Why do giraffes have long necks?
Show answer & explanation
Answer: Reach high foliage other can't
Intimidate predators with height — Wrong. Height provides predator visibility, but primary evolutionary advantage is feeding—accessing foliage competitors can't reach.
Reach high foliage other can't ✓ — Correct! Competitive feeding advantage! Darwin's theory: natural selection favored longer necks. Benefits: (1) Browse acacia trees 6m (20ft) high—less competition for food. (2) Spot predators from distance. (3) Males use necks in 'necking' battles for dominance. Giraffes have 7 cervical vertebrae (same as humans!) but each 25cm (10in) long. Powerful heart pumps blood 2m upward to brain (2× human blood pressure). Specialized valves prevent blood rush when lowering head. Unique evolutionary adaptation!
Drink water without bending — Wrong. Giraffes actually struggle to drink—they must awkwardly splay their legs to reach water. Long necks evolved for feeding on high trees, not for drinking convenience.
More Animal Behavior questions
- A platypus lays eggs but feeds hatchlings milk without nipples. What makes that less contradictory?
- Male platypuses have venomous ankle spurs. Why are they probably not mainly prey-hunting tools?
- Platypuses have ~40,000 electroreceptors, but short-beaked echidnas have ~400. What best explains the drop?
- Why does a hunting platypus sweep its bill side to side instead of just pointing it forward?
- What can a platypus bill read from a shrimp's muscles rather than from water motion?
- When should you worry if a cat suddenly gets very clingy?