parental behaviour Flashcards
geckos
- never meets parents as they die after laying their eggs
why is it an evolutionary puzzle that parents give resources to their offspring
they don’t get a better chance of survival from it
parental care
-educating and teaching the young
-any form of behaviour that increases the fitness of the offspring
parental investment (PI)
-any expenditure by parents on and individual offspring that reduces their potential to invest in other present and future offspring
-in other words anything parents do to help offspring which decreases chances of future offspring
who should care?
-maternal care is more common than paternal care
-females lose more f they don’t help their offspring
-only females lactate
-internal fertilisation (male can abandon female)
sex ratio
-pool of sexually active females is smaller than the males
-parental investment is the relative amount of investment by each sex
-the more you invest in current offspring, the less you do in later offspring
-concept of PI is about trade-offs as it is assumed that the individuals have a finite amount of resources
-PI determines competition
varying levels of male PI
-females invest more, males prefer a polygynous mating system
-or males and females can invest the same amount e.g. mute swan
-or males invest more than females e.g. jacana (roles revered)
double-clutching
-e.g. Temmincks stint
-male and female parental care
-multiple males
-double-clutching I where the female lays 2 clutched of 4 eggs, where the female looks after one clutch and the male the other, female is therefore more available to mate and make more clutches
bi-parental care
-advantageous to work together
-common in species where offspring are highly altricial and require a lot of car e.g. many birds
conflict over parent care
-e.g. peter’s fish
-male/female where eggs are kept safely in their mouth
-called mouth-brooding fish
-can’;t eat therefore and more likely to die
-females mouth-brooding means their next itch there will be less, however mouth-brooding doesn’t effect the males fertility
-male bias: not advantageous therefore males mouth-brood
-female bias: males gain a lot as they can copulate with other females, more males abandoning their brood
misdirected care and how to avoid it
-e.g. Mexican free-tailed bats - all look the same but many colonies have evolved adaptations to avoid misdirected care, including complex communication signals
parental cost-cutting
-adult females lays eggs in another females nest where the new female will have to look after someone else’s offspring
can adoption be adaptive?
-we don’t know
-many duck species invite abandoned broods to their pack because without the duck the pack will die
what’s the ultimate dictation of parental care strategies
ratio of cost to benefits for each sex
