Parental Care Flashcards
Define Parental Care
a behavioural and evolutionary strategy adopted by some animals, involving a parental investment being made to the evolutionary fitness of offspring
What are the costs to parental care?
- Less quantity of offspring
- Lots of energy expenditure
- Lots of food expenditure
- Require protection
What are some benefits to parental care?
- Higher rates of offspring survival = pass on offspring
Which animal groups have higher rates of parental care?
Mammals (k selected species)
Birds
Which animals groups have lower rates of parental care
Amphibians
Fish (r selected species)
Reptiles
What is parental care like in fishes
- Virtually no parental care
- High fecundity (large numbers of young produced, lower survival rate)
- Resources widely spread in environment
What is the trade off for parental care
Chose between investing time in young so they survive, or spawning again – looking at best success rate, best fitness rate
Define fecundity
The ability to produce an abundance of offspring (fertility)
Reproductive potential
What requires more parental investment energy; large or small eggs?
Large eggs = more energy needed
What kinds of fish have well-developed large eggs
Freshwater bony fish +
Sharks, skates, rays (elasmobranchs)
What type of fish have small, relatively under developed eggs?
Most salt water bony fish
What types of eggs are planktonic?
Small, relatively under developed eggs
What types of eggs are lecithotrophic?
Intermediate eggs
Define lecithotrophic
A form of development in which the embryo receives no nutrition other than the yolk originally contained within its egg
Define Planktonic
The small or microscopic organisms that drift or swim weakly in a body of water, including bacteria, diatoms, jellyfish, and various larvae
What are 3 costs to parental care in birds?
May reduce parent’s survival (lower resources)
Energy input is high
Brood size can affect quality of parental care
Greater risk of predation
Prevents mating again (Hamilton’s rule)
What are 3 benefits to parental care in birds?
Increases survival rate of young
Parents provide protection against predators
Parents provide thermal heat
Parents provide food
Antibodies in egg yolk can provide immune support
Maternal micronutrients in the egg can influence sexual ornamentations in adulthood (Zebra finches)