PSYC 3201 Lecture Notes - Lecture 46: Altricial, Precocial, Photic Zone
25 Dec 2016
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Altricial semialtricial (type 1 and 2) semi-precocial precocial (type 1-4) Little or no down feathers (or fur for mammals) Opossums are extremely altricial at birth, they are born in an embyonic-like state and move to the pouch to develop further. Type 1 has eyes close and type 2 has eyes open. Stay at nest, though able to walk and leave. Shown food, but must eat it themselves. Independent of parents (completely on their own from birth) Mound-like nest made by parents where it lays its eggs. Underneath eggs are dead-vegetation for heat and the eggs are covered with sand. Day 3: non-visual photic (non-visual light sensitivity) Receptors in skin that can sense light. If you turn egg, embryo will try to correct itself. Preservation in timing of developmental events across evolution. Exception: humans are the only altricial species where all of these are developed. In precocial species, all of these develop prenatally.
