7: Parental Behaviour Flashcards
2 dimensions of human parental behavior
expectation and support
4 categories based off the 2 dimensions
neglectful = low/low
permissiveness = low/high
authoritarian = high/low
authoritative = high/high
alloparenting
parenting has both paternal and maternal behaviors but often extends to include broader social groups too
2 things determine the degree to which offspring require parental assistance in order to survive to reproductive age
altricial and precocial
- altricial young get more parenting
altricial
being relatively un or under developed at parturition
precocial
being relatively well developed at parturition
what is one evolutionary strategy to avoid costs of parenting
the overproduction of precocial young (ex mosquitoes)
kin selection
mechanism that can promote alloparenting, in which fitness is given to genetic relatives of those providing care
hamiltons rule for altruism
r> C/B
where r is the coefficient of relatedness that can range from 0 to 1
- 0 = no relation above average and 1 = a clone
- parents are related to offspring at r = 0.5 and offspring are related to themselves at r = 1
where B is the quantification of the fitness benefit given to the offspring
where C is the quantification of the fitness cost incurred by the caregiver
parent offspring conflict theory
Depending on the ecological
circumstances of a particular
species, there time point at which
the cost overcomes the benefits
varies, but it inevitably arrives
what does early care termination result in
parents allowed to reinvest in new young
what does late care termination result in
allows young to maximize their benefit
parental behavior in female sex
incur more proximal costs than males
for their investment in offspring
parental behavior in male sex
Paternal investment is rare, so sexual selection itself becomes a trade-off between the selection of low- vs. high-investment males
low investment males vs high investment males
Low-investment males have more time for inter-male competition
High-investment males are therefore less likely to be able to dominate low investment males in inter-male competition
mother tree
local douglas firs that preferentially redistribute nutrients to related
local saplings and other plants
what is this redistribution facilitated by
a network of fungi that act as sources and sinks for the various molecules that can be “called for” by both the plants and the fungi themselves
exceptions of fish engaging in parenting behavior
yolk composition and other feeding
in which fish does the hormonal content of the yolk affect morphology
tropical damselfish
what hormones in TD fish yolk affect morphology
cortisol decreases larvae length and Test increases yolk size
daffodil cichlid alloparents vs parents
allos have higher levels of cortisol
which fish feed off the mucus made in the skin of their parents and why
midas cichlids
- because mucus has prolactin, GH and T4
what are the exceptions of parental care in amphibians
egg attendance, egg transport
tadpole attendance, tadpole transport, tadpole feeding and internal gestation in the oviduct
what does some reptiles show the first signs of
dyadic mate preference
what is tissue development in larvae controlled by
T3, T4, CORT and PRL
what can tip the balance in sex determination for amphibians and reptiles
steroids in the egg yolk
what induces egg laying in amph/rep
nonapeptides
male birds parenting facts (3)
unlike other vertebrate classes, most male birds will provide some parental support for new hatchlings or egg incubation
males in 60% of subfamilies provide some kind of parental care
alloparenting is common in bird species but specifically with older male siblings providing support
why are pigeons and doves unique in sense of maternal endocrinology
both males and females have a crop sac with crop milk
what has behav endo in birds been mainly focused on
atypical birds like chickens, pigeons and doves
broodiness
when females and often males provide parental support by incubating eggs and warming hatchlings
what can induce broodiness in non-broody hens
blood serum from broody hens, this is bc of the prolactin
when are prolactin levels high in bird moms
during incubation, even for precocial young
prolactin levels for altricial young birds
levels remain high for the duration of chick rearing, levels correspond to the length of that rearing
bird egg laying and hormones
parasitic parents have increases in prolactin immediately after egg laying
egg laying itself is preceded by increases in steroid hormones and LH and FSH
example of parasitic form of parenting in birds
the cuckoo
- lays their eggs in the nests of other birds so host mom will misidentify the hatchlings as their own
- cuckoo hatches first and take disproportionate amount of regurgitated food from host mom
- cuckoo has instinct to push other eggs out before they hatch
reproductive cycle in ringdove moms
nest building, egg laying, incubation, hatching and post-hatching behavior
how is incubation initiated and sustained in ring dove moms
started by high levels of progesterone and sustained by mid incubation increase in prolactin
ringdoves - what do crop sacs require
prolactin which can be inhibited by corticosterone
what are capons inclined to
broodiness
perching birds- nest building is strongly related to what
a decrease in androgen levels BUT androgen levels need to increase in response to territorial defense requirements in males
what do paternal male birds show increased levels in
prolactin
what is female birds hormonal profile dependent on
nest building and courtship
- males hormonal profile is independent from this!!!
nest building in male birds and HORMONES!
doves: nest building requires Test to be high instead of progesterone
mesotocin and vasotocin antagonists decrease nest building behavior
what expresses vasoactive intestinal peptide VIP
brain areas networked w the POA = the medial amygdala and the bed nucleus of the stria terminalis BNST
what is VIP linked to
nesting
what receptor density decreases in the POA of parenting birds
androgen
what receptor density varies with courtship and brooding, and where and what are the exceptions
prolactin receptor density decreases in the nucleus tuberis but increases in the POA
- exception is the parasitic cowbird that has fewer POA receptors
testosterone injections in male juncos
resulted in decreased parental behavior but did NOT affect the levels of prolactin or prolactin receptors
what are mammals named after
the gland that produces the milk
milk = the characteristic nutritive substance produced for its young
3 subgroups of mammals
monotremes, marsupials, placentals
marsupials
latin for pouch
- has 3 phases of parenting
monotremes
no nipple, lays eggs
placentals
most mammals, named for the specialized organ
monotremes - which post pituitary hormones change
mesotocin becomes oxytocin
vasotocin becomes vasopressin
monotremes - what brain parts reflex low functionality in certain animals
the small size of the supraoptic and paraventricular nuclei in both enchidna and the platypus
monotreme hormones
monotreme prolactin and GH show closer similarity to other mammals than other reptiles
monotremes - lactation hormones
regulated by insulin or CORT
marsupials
