Why do meerkats stand upright?

Answer: Sentinel lookout for predators

Sentinel lookout for predators ✓ — Correct! Cooperative sentinel behavior! Meerkats stand upright on hind legs for predator surveillance. System: (1) Sentinel duty—one stands guard while others forage. (2) Elevated view—360° visual scan for eagles, jackals. (3) Alarm calls—different calls for aerial vs ground threats. (4) Rotation—sentinels take turns (fairness). Cooperative breeding group (mob). Also sunbathe standing (warming, but sentinel primary). Balance aided by tail. Eusocial behavior—nepotistic altruism benefits kin. Sentinel sacrifices foraging but gains inclusive fitness!

Stretching their back muscles — Wrong. Meerkats don't stand upright to stretch muscles—they can stretch in other positions. Upright stance is sentinel behavior for spotting predators from elevated viewpoints.

Establishing territory dominance — Wrong. Upright stance is sentinel behavior (predator detection), not territorial display. Meerkats cooperate within groups for survival.