Parental investment

Size of gametes

Ovum is much larger than sperm.

Yolk provides nutritional investment.

Hatching and birth

Ovipary

Female deposits undeveloped egg.

Example: birds

Parents incubate eggs and feed hatchlings.

Ovovivipary

Embryo develops within mother, but without nutritional investment from mother.

Vivipary

Embryo develops within mother with nutritional investment from mother.

Example: placental mammals

Gestation

Lactation

Sending kids to college

Acadian Flycatcher incubating eggs