True
What can happen if the trade-offs are too high for the parent?
Abandonment
Infanticide
True or false
There are some cases where the female will invest more resources into rearing the offspring if their farther is a particularly attractive male
This can also be seen in males if they’re in a species where the male rears the offspring
True
There is also conflict between siblings to get the resources they need to develop, which can lead to what?
Siblicide
How does siblicide frequency vary between species?
Siblicide frequency varies between species
In some species siblicide is obligate
Obligate = they always do it since it’s programmed into them
In some species siblicide is facultative
Facultative = occuring optionally in response to circumstances rather than by nature
In species where siblicide is facultative siblicide may depend on what 2 things?
Environmental conditions
Resource availability
Who is each individual offspring competing with?
Current siblings
Future siblings
Each individual offspring is competing with its current siblings and its future siblings for their parents care and attention
Give an example of facultative siblicide
In bird species where eggs are laid days apart the eggs will hatch at different times
In these species siblicide is dependent on food availability
If the older sibling is below the weight they should be at that point in their development then they’re more likely to attack or eat the younger siblings
This is so the older sibling doesn’t need to share resources as much
When siblicide is facultative the younger siblings use what mechanism to avoid being attacked?
When the body weight difference between the siblings is greater, then the smaller sibling won’t beg for food as much
This reduces the attention of the older/larger individuals
Why have offspring evolved supernormal stimuli?
Offspring have evolved supernormal stimuli to try to trick their parents to continue to provide them with the care they want
Give some examples of supernormal stimuli
Offspring, particularly mammalian offspring, have big eyes relative to their head size
This is used to trick parents into caring for them
Cats will pur at a frequency similar to that of a crying baby so that they can get more attention from humans
Another stimulus to trick parents into giving them more attention is how the offspring cry for food
Offspring can manipulate the call frequency and call intensity to do this
In species with darker more salient linings inside their mouths they’re fed more per hour
True or false
Supernormal stimuli are species specific
False
Supernormal stimuli are not species specific since they can work on individuals of another species as well
Redder salient mouth linings are found in birds with what kind of mating practice
Redder salient linings are found in birds where they have extra pair matings
More salient mouths are seen in species where the clutch/brood are made up of multiple parents
True or false
An example of supernormal stimuli is seen with parasitic bird species that lay their eggs in other bird species nests
True
Parasitic bird offspring are greedier, bigger and beg the most
The parasitic offspring use supernormal stimuli to trick their foster parents to give them more attention than the offspring that actually belong to the parents
What are causal factors?
Causal factors are external or internal stimuli that trigger behaviour
Give some examples of causal explanation models
Models of maternal behaviour directed at altricial species are seen with rats
A model of maternal behaviour directed at precocial species are seen with sheep
Pigs have been used to study pheromones as a potential causal factor
What are the 5 phases of maternal behaviour seen as the offspring develops?
Nesting Nursing Licking and grooming Protection and learning Weaning
What happens in the nesting phase of maternal behaviour?
In several species the female will build a nest and prepare the environment for their young to be born into
This a phase seen before the offspring is born
In some species they build a complex nest structure in the nesting phase
In other species the animals will do preparation type behaviours to make their immediate surroundings more suitable for new borns
What happens in the nursing phase of maternal behaviour?
Once the offspring is born nursing is the next step seen in mammalian females
In this phase females will feed the offspring
What happens in the licking and grooming phase of maternal behaviour?
Licking and grooming is an essential behaviour particularly seen in altricial young
This is because licking and grooming is important for:
- forming a strong bond between mother and young
- impacting the offsprings phenotype as an adult
- allowing the young to pass faeces and urine
- the hormonal effects which will determine masculinisation
What happens in the protection and learning phase of maternal behaviour?
The female will display protective behaviour towards the offspring
The female will also start teaching their offspring essential life skills/lessons
What is an example of protective maternal behaviour?
Retrieving the offspring if they wander too far away
What happens in the weaning phase of maternal behaviour?
In this phase the mother child bond changes
The female will distance themselves from their offspring and be more aggressive towards their young
This encourages the offspring to leave and be more independent
What can we see in captive settings if the young are weaned earlier than normal?
In captive settings we can see maladaptivebot malfunctional forms of parental behaviour if the young are rejected earlier than normal
True or false
Most species show some degree of nesting behaviour
True
Hormones control the initiation of the nesting phase of maternal behaviour by controlling the timing of this phase
Which 2 hormones do this?
Estrogen
Progesterone
How can environmental factors effect maternal behaviour nesting phases?
Environmental factors can:
Tweak nesting phase timing
Determine where the nest is located/made
Illicit certain forms of nesting behaviour to be more or less complex in their expression
In mammals the onset of maternal behaviour is determined mostly by which ovarian hormones?
Estrogen
Progesterone
What change in the estrogen:progesterone triggers maternal behaviour?
High estrogen and low progesterone concentrations trigger maternal behaviour
Name some other hormones that trigger maternal behaviour and what their roles are
Oxytocin
When oxytocin is acting as a hormone it’s important for the rapid onset of maternal behaviour
Oxytocin later on can act as a neurotransmitter to encourage bonding behaviour
Prolactin
Prolactin is only important for milk production and has no real effect on behaviour
Prolactin is important for controlling milk quantity and composition
True or false
Breeds can also show differences in maternal behaviour
True
In animals emotional stimuli are processed by the right hemisphere of the brain
How is this shown to affect maternal behaviour in humans?
In humans, evidence suggests that when babies are under 12 weeks old that the mother will tend to orient the baby towards the left side of their body
Studies suggest that mother’s unconsciously position their babies in a position that maximises their emotional processing of their newborn
What is cooperative breeding?
Cooperative breeding is a social system in which group members help raise dependent young that are not their own
What is cooperative breeding seen as?
Cooperative breeding is seen as a special case of altruism in animals
What can affect individuals within a species to cause changes in how often cooperative breeding behaviour occurs?
Environmental and climatic conditions can affect individuals within a species causing changes in how often cooperative breeding behaviour occurs
True or false
Weaning is a gradual process in which offspring are slowly encouraged to eat foods other than their mothers milk until the young are completely off milk permanently
In some species weaning also continues after the young no longer take milk until the offspring are completely capable of being independent
True
Give some examples of further weaning past no more milk?
Relying on adults for learning
Relying on adults for protection
The timing of weaning can also depend on the offsprings sex in some species
Give an example of this
An example of this is that in social species:
- males will leave the social group forever
- females will remain in the social group and remain dependent on the group in some way
True or false
The larger the litter size the earlier the weaning process will occur
True
True or false
Weaning is a process only seen in mammals
False
In non-mammalian species they are just weaned off other things instead of milk
Give an example of how maternal behaviour effects the phenotype of their offspring when they become adults
The amount of maternal care a mother gives to their young programs what the offspring will consider to be an appropriate stress response when they’re adults
