Bio- Birds - Y8 Topic 3 - CONCISE

1. Bird Migration

Birds migrate to access food, nesting sites, and to avoid harsh weather.

Summer: Breed in spring/summer.

Winter: Reside in milder climates during cold months.

Passage: Stopovers used for resting and refueling during travel.

    2. Skeletal Adaptations and Tissues

Keel: Large surface for flight muscle attachment.

Furculum: Stores and releases energy; maintains thoracic integrity.

Hollow Bones: Mimimize weight using air sacs and internal struts.

Connective Tissues: Tendons (muscle-to-bone force), Ligaments (joint stability), and Cartilage (friction reduction).

    3. Aerodynamics and Feathers

Aerofoil: Wing shape (curved top, flat bottom) creates a pressure difference generating lift.

Feather Types:

Flight: Provide thrust and lift.

Contour: Streamlining and protection.

Down: Traps air for insulation.

Preening: Using the beak to realign barbs and apply waterproofing oil.

    4. Digestive System

Crop: Muscle pouch for temporary food storage.

Gizzard: Thick-walled organ that uses swallowed stones to grind food.

Pellets: Regurgitated indigestible materials.

    5. Reproduction and Selection

Internal Fertilization: Prevents gamete desiccation before shell formation.

Mating rituals: Allow assessment of genetic fitness, driving Natural Selection.

Pair Bonds: Shared parental care increases offspring survival rates and prevents extinction.