Diversity of Reproductive Strategies-Reproduction in Vertebrates Flashcards
Precocial and Altricial Development
Precocial and Altricial Development
Two different methods of development of their young have evolved among birds. These are Precocial Development and Altricial Development
Precocial Development
The females of Precocial Development species collected and ate this food to produce eggs with lots of energy
The young of birds (called nestlings or hatchlings) capable of Precocial Development are quite well-developed when they hatch and show the following characteristics:
Eyes are open when they hatch
Bodies are covered with soft feathers called downs
Able to move about soon after hatching
Able to feed themselves
Independent of their parents
e.g. Turkeys and Quails show Precocial Development
Altricial Development
The environment probably had little food environment, so, females of altricial development species produced eggs with not as much energy as those Precocial Development species
The young of birds capable of Altricial Development are poorly-developed when they hatch and show the following characteristics:
Eyes are closed when the hatch
Bodies do not have down feathers
Unable to move about soon after hatching
Unable to feed themselves
Depend on their parents
In-between Species
There are many birds and species that do not fit neatly into either the ‘Precocial’ or ‘Altricial’ development groups. Hawks have their eyes open and down feathers when the hatch (Precocial Characteristics), but are unable to move about soon after hatching, unable to feed themselves and require their parents for feeding and protection (Altricial Characteristics). Owls, have down feathers (Precocial Characteristics) but show all other characteristics of Altricial Development
Parental Care
In the building of nests and burrows
In the care of eggs
In the provision of food for the unborn/ un-hatched young
In providing the young with food after hatching/birth
In protecting the young
In providing social assistance to mature offspring
